Cylinder pressure

[rambo]

My first turbo diesel a 01 3500 w some modes to pull better. A Smarty programmer, S362 turbo, stk head bolts, stk injectors, 5' straight pipe exhaust axle dump, 3 piece exspantion joint  exhaust manifold, BD exhaust brake.  My questions are,  when applying the exhaust brake  exh. pressure will increase from flow restrictions causing  heat to build up raising  pressure even more, can the clamping force of stk exh. hardware or head bolts  fail or stretch an loosen causing gaskets to move  an leak?   If possible can these press. be monitored and managed?

[Me78569]

the eb isn't even close to the amount of pressure that happens when combustion happens.  

 

 

 

[rambo]

Thx for the help.

 

[015point9]

 " If possible can these press. be monitored and managed?"

 

Yep.  https://m.youtube.com/watch?v=TSuv88KFRkI

 

[Tractorman]

5 hours ago, rambo said:

My questions are,  when applying the exhaust brake  exh. pressure will increase from flow restrictions causing  heat to build up raising  pressure even more, can the clamping force of stk exh. hardware or head bolts  fail or stretch an loosen causing gaskets to move  an leak?

 

Typically, the maximum back pressure generated by the use of the exhaust brake  is about 60 psi and exhaust manifold temperature will stay well under 500 degrees no matter the length of time used.  I don't think there is anything to be concerned about.  I have been using an exhaust brake for over 300,000 miles and I still have the original exhaust manifold setup.  I use this exhaust brake many, many times per trip on every trip. 

 

5 hours ago, rambo said:

If possible can these press. be monitored and managed?

 

I am sure they can, but I think it would be a preference,  not a need.

 

- John

 

[trreed]

All cylinder pressure comes from the compression ratio and the injection timing.  Boost and drive pressure are minuscule compared to the pressure right before the actual ignition event. 

The head bolts would only fail if the cylinder pressure could overcome their tensile strength.  I'm not sure what the STK bolts are rated to, but I doubt you'll have an issue with your setup. 

[Dieselfuture]

This may be off-topic, but when I was having issues with valve seals failing after a new head rebuild because they would work themselves off the seats and get hammered by spring retainers, I had to come up with a solution which ended up being using Ford valve seals that I modified to fit on my head. Not the best way by any means but I did not want to take the head off to do machine work to accept the right style of top hat valve seals. So far they are holding up. Where I'm going with this is when I removed valve springs and seals, there was a little bit of carbon between the valve stem and the valve guide, the valves were a bit sticky going up and down because of carbon. That would probably contribute to more wear between valve and the guide. My assumption is that this carbon works itself in there when I use the exhaust brake. 

In conclusion, some put 500k on the head using exhaust brake and don't seem to have issues and in my case half the valve guides were shot with 157k and po didn't have to exhaust brake, I installed it at 130k I kind of doubt that in 27k I wore out guides using exhaust brake. But wanted to note that carbon works itself between the valve and the a guide when using one.

[AH64ID]

5 hours ago, Tractorman said:

 

Typically, the maximum back pressure generated by the use of the exhaust brake  is about 60 psi and exhaust manifold temperature will stay well under 500 degrees no matter the length of time used. 

 

 

My EB will hold the temps well above 500° depending on the temp of the manifold when the EB was engaged. Lets say I just finished climbing a 6% grade at 1100° and immediately start down the other side at 6% with the EB on. It takes 3+ miles for the manifold temp to drop below 600°. 

 

It's actually not a bad thing, as this slow reduction in temps doesn't put the valves thru such wild temp swings. 

 

 

IIRC minimum psi for combustion is around 350 psi, so yes 60 psi is nothing for the cylinder. 

[Mopar1973Man]

Typically my truck run in the 450-500*F range with exhaust brake on. 

[015point9]

I lost one of the plug bolts coming down the siskiyous towing wives trailer.  I burned a hole about the size of a silver dollar what's above the hole.  Scared me and my wife half a death as it made a hell of a noise.  BD recommended some type of "security" wire,  so the plug bolts wouldn't  come out again.  After looking for "stainless steel dowling" about half a day.  Finaly brain engaged. At bicycle shop picked up some "stainless steel dowling".  Better known as a bicycle spoke.  

[NIsaacs]

10 hours ago, AH64ID said:

 

My EB will hold the temps well above 500° depending on the temp of the manifold when the EB was engaged. Lets say I just finished climbing a 6% grade at 1100° and immediately start down the other side at 6% with the EB on. It takes 3+ miles for the manifold temp to drop below 600°. 

 

It's actually not a bad thing, as this slow reduction in temps doesn't put the valves thru such wild temp swings. 

 

 

IIRC minimum psi for combustion is around 350 psi, so yes 60 psi is nothing for the cylinder. 

 

 

I agree. My temps are over 500 at idle when I use it for warm up. On a 5 mile 6% down grade, heavy load and high RPM mine is more like 800.

[Dieselfuture]

@015point9 that's the same exhaust brake I have on my truck seem to work very well. How long did you have yours.

[015point9]

3 hours ago, Dieselfuture said:

@015point9 that's the same exhaust brake I have on my truck seem to work very well. How long did you have yours.

Since 05 or 06.  Always worked well other than that bolt falling out as mentioned above.

  But for other reasons I am never going to buy any BD product again. 

[rambo]

Thank you all, for sharing your time and experience.