supercharged td 6.5

[graffixx2000]

Hi all just a heads up we are building a wide cherokee project and working on a 1995 6.5td. lowered the compression to 11.1 and put an eaton m90 supercharger on top with about 10lbs boost fed with a large (25cm or so)turbo at about 20lbs im not to sure what the machine shop is doing yet to the rods and such to keep them in place but my next issue is fuel and cool if anyone has any custom ideas to get fuel into this thing i need some help final cfm is over 3000 as you will find we are not of the shelf people and would prefer to custom build our own or convert others thanks

[Cowracer]

Hi all just a heads up we are building a wide cherokee project and working on a 1995 6.5td. lowered the compression to 11.1 and put an eaton m90 supercharger on top with about 10lbs boost fed with a large (25cm or so)turbo at about 20lbs im not to sure what the machine shop is doing yet to the rods and such to keep them in place but my next issue is fuel and cool if anyone has any custom ideas to get fuel into this thing i need some help final cfm is over 3000 as you will find we are not of the shelf people and would prefer to custom build our own or convert others thanks

Welcome to the Diesel Page. This is quite an ambitious project. Probably, your best bet would be a DB4 mechanical pump, or adapting a totally different pump altogether. Bill Heath had an inline pump on his 6.2 that worked well.

I doubt the supercharger/turbocharger setup would have any performance gains over running an HX35 holeset and a big intercooler, but to each his own.

How did you go about getting 11:1 compression pistons?

Tim

[kevin77]

What about two db4 mechanical injector pumps? I thought I saw a 6.2 diesel tractor around here somewhere with dual pumps?

Kevin

[graffixx2000]

I didnt figure a diesel to run at 11.1 comp. thats why Im using the supercharger at 10 lbs brings the ratio up to 18.5 to 1 plus 20 from the switzer brings about 33.5 to 1 which is not to far from around 32.5 to 1 that came stock only bringin the total cubic inches from 400 to over 3000 and yes this is all theory but i have had a lot of exp. with my turbo pro street harley
............. and yes still open for criticism
as far as compression lowering that is machine shop but I heard talk of cutting pistons and shortining rods

and i must add a stock 6.5 td eats about 700 cfm full tilt

[Turbine Doc]

Bill Heath & I were discussing his 6.2 drag truck, twin turbo small turbo feeding the big one, Navstar inline pump, 15:1 CR shave top pistons & lowered wrist pin, wicked hot for a drag strip, but that was all it was good for, took about 15 minutes to get it to start & idle worth a darn until it got good and warmed up. Had special pan heater to keep the temp up and oil thin, before getting too involved you might want to email him with your thoughts, he raced his for 8 seasons until the rear let go, and his other special goodies to go fast got stolen while he was investigating how bad it let go.

Bottom end was okay, valve train was a little beat up.

[john8662]

if I understand correctly.

If you think that 11:1 and adding 10psi boost to get to 18:1 is going to be a hot rod, you'll be pleasantly disappointed.

In my logic (without technically studying varying c/r with a blower/turbo) just getting to 18:1 with the blower will be like having a non blower non turbo 6.5.

It's been proven that the 21:1 C/R these engines are stock is way too high for high performance, but it's also been proven that 18:1 works well.

I wouldn't go anything lower than 17:1, especially in this indirect injected engine.

Starting will be the bear, for sure! I do doubt that 11:1 would ever fire. Afterall I don't think that the supercharger will be turning fast enough in that short of a duration to start the engine, then KEEP it running.

Afterall, 10psi is for beginners! You'll want 20+ psi to have some fun.

That turbo or supercharger ain't nothing but a variable compression regulator (sort of).

J

[graffixx2000]

do the math if i am correct more air means more fuel for every lb of boost you increase cfm x 10% expedentialy so at 11.1 + 10lbs = 18.48-1 and over 800 cubes wouldnt it make more power the blower is an eaton m 90 and create boost at low rpms but you do have me concerned about makeing enough at idle i need to research some more for sure i do know vw is using simular system on a 1.5 ltr making 170 hp

[trbankii]

I second John. It goes beyond the math on a sheet of paper. Sure, you can add the compression and the boost and come up with a number. But you are not going to get 10 lbs. of boost while cranking it over and it just isn't going to start. Diesels and gassers are a bit different there.

[DmaxMaverick]

The gear (pulley) ratio required of the SC at 600 RPM's to gain 10 PSI would probably negate any power produced at that speed. Meaning, it wouldn't run. It would have to be under load, all the time. The parasitic loss would overcome the power output. I don't think this would be any type of an issue, though. 11:1 compression won't fire. You'd need a significant heat source like really hot GP's, and an intake heater. You may get away with it if you were able to use an air starter. Still, a SC would be much better suited to assist the CR, rather than rely on it for the CR. The math works, but the reality will be disappointing. There is a cost accompanied with the CR trade-off, and the cost will exceed the return. A 100 HP gain won't mean anything if it costs you 110 HP to create it.

[Turbine Doc]

There are turbo / supercharged Diesels used in marine industery all the time, but they have unlimited cooling water supply, so it can be done, not at 11:1 just not sure the 6.5 in a truck turbo/ supercharged is a viable option. Here is a 6.5 with supercharging http://allmarinediesel.com/Tigershark%20Page.htm but it's kinda pricey I think you can get a new truck for what the engine costs, and you still have to deal with keeping it cool, plus boats tend to pick a speed and run with it, a truck is a variable speed engine so your engine has to be capable of operating over a wider power band, one thing to note though they don't list it for the tigershark 18:1 is the CR for the other engines they use with a DB2 mechanical pump

[graffixx2000]

volkswagon is also doing it but i am not sure crs keep up the good input and i do agree it may not start i thought about propane injectio for startup but maybe i should just bring cr up before it is to late .....the sc draws 43 hp to max rpm @10 lbs

[JeepSJ]

the sc draws 43 hp to max rpm @10 lbs

Oh, it will be eating a lot more than 43 hp to build 10 psi...

Have fun with packaging that all into the engine compartment of that Cherokee. One of your big problems is where to mount a radiator big enough to cool that beast.

[graffixx2000]

earlier i explaned it is a cherokee body widened 15 inches sitting on a 3/4 ton suburban chassis shortened 28 inches there probobly enough room for an old detroit and the chart rates it at around 65 hp at 800 cfm at 10 lbs

[malcolms]

17:1 would be the minimum to get the engine to fire, unless you started it on propane then switched to diesel. The blower could not supply enough air to fire the diesel, at idle the blower could be overdriven to compensate for low pressure.