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post #1 of (permalink) Old 03-24-2000, 03:01 PM
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Hey CJDave...why no s/c??

I've been thinking about this whole supercharger v. turbocharger issue. Why on earth does everyone use turbos on diesels instead of superchargers? A supercharger could be set up to give good boost way down low (where you need it anyhow) in such a fashion that even a wastegated turbo couldn't hope to compete. So what's the deal? Reliability/durability should be comparable...except there wouldn't be any worries about cooking the bearings on a supercharger. Did anyone ever supercharge diesels? We've got an old Farmall M tractor with a supercharger on it...it pulled the teeth of everything in the county when we first got it. Nothing could touch its supercharged straight 4 gas engine until we got the big normally aspirated straight six 560 Farmall...so I know superchargers are durable and potent. Why have they fallen out of favor?

Trying to come up with a witty line to end all of my posts...
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post #2 of (permalink) Old 03-24-2000, 03:30 PM
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Re: Hey CJDave...why no s/c??

All the 2 stroke Detroits (at least the ones that I've seen) have been supercharged.....heck I'm sure that all the superchargers that were used for many years in any AAFuel or super street rod for that matter were reworked GM 6V-71 blowers although the actual "blower" design appears fairly common thoughout industrial applications for fuel oil atomization in boilers for example and some Ingersol Rand compressors. In all the aplications that I've seen this type of blower/compressor in a stationary installation the units require an "oil bath" which, as the IR manual states, "acts as more of a coolant than a lubricant". I would imagine that the turbo is an easier and cheaper installation.......saps little power in it's production of additional power.....and has a broader range of applications.
I'm sure Dave has the fat, as well as the skinny on this......but I figured he could finish my education on this as well if I added my incomplete (and perhaps flawed) take on it.

GeeAea

Figures don't lie ....... but liars sure do figure.
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post #3 of (permalink) Old 03-24-2000, 05:38 PM
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Re: Hey CJDave...why no s