I have an old cast iron techumseh engine I am trying to rebuild. (The
rod broke). I am putting it back together. At the bottom of the
stroke I can hear a sound and there seems to be some slight "play"
where the rod does not move the poston any. I think the same at the
top of the stroke.

Is this a problem or am I being overly cautious? This is my first
rebuild and have learned alot but wanted to get your opinion. I have a
video posted he

http://www.youtube.com/watch?v=WG_kcd9VV3Q

On Wed, 31 Dec 2008 14:43:28 -0800, stryped wrote:

I have an old cast iron techumseh engine I am trying to rebuild. (The
rod broke). I am putting it back together. At the bottom of the stroke
I can hear a sound and there seems to be some slight "play" where the
rod does not move the poston any. I think the same at the top of the
stroke.

Is this a problem or am I being overly cautious? This is my first
rebuild and have learned alot but wanted to get your opinion. I have a
video posted he

http://www.youtube.com/watch?v=WG_kcd9VV3Q

This does not sound normal to me. Did you check the rod bearing fit with
plastigage? Just a guess, I am no engine mechanic.
Terry

On Dec 31, 5:43*pm, Terry wrote:
On Wed, 31 Dec 2008 14:43:28 -0800, stryped wrote:
I have an old cast iron techumseh engine I am trying to rebuild. (The
rod broke). I am putting it back together. *At the bottom of the stroke
I can hear a sound and there seems to be some slight "play" where the
rod does not move the poston any. I think the same at the top of the
stroke.

Is this a problem or am I being overly cautious? This is my first
rebuild and have learned alot but wanted to get your opinion. I have a
video posted he

http://www.youtube.com/watch?v=WG_kcd9VV3Q

This does not sound normal to me. Did you check the rod bearing fit with
plastigage? Just a guess, I am no engine mechanic.
Terry

This engine does not use a "bearing" per se. It is just an aluminum
rod on the crankshaft.

On Wed, 31 Dec 2008 16:17:10 -0800, stryped wrote:

On Dec 31, 5:43Â*pm, Terry wrote:
On Wed, 31 Dec 2008 14:43:28 -0800, stryped wrote:
I have an old cast iron techumseh engine I am trying to rebuild. (The
rod broke). I am putting it back together. Â*At the bottom of the
stroke I can hear a sound and there seems to be some slight "play"
where the rod does not move the poston any. I think the same at the
top of the stroke.

Is this a problem or am I being overly cautious? This is my first
rebuild and have learned alot but wanted to get your opinion. I have
a video posted he

http://www.youtube.com/watch?v=WG_kcd9VV3Q

This does not sound normal to me. Did you check the rod bearing fit
with plastigage? Just a guess, I am no engine mechanic. Terry

This engine does not use a "bearing" per se. It is just an aluminum rod
on the crankshaft.

Any place where metal rubs metal is a bearing. Period. It may not have
a _separate_ bearing, but its still a bearing, and clearances still
matter.

A slight play top and bottom is not only to be expected, it's pretty much
essential -- no play would mean no clearance in the big and little end
bearings, which would mean a trashed engine in the near future. The
bearing play gets magnified A LOT by the fact that the piston moves not
at all at true top dead center and bottom dead center - that's where the
'dead' comes from. So the crank has to move enough into its curve to
start pulling on the piston.

There shouldn't be much clearance there -- I'm not even going to hazard a
guess at what is right, but it's in the single-digit or low double digit
thousandths for each bearing.

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

Tim Wescott wrote:
On Wed, 31 Dec 2008 16:17:10 -0800, stryped wrote:

On Dec 31, 5:43 pm, Terry wrote:
On Wed, 31 Dec 2008 14:43:28 -0800, stryped wrote:
I have an old cast iron techumseh engine I am trying to rebuild.
(The rod broke). I am putting it back together. At the bottom of
the stroke I can hear a sound and there seems to be some slight
"play" where the rod does not move the poston any. I think the
same at the top of the stroke.

