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compression gauge puzzler
The gauge on my old compression tester decided it had served well enough after several years of non-use, it's demise helped along by a good dose of rust. I needed one for a project car I just started working on so I went ebay shopping for a replacement gauge to go on my hose & adapters.
I found a Proto CTR-20 gauge on ebay, USA made, brand new according to seller, with a release valve for a good price of $15 including shipping but there isn't a check valve to hold the pressure for cumulative readings. On my old gauge, it must be built into the gauge's body as I don't see any kind of external check valve on it. When cranking the engine, the needle jumps up to max and back to zero for each cycle. I'm not familiar with how a standard automotive compression tester is supposed to work here, other than it should hold the pressure and increase the reading a bit with each crank cycle of the motor. Can anyone enlighten me on how to get this working the way I remember it should? Here's the gauge screwed onto my hose: http://www.token.crwoodturner.com/im...iongauge01.jpg http://www.token.crwoodturner.com/im...iongauge02.jpg |
compression gauge puzzler
Ken Grunke wrote:
The gauge on my old compression tester decided it had served well enough after several years of non-use, it's demise helped along by a good dose of rust. I needed one for a project car I just started working on so I went ebay shopping for a replacement gauge to go on my hose & adapters. I found a Proto CTR-20 gauge on ebay, USA made, brand new according to seller, with a release valve for a good price of $15 including shipping but there isn't a check valve to hold the pressure for cumulative readings. On my old gauge, it must be built into the gauge's body as I don't see any kind of external check valve on it. When cranking the engine, the needle jumps up to max and back to zero for each cycle. I'm not familiar with how a standard automotive compression tester is supposed to work here, other than it should hold the pressure and increase the reading a bit with each crank cycle of the motor. Can anyone enlighten me on how to get this working the way I remember it should? Here's the gauge screwed onto my hose: http://www.token.crwoodturner.com/im...iongauge01.jpg http://www.token.crwoodturner.com/im...iongauge02.jpg Not how it's supposed to work. Most of them use a check valve in the plug adapter fitting on the end of the hose. 99% use a tire valve core type valve. Looks just like the release valve in that T fitting on the old gauge. Oh the old unit uses nothing more than a bog standard air pressure gauge with a "compression tester" face on it. The spark adapter fittings are the part that makes it special. -- Steve W. |
compression gauge puzzler
"Steve W." wrote in message ... tire valve core "Schrader" |
compression gauge puzzler
"Steve W." wrote in message
... Oh the old unit uses nothing more than a bog standard air pressure gauge with a "compression tester" face on it. The spark adapter fittings are the part that makes it special. Steve W. If the check valve was further up the hose the dead space would lower the reading. |
compression gauge puzzler
On Tue, 19 Mar 2013 13:16:18 -0700 (PDT), Ken Grunke
wrote: The gauge on my old compression tester decided it had served well enough after several years of non-use, it's demise helped along by a good dose of rust. I needed one for a project car I just started working on so I went ebay shopping for a replacement gauge to go on my hose & adapters. I found a Proto CTR-20 gauge on ebay, USA made, brand new according to seller, with a release valve for a good price of $15 including shipping but there isn't a check valve to hold the pressure for cumulative readings. On my old gauge, it must be built into the gauge's body as I don't see any kind of external check valve on it. When cranking the engine, the needle jumps up to max and back to zero for each cycle. I'm not familiar with how a standard automotive compression tester is supposed to work here, other than it should hold the pressure and increase the reading a bit with each crank cycle of the motor. Can anyone enlighten me on how to get this working the way I remember it should? Here's the gauge screwed onto my hose: http://www.token.crwoodturner.com/im...iongauge01.jpg http://www.token.crwoodturner.com/im...iongauge02.jpg It jumps to 300 lbs on each crank and then drops off again? The gauge is missing a check valve in the bottom of the hose above the spark plug adapter The methodology of the left has always been: 1. Lie 2. Repeat the lie as many times as possible 3. Have as many people repeat the lie as often as possible 4. Eventually, the uninformed believe the lie 5. The lie will then be made into some form oflaw 6. Then everyone must conform to the lie |
compression gauge puzzler
On Mar 19, 1:16*pm, Ken Grunke wrote:
The gauge on my old compression tester decided it had served well enough after several years of non-use, it's demise helped along by a good dose of rust. I needed one for a project car I just started working on so I went ebay shopping for a replacement gauge to go on my hose & adapters. I found a Proto CTR-20 gauge on ebay, USA made, brand new according to seller, with a release valve for a good price of $15 including shipping but there isn't a check valve to hold the pressure for cumulative readings. On my old gauge, it must be built into the gauge's body as I don't see any kind of external check valve on it. When cranking the engine, the needle jumps up to max and back to zero for each cycle. I'm not familiar with how a standard automotive compression tester is supposed to work here, other than it should hold the pressure and increase the reading a bit with each crank cycle of the motor. Can anyone enlighten me on how to get this working the way I remember it should? Here's the gauge screwed onto my hose:http://www.token.crwoodturner.com/im...iongauge02.jpg What's puzzling to me is why you purchased this gauge other than you were looking to squeeze a penny as hard as possible. :) |
