818 now with turbo and pics.

Cummins also made a big cam 4,it was the last in the series of big cam engines. It was never popular because of the low flow cooling. And the desired exh. Manifold you fellas want is called the pulse manifold, i highly recoment you get a new aftermarket manifold as the used ones are notorious to leak.

Squirt-Truck said:

A/F ratio on a diesel???
Can someone help me out and explain that comment?

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I simply meant that by putting aturbo into the mix, then the fuel supply hitting the injectors via the injection pump would have to be altered to find the desired fuel to oxygen/boost setting for combustion to keep EGTs in check. Case in point turning up the fuel screw on a 6.2 when a turbo is installed, if the screw is not turned up some the 6.2 runs lean and starts to heat up. Contrary to popular belief diesels do have a mild air/fuel ratio. This ratio takes place in the combustion chamber in the nanoseconds between injection and combustion when atomization is taking place. To much fuel leaves a thick black oily smoke trail, to little results in the white gray smoke tapering to none mixed withe bad performance, just to tip the iceberg of symtoms.

Did we ever get an mpg rating with the 16.00R20 tires and the turbo with fuel line split mods? I'm pretty curious, I'll be doing these same modifications so I suppose I'll find out, but it'd be nice to know what to potentially expect after mods are complete.

doing the fuel line split mod will give you nothing extra because in 250-300 hp the fuel pressure is almost at its lowest setting. mpg should be around 5 mpg empty

So adding a turbo and doing the fuel line split does nothing for mileage? I figured since the engine isn't working nearly as hard as it was without the turbo, it would increase fuel mileage a couple miles to the gallon, maybe hitting 8 or 9. Am I just not understanding how a turbo works then?

Wastelander said:

So adding a turbo and doing the fuel line split does nothing for mileage? I figured since the engine isn't working nearly as hard as it was without the turbo, it would increase fuel mileage a couple miles to the gallon, maybe hitting 8 or 9. Am I just not understanding how a turbo works then?

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adding the turbo will help your engines responsiveness and give you a better momentum up the hills. the fuel line mod will help give cyl #6,7,8, the fuel that is usually starved in those cyl. the civy versions of the 855 Cummins have had the dual fuel for years..... by giving all cyl the same fuel pressure each squirt of the inj will be the same (providing inj are clean and functioning correctly) then each cyl will perform the same instead of have 3 weak cyl.
As for milage,,,,, the 855 Cummins will likely get 5mpg regardless. the killer in these trucks is that you are usually driving them at redline most of the time due to the extremely low gears in the axles and lack of a multi speed trans allowing you to keep the engine in the oportune RPM range for power versus speed/RPMs.
I just got done adding a turbo and Jakes to mine. If you want questions of these kind of modifications your best bet is the "5 ton Hotrodding" section on here. You wont be slammed as much for trying to think outside the box.

Has anyone attempted an intercooler? I put a big air to air intercooler on my 925A2 by moving the radiator back 3 1/2 inches. I am going to put a turbo charger on my 818 and would like to attempt an intercooler just wanted some input.

4XDesign said:

Has anyone attempted an intercooler? I put a big air to air intercooler on my 925A2 by moving the radiator back 3 1/2 inches. I am going to put a turbo charger on my 818 and would like to attempt an intercooler just wanted some input.View attachment 756287

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What intercooler did you use for the 925?

https://www.steelsoldiers.com/showthread.php?126716-M925A2-to-M932LA2-Conversion/page6
post #57 this is the info from when I actually did the install.