Is this a problem or am I being overly cautious? This is my first
rebuild and have learned alot but wanted to get your opinion. I
have a video posted he

http://www.youtube.com/watch?v=WG_kcd9VV3Q

This does not sound normal to me. Did you check the rod bearing fit
with plastigage? Just a guess, I am no engine mechanic. Terry

This engine does not use a "bearing" per se. It is just an aluminum
rod on the crankshaft.

Any place where metal rubs metal is a bearing. Period. It may not
have a _separate_ bearing, but its still a bearing, and clearances
still matter.

A slight play top and bottom is not only to be expected, it's pretty
much essential -- no play would mean no clearance in the big and
little end bearings, which would mean a trashed engine in the near
future. The bearing play gets magnified A LOT by the fact that the
piston moves not at all at true top dead center and bottom dead
center - that's where the 'dead' comes from. So the crank has to
move enough into its curve to start pulling on the piston.

There shouldn't be much clearance there -- I'm not even going to
hazard a guess at what is right, but it's in the single-digit or low
double digit thousandths for each bearing.

Probably on the order of .002-.004 on the big end - looser is better up to
a point with a splash lubrication system . Check the fit with plastigage
with the piston about halfway up the bore , if it's too loose the rod cap
can be filed or lightly sanded to close it up a bit . BE VERY CAUTIOUS if
you need to sand or file - a little bit goes a long ways when you're talking
thousandths . You must also be cautious to take an even amount off both
sides - the mating surfaces MUST be flat and parallel with each other .
--
Snag
every answer
leads to another
question

On Dec 31, 7:15*pm, "Terry Coombs" wrote:
Tim Wescott wrote:
On Wed, 31 Dec 2008 16:17:10 -0800, stryped wrote:

On Dec 31, 5:43 pm, Terry wrote:
On Wed, 31 Dec 2008 14:43:28 -0800, stryped wrote:
I have an old cast iron techumseh engine I am trying to rebuild.
(The rod broke). I am putting it back together. At the bottom of
the stroke I can hear a sound and there seems to be some slight
"play" where the rod does not move the poston any. I think the
same at the top of the stroke.

Is this a problem or am I being overly cautious? This is my first
rebuild and have learned alot but wanted to get your opinion. I
have a video posted he

http://www.youtube.com/watch?v=WG_kcd9VV3Q

This does not sound normal to me. Did you check the rod bearing fit
with plastigage? Just a guess, I am no engine mechanic. Terry

This engine does not use a "bearing" per se. It is just an aluminum
rod on the crankshaft.

Any place where metal rubs metal is a bearing. *Period. *It may not
have a _separate_ bearing, but its still a bearing, and clearances
still matter.

A slight play top and bottom is not only to be expected, it's pretty
much essential -- no play would mean no clearance in the big and
little end bearings, which would mean a trashed engine in the near
future. *The bearing play gets magnified A LOT by the fact that the
piston moves not at all at true top dead center and bottom dead
center - that's where the 'dead' comes from. *So the crank has to
move enough into its curve to start pulling on the piston.

There shouldn't be much clearance there -- I'm not even going to
hazard a guess at what is right, but it's in the single-digit or low
double digit thousandths for each bearing.

* Probably on the order of .002-.004 on the big end - looser is better up to
a point with a splash lubrication system . Check the fit with plastigage
with the piston about halfway up the bore *, if it's too loose the rod cap
can be filed or lightly sanded to close it up a bit . BE VERY CAUTIOUS if
you need to sand or file - a little bit goes a long ways when you're talking
thousandths . You must also be cautious to take an even amount off both
sides - the mating surfaces MUST be flat and parallel with each other .
--
* Snag
* every answer
* leads to another
* question- Hide quoted text -

- Show quoted text -

Sorry, I di dnot mean to infer that there was no bearing. It is just
that it seems alot of people mean a "main" bearing separate of the rod
when you say "rod bearing".