compression gauge puzzler
Steve W. wrote:
Ken Grunke wrote: The gauge on my old compression tester decided it had served well enough after several years of non-use, it's demise helped along by a good dose of rust. I needed one for a project car I just started working on so I went ebay shopping for a replacement gauge to go on my hose & adapters. I found a Proto CTR-20 gauge on ebay, USA made, brand new according to seller, with a release valve for a good price of $15 including shipping but there isn't a check valve to hold the pressure for cumulative readings. On my old gauge, it must be built into the gauge's body as I don't see any kind of external check valve on it. When cranking the engine, the needle jumps up to max and back to zero for each cycle. I'm not familiar with how a standard automotive compression tester is supposed to work here, other than it should hold the pressure and increase the reading a bit with each crank cycle of the motor. Can anyone enlighten me on how to get this working the way I remember it should? Here's the gauge screwed onto my hose: http://www.token.crwoodturner.com/im...iongauge01.jpg http://www.token.crwoodturner.com/im...iongauge02.jpg Not how it's supposed to work. Most of them use a check valve in the plug adapter fitting on the end of the hose. 99% use a tire valve core type valve. Looks just like the release valve in that T fitting on the old gauge. Oh the old unit uses nothing more than a bog standard air pressure gauge with a "compression tester" face on it. The spark adapter fittings are the part that makes it special. Perhaps Ken can rescue the adapters with check valves off the old gauge. The fittings are probably standard pipe thread with some Teflon tape. My compression gauge has a two piece adapter. The adapter for larger spark plug threads can be unscrewed for the smaller plug sizes. Once this part is unscrewed, the tire valve type check valve is clearly visible and can be removed/replaced with a (cheap) special tool. -- Paul Hovnanian ------------------------------------------------------------------ 2 + 2 = 5 for extremely large values of 2. |
compression gauge puzzler
PrecisionmachinisT wrote:
"Steve W." wrote in message ... tire valve core "Schrader" Yep, A Schrader type valve core. However some folks don't know that name. -- Steve W. |
compression gauge puzzler
Jim Wilkins wrote:
"Steve W." wrote in message ... Oh the old unit uses nothing more than a bog standard air pressure gauge with a "compression tester" face on it. The spark adapter fittings are the part that makes it special. Steve W. If the check valve was further up the hose the dead space would lower the reading. I have units with the valve at the tip and one with the valve right at the gauge. No difference in the readings but they ones at the adapters are easier to change out. -- Steve W. |
compression gauge puzzler
On Mar 19, 9:31*pm, "Steve W." wrote:
Jim Wilkins wrote: "Steve W." wrote in message ... Oh the old unit uses nothing more than a bog standard air pressure gauge with a "compression tester" face on it. The spark adapter fittings are the part that makes it special. Steve W. If the check valve was further up the hose the dead space would lower the reading. I have units with the valve at the tip and one with the valve right at the gauge. No difference in the readings but they ones at the adapters are easier to change out. -- Steve W. I like the ones that have a quality rubber condom around the gauge. How soon before we start taking about what we use to check TDC? |
compression gauge puzzler
ugh this Google Group thing is scary, I'll get me a *real* newsgroup reader....
So I am missing the Schrader valve, I don't see it in the hose end where the adapters screw on to, nor in the fitting at the gauge. So it's either inside the gauge or it's just plain lost. I haven't used the thing for eons, it sat on a shelf in the garage but I do remember it working back in the day when I still had most of my hair and better eyesight. I did buy the thing new and used it a few times. It jumps to 300 lbs on each crank and then drops off again? No Gunner it goes up to whatever that cylinder's pressure is, the four cylinders varied between 150 and 200 on a 20 yr old engine. The gauge is missing a check valve in the bottom of the hose above the spark plug adapter Bingo, I had everything apart and do not see any check valve or schrader valve. What's puzzling to me is why you purchased this gauge other than you were looking to squeeze a penny as hard as possible. :) Sure I'm trying to save a couple bucks, and also trying to avoid the Chinese crap that is rampant on ebay (and everywhere else). I live in the boonies and don't hit the metropolis very often. And yes, I am a penny pincher on a limited income. Perhaps Ken can rescue the adapters with check valves off the old gauge. The fittings are probably standard pipe thread with some Teflon tape. My compression gauge has a two piece adapter. The adapter for larger spark plug threads can be unscrewed for the smaller plug sizes. Once this part is unscrewed, the tire valve type check valve is clearly visible and can be removed/replaced with a (cheap) special tool. Paul, I am using the adapters and hose from my old tester with the new gauge in place of the rusty old one. Maybe at some point the check valve fell out when I was switching adapters? Dunno. Guys, thanks for the replies, I'm gonna sleep on it and maybe look for another gauge on ebay in the morning. BTW the seller was a fabulous guy who offered a full refund including shipping. I searched high and low for the box the gauge came in and told him I couldnt find it, expecting him to refuse the refund. But he answered back don't even bother returning the unit, just use it for a paperweight and then he refunded the full amount. Now there's a nomination for ebay seller of the year :) |
compression gauge puzzler
On Mar 19, 11:05*pm, Ken Grunke wrote:
