OK. So I was watching an episode of the U.S. documentary series "Undercover
Stings" a couple of nights ago, and the camera focused briefly on a post by
the side of the road. It had two square signs on it. The upper green one
said "Starke City Limit" which I understood, but the one below it - white
background, black lettering, black line all around the edge, said "Engine
Braking Prohibited". What does this mean ? I understand what engine braking
is - here in the UK at least - but does it mean something different your
side of the pond, and why would it be prohibited anywhere ?

Arfa

Google "jake brake"


Tom

"Arfa Daily" wrote in message
...
OK. So I was watching an episode of the U.S. documentary series
"Undercover Stings" a couple of nights ago, and the camera focused briefly
on a post by the side of the road. It had two square signs on it. The
upper green one said "Starke City Limit" which I understood, but the one
below it - white background, black lettering, black line all around the
edge, said "Engine Braking Prohibited". What does this mean ? I understand
what engine braking is - here in the UK at least - but does it mean
something different your side of the pond, and why would it be prohibited
anywhere ?

Arfa

On Sun, 24 Jun 2012 18:15:11 +0100, "Arfa Daily"
wrote:

OK. So I was watching an episode of the U.S. documentary series "Undercover
Stings" a couple of nights ago, and the camera focused briefly on a post by
the side of the road. It had two square signs on it. The upper green one
said "Starke City Limit" which I understood, but the one below it - white
background, black lettering, black line all around the edge, said "Engine
Braking Prohibited". What does this mean ? I understand what engine braking
is - here in the UK at least - but does it mean something different your
side of the pond, and why would it be prohibited anywhere ?

Arfa
If you don't want to google "Jake Brake" then I'll explain a little.
The exhaust valve is held open after the air is compressed in the
cylinder. A similar device used to be available, and probably still
is, for use on 2 stroke engine powered dirt bikes and they are both
compression release devices. So most of the energy used to compress
the air is lost before it can cause the piston to rebound. The reason
they aren't allowed in city limits is because they are so loud.
Eric

On Jun 24, 10:15*am, "Arfa Daily" wrote:
OK. So I was watching an episode of the U.S. documentary series "Undercover
Stings" a couple of nights ago, and the camera focused briefly on a post by
the side of the road. It had two square signs on it. The upper green one
said "Starke City Limit" which I understood, but the one below it - *white
background, black lettering, black line all around the edge, said "Engine
Braking Prohibited". What does this mean ? I understand what engine braking
is - here in the UK at least - but does it mean something different your
side of the pond, and why would it be prohibited anywhere ?

Arfa

Interesting! Just saw this sign real!.

Driving towards Flagstaff, AZ on Highway 17 saw a sign that said
"Engine Braking Prohibited", way out in the wilds, no one around.

Plus, the slope was so gentle? Maybe for the trucks?

Could be pollution? There was no way an automobile's engine would
brake on that slope. Must be to keep the trucks from trying to save
their brakes.

On Jun 24, 10:15*am, "Arfa Daily" wrote:
OK. So I was watching an episode of the U.S. documentary series "Undercover
Stings" a couple of nights ago, and the camera focused briefly on a post by
the side of the road. It had two square signs on it. The upper green one
said "Starke City Limit" which I understood, but the one below it - *white
background, black lettering, black line all around the edge, said "Engine
Braking Prohibited". What does this mean ? I understand what engine braking
is - here in the UK at least - but does it mean something different your
side of the pond, and why would it be prohibited anywhere ?


http://www.jacobsvehiclesystems.com/...elease-brakes/

Hearing the jake brake's rowr rowr rowr (or blaaa aa aa aa aa) as big
trucks go downhill will keep you from sleeping.

Jacobs also makes exhaust brakes.

On Jun 24, 11:40*am, Robert Macy wrote:
On Jun 24, 10:15*am, "Arfa Daily" wrote:

OK. So I was watching an episode of the U.S. documentary series "Undercover
Stings" a couple of nights ago, and the camera focused briefly on a post by
the side of the road. It had two square signs on it. The upper green one
said "Starke City Limit" which I understood, but the one below it - *white
background, black lettering, black line all around the edge, said "Engine
Braking Prohibited". What does this mean ? I understand what engine braking
is - here in the UK at least - but does it mean something different your
side of the pond, and why would it be prohibited anywhere ?

Arfa

Interesting! Just saw this sign real!.

Driving towards Flagstaff, AZ on Highway 17 saw a sign that said
"Engine Braking Prohibited", way out in the wilds, no one around.

Plus, the slope was so gentle? Maybe for the trucks?

Could be pollution? *There was no way an automobile's engine would
brake on that slope. *Must be to keep the trucks from trying to save
their brakes.