I measured the crank journal and it was within specs of my book. The
rod is brand new. I went ahead since my last post and put the cam in.
The sound is much less pronounced. Where do you think I should go from
here? I did not quite understand what you meant about "filing" the
bearing.

"stryped" wrote in message
...
On Dec 31, 7:15 pm, "Terry Coombs" wrote:
Tim Wescott wrote:
On Wed, 31 Dec 2008 16:17:10 -0800, stryped wrote:



snip



Probably on the order of .002-.004 on the big end - looser is better up to
a point with a splash lubrication system . Check the fit with plastigage
with the piston about halfway up the bore , if it's too loose the rod cap
can be filed or lightly sanded to close it up a bit . BE VERY CAUTIOUS if
you need to sand or file - a little bit goes a long ways when you're
talking
thousandths . You must also be cautious to take an even amount off both
sides - the mating surfaces MUST be flat and parallel with each other .
--
Snag
every answer
leads to another
question- Hide quoted text -

- Show quoted text -

Sorry, I di dnot mean to infer that there was no bearing. It is just
that it seems alot of people mean a "main" bearing separate of the rod
when you say "rod bearing".

I measured the crank journal and it was within specs of my book. The
rod is brand new. I went ahead since my last post and put the cam in.
The sound is much less pronounced. Where do you think I should go from
here? I did not quite understand what you meant about "filing" the
bearing.

first step - did you get some plastigauge and measure the clearance? if so,
what is it?

Once you know what the clearance actually is, then we can advise you on what
to do next.

filing the bearing - take a couple of swipes on the flat surface through
which the bolts go on each side to make the bearing fit tighter. Do not do
this until you have measured the clearance with plastigauge like three
people have told you




** Posted from http://www.teranews.com **

On Dec 31, 9:17*pm, "Bill Noble" wrote:
"stryped" wrote in message

...
On Dec 31, 7:15 pm, "Terry Coombs" wrote:

Tim Wescott wrote:
On Wed, 31 Dec 2008 16:17:10 -0800, stryped wrote:

snip







Probably on the order of .002-.004 on the big end - looser is better up to
a point with a splash lubrication system . Check the fit with plastigage
with the piston about halfway up the bore , if it's too loose the rod cap
can be filed or lightly sanded to close it up a bit . BE VERY CAUTIOUS if
you need to sand or file - a little bit goes a long ways when you're
talking
thousandths . You must also be cautious to take an even amount off both
sides - the mating surfaces MUST be flat and parallel with each other .
--
Snag
every answer
leads to another
question- Hide quoted text -

- Show quoted text -

Sorry, I di dnot mean to infer that there was no bearing. It is just
that it seems alot of people mean a "main" bearing separate of the rod
when you say "rod bearing".

I measured the crank journal and it was within specs of my book. The
rod is brand new. I went ahead since my last post and put the cam in.
The sound is much less pronounced. Where do you think I should go from
here? I did not quite understand what you meant about "filing" the
bearing.

first step - did you get some plastigauge and measure the clearance? *if so,
what is it?

Once you know what the clearance actually is, then we can advise you on what
to do next.

filing the bearing - take a couple of swipes on the flat surface through
which the bolts go on each side to make the bearing fit tighter. *Do not do
this until you have measured the clearance with plastigauge like three
people have told you

** Posted fromhttp://www.teranews.com**- Hide quoted text -

- Show quoted text -

Can I get it at autozone?

"stryped" wrote in message
...
On Dec 31, 9:17 pm, "Bill Noble" wrote:
"stryped" wrote in message

...

snip


first step - did you get some plastigauge and measure the clearance? if
so,
what is it?

Once you know what the clearance actually is, then we can advise you on
what
to do next.

filing the bearing - take a couple of swipes on the flat surface through
which the bolts go on each side to make the bearing fit tighter. Do not do
this until you have measured the clearance with plastigauge like three
people have told you

** Posted fromhttp://www.teranews.com**- Hide quoted text -

- Show quoted text -

Can I get it at autozone?