ugh this Google Group thing is scary, I'll get me a *real* newsgroup reader... So I am missing the Schrader valve, I don't see it in the hose end where the adapters screw on to, nor in the fitting at the gauge. *So it's either inside the gauge or it's just plain lost. I haven't used the thing for eons, it sat on a shelf in the garage but I do remember it working back in the day when I still had most of my hair and better eyesight. I did buy the thing new and used it a few times. It jumps to 300 lbs on each crank and then drops off again? No Gunner it goes up to whatever that cylinder's pressure is, the four cylinders varied between 150 and 200 on a 20 yr old engine. The gauge is missing a check valve in the bottom of the hose above the spark plug adapter Bingo, I had everything apart and do not see any check valve or schrader valve. What's puzzling to me is why you purchased this gauge other than you were looking to squeeze a penny as hard as possible. :) Sure I'm trying to save a couple bucks, and also trying to avoid the Chinese crap that is rampant on ebay (and everywhere else). I live in the boonies and don't hit the metropolis very often. And yes, I am a penny pincher on a limited income. Perhaps Ken can rescue the adapters with check valves off the old gauge. The fittings are probably standard pipe thread with some Teflon tape. My compression gauge has a two piece adapter. The adapter for larger spark plug threads can be unscrewed for the smaller plug sizes. Once this part is unscrewed, the tire valve type check valve is clearly visible and can be removed/replaced with a (cheap) special tool. Paul, I am using the adapters and hose from my old tester with the new gauge in place of the rusty old one. *Maybe at some point the check valve fell out when I was switching adapters? Dunno. Guys, thanks for the replies, I'm gonna sleep on it and maybe look for another gauge on ebay in the morning. BTW the seller was a fabulous guy who offered a full refund including shipping. I searched high and low for the box the gauge came in and told him I couldnt find it, expecting him to refuse the refund. But he answered back don't even bother returning the unit, just use it for a paperweight and then he refunded the full amount. Now there's a nomination for ebay seller of the year :) "Sure I'm trying to save a couple bucks, and also trying to avoid the Chinese crap that is rampant on ebay (and everywhere else). I live in the boonies and don't hit the metropolis very often. And yes, I am a penny pincher on a limited income." New quality tools are almost never cheap. http://www.matcotools.com/catalog/pr...N-TESTING-SET/ |
compression gauge puzzler
You might try putting some soapy water or spit around the fitting where the
release button is, just below the gage to see if bubbles are present with some pressure applied. Then, if that release button assembly can be disassembled, you might find a fleck of dirt or possibly a missing ball or spring. In the section where the button is, there should probably be a check valve which holds the pressure in the gage until the user presses the button. There are also some types of compression testers which have the check/tire valve core located at the end of the tube where the rubber tip is (which is intended to seal in the spark plug hole. But the release button on the Proto gage should engage something acting as a check valve. Another less likely fault could be that there is an internal leak in the Proto gage, which is a little more complicated to check and repair, but possible. -- WB .......... "Ken Grunke" wrote in message ... The gauge on my old compression tester decided it had served well enough after several years of non-use, it's demise helped along by a good dose of rust. I needed one for a project car I just started working on so I went ebay shopping for a replacement gauge to go on my hose & adapters. I found a Proto CTR-20 gauge on ebay, USA made, brand new according to seller, with a release valve for a good price of $15 including shipping but there isn't a check valve to hold the pressure for cumulative readings. On my old gauge, it must be built into the gauge's body as I don't see any kind of external check valve on it. When cranking the engine, the needle jumps up to max and back to zero for each cycle. I'm not familiar with how a standard automotive compression tester is supposed to work here, other than it should hold the pressure and increase the reading a bit with each crank cycle of the motor. Can anyone enlighten me on how to get this working the way I remember it should? Here's the gauge screwed onto my hose: http://www.token.crwoodturner.com/im...iongauge01.jpg http://www.token.crwoodturner.com/im...iongauge02.jpg |
compression gauge puzzler
Wild_Bill wrote:
In the section where the button is, there should probably be a check valve which holds the pressure in the gage until the user presses the button. Nope, it's just the release valve. That works fine. I can blow into the hose with all my cheekmuscles, and the button will release the pressure - there is nothing between the gauge and the plug adapter, only a free passage. Same with the old gauge, it has only the release valve. That one is a Schrader valve in a T-fitting just below the gauge which is plainly seen in my first pictu http://www.token.crwoodturner.com/im...iongauge01.jpg I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. |
compression gauge puzzler
"Steve W." wrote in message ... PrecisionmachinisT wrote: "Steve W." wrote in message ... tire valve core "Schrader" Yep, A Schrader type valve core. However some folks don't know that name. Well, they do now... |
compression gauge puzzler
"Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. |
compression gauge puzzler
On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT"
wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. -- Ed Huntress |
compression gauge puzzler
On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress
wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. Whup, I hit "send" too fast. The leak-down tester also has a Schrader valve, for filling the cylinder with air. Am I repeating stuff that's been said? If so, I apologize. -- Ed Huntress |
compression gauge puzzler
Ed Huntress wrote:
On Wed, 20 Mar 2013 21:56:51 -0400, wrote: On Wed, 20 Mar 2013 21:38:05 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 18:24:12 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:04 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. I don't understand that. All you care about is the air you get into the cylinder, right? I used to do a lot of leakdown tests, and I think I remember how they were done. All I did was pump the cylinder up to some pressure and time how long it takes to drop to some lower pressure. Do the test dry, then wet, in each cylinder. If it falls faster when dry, it's rings. If it's the same time when wet, it's valves. Am I missing something? I guess you can do it that way, but it's not terribly effective or accurate. A normal leakdown tester feeds 80psi to one side of a restriction, which feeds the air into the cyl. Guage on inlet (generally 80 psi) and on the cyl side. With no leakage at all you get 80/80. If you have a small leakdown (normal) you may have 80/75. A sognificant leak may give you 80/60 or 80/50. Then you listen in the intake, exhaust, and crankcase to tell where the air is going. Yeah, I can see that it's very quick to diagnose several problems. But watch out what you call "normal." g Unless I'm mistaken, those two-gauge deals didn't exist when I was club racing, in the late '60s and early '70s. At least, it wasn't equipment that we bottom-dollar sports car types had. The ones we used were "normal" then. I do see a limitiation of this newer device, compared to the old ones, however. I described it in one of my posts to Jon. The leakdown testers were used in aviation. The calibrated leak in the tester has a spec. for hole size and length as well as other dimensions. There are more than one size of calibrated leak. For larger cylinders such as a 200 Cu In on a 1820 Wright you had to use a larger calibrated leak gauge or every reading would indicate a bad cylinder. http://en.wikipedia.org/wiki/Leak-down_tester John |
compression gauge puzzler
On Wed, 20 Mar 2013 06:32:46 -0700 (PDT), Ken Grunke
wrote: Wild_Bill wrote: In the section where the button is, there should probably be a check valve which holds the pressure in the gage until the user presses the button. Nope, it's just the release valve. That works fine. I can blow into the hose with all my cheekmuscles, and the button will release the pressure - there is nothing between the gauge and the plug adapter, only a free passage. Same with the old gauge, it has only the release valve. That one is a Schrader valve in a T-fitting just below the gauge which is plainly seen in my first pictu http://www.token.crwoodturner.com/im...iongauge01.jpg I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Yes, and they usually fit into the line as you assumed. My old Snap-On has some at the air fitting end and some at the plug end. Look for internal threads at both ends of your adapter, Ken. The only thing which may be missing is a schrader valve insert. -- In order to become the master, the politician poses as the servant. --Charles de Gaulle |
compression gauge puzzler
On Wed, 20 Mar 2013 06:32:46 -0700 (PDT), Ken Grunke
wrote: Wild_Bill wrote: In the section where the button is, there should probably be a check valve which holds the pressure in the gage until the user presses the button. Nope, it's just the release valve. That works fine. I can blow into the hose with all my cheekmuscles, and the button will release the pressure - there is nothing between the gauge and the plug adapter, only a free passage. Same with the old gauge, it has only the release valve. That one is a Schrader valve in a T-fitting just below the gauge which is plainly seen in my first pictu http://www.token.crwoodturner.com/im...iongauge01.jpg I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Is there an internal thread anywhere in the end of the hose/fitting? If so, pop a tire valve in and try it A tire valve may drop your pressure reading a bit more than the "proper" valve - some testers uses special valves, some used regular tire valves - some long - some short. Long will have less effect on the reading if it can be used (softer spring) |
compression gauge puzzler
On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress
wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. A leakdown tester should have 2 guages and WILL have a connector for compressed air. |
compression gauge puzzler
|
compression gauge puzzler
On Mar 20, 6:04*pm, Ed Huntress wrote:
On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. *A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. |
compression gauge puzzler
On Mar 20, 6:24*pm, jon_banquer wrote:
On Mar 20, 6:04*pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. *A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. It's about doing a comparison. You're always going to have a percentage of leak and you want about the same percentage of leak for every cylinder. Watch this. It's a well done video: http://www.youtube.com/watch?v=QNf0IOIvIcY |
compression gauge puzzler
On Mar 19, 9:35*pm, jon_banquer wrote:
On Mar 19, 9:31*pm, "Steve W." wrote: Jim Wilkins wrote: "Steve W." wrote in message ... Oh the old unit uses nothing more than a bog standard air pressure gauge with a "compression tester" face on it. The spark adapter fittings are the part that makes it special. Steve W. If the check valve was further up the hose the dead space would lower the reading. I have units with the valve at the tip and one with the valve right at the gauge. No difference in the readings but they ones at the adapters are easier to change out. -- Steve W. I like the ones that have a quality rubber condom around the gauge. How soon before we start taking about what we use to check TDC? Still waiting for how others check TDC. I bet my method is better and more accurate. ;) |
compression gauge puzzler