Couldn't find a reference in the Arizona Revised Statutes, but here's
the law in Oregon. The offense of engine braking requires use of an
engine brake that is unmuffled. So letting your gas engine rev up down
hill would not be an offense.

http://www.oregonlaws.org/ors/811.492

§ 811.492¹
Engine braking

• penalty
• exception

(1) A person commits the offense of engine braking if the person is
operating a motor vehicle on a highway and uses an unmuffled engine
brake.

(2) The offense described in this section, engine braking, is a Class
A traffic violation.

(3) A person is not in violation of this section if the person uses an
unmuffled engine brake in an emergency situation to avoid imminent
danger to a person or to property. [1993 c.314 §7]

On Sun, 24 Jun 2012 18:15:11 +0100, "Arfa Daily"
wrote:

white
background, black lettering, black line all around the edge, said "Engine
Braking Prohibited". What does this mean ?

As others have mentioned, using Jacobs Brakes is rather noisy. I used
to live in the dormatories at Cal Poly Pomona. Behind the dorms is
Kellogg Hill and the San Bernardino Freeway. Sleeping was sometimes a
challenge. The hill is rather steep and the truckers would user their
Jake Brake despite threats of dire consequences if caught. It was
explained that if they rode their brakes down the hill, it would
usually end up smoking by the time they arrived at the bottom. Safety
first.

For the non-truckers:
http://farm3.staticflickr.com/2019/2059300689_8b09884913_z.jpg

This version is more of a challenge:
http://www.flickr.com/photos/delina/3403317633/
Trucks without mufflers?

Perhaps adding "ignore this sign" might be useful?
http://www.habitatadvocate.com.au/wp-content/uploads/2011/12/Trucks-avoid-using-engine-brakes-sign.jpg




--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"spamtrap1888" wrote in message
...
On Jun 24, 10:15 am, "Arfa Daily" wrote:
OK. So I was watching an episode of the U.S. documentary series
"Undercover
Stings" a couple of nights ago, and the camera focused briefly on a post
by
the side of the road. It had two square signs on it. The upper green one
said "Starke City Limit" which I understood, but the one below it -
white
background, black lettering, black line all around the edge, said "Engine
Braking Prohibited". What does this mean ? I understand what engine
braking
is - here in the UK at least - but does it mean something different your
side of the pond, and why would it be prohibited anywhere ?


http://www.jacobsvehiclesystems.com/...elease-brakes/

Hearing the jake brake's rowr rowr rowr (or blaaa aa aa aa aa) as big
trucks go downhill will keep you from sleeping.

Jacobs also makes exhaust brakes.


Ah-ha ! I thought that it might be something to do with trucks because with
most cars in the U.S. (at least the ones that I've driven) being auto
transmission, I couldn't imagine that there would be any way that engine
braking could easily be produced. I have heard of a Jake Brake on Ice Road
Truckers and IRT Deadliest Roads, but never really understood how it worked.
I don't recall them ever having commented about engine noise from using it,
but I guess that might not be too much of an issue in the wilds of Alaska or
Canada. In saying that though, I would have thought that it would have been
picked up on the soundtracks of those programmes if it was that loud ?

I have no idea whether there is a similar system fitted to UK trucks, but I
can't say that I've ever heard anything that sounded out of the ordinary
with a truck engine, so maybe not. I have seen signs here though at the
start of long downhill grades that tell trucks to engage a low gear, and
that was my understanding of what the term "engine braking" meant - taking
advantage of the engine's inherent compression, multiplied by the low gear
ratio, to produce an overun 'drag' to prevent the truck running away in a
manner that couldn't be readily corrected by use of the brakes, because of
brake fade, which I've also seen mentioned on IRT. Is this not the same
thing ? What is the difference / advantage of the Jake Brake over what I've
described, given that it is apparently noisy ?

Arfa

Arfa Daily wrote:

"spamtrap1888" wrote in message
...
On Jun 24, 10:15 am, "Arfa Daily" wrote:
OK. So I was watching an episode of the U.S. documentary series
"Undercover
Stings" a couple of nights ago, and the camera focused briefly on a post
by
the side of the road. It had two square signs on it. The upper green one
said "Starke City Limit" which I understood, but the one below it -
white
background, black lettering, black line all around the edge, said "Engine
Braking Prohibited". What does this mean ? I understand what engine
braking
is - here in the UK at least - but does it mean something different your
side of the pond, and why would it be prohibited anywhere ?


http://www.jacobsvehiclesystems.com/...elease-brakes/

Hearing the jake brake's rowr rowr rowr (or blaaa aa aa aa aa) as big
trucks go downhill will keep you from sleeping.

Jacobs also makes exhaust brakes.


