It's just a manifold with every port suppose to having a equal distance to the flange. The turbo bolts to that flange. I don't think the benefit if any is worth it. The black thing is a waste gate welded into the base.

The theory is that a "header" or "manifold" with equal length runners makes more power.

A compound turbo set up utilizes 2 turbos different sizes. One smaller turbo that spools up quickly to help get off the line and 1 larger turbo that flows more air to produce more power midrange and topend.

Twin turbos would be a pair of identical turbos, more commonly found on V6 engines like the Stealth TT/mitsubishi 3000GT, the Nissan GTR, etc.

Twin turbos are also found on the Mercury Racing 1100 and 1350s.

Like JD said equal length runners for all cylinders

- some reasons are for a 1 - 5 - 3 - 6 - 2 - 4 firing order with a typical split log exhaust where 1-2-3 all go together into one side of an axial divided turbo housing and 3-4-5 go together into the other side of the split housing the time/distances between pulses reaching the compressor will vari and not yield a smooth flow of air to spin it. If all the runners are equal and long enough the timing between pulse is equal and the air flow is very smooth.

Also, the reversion comes into play as well with air passing across the other exhaust valves so close and backpressure from the turbo the pressure pulse in the manifold so close to the exhaust valves can actually help lift them off their seats leading to cylinder leakage but more often burnt exhaust valves and seats.

In normal duty on an in-line the distance between the ports vs distance to the turbo is so small I doubt it matters even for short high power runs.

In long distance high output turbo engines manifolds like that are very important to ensure durability for reasons I mentioned above plus a few more.

JD - how do you manage intake valve flutter or float with 80 psi of boost, you must be running some strong springs?

I should have had upgrades springs etc. Most people do but didn't and got away with it.

yea joe think it was gas, on rag sometimes that theynstarted those Isotta's and Iveco's with buggers smoked lots till on turbo. the problem is weight of carring all that crap loads down boat, which requires more power to lift back out to regain speed. intercepted at end of run 40 ft lobster boat(5tons pot) with sabre marine 300hp Merlin, after 17 hours chase rod gave out. think failure was from cramped space. that boat actually had intake snorkle flow across radiator(using as pre-intercooler) to reduce engine compartment and intake air. used to get parts from S-E Cummins when 903 marine project started, they ran that mule all day at 650hp, whole building shook. new turbo stuff, shapes inducer/exducer and material will help dual turbos do more with less strain. good conversation.

on those ccummins "B" blocks, they were cast in several places. in 90's they used thin cast brazillian blocks, that could account for different yeild points. originally the "B" block was sold as disposable engine, in early 80's when it hit market. wonder how mercury verado firing order would do over the 1-5-3-6-2-4 pattern. suppoed to have N-V-H in 3-4000rpm range, this could hurt all around performance.

gottcha, i guess it was that waste gate that threw me. Looked like some pipes were going to that and others were going to the flange. I understand equal length runners, in the pic for some reason it didnt look like they all went to the turbo flange. Wild stuff, thanks . . . . . carry on . . . .

To answer your original question, speaking with one of my Cummins gear head buddies over the weekend, he said yes if you use the 24V head it will work.. If you went with the 12V head, the piston combustion chamber "bowl" would be totally wrong for the nozzle position.

On after-cooling options. Know many diesel drag racers who run nitrous and no charge cooler. Works great when you want instant cooling for a few seconds, however not very useful in the boat. My design was to go with a water over air charge cooler plus water/methanol injection. I used a 4gallon fuel cell for the water/meth bottle and control it by the ECM [TP+boost+rpm] trigger. You could also trigger it by boost psi and a PID controller using an EGT probe for like $50..

Since no problems finding water in a boat, I figured this was a good choice. Couple nozzles [see brass fittings in intake below] , a pump, and some plastic tube, your done for cheap.. Also left an extra bung to add a NOS nozzle in there. Never know when ya might need a little 100hp shot...



Offshorexcursion; best part about that header would be the ability to heavily wrap it.. With full header wrap from heads to turbo, plus Inconel jell covers [$$$] over the manifolds, up-pipes, and turbo, my engine compartment temps still reach 140+ on the IAT gauge above 3/4 throttle. I know of another truck Dmax in a boat not fully wrapped that's melted the fuel return lines from the injectors.

Water Meth injection can work well, I would reccomend using a high performance kit though. Most the kits out there don't produce enough psi and the water does not maintain atomization. When that happens it runs up the intake and pools in number 5 and 6...bad. http://www.gohypermax.com/Catalog.as...2-f92e46a15354

Just for fun here but this is what you really need.
http://www.gohypermax.com/ProductDis...4-21a74bead44c
Than this!
http://www.gohypermax.com/ProductDis...c-8df2dccc5adb