On Wed, 20 Mar 2013 18:24:12 -0700 (PDT), jon_banquer
wrote: On Mar 20, 6:04*pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. *A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. I don't understand that. All you care about is the air you get into the cylinder, right? I used to do a lot of leakdown tests, and I think I remember how they were done. All I did was pump the cylinder up to some pressure and time how long it takes to drop to some lower pressure. Do the test dry, then wet, in each cylinder. If it falls faster when dry, it's rings. If it's the same time when wet, it's valves. Am I missing something? |
compression gauge puzzler
On Mar 20, 6:38*pm, Ed Huntress wrote:
On Wed, 20 Mar 2013 18:24:12 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:04 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced.. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. I don't understand that. All you care about is the air you get into the cylinder, right? I used to do a lot of leakdown tests, and I think I remember how they were done. All I did was pump the cylinder up to some pressure and time how long it takes to drop to some lower pressure. Do the test dry, then wet, in each cylinder. If it falls faster when dry, it's rings. If it's the same time when wet, it's valves. Am I missing something? It's a percentage test with two gauges. If you have cylinder(s) with major discrepancies you find out where the air is leaking to. If you hear air in the exhaust pipe it's a bad exhaust valve. If you hear air in the intake it's a bad intake valve. If you hear air in the crankcase (check where oil dipstick is) it's bad piston rings. |
compression gauge puzzler
On Wed, 20 Mar 2013 18:35:00 -0700 (PDT), jon_banquer
wrote: On Mar 20, 6:24*pm, jon_banquer wrote: On Mar 20, 6:04*pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. *A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. It's about doing a comparison. You're always going to have a percentage of leak and you want about the same percentage of leak for every cylinder. Watch this. It's a well done video: http://www.youtube.com/watch?v=QNf0IOIvIcY That's interesting, and I'm sure it's faster to use than the old ones. From what he demonstrated, though, I see no way to identify ring versus valve problems. I guess you could run the test wet as well with that rig, but it's a different animal. You could pump mine up with a bicycle pump, if you had to, but I always had a little compressor handy. -- Ed Huntress |
compression gauge puzzler
On Mar 20, 6:49*pm, Ed Huntress wrote:
On Wed, 20 Mar 2013 18:35:00 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:24 pm, jon_banquer wrote: On Mar 20, 6:04 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. It's about doing a comparison. You're always going to have a percentage of leak and you want about the same percentage of leak for every cylinder. Watch this. It's a well done video: http://www.youtube.com/watch?v=QNf0IOIvIcY That's interesting, and I'm sure it's faster to use than the old ones. From what he demonstrated, though, I see no way to identify ring versus valve problems. I guess you could run the test wet as well with that rig, but it's a different animal. You could pump mine up with a bicycle pump, if you had to, but I always had a little compressor handy. -- Ed Huntress Consider that you are going to have to take the engine apart if you have "dead holes" anyway so the need for exact specifics doesn't really matter that much. All you're really looking to see is if you have "dead holes" and generally what the problem might be. |
compression gauge puzzler
On Mar 20, 6:53*pm, jon_banquer wrote:
On Mar 20, 6:49*pm, Ed Huntress wrote: On Wed, 20 Mar 2013 18:35:00 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:24 pm, jon_banquer wrote: On Mar 20, 6:04 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. It's about doing a comparison. You're always going to have a percentage of leak and you want about the same percentage of leak for every cylinder. Watch this. It's a well done video: http://www.youtube.com/watch?v=QNf0IOIvIcY That's interesting, and I'm sure it's faster to use than the old ones. From what he demonstrated, though, I see no way to identify ring versus valve problems. I guess you could run the test wet as well with that rig, but it's a different animal. You could pump mine up with a bicycle pump, if you had to, but I always had a little compressor handy. -- Ed Huntress Consider that you are going to have to take the engine apart if you have "dead holes" anyway so the need for exact specifics doesn't really matter that much. All you're really looking to see is if you have "dead holes" and generally what the problem might be. The problem with the method he shows is what happens when you don't have a distributor to put each cylinder at TDC on the compression stroke so the leak down test can be done. That's why I want to talk about checking TDC and how others do it. ;) |
compression gauge puzzler
On Wed, 20 Mar 2013 21:38:05 -0400, Ed Huntress
wrote: On Wed, 20 Mar 2013 18:24:12 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:04*pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. *A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. I don't understand that. All you care about is the air you get into the cylinder, right? I used to do a lot of leakdown tests, and I think I remember how they were done. All I did was pump the cylinder up to some pressure and time how long it takes to drop to some lower pressure. Do the test dry, then wet, in each cylinder. If it falls faster when dry, it's rings. If it's the same time when wet, it's valves. Am I missing something? I guess you can do it that way, but it's not terribly effective or accurate. A normal leakdown tester feeds 80psi to one side of a restriction, which feeds the air into the cyl. Guage on inlet (generally 80 psi) and on the cyl side. With no leakage at all you get 80/80. If you have a small leakdown (normal) you may have 80/75. A sognificant leak may give you 80/60 or 80/50. Then you listen in the intake, exhaust, and crankcase to tell where the air is going. |
