|07-24-2006 07:57 PM|
Turbos are Dumb
Yup, dumb. They don't know if you are running a gas engine or a diesel and they don't care. All they know is the volume of exhaust driving them and the volume of air they are compressing.
So, since a 700 cu. in 4-stroke diesel at 2100 rpm uses the same amount of air as a 350 cu. in. gas engine at 4200 rpm, the turbo won't know the difference.
However, big diesel turbos are built for long service life which means heavy parts and slow spool up, so you may want to look into what size diesel turbo really converts to your gas engines needs.
By the way, all those GMC "Roots type" blowers were originally developed for diesels. (I know, I know, it's not a turbo. But it's a blower none-the-less and it certainly found its way onto gas engines.)
|07-24-2006 06:28 PM|
|evilone||I hate to hi jack this thread,buy would some of you guys look at my thread called "turbo help"?|
|07-24-2006 06:00 PM|
There are several good books out there. The most popular are "Turbochargers" by Hugh Macinnes, and "Maximum boost" by Corkey Bell. My comparison of the gas and Diesel were just a simple comparison to show a gas and Diesel using the same amount of air at different RPMs.
I can't say what your motor will handle. 5 psi is probably safe on a low compression motor with stockish heads. My usual technique, which I don't recommend, is to keep adding boost until something breaks. I've only blown head gaskets and broke pistons so far. That's on two different cars on three different occasions. No broken cranks or blocks yet. Chevies, and Fords will both blow head gaskets with too much boost.
I think an HX-35 is a good cheap start. A pair of t-3's off a couple turbo coupes or something else. Look around see what you can find a deal on and post what you've found here or at JYturbo. Someone will know if it will work.
I've blown through a carb but I find efi much easier.
Links to guys who know:
check out the calculators here:
|07-24-2006 05:43 PM|
|07-24-2006 04:48 PM|
Hey, thanks for the info!
I did have a few questions about engine set-ups.
My 350 sbc... I don't know the exact numbers, but no more than 300 or so hp. would I be safe to assume that a single hx-35 would be okay to use?
Also... how much boost can i run without worrying about having to upgrade engine parts?
I'm still a bit lost on this comparing boost and rpms between diesel and gas. Is it generally half the boost at twice the rpm, or did it just happen to be that way with your particular comparison?
.... is it possible to use a turbo on a carburated engine?
One last question... what is a good source of information that I could look at? I'm a bit lost when it comes to all these turbocharging details.
|07-22-2006 04:45 PM|
Thanks, Kevin. I don't know enough about turbos to make it as clear as you did. I just knew that it could be done effectively.
|07-22-2006 03:09 PM|
I use diesel turbos on gas motors. Used diesel turbo's can be found cheap. I have a HX-35 from a Cummins on a Ford 302. I had a pair of HY-35's, also from a Cummins, on a 327. They are currently being put on a 454 but may be a little small. If they are I'll try some HX-40's or 50's. You need to compare the boost levels and max rpm of the donor and compare that to your project. A 5.9L diesel with 25lbs of boost at a max of 3000 RPM is roughly comparable to your 5.7L gas motor at 12.5lbs of boost at 6000 RPM. Some of the manufacturers have compressor maps on they're sites or offer flow information. The HX-35 flows .46 kg/s at three atmospheres, which, correct me if I'm wrong, converts to 800 CFM at 44 psig.
|07-21-2006 09:45 PM|
hmm well that is interesting. I'll have to check into that stuff. It seems a bit of research could save me a few thousand dollars. Sounds like a deal.
Now...to find that info
|07-21-2006 09:01 PM|
Sometimes they work, sometimes they don't. I personally wouldn't use a Diesel turbo.
In most cases, the turbo will either be too big or too small for the application. You will either run out of engine at 4000 RPM or you won't get any boost until 4000 RPM...
It is better to do as much research about your application as possible, then find a select group of turbos that fit your specs, engine size(ci), cfm, power range, etc.
Then if a diesel turbo ends up with the specs you need, then lucky you because they are very plentiful.
|07-21-2006 08:57 PM|
As blob said, a turbo is a turbo. A turbo for a 400 cu. in. diesel would work on a 400 in gas engine. Then, depending on the expansion rate of the exhaust gases, you may have to make adjustments. The best way to find out is to inquire with someone that handles turbochargers. They can tell you what turbo you can use.
|07-21-2006 08:43 PM|
|07-20-2006 08:53 PM|
See, that's what I was thinking. It does the same thing.... just at a lower rpm. I have a 69 camaro, 350 sbc, mild build, TH350, 3.08's. Would the lower operating range of the turbo affect higher rpm power negatively? I hardly drive on the highway at all, so its mostly just crusing around town. But of course you know I'm talking about throwin it back into first at 30 mph when someone wants to race. heh.
I know I could just change the cam to get more power, but turbos sound cool and well... i want it. Then again i'd have to tinker with a bunch of stuff I know nothing about...but that's what you guys are here for, isn't it?
|07-20-2006 08:20 PM|
|Blob||sure you can do it, heck you CAN do anything you want. You will just have to make sure the turbine and compressure housing are matched to how you want them to preform on your engine, otherwise a turbo is a turbo|
|07-20-2006 06:06 PM|
|Deuce||I seriously ... doubt it ... diesels operate at such a lower RPM than gasoline engines ... But do not know the absolute answer ...|
|07-20-2006 05:31 PM|
Diesel turbos on gasoline engine?
Is it possible to use a turbo from a diesel engine on a gasoline engine? I was thinking about it on the way home the other day and I figured i'd ask about it.