Ah-ha ! I thought that it might be something to do with trucks because with
most cars in the U.S. (at least the ones that I've driven) being auto
transmission, I couldn't imagine that there would be any way that engine
braking could easily be produced. I have heard of a Jake Brake on Ice Road
Truckers and IRT Deadliest Roads, but never really understood how it worked.
I don't recall them ever having commented about engine noise from using it,
but I guess that might not be too much of an issue in the wilds of Alaska or
Canada. In saying that though, I would have thought that it would have been
picked up on the soundtracks of those programmes if it was that loud ?

I have no idea whether there is a similar system fitted to UK trucks, but I
can't say that I've ever heard anything that sounded out of the ordinary
with a truck engine, so maybe not. I have seen signs here though at the
start of long downhill grades that tell trucks to engage a low gear, and
that was my understanding of what the term "engine braking" meant - taking
advantage of the engine's inherent compression, multiplied by the low gear
ratio, to produce an overun 'drag' to prevent the truck running away in a
manner that couldn't be readily corrected by use of the brakes, because of
brake fade, which I've also seen mentioned on IRT. Is this not the same
thing ? What is the difference / advantage of the Jake Brake over what I've
described, given that it is apparently noisy ?

Arfa

It doesn't heat up and boil the brake fluid when you're coming down a
mountain pass with a full load. (Here in NA we have real mountains.)

Cheers

Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

Per Robert Macy:
"Engine Braking Prohibited", way out in the wilds, no one around.

Plus, the slope was so gentle? Maybe for the trucks?

They're *really* loud.... as in you don't want tb within even
miles of the noise - especially, I'd think, on wide-open country
without a lot of trees/hills to mitigate it.

As far as the gentleness of the slope goes, I don't have any
experience with heavily-loaded trucks, but I'd guess that if any
braking at all is required, the first choice from a cost-savings
perspective would be the compression brake, since it doesn't wear
out any consumables.
--
Pete Cresswell

On Jun 24, 4:06*pm, "(PeteCresswell)" wrote:



They're *really* loud.... as in you don't want tb within even
miles of the noise - especially, I'd think, on wide-open country
without a lot of trees/hills to mitigate it.



Well, they're not THAT loud. In hilly residential areas they frown
upon them. Around here, truckers also use them instead of the
standard brakes to scare the beejeezus out of people who cut in front
of them or otherwise drive like jerks. Drivers know a horn is
intentionally applied, but don't understand the horrible noise a truck
on the jake bearing down on them is making.

John

On Sun, 24 Jun 2012 16:00:41 -0400, Phil Hobbs
wrote:


I have no idea whether there is a similar system fitted to UK trucks, but I
can't say that I've ever heard anything that sounded out of the ordinary
with a truck engine, so maybe not. I have seen signs here though at the
start of long downhill grades that tell trucks to engage a low gear, and
that was my understanding of what the term "engine braking" meant - taking
advantage of the engine's inherent compression, multiplied by the low gear
ratio, to produce an overun 'drag' to prevent the truck running away in a
manner that couldn't be readily corrected by use of the brakes, because of
brake fade, which I've also seen mentioned on IRT. Is this not the same
thing ? What is the difference / advantage of the Jake Brake over what I've
described, given that it is apparently noisy ?

Arfa

It doesn't heat up and boil the brake fluid when you're coming down a
mountain pass with a full load. (Here in NA we have real mountains.)

Neither does overrun engine braking without compression release.
Suck, squeeze, phut, blow.
The suck provides a bit of braking as it's on a shut throttle at idle
setting and the vacuum resists the piston downward motion.
The squeeze doesn't do much as it's not got much air to squeeze.
The bang usually isn't. Mixture will be so far off it misfires.
Injection systems cut the fuel.
The blow does most braking as exhaust valve opens before BDC the
cylinder will suck air in from exhaust and then expel it on the up
stroke.
It's effective on small vehicles but not trucks. To stop a truck the
engine would be revved to destruction before it did anything really
noticeable.

Release of compression.
Suck, blow, suck, blow.
The compression release valve is un-throttled so a large volume of air
is induced/expelled. Pumping losses are very high resulting in a lot
(about x4) more braking than overrun braking.

I don't think anyone in Europe uses them. That's why we have sand drag
"escape" roads on steep hills that descend more than a few 10's of
meters.
--
Peter Hill
Spamtrap reply domain as per NNTP-Posting-Host in header
Can of worms - what every fisherman wants.
Can of worms - what every PC owner gets!

Peter Hill wrote:

On Sun, 24 Jun 2012 16:00:41 -0400, Phil Hobbs
wrote:

I have no idea whether there is a similar system fitted to UK trucks, but I
can't say that I've ever heard anything that sounded out of the ordinary
with a truck engine, so maybe not. I have seen signs here though at the
start of long downhill grades that tell trucks to engage a low gear, and
that was my understanding of what the term "engine braking" meant - taking
advantage of the engine's inherent compression, multiplied by the low gear
ratio, to produce an overun 'drag' to prevent the truck running away in a
manner that couldn't be readily corrected by use of the brakes, because of
brake fade, which I've also seen mentioned on IRT. Is this not the same
thing ? What is the difference / advantage of the Jake Brake over what I've
described, given that it is apparently noisy ?