compression gauge puzzler
On Wed, 20 Mar 2013 18:45:39 -0700 (PDT), jon_banquer
wrote: On Mar 20, 6:38*pm, Ed Huntress wrote: On Wed, 20 Mar 2013 18:24:12 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:04 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. I don't understand that. All you care about is the air you get into the cylinder, right? I used to do a lot of leakdown tests, and I think I remember how they were done. All I did was pump the cylinder up to some pressure and time how long it takes to drop to some lower pressure. Do the test dry, then wet, in each cylinder. If it falls faster when dry, it's rings. If it's the same time when wet, it's valves. Am I missing something? It's a percentage test with two gauges. If you have cylinder(s) with major discrepancies you find out where the air is leaking to. If you hear air in the exhaust pipe it's a bad exhaust valve. If you hear air in the intake it's a bad intake valve. If you hear air in the crankcase (check where oil dipstick is) it's bad piston rings. OK, I can see where that's a lot faster, and it actually combines the equivalent of a regular compression test (sort of) and an old-fashioned leak-down test. With the older equipment, you only would do a leak-down test if all cylinders looked good in the regular test but you had some reason to believe one or more cylinders still had a problem. You could do both tests dry and then wet to try to isolate the problem a bit; pressure loss with a wet cylinder meant a valve or head-gasket problem, so you had to pull the head in either case. The only thing I see wrong with the newer device is that it only checks the rings at TDC, while a conventional compression test will show a cylinder is off from any problem along the whole stroke -- like a scored cylinder that isn't scored along the full length of the stroke (an engine that's been over-revved a lot, or which has a cracked lower ring). Also, a valve that's out of adjustment, or which has a sticky lifter, but which is still fully closed at TDC on the compression stroke, will not show you the valve problem. Anyway, it's not something I'm likely to do again. I just thought, mistakenly, that the OP might have been looking at an old-style leak-down tester. It appears that it was just a missing Schrader valve stem in a conventional compression tester. That's what we save old bicycle inner-tubes for -- spare Schrader stems, and gasket material. -- Ed Huntress |
compression gauge puzzler
On Wed, 20 Mar 2013 18:53:49 -0700 (PDT), jon_banquer
wrote: On Mar 20, 6:49*pm, Ed Huntress wrote: On Wed, 20 Mar 2013 18:35:00 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:24 pm, jon_banquer wrote: On Mar 20, 6:04 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. It's about doing a comparison. You're always going to have a percentage of leak and you want about the same percentage of leak for every cylinder. Watch this. It's a well done video: http://www.youtube.com/watch?v=QNf0IOIvIcY That's interesting, and I'm sure it's faster to use than the old ones. From what he demonstrated, though, I see no way to identify ring versus valve problems. I guess you could run the test wet as well with that rig, but it's a different animal. You could pump mine up with a bicycle pump, if you had to, but I always had a little compressor handy. -- Ed Huntress Consider that you are going to have to take the engine apart if you have "dead holes" anyway so the need for exact specifics doesn't really matter that much. All you're really looking to see is if you have "dead holes" and generally what the problem might be. I'm sure it's a practical solution or they wouldn't go to that complication. And in a commercial shop, time is money, and the old way of running those tests could take a whole Saturday morning. If it was a Bristol or a Jag engine, it was worth the play time. Otherwise, not. God save me from ever having to do a hot valve-lash job on a six-cylinder Triumph again... -- Ed Huntress |
compression gauge puzzler
On Mar 20, 7:14*pm, Ed Huntress wrote:
On Wed, 20 Mar 2013 18:53:49 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:49 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 18:35:00 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:24 pm, jon_banquer wrote: On Mar 20, 6:04 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. It's about doing a comparison. You're always going to have a percentage of leak and you want about the same percentage of leak for every cylinder. Watch this. It's a well done video: http://www.youtube.com/watch?v=QNf0IOIvIcY That's interesting, and I'm sure it's faster to use than the old ones. From what he demonstrated, though, I see no way to identify ring versus valve problems. I guess you could run the test wet as well with that rig, but it's a different animal. You could pump mine up with a bicycle pump, if you had to, but I always had a little compressor handy. -- Ed Huntress Consider that you are going to have to take the engine apart if you have "dead holes" anyway so the need for exact specifics doesn't really matter that much. All you're really looking to see is if you have "dead holes" and generally what the problem might be. I'm sure it's a practical solution or they wouldn't go to that complication. And in a commercial shop, time is money, and the old way of running those tests could take a whole Saturday morning. If it was a Bristol or a Jag engine, it was worth the play time. Otherwise, not. God save me from ever having to do a hot valve-lash job on a six-cylinder Triumph again... -- Ed Huntress Many commercial auto repair shops don't even know what a leak down test is and all they know and do are compression tests. |
compression gauge puzzler
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compression gauge puzzler
On Wed, 20 Mar 2013 22:03:57 -0400, BQ340
