Exhaust Brake on a Two-Stroke???

[rv_safetyman]

Have a good friend with a Prevost and 8V92 and he installed an exhaust brake ("potato in exhaust" type).  He has not had it on long and it looks like he might have lost an exhaust valve.  He is thinking they may be related.

I had not heard of an installation of an exhaust brake on a two-stroke.  Anyone know of a successful installation?

Jim

[luvrbus]

Bad mistake using a PAC brake on a 2 stroke Jim most of the time it will break compression ring first I should have read the DD before we installed one on Shane's 6V92TA it blew the compression rings on 3 cylinders lucky for me it was his idea and he bought the Pac Brake.fwiw he now has Jake's.
Jim I would have your friend check the bridge adjustment on the 8v92 on all cylinders I have saw people use that adjustment to get valve clearances and it will cost you a valve.
If he put a hole in the head Don Fairchild has 2 at a good price and I also have 4 rebuilt heads of the later casting numbers


good luck

[Bob Belter]

Ahoy, 'exhaust brakers',

I have Jakes on my Cummins, so no dog in the fight, but an exhaust brake certainly puts lottsa pressure into the exhaust system. 

What happens to the exhaust valve guide seals under these circumstances?  They work OK, but why?

Enjoy   /s/   Bob 

[Ncbob]

To the b est of my recollection, and it ins't that good anymore, I can't remember ANY engine which used valve seals on the exhaust valves. Too Hot! On the 71 series we had a special tool for knurlizing the valve guides for a proper fit.

NCbob

[luvrbus]

2 strokes have oil seals for valves 1 on each valve 


good luck

[TomC]

JIM- I'll say this as politely as I can- R E M O V E  T H A T  E X H A U S T  B R A K E!!!!!  2 Strokes are not designed for stuffed up exhaust brakes.  They impose tremendous pressure on the piston and rings, but more then that, that blower takes all the force since it is a positive displacement pump-you run the risk of blowing the blower right off the top of the engine (think dragster blowing a blower!).  Have your friend remove the exhaust brake and install Jake Brakes-like immediately.  He'll thank you for not having serious engine trouble ($$$$).  Good Luck, TomC