Arfa

It doesn't heat up and boil the brake fluid when you're coming down a
mountain pass with a full load. (Here in NA we have real mountains.)


Neither does overrun engine braking without compression release.

snip
Piston engines are about 80% efficient as compressors, iirc. So the
amount of braking from overrun with a shut throttle is small. Also,
diesels don't have throttles!

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

"Peter Hill" wrote in message
news
On Sun, 24 Jun 2012 16:00:41 -0400, Phil Hobbs
wrote:


I have no idea whether there is a similar system fitted to UK trucks,
but I
can't say that I've ever heard anything that sounded out of the ordinary
with a truck engine, so maybe not. I have seen signs here though at the
start of long downhill grades that tell trucks to engage a low gear, and
that was my understanding of what the term "engine braking" meant -
taking
advantage of the engine's inherent compression, multiplied by the low
gear
ratio, to produce an overun 'drag' to prevent the truck running away in
a
manner that couldn't be readily corrected by use of the brakes, because
of
brake fade, which I've also seen mentioned on IRT. Is this not the same
thing ? What is the difference / advantage of the Jake Brake over what
I've
described, given that it is apparently noisy ?

Arfa

It doesn't heat up and boil the brake fluid when you're coming down a
mountain pass with a full load. (Here in NA we have real mountains.)

Neither does overrun engine braking without compression release.
Suck, squeeze, phut, blow.
The suck provides a bit of braking as it's on a shut throttle at idle
setting and the vacuum resists the piston downward motion.
The squeeze doesn't do much as it's not got much air to squeeze.
The bang usually isn't. Mixture will be so far off it misfires.
Injection systems cut the fuel.
The blow does most braking as exhaust valve opens before BDC the
cylinder will suck air in from exhaust and then expel it on the up
stroke.
It's effective on small vehicles but not trucks. To stop a truck the
engine would be revved to destruction before it did anything really
noticeable.

Release of compression.
Suck, blow, suck, blow.
The compression release valve is un-throttled so a large volume of air
is induced/expelled. Pumping losses are very high resulting in a lot
(about x4) more braking than overrun braking.

I don't think anyone in Europe uses them. That's why we have sand drag
"escape" roads on steep hills that descend more than a few 10's of
meters.
--
Peter Hill
Spamtrap reply domain as per NNTP-Posting-Host in header
Can of worms - what every fisherman wants.
Can of worms - what every PC owner gets!


We do have sand drag escape roads here, although not many of them. There is
one at the bottom of a very long downgrade on a road in Devon that I used to
travel on regularly when going to carry out service work at a site that was
a customer of mine at the time. I think that I'm beginning to understand the
difference now, and I'm pretty sure that we do not have them fitted here -
in the UK at least. There are some fairly steep grades scattered around the
UK, but most of the mountainous areas are in Wales and Scotland, both of
which are fairly sparsely populated, so not too much truck traffic other
than on the main roads, which are largely flat. There are plenty of
mountainous areas in mainland Europe though, so you might have thought that
trucks operating in these areas might employ such supplemental braking ?

Arfa

On Jun 24, 12:34*pm, "Arfa Daily" wrote:

I have no idea whether there is a similar system fitted to UK trucks, but I
can't say that I've ever heard anything that sounded out of the ordinary
with a truck engine, so maybe not.

A quick google shows Jacobs brakes are fitted to ERF (Foden) trucks,
which use Cummins diesel engines. I couldn't find anything regarding
Perkins' engines.


I have seen signs here though at the
start of long downhill grades that tell trucks to engage a low gear, and
that was my understanding of what the term "engine braking" meant - taking
advantage of the engine's inherent compression, multiplied by the low gear
ratio, to produce an overun 'drag' to prevent the truck running away

Unlike in a spark ignition engine, apparently, in a Diesel, air is
free to move through the cylinders. (A spark ignition engine's
throttle changes the amount of air, and thus fuel, flowing through the
engine. The Diesel's airflow is constant; the accelerator pedal
changes the amount of fuel flowing only.) Thus the engine's inherent
compression is immediately followed by the engines's inherent
expansion, with only a negligible net slowing effect. The Jake brake
interrupts the flow and changes the engine into an air compressor.


in a
manner that couldn't be readily corrected by use of the brakes, because of
brake fade, which I've also seen mentioned on IRT.

Brake fade is related to heat. When sufficiently hot, the coefficient
of friction of the brake lining of the (in heavy trucks, still drum
shoes) is relatively low. There are other causes of fade, too. Here at
the tops of hills, you will see spots to pull over and let your brakes
cool.