wrote: On 3/20/2013 9:49 PM, Ed Huntress wrote: That's interesting, and I'm sure it's faster to use than the old ones. From what he demonstrated, though, I see no way to identify ring versus valve problems. I guess you could run the test wet as well with that rig, but it's a different animal. You could pump mine up with a bicycle pump, if you had to, but I always had a little compressor handy. You would use a stethoscope to locate where the leak is. Valve leaks you would hear in the exhaust or carb. Ring leaks you would hear in the dipstick tube. MikeB It's very interesting and it looks slick. I'm sure one would be on my Christmas list if I were 45 years younger. d8-) -- Ed Huntress |
compression gauge puzzler
On Wed, 20 Mar 2013 12:39:24 -0400, John
wrote: Ed Huntress wrote: On Wed, 20 Mar 2013 21:56:51 -0400, wrote: On Wed, 20 Mar 2013 21:38:05 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 18:24:12 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:04 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. I don't understand that. All you care about is the air you get into the cylinder, right? I used to do a lot of leakdown tests, and I think I remember how they were done. All I did was pump the cylinder up to some pressure and time how long it takes to drop to some lower pressure. Do the test dry, then wet, in each cylinder. If it falls faster when dry, it's rings. If it's the same time when wet, it's valves. Am I missing something? I guess you can do it that way, but it's not terribly effective or accurate. A normal leakdown tester feeds 80psi to one side of a restriction, which feeds the air into the cyl. Guage on inlet (generally 80 psi) and on the cyl side. With no leakage at all you get 80/80. If you have a small leakdown (normal) you may have 80/75. A sognificant leak may give you 80/60 or 80/50. Then you listen in the intake, exhaust, and crankcase to tell where the air is going. Yeah, I can see that it's very quick to diagnose several problems. But watch out what you call "normal." g Unless I'm mistaken, those two-gauge deals didn't exist when I was club racing, in the late '60s and early '70s. At least, it wasn't equipment that we bottom-dollar sports car types had. The ones we used were "normal" then. I do see a limitiation of this newer device, compared to the old ones, however. I described it in one of my posts to Jon. The leakdown testers were used in aviation. The calibrated leak in the tester has a spec. for hole size and length as well as other dimensions. There are more than one size of calibrated leak. For larger cylinders such as a 200 Cu In on a 1820 Wright you had to use a larger calibrated leak gauge or every reading would indicate a bad cylinder. http://en.wikipedia.org/wiki/Leak-down_tester John Very interesting. Thanks, John. -- Ed Huntress |
compression gauge puzzler
Ed Huntress wrote:
On Wed, 20 Mar 2013 18:45:39 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:38 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 18:24:12 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:04 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. I don't understand that. All you care about is the air you get into the cylinder, right? I used to do a lot of leakdown tests, and I think I remember how they were done. All I did was pump the cylinder up to some pressure and time how long it takes to drop to some lower pressure. Do the test dry, then wet, in each cylinder. If it falls faster when dry, it's rings. If it's the same time when wet, it's valves. Am I missing something? It's a percentage test with two gauges. If you have cylinder(s) with major discrepancies you find out where the air is leaking to. If you hear air in the exhaust pipe it's a bad exhaust valve. If you hear air in the intake it's a bad intake valve. If you hear air in the crankcase (check where oil dipstick is) it's bad piston rings. OK, I can see where that's a lot faster, and it actually combines the equivalent of a regular compression test (sort of) and an old-fashioned leak-down test. With the older equipment, you only would do a leak-down test if all cylinders looked good in the regular test but you had some reason to believe one or more cylinders still had a problem. You could do both tests dry and then wet to try to isolate the problem a bit; pressure loss with a wet cylinder meant a valve or head-gasket problem, so you had to pull the head in either case. The only thing I see wrong with the newer device is that it only checks the rings at TDC, while a conventional compression test will show a cylinder is off from any problem along the whole stroke -- like a scored cylinder that isn't scored along the full length of the stroke (an engine that's been over-revved a lot, or which has a cracked lower ring). Also, a valve that's out of adjustment, or which has a sticky lifter, but which is still fully closed at TDC on the compression stroke, will not show you the valve problem. Anyway, it's not something I'm likely to do again. I just thought, mistakenly, that the OP might have been looking at an old-style leak-down tester. It appears that it was just a missing Schrader valve stem in a conventional compression tester. That's what we save old bicycle inner-tubes for -- spare Schrader stems, and gasket material. Actually you can use a leak-down tester through the entire stroke IF you have the proper tools to rotate the crank. For a very fast way of checking for a dead hole in an engine you don't use a compression tester anyway. Toss a scope on there. One channel will use an inductive pick-up on the pos battery lead. The other goes to any plug wire. One channel gets set to measure the amp flow and the other acts as a trigger. Pull the power to the injectors or unhook the fuel line or pump so the engine doesn't start. Then crank it over with the starter and look at the amp readings. If all the holes are good you will see nice even amp draws across the engine. Any cylinder not pulling it's share will show as decreased amp draw. To see it in action - http://www.youtube.com/watch?v=WKdZsWU2ZmI -- Steve W. |
compression gauge puzzler
On Thu, 21 Mar 2013 02:19:21 -0400, "Steve W."
