As some know, I made my own pnuematically operated EBPV for an exhaust break. The subject came up on a car hauling forum I also frequent, and one of the diesel gurus there said excessive backpressure from an exhaust break can cause valve float or lifter jacking- either way the end result is a valve hitting the piston- never a good thing.

He also went on to say that International told Jacobs to not make a break for it due to the above reason. However, PacBrake makes one, so who's right? Anyone got any info on this? The last thing I need is to be going down a big hill grossing 31,000 lbs and blow the engine!

 

Long and short...

Yes, with our valve train you can damage the valves and pistons with an exhaust brake. You need to have a wastegate in it some how that will blow off pressures above 70 or so psi.

I would NOT run a home made exhaust brake on a PSD.

Pac brake makes one, BD mades one, Banks makes one... there are a few others, however you must have a blow off of some kind.

 

Any way to measure backpressure? Can I get a comparable reading from the EBP sensor? I don't recall seeing any of the commercially made ones having a wastegate on them either.

 

Hey Danny....

>>>BD exhaust brake 7.3<<<

 

Tnaks Timmy, and that's even near my house, well when I'm home that is- I'm typing to you guys from Afghanistan right now. But even if I wanted it, I can ru nthat on the van turbo, it doesn't have the exhaust housing to fit it (no wastegate). I also noticed, the kit doesn't have a wastegate either. Here's a pic of what I did, same design as the BD, but I put my entire thing together for about $110.

 

It has a wastegate or a blow off valve in the flapper itself. They all do, be it the spring will not hold past a set point or a bleeder valve or a wastegate.

Trust me, you run over 70-80 psi, you will be replacing push rods.

 

Thanks again Joe, I'll have to take a better look at one of them to see how they get around the issue. Going back to the EBPS, do you know how to translate the voltage reading to exhaust psi? I figured if I could do that, that'll tell me approximately how much back pressure I'm generating. I also do my best to keep the rpms around 2500 max when I hit the break, I never use it in an "oh crap" situation, just to suppliment the breaks (duh LOL)

 

So, with an interference engine we have, I understand now that I need to be careful doing exhaust brake. How about vaccum? would "excessive vaccum damage our PSD? If not why not use vaccum instead of pressure. installing and maintaining a butterfly on the intake side seems easier than the hot exhaust side. Erwin

 

OT- I just realized I've been speeling it BREAK like I'm trying to destroy something. Jeez what a dumbazz.... I need to wake up, I gotta man a mchine gun post in a couple of hours...

 

Darn Danny. I would think you are trying to destroy something if you are going to man a machine gun post.

 

Stay safe out there, bud..

If this can be incorporated into the exhaust side, then plumbed into the downpipe, could this idea work, exceptthe fact, try'n to find one that can withstand 1200+ degrees at a given time...

High Temperature Check Valve - Canyon engineering

Has cracking pressure of 70psi +/- 8psi, just it can only withstand 550*F

 

Well, I will cut down a taliban guy if he tries something funny- OR I could just flip down my NVG and turn on my IR laser, and he won't even know what hit him LOL.

Back to the post, hijacking my own thread WTF LOL.... I just went to PacBrakes sight and they have a spring operated valve on the buttefly valve that I won't attempt to replicate. I do have an inline pressure regulator on the pnuematic cylinder, and I think I have it set to 60psi. Of course I'd have to do a bunch of equations to see how much pressure my .5" ID piston is putting against the 3" OD butterfly (is that Marv that always baffles us with math?) but I'm sure I can adjust the air pressure down to where about 50 psi of exhaust back pressure would overide the cylinder strength. What to you guys think?

Damn, I gotta go man my post, catch you guys later. Post, shower, sleep (it's 0040 here)

 

I dont know if they make them for pickups but jake brakes are better then exhaust brakes. A jake is quite a bit louder but puts almost no strain on the engine due to the fact that it decreases pressure. Instead of putting a ton of pressure into the engine like the exhaust brake it releases the air at the top of the cylinder stroke which makes it work harder to pull its self back down. Its kinda like a constant waste gate. It gets installed in the valve train instead of in the exhaust system. Jakes have %60 to %80 more brake power then exhaust brake. I think they sound nice too haha. The only thing is you have to turn the jake off going through most towns due to the noise but its just a pickup so it probably wouldnt matter, Not like its some big straight pipe, cat turbo Pete thats roaring down the road haha. Might be worth researching.

 

They do not make them for a powerstroke, or most mid sided diesels.

 

Didnt think so. its a shame its a much better braking system. Ive never really looked into it. My pickups standard tranny so I really dont need a brake