Is this not the same
thing ? What is the difference / advantage of the Jake Brake over what I've
described, given that it is apparently noisy ?


Here's an interesting historical treatment with some description, but
mostly focusing on the inventor:

http://files.asme.org/ASMEORG/Commun...marks/5577.pdf

On Mon, 25 Jun 2012 01:14:23 +0100, "Arfa Daily"
wrote:

We do have sand drag escape roads here, although not many of them. There is
one at the bottom of a very long downgrade on a road in Devon that I used to
travel on regularly when going to carry out service work at a site that was
a customer of mine at the time.

There is one on A379 into Dartmouth.
http://goo.gl/maps/uwyl

There is another on A46 at Bath on approach from Pennsylvania
http://goo.gl/maps/jVYo
--
Peter Hill
Spamtrap reply domain as per NNTP-Posting-Host in header
Can of worms - what every fisherman wants.
Can of worms - what every PC owner gets!

[quote=Peter Hill;2881393]On Sun, 24 Jun 2012 16:00:41 -0400, Phil Hobbs
wrote:


I have no idea whether there is a similar system fitted to UK trucks, but I
can't say that I've ever heard anything that sounded out of the ordinary
with a truck engine, so maybe not. I have seen signs here though at the
start of long downhill grades that tell trucks to engage a low gear, and
that was my understanding of what the term "engine braking" meant - taking
advantage of the engine's inherent compression, multiplied by the low gear
ratio, to produce an overun 'drag' to prevent the truck running away in a
manner that couldn't be readily corrected by use of the brakes, because of
brake fade, which I've also seen mentioned on IRT. Is this not the same
thing ? What is the difference / advantage of the Jake Brake over what I've
described, given that it is apparently noisy ?

Arfa

It doesn't heat up and boil the brake fluid when you're coming down a
mountain pass with a full load. (Here in NA we have real mountains.)

Neither does overrun engine braking without compression release.
Suck, squeeze, phut, blow.
The suck provides a bit of braking as it's on a shut throttle at idle
setting and the vacuum resists the piston downward motion.
The squeeze doesn't do much as it's not got much air to squeeze.
The bang usually isn't. Mixture will be so far off it misfires.
Injection systems cut the fuel.
The blow does most braking as exhaust valve opens before BDC the
cylinder will suck air in from exhaust and then expel it on the up
stroke.
It's effective on small vehicles but not trucks. To stop a truck the
engine would be revved to destruction before it did anything really
noticeable.

Release of compression.
Suck, blow, suck, blow.
The compression release valve is un-throttled so a large volume of air
is induced/expelled. Pumping losses are very high resulting in a lot
(about x4) more braking than overrun braking.

I don't think anyone in Europe uses them. That's why we have sand drag
"escape" roads on steep hills that descend more than a few 10's of
meters.
--
European trucks do have them but here they're called "exhaust brakes". I can vouch for the noise they make as I've driven trucks with them. I can also hear the trucks here using them going down the A21 which is approx 2 miles from my house!

Arfa Daily wrote:


"spamtrap1888" wrote in message
...
On Jun 24, 10:15 am, "Arfa Daily" wrote:
OK. So I was watching an episode of the U.S. documentary series
"Undercover
Stings" a couple of nights ago, and the camera focused briefly on a post
by
the side of the road. It had two square signs on it. The upper green one
said "Starke City Limit" which I understood, but the one below it -
white
background, black lettering, black line all around the edge, said "Engine
Braking Prohibited". What does this mean ? I understand what engine
braking
is - here in the UK at least - but does it mean something different your
side of the pond, and why would it be prohibited anywhere ?


http://www.jacobsvehiclesystems.com/...elease-brakes/

Hearing the jake brake's rowr rowr rowr (or blaaa aa aa aa aa) as big
trucks go downhill will keep you from sleeping.

Jacobs also makes exhaust brakes.


Ah-ha ! I thought that it might be something to do with trucks because with
most cars in the U.S. (at least the ones that I've driven) being auto
transmission, I couldn't imagine that there would be any way that engine
braking could easily be produced. I have heard of a Jake Brake on Ice Road
Truckers and IRT Deadliest Roads, but never really understood how it worked.
I don't recall them ever having commented about engine noise from using it,
but I guess that might not be too much of an issue in the wilds of Alaska or
Canada. In saying that though, I would have thought that it would have been
picked up on the soundtracks of those programmes if it was that loud ?

I have no idea whether there is a similar system fitted to UK trucks, but I
can't say that I've ever heard anything that sounded out of the ordinary
with a truck engine, so maybe not. I have seen signs here though at the

I wonder if vehicle size difference is part of the reason jake brakes
would seem to be less common outside the US.

a large truck in europe is small here in the US.

I think only Australia outdoes the US with their road trains.