wrote: Ed Huntress wrote: On Wed, 20 Mar 2013 18:45:39 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:38 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 18:24:12 -0700 (PDT), jon_banquer wrote: On Mar 20, 6:04 pm, Ed Huntress wrote: On Wed, 20 Mar 2013 19:59:49 -0400, wrote: On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress wrote: On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT" wrote: "Ken Grunke" wrote in message ... I am assuming there has to be a separate check valve INLINE between the plug adapter and the gauge below the release valve. That is what I am missing. It may be a fitting I had, but absent-mindedly misplaced. Could be a spring and or check ball is missng or gunked up at the spark plug fitting end... --FWIW blowing into the end with your mouth probably won't produce enough hose expansion to actuate a ball type check valve. Sorry for jumping into the middle without having read the thread, but there are two kinds of compression testers: the regular kind, which have a button to activate the check-release valve; and leak-down testers, which have no such valve. I have both. They look almost the same. Perhaps, if Ken's tester doesn't have a check valve, he has a leakdown tester. If so, it will have a spark-plug-thread terminal end. Regular testers *may* have such a thread. Mine just has a tapered rubber plug. A leakdown tester should have 2 guages and WILL have a connector for compressed air. Mine has one gauge. It's around 45 years old. And as I noted in an addition to the post above, it has a Schrader valve for pumping up the cylinder. What's the second gauge for? With mine, you just attach it, make sure both valves are closed, and pump it up. Test dry, then test wet (with about an ounce of oil in the cylinder; more for a V-engine). Is there something else that I've missed? -- Ed Huntress One gauge tells you your air input pressure, the other your cylinder pressure. I don't understand that. All you care about is the air you get into the cylinder, right? I used to do a lot of leakdown tests, and I think I remember how they were done. All I did was pump the cylinder up to some pressure and time how long it takes to drop to some lower pressure. Do the test dry, then wet, in each cylinder. If it falls faster when dry, it's rings. If it's the same time when wet, it's valves. Am I missing something? It's a percentage test with two gauges. If you have cylinder(s) with major discrepancies you find out where the air is leaking to. If you hear air in the exhaust pipe it's a bad exhaust valve. If you hear air in the intake it's a bad intake valve. If you hear air in the crankcase (check where oil dipstick is) it's bad piston rings. OK, I can see where that's a lot faster, and it actually combines the equivalent of a regular compression test (sort of) and an old-fashioned leak-down test. With the older equipment, you only would do a leak-down test if all cylinders looked good in the regular test but you had some reason to believe one or more cylinders still had a problem. You could do both tests dry and then wet to try to isolate the problem a bit; pressure loss with a wet cylinder meant a valve or head-gasket problem, so you had to pull the head in either case. The only thing I see wrong with the newer device is that it only checks the rings at TDC, while a conventional compression test will show a cylinder is off from any problem along the whole stroke -- like a scored cylinder that isn't scored along the full length of the stroke (an engine that's been over-revved a lot, or which has a cracked lower ring). Also, a valve that's out of adjustment, or which has a sticky lifter, but which is still fully closed at TDC on the compression stroke, will not show you the valve problem. Anyway, it's not something I'm likely to do again. I just thought, mistakenly, that the OP might have been looking at an old-style leak-down tester. It appears that it was just a missing Schrader valve stem in a conventional compression tester. That's what we save old bicycle inner-tubes for -- spare Schrader stems, and gasket material. Actually you can use a leak-down tester through the entire stroke IF you have the proper tools to rotate the crank. So you have to back off the rocker arms or remove the camshaft? For a very fast way of checking for a dead hole in an engine you don't use a compression tester anyway. Toss a scope on there. One channel will use an inductive pick-up on the pos battery lead. The other goes to any plug wire. One channel gets set to measure the amp flow and the other acts as a trigger. Pull the power to the injectors or unhook the fuel line or pump so the engine doesn't start. Then crank it over with the starter and look at the amp readings. If all the holes are good you will see nice even amp draws across the engine. Any cylinder not pulling it's share will show as decreased amp draw. To see it in action - http://www.youtube.com/watch?v=WKdZsWU2ZmI Yeah, I've seen descriptions of that. -- Ed Huntress |
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