********************************

Look - at the risk of being an ass - can you please try to think a little
bit for yourself from time to time - we have given you the name of a
specific product. you know that autozone has a web site with their catalog
on line, you know how to use a computer - you know how to type - please try
to answer this kind of simple question - then ask again -

you didn't ask "what is plastigage" - but I am going to just presume that
you dont' know what we are talking about - so start here
http://www.ehow.com/how_2142943_use-...learances.html

and, to make my point that you can do this yourself, here is the autozone
link
http://www.autozone.com/servlet/UiBr...3d8004c8bd.jsp

so, now, engage a second synapse and tell us what you find so we can offer
some useful advise


** Posted from http://www.teranews.com **

On Jan 1, 5:11 pm, "Bill Noble" wrote:
"stryped" wrote in message


you didn't ask "what is plastigage" - but I am going to just presume that
you dont' know what we are talking about - so start herehttp://www.ehow.com/how_2142943_use-plastigage-measure-clearances.html


Thanks for the link Bill - I heard of the stuff, but had no idea how
to use it, being but a mere beginner in engineering. I can assume the
same procedure is used to measure con rod clearances to the
crankshaft?
(and theres lots of other interesting mechanical engineering type
stuff there too)

Andrew VK3BFA.

On Dec 31 2008, 9:59*pm, stryped wrote:
On Dec 31 2008, 10:17 pm, "Bill Noble" wrote:
"stryped" wrote in message
On Dec 31, 7:15 pm, "Terry Coombs" wrote:
Tim Wescott wrote:
stryped wrote:
I measured the crank journal and it was within specs of my book. The
rod is brand new. I went ahead since my last post and put the cam in.
The sound is much less pronounced. Where do you think I should go from
here? I did not quite understand what you meant about "filing" the
bearing.

The Haynes small engine manual 10341, 1998 edition, shows crank
journal diameter for the Tecumseh HH60 as 1.0615 - 1.0620, rod bearing
as 1.0630 - 1.0635. There are details and warnings about installing
the piston and torquing the rod nuts, but nothing on checking bearing
clearance.

I use Plastigage anyway. It's a soft plastic wire you flatten in the
bearing clearance and then compare to a thickness chart on the
package, a cheap and simple alternative to measuring instruments that
read to 0.0001".

I don't have a Tecumseh manual and the Briggs & Stratton factory
manual is similar to Haynes. Page 9.2 of the 3/84 edition: "If,
however, the crankpin bearing in the connecting rod is worn, the rod
should be replaced. Do not attempt to 'file' or 'fit' the rod".

The Haynes book is apparently for amateurs and small shops, its advice
for some wear conditions is "take it to a machine shop". The section
on precision measurement doesn't mention Plastigage. That's why I buy
the factory manual for my vehicles, it assumes YOU have to fix
everything somehow and suggests how to machine tools and parts.

Jim Wilkins

On Jan 1, 7:16*am, Jim Wilkins wrote:
On Dec 31 2008, 9:59*pm, stryped wrote:
On Dec 31 2008, 10:17 pm, "Bill Noble" wrote:

"stryped" wrote in message
On Dec 31, 7:15 pm, "Terry Coombs" wrote:
Tim Wescott wrote:
stryped wrote:
I measured the crank journal and it was within specs of my book. The
rod is brand new. I went ahead since my last post and put the cam in.
The sound is much less pronounced. Where do you think I should go from
here? I did not quite understand what you meant about "filing" the
bearing.

The Haynes small engine manual 10341, 1998 edition, shows crank
journal diameter for the Tecumseh HH60 as 1.0615 - 1.0620, rod bearing
as 1.0630 - 1.0635. There are details and warnings about installing
the piston and torquing the rod nuts, but nothing on checking bearing
clearance.