It's the same with railways, a large european freight train would be
crushed to bits in a crash with a commuter passenger train from the US.
Laws here don't permit passenger trains to be made of paper cups and used
tissue like in germany. Everything is large and heavy.

Canada does run longer heavier trains than in the US though.

John-Del wrote:
On Jun 24, 4:06 pm, "(PeteCresswell)" wrote:



They're *really* loud.... as in you don't want tb within even
miles of the noise - especially, I'd think, on wide-open country
without a lot of trees/hills to mitigate it.



Well, they're not THAT loud. In hilly residential areas they frown
upon them. Around here, truckers also use them instead of the
standard brakes to scare the beejeezus out of people who cut in front
of them or otherwise drive like jerks. Drivers know a horn is
intentionally applied, but don't understand the horrible noise a truck
on the jake bearing down on them is making.

John

http://www.youtube.com/watch?v=qocMoTOVn6Q

Greg

Peter Hill wrote:


The suck provides a bit of braking as it's on a shut throttle at idle
Uhhh, there's no throttle on a Diesel.
setting and the vacuum resists the piston downward motion.
The squeeze doesn't do much as it's not got much air to squeeze.
The bang usually isn't. Mixture will be so far off it misfires.
There will be no fuel sent to the cylinders when the compression brake
is applied.

It's effective on small vehicles but not trucks. To stop a truck the
engine would be revved to destruction before it did anything really
noticeable.

Actually, the Jacobson brake is QUITE effective, and can deliver about the
same braking effort as the engine at full power.

Jon

"gregz" wrote in message
...
John-Del wrote:
On Jun 24, 4:06 pm, "(PeteCresswell)" wrote:



They're *really* loud.... as in you don't want tb within even
miles of the noise - especially, I'd think, on wide-open country
without a lot of trees/hills to mitigate it.



Well, they're not THAT loud. In hilly residential areas they frown
upon them. Around here, truckers also use them instead of the
standard brakes to scare the beejeezus out of people who cut in front
of them or otherwise drive like jerks. Drivers know a horn is
intentionally applied, but don't understand the horrible noise a truck
on the jake bearing down on them is making.

John

http://www.youtube.com/watch?v=qocMoTOVn6Q

Greg


OK. I guess that puts it in perspective. So, was the driver's foot off the
pedal all the way down that incline, after he'd switched on the Jake brake ?
Why did the sound drop right down at the bottom, before the switch was
disengaged ? Is it because the engine is no longer in over-run condition, or
because accelerator has been reapplied ?

Arfa

On 6/26/2012 8:06 PM, Cydrome Leader wrote: with a truck engine, so
maybe not. I have seen signs here though at the

I wonder if vehicle size difference is part of the reason jake brakes
would seem to be less common outside the US.

a large truck in europe is small here in the US.

I think only Australia outdoes the US with their road trains.

It's the same with railways, a large european freight train would be
crushed to bits in a crash with a commuter passenger train from the US.
Laws here don't permit passenger trains to be made of paper cups and used
tissue like in germany. Everything is large and heavy.

Canada does run longer heavier trains than in the US though.





Ever been out of the States? Europeans don't use steam any more you
know. I think you will find the max laden truck weight is higher in
Europe. US trucks are so crap, 1950's engines. Crawl up hill, no brakes
down hill. Driven by suicidal Mex's. Always tailgating, All chrome and
no safety gear, no spray suppression, no side bars, ineffective tail
bars, totally lethal to other drivers. Stay well away from them on
interstates. We have a couple rollover almost every day here in NJ.
Usually trash trucks from NY. JC

Per Archon:
US trucks are so crap, 1950's engines. Crawl up hill, no brakes
down hill. Driven by suicidal Mex's. Always tailgating, All chrome and
no safety gear, no spray suppression, no side bars, ineffective tail
bars, totally lethal to other drivers. Stay well away from them on
interstates. We have a couple rollover almost every day here in NJ.

Can't comment on equipment bc I don't know diddley.

But I drive in the Philadelphia/South Jersey area and it seems to
me like 98% of the drivers are pretty good. Yeah, every so often
one sees the guy who thinks he's driving a car... but I'd bet he
is not a professional driver, and maybe not even legal.

The vast majority of the time they look to me like they are
driving about as safe as they can given so many automobile
drivers texting, talking on cell phones, passing on the right,
and so-forth.
--
Pete Cresswell

On Jun 28, 4:59*pm, Archon wrote:
On 6/26/2012 8:06 PM, Cydrome Leader wrote: with a truck engine, so
maybe not. I have seen signs here though at the











I wonder if vehicle size difference is part of the reason jake brakes
would seem to be less common outside the US.

a large truck in europe is small here in the US.

I think only Australia outdoes the US with their road trains.

It's the same with railways, a large european freight train would be
crushed to bits in a crash with a commuter passenger train from the US.
Laws here don't permit passenger trains to be made of paper cups and used
tissue like in germany. Everything is large and heavy.

