mat_gon_jinn

Hey all, just purchased a sc14 supercharger off eBay with the intention of jamming in my '85 ln61 2.4l diesel 4runner in place of the disfunctional a/c compressor. Don't need advice or anything, just looking for peoples input, some opinions regarding engine life, how much boost would be ideal, how long they reckon the motor will last etc. Also what sort of oil to use in the super charger. Planning on just using diesel engine oil, superchargers that come out on the diesel engine from factory just use oil from the sump, turbo's just use oil from the sump, so why not?... Sounds cool to me.

Let your thoughts fly.

stormin94

I've never heard of a Super Charged Diesel, but I do like the idea. I've always wondered why there aren't many, if any of those around.

1990yota-pickup

diesel enginges can take turbos and super chagers too. a prime exaple is a detriot diesel 6v53t.. it turbocharged from the exhuast and the blower/superchager is on top of the engine..

91diesel

6-71 and 8-71 blowers were from diesels originally. the 71 was the displacement of a cylinder and 6 or 8 was the # of cylinders on the motor. A diesel doesn't have an air/fuel ratio to speak of, they can run any combination. In fact they idle because of a low input of fuel not because of a throttle body (I took mine out, it was only for the egr anyway). Therefore you can run pretty much any boost that is safe for the super charger to run without spinning itself to pieces.

dannomite

To be fair when talking about the Detroit diesels they are two strokes and need the blowers to efficiently scavenge the exhaust gas out of the cylinder in order to run. They are not there for power. That is why Detroit put the turbos on, to give them a little pep. 91 diesel I am now sure if I am misinterpreting what you wrote. It is not ok to run as much boost as is possible to get from a supercharger. You need to make sure you are not overpressuring the cylinders and that you are not going to start tearing things apart. This is why on the diesels in pulling trucks they rebuild with low compression pistons and oring and head stud etc. I am not familiar with this particular set up so maybe you are saying that this supercharger and engine combo is incapable of overpressuring and if that is the case then boost away. I was simply not wanting to encourage someone to go and run 50 psi of boost and blow there engine apart.

91diesel

The guy that sold me my drivetrain (this is gonna start getting really second hand here in a minute) has done a lot of reading regarding boosting motors and the stress involved and it runs into this, There is far more stress on the piston rings and wristpins everytime they change direction in the motor than is possible with boosting. Now headgaskets are another thing entirely and remember that compressing air heats it and that causes it's own issues if you don't intercool it. My diesel showed a much bigger difference in water temps after intercooling it than when I installed a 4 core v8 copper radiator.....
I was just trying to say that unlike gas boosted motors, you don't have to worry about a lean a/f ratio burning up your motor, with diesels it's the opposite, you have to worry about too much fuel burning up the motor. To see any real benefit of boost you'd also have to modify or tune the IP to give it more fuel, and an egt guage to keep from melting everything!

dannomite

I see. Thanks for the clarification/addition of info.