I use Plastigage anyway. It's a soft plastic wire you flatten in the
bearing clearance and then compare to a thickness chart on the
package, a cheap and simple alternative to measuring instruments that
read to 0.0001".

I don't have a Tecumseh manual and the Briggs & Stratton factory
manual is similar to Haynes. Page 9.2 of the 3/84 edition: "If,
however, the crankpin bearing in the connecting rod is worn, the rod
should be replaced. Do not attempt to 'file' or 'fit' the rod".

The Haynes book is apparently for amateurs and small shops, its advice
for some wear conditions is "take it to a machine shop". The section
on precision measurement doesn't mention Plastigage. That's why I buy
the factory manual for my vehicles, it assumes YOU have to fix
everything somehow and suggests how to machine tools and parts.

Jim Wilkins

What are the "details and warnings" on installing the pistons?

Bill Noble wrote:
(...)

you didn't ask "what is plastigage" - but I am going to just presume that
you dont' know what we are talking about - so start here
http://www.ehow.com/how_2142943_use-...learances.html

Bill, did you see the same thing I did?

The photo in step four implies a clearance of 0.0015" when the real
reading is 0.001". The user took the reading between the 0.001" line and
the 0.0015" line, not between the 'zero' line and the 0.001" line.

Would be an easy mistake to make, given the different sort of ruler shown
in 'figure 4' of the factory document:
http://www.plastigaugeusa.com/how.html

--Winston

On Thu, 01 Jan 2009 15:05:11 -0800, the infamous Winston
scrawled the following:

Bill Noble wrote:
(...)

you didn't ask "what is plastigage" - but I am going to just presume that
you dont' know what we are talking about - so start here
http://www.ehow.com/how_2142943_use-...learances.html

Bill, did you see the same thing I did?

The photo in step four implies a clearance of 0.0015" when the real
reading is 0.001". The user took the reading between the 0.001" line and
the 0.0015" line, not between the 'zero' line and the 0.001" line.

Unless there's a really bad parallax error there, I read 0.0015", too.
What are you saying, Winnie? There's no way to misinterpret the 0.001
and 0.0015" marks. The line between them is pencilmark thin. 'Sprain,
preese.


Would be an easy mistake to make, given the different sort of ruler shown
in 'figure 4' of the factory document:
http://www.plastigaugeusa.com/how.html

Granted, this one might be a slight bit easier to read. But the error
you speak of is gross and I can't see it being made.

------
We're born hungry, wet, 'n naked, and it gets worse from there.

Larry Jaques wrote:
(...)

Unless there's a really bad parallax error there, I read 0.0015", too.
What are you saying, Winnie? There's no way to misinterpret the 0.001
and 0.0015" marks. The line between them is pencilmark thin. 'Sprain,
preese.

You are absolutely right. I had my keyboard on and brain off.
Somehow, I figured the width of the squashed plastigage would be directly,
not inversely proportional to clearance. My Bad!

--Winston

On Thu, 01 Jan 2009 18:25:07 -0800, the infamous Winston
scrawled the following:

Larry Jaques wrote:
(...)

Unless there's a really bad parallax error there, I read 0.0015", too.
What are you saying, Winnie? There's no way to misinterpret the 0.001
and 0.0015" marks. The line between them is pencilmark thin. 'Sprain,
preese.

You are absolutely right. I had my keyboard on and brain off.
Somehow, I figured the width of the squashed plastigage would be directly,
not inversely proportional to clearance. My Bad!

polishes fingernails on chest I don't have a Dana Corporation
Doctor of Motors Student Citation for nothing.

------
We're born hungry, wet, 'n naked, and it gets worse from there.

On Jan 1, 8:31*am, stryped wrote:
...

What are the "details and warnings" on installing the pistons?

About a page of text that describes stamped alignment arrows and such
for various engine models and how not to break the new rings.

What do you have?
"I measured the crank journal and it was within specs of my book. "

Jim Wilkins