Canada does run longer heavier trains than in the US though.

Ever been out of the States? Europeans don't use steam any more you
know. I think you will find the max laden truck weight is higher in
Europe. US trucks are so crap, 1950's engines. Crawl up hill, no brakes
down hill. Driven by suicidal Mex's. *Always tailgating, All chrome and
no safety gear, no spray suppression, no side bars, ineffective tail
bars, totally lethal to other drivers. Stay well away from them on
interstates. We have a couple rollover almost every day here in NJ.
Usually trash trucks from NY. JC

At least in North America the truck tractor's exhaust does not point
right at the motorist in the next lane. And the semitrailers are
almost always metal boxes, not cloth-covered frames.

"spamtrap1888" wrote in message
...
On Jun 28, 4:59 pm, Archon wrote:
On 6/26/2012 8:06 PM, Cydrome Leader wrote: with a truck engine, so
maybe not. I have seen signs here though at the











I wonder if vehicle size difference is part of the reason jake brakes
would seem to be less common outside the US.

a large truck in europe is small here in the US.

I think only Australia outdoes the US with their road trains.

It's the same with railways, a large european freight train would be
crushed to bits in a crash with a commuter passenger train from the US.
Laws here don't permit passenger trains to be made of paper cups and
used
tissue like in germany. Everything is large and heavy.

Canada does run longer heavier trains than in the US though.

Ever been out of the States? Europeans don't use steam any more you
know. I think you will find the max laden truck weight is higher in
Europe. US trucks are so crap, 1950's engines. Crawl up hill, no brakes
down hill. Driven by suicidal Mex's. Always tailgating, All chrome and
no safety gear, no spray suppression, no side bars, ineffective tail
bars, totally lethal to other drivers. Stay well away from them on
interstates. We have a couple rollover almost every day here in NJ.
Usually trash trucks from NY. JC

At least in North America the truck tractor's exhaust does not point
right at the motorist in the next lane. And the semitrailers are
almost always metal boxes, not cloth-covered frames.


Well, to be fair, the exhausts on an awful lot of European trucks also run
vertically up the back of the cab like Kenworths and Peterbilts. And most
trailers are also metal box construction. The curtain-siders (it's not
really 'cloth' - more of a *very* tough plasticised tarp) are used for the
most part for the special purpose of 'palletized deliveries' which is maybe
something that's not done in the U.S. ??

It's a system where a central company runs goods around the country for many
different clients on the same truck. Schedules are arranged such that as
goods are dropped off in towns, more goods are picked up to keep the truck
moving around as full as possible. It cuts down on fuel wastage and road
wastage by not having 'returning to depot' trucks running around empty, and
cuts down on costs for the companies that are having their goods shipped by
them not having to maintain their own truck fleet, or having to try to keep
their own trucks full.

The system only works if the goods to be shipped are palletised, and able to
be got at, no matter where their load point is on the trailer. So, they are
stacked on a curtain-sider, in two rows, running the length of the trailer.
That way, when the driver reaches a drop-off point, he can just pull back
the curtain on the appropriate side, to allow the fork truck to get in there
and remove the pallets. When he arrives at another collection, the
previously emptied space is again easily accessible to be reloaded. The
curtain material is very tough, and pretty much affords the same protection
to the load, as an aluminium box trailer. And if the trailer bed has been
properly loaded, there is no issue with the goods moving about.

Some companies that have their own trucks, still use curtain-siders, because
their goods are palletised anyway, and it can just be easier to load and
unload in some goods depots, if the fork truck can get to the sides of the
trailer, rather than the driver having to manually pallet-truck the goods to
the back, or handball boxes to the back as would be the case with a box
trailer. Just horses for courses, I guess.

Arfa

The U.S. may be just geographically too large for such a system to work ??

Per Arfa Daily:
The curtain-siders (it's not
really 'cloth' - more of a *very* tough plasticised tarp) are used for the
most part for the special purpose of 'palletized deliveries' which is maybe
something that's not done in the U.S. ??

I've seen trailers like that in the USA. Never had a clue as to
their function, though - and I don't know what was inside (i.e.
if the cargo was palletized).
--
Pete Cresswell

On Jun 29, 6:24*pm, "Arfa Daily" wrote:
"spamtrap1888" wrote in message

...



On Jun 28, 4:59 pm, Archon wrote:
On 6/26/2012 8:06 PM, Cydrome Leader wrote: with a truck engine, so
maybe not. I have seen signs here though at the

I wonder if vehicle size difference is part of the reason jake brakes
would seem to be less common outside the US.

a large truck in europe is small here in the US.

I think only Australia outdoes the US with their road trains.

It's the same with railways, a large european freight train would be
crushed to bits in a crash with a commuter passenger train from the US.
Laws here don't permit passenger trains to be made of paper cups and
used
tissue like in germany. Everything is large and heavy.

