Pressure Wave Terminator/Resonator Box ?

[JavaJeep-INDONESIA]

I was reading one of David Vizards books (Budget Building Small Block Chevs) and on page 129 he mentions building a pressure wave terminator box after the headers to reduce the downstream effects of pipe dia and length , basically the remainder of the system becomes a vent to atmosphere

The rule he uses for the Box volume is 8 to 15 times the capacity of one cylinder

I am looking at this as I run snorkel exhausts (exhaust stacks) on all my jeeps for deep water fording and thought this may be a good idea to reduce the effects of running such a long exhaust system without going to a large pipe diameter.

I run a 1.75" dia system on my old Willys 132 cu in 4cyl in FrankenJeep and will go to a single 2.5" or 3" system when the 350 V8 goes in.

The thing is I have NEVER seen anyone use one on a vehicle

Is anyone using a "Pressure Wave Terminator/Resonator Box" ?

Does it work ?

[Big Dave]

When used after a muffler they are called resonance chambers. I would think you would follow the militaries lead on the exhaust and intake and take both out above the roof. A larger diameter pipe will have a harder time keeping water out of the exhaust pipe and mufflers than a smaller pipe (water pressure is constant at an given depth and the surface area increases with the diameter). If you had the exit under about three foot of water the pressure could fill you exhaust to the point of stalling the engine due to exhaust gas reversion.

By the way as I recall Indonesia is hilly. Hills and flowing water are not a good idea for fording deep streams unless your truck is large and heavy (otherwise it becomes a leaky raft going down stream).

Big Dave

[clay]

I have read the same book and I understand the principle, however I don't use one. A single 3" pipe should be fine for the 350. How much pipe are you talking about? Thinking about a car, there can be a fair amount of pipe with some pretty wicked turns by the time you get it over the rearend and out the back. Clay

[JavaJeep-INDONESIA]

Exhaust systems are

Jeep J20 - I6 258 cubes - 2.25" system with the exhaust snorkel behind the cab - so from the end of the header about 10 feet

Willys Jeep - Chev 350 truck motor - 2.5" to 3" exhaust snorkel at the rear of the tub - from the end of the header about 15 feet

Big Dave is correct , I have done river crossings where I have got through due to the exhaust snorkel where others have stopped in the middle and filled their engines with water. The Willys doesnt need to be heavy as in deep water the tub will fill with water stopping it from floating away

I've regularly had water up to my seat base and had to put in switches to deactivate the alternator and starter and both cooling fans are electric so they can be switched off also, I had one instance where is some really claggy mud like a slurry the starter motor came on on its own due to a short , I was pulling about 3,000 rpm at the time and thought I had a rock in the bellhousing. The starter motor and aternator were red hot after that episode and I ended up having to replace both a few weeks later.

The Willys is off the road for the next 12 months and is stripped back to the chassis for a major overhaul so the J20 will be first , it is also being stripped back to the chassis but its not getting a lot of mods so it will be back on the road early 2009. I'll experiment with the resonator box on the J20 first

[FRITODAVE]

Flattrack motorcycles have been using something very similar to that since the 70's. It provides noise reduction and power gains at certain rpms.