exhaust brake add-on

hvguy · #1 08-22-2010, 10:04 AM

I have seen big trucks with engine brakes, even the newer 6.7L cummins has an engine brake... so I was thinking making an exhaust brake for the D24.

For an EXHAUST brake you only need a butterfly valve type mechanism in-line with the exhaust system, close the valve for braking action.

seems simple enough,

for those who dont know what this is: here is a step-by-step installation on a cummins 24-valve which will basically be the same thing for the d24.
http://www.youtube.com/watch?v=Tqegu2YKeKY

RLDSL · #2 11-06-2010, 09:53 AM

Probably not a good idea. There are a number of mid range diesels where they recomend heavily against usage of an exhaust brake. THey build up a lot of back pressure and can end up floating the valves, leading to contact with the pistons in extreme cases. Some are getting around it with heavier valve springs, but even then teh jury is still out I seriously doubt the valve springs in a d24 would be up to the job.

Jason · #3 11-08-2010, 06:28 PM

I would agree, the extra back pressure wouldn't be good for it... The cummins engine is a much heavier duty setup than the D24. Not like you can tow enough with one for you to need it. I suppose for the novelty it would work, but it would be hard on it.

Jason

Ruby Rhod · #4 11-10-2010, 05:56 AM

All the diesels use VGT turbo as the exhaust brake and they run upwards of 70psi backpressure.

casioqv · #5 01-06-2011, 11:07 AM

I don't know how much it would help, but I think a gas engine throttle body on the intake wouldn't be dangerous to the engine and would improve engine braking somewhat. Some old Mercedes diesels had this from the factory.

VolvoForLife! · #6 07-13-2011, 12:37 AM

The MBs used it to control the injection pump only. 14psi of atmospheric pressure is not as good as 30+psi of exhaust pressure.

casioqv · #7 07-13-2011, 08:42 AM

Quote:

Originally Posted by VolvoForLife!

The MBs used it to control the injection pump only. 14psi of atmospheric pressure is not as good as 30+psi of exhaust pressure.

It would still give gasoline engine level engine braking. A B230FT car can bring a 3,000lb trailer down a steep mountain without riding the brakes at 3000+ rpm, something that a stock D24T can't do.

I think in practice a throttle body brake on a D24T would let you control hill descent without riding the brakes with any size trailer the car itself could safely tow, which is basically the point of an exhaust brake.

VolvoForLife! · #8 07-20-2011, 01:11 PM

It would also destroy your valve stem seals, they aren't designed for manifold vacuum.