Canada does run longer heavier trains than in the US though.

Ever been out of the States? Europeans don't use steam any more you
know. I think you will find the max laden truck weight is higher in
Europe. US trucks are so crap, 1950's engines. Crawl up hill, no brakes
down hill. Driven by suicidal Mex's. *Always tailgating, All chrome and
no safety gear, no spray suppression, no side bars, ineffective tail
bars, totally lethal to other drivers. Stay well away from them on
interstates. We have a couple rollover almost every day here in NJ.
Usually trash trucks from NY. JC

At least in North America the truck tractor's exhaust does not point
right at the motorist in the next lane. And the semitrailers are
almost always metal boxes, not cloth-covered frames.

Well, to be fair, the exhausts on an awful lot of European trucks also run
vertically up the back of the cab like Kenworths and Peterbilts. And most
trailers are also metal box construction. The curtain-siders (it's not
really 'cloth' - more of a *very* tough plasticised tarp) are used for the
most part for the special purpose of 'palletized deliveries' which is maybe
something that's not done in the U.S. ??

It's a system where a central company runs goods around the country for many
different clients on the same truck. Schedules are arranged such that as
goods are dropped off in towns, more goods are picked up to keep the truck
moving around as full as possible. It cuts down on fuel wastage and road
wastage by not having 'returning to depot' trucks running around empty, and
cuts down on costs for the companies that are having their goods shipped by
them not having to maintain their own truck fleet, or having to try to keep
their own trucks full.

The system only works if the goods to be shipped are palletised, and able to
be got at, no matter where their load point is on the trailer. So, they are
stacked on a curtain-sider, in two rows, running the length of the trailer.

On Sun, 24 Jun 2012 16:06:14 -0400, (PeteCresswell) wrote:

Per Robert Macy:
"Engine Braking Prohibited", way out in the wilds, no one around.

Plus, the slope was so gentle? Maybe for the trucks?

They're *really* loud.... as in you don't want tb within even miles of
the noise - especially, I'd think, on wide-open country without a lot of
trees/hills to mitigate it.

They are only really loud when modified by idiot drivers who want them to
be really loud. Otherwise, they are only slightly louder than a well
muffled engine.

As far as the gentleness of the slope goes, I don't have any experience
with heavily-loaded trucks,

I have experience with heavy trucks. They still have drum brakes and you
would be surprised how quickly they can fade under certain conditions.
Obviously when fully loaded and down a long grade; but also fully loaded
and after only three or four sudden stops from highway speeds. These
sudden stops from highway speeds are common due to traffic lights when
driving on the outskirts of towns on non-interstate highways.

The jake brake saves wear and tear and prevents brake fade due to
heating. Properly used, it adds to public safety.

There is one major safety drawback of engine braking. Only the driven
axles (typically one axle) does the braking. So on any road that has poor
traction (wet, snow, blowing sand, and goodness forbid ice). So jake
brakes are known to cause jackknifing on slick roads.

but I'd guess that if any braking at all is
required, the first choice from a cost-savings perspective would be the
compression brake, since it doesn't wear out any consumables.

100% correct.

--
Tony Sivori

OK, so the curtain sides are a way of managing LTLs (Less than
Truckload Lots). In North America the tendency would be to load up a
trailer with goods going to the same city, then unload for city
delivery at their local terminal, onto smaller trucks (even tractor-
semitrailer rigs, but perhaps with only one driving axle and one
trailer axle), from back to front in the order of the city driver's
route.

Sometimes side access to palletized loads is required. Flatbeds are
popular for dense freight: side panels can be removed and single
pallets unloaded. The entire load can be tarped in case of inclement
weather.

One unique application for flatbeds is grass sod delivery. A miniature
fork lift truck is mounted to the back of the flatbed. The truck
driver lowers it to the ground and unloads as many sod pallets as the
homeowner has ordered.

Another is for moving household goods. One semitrailer might hold the
contents of four or five households. If, for any reason, either the
new residence or the residents are unavailable when the movers arrive,
the contents are crated up at the mover's warehouse. Then a separate
flatbed carries these huge crates when both the new home and the
customers are ready.

Yes, I think that it's probably a matter of physical geography. North
America is a vast country, but with comparatively 'compact' population
centres, and huge tracts of nothing between. That probably makes it better
to just run full trucks from one depot to another. In the UK, it is of
course much smaller, but with equally dense population centres. That makes
those centres much closer together, so makes the palletised distribution
model eminently practical. It was poularised by a woman called Hilary Devey
who now runs the biggest network in the UK if not Europe. She is a TV
personality also as one of the entrepeneurs on Dragons Den which has the
U.S. equivalent Shark Tank. It's a very practical system of distribution,
and has made her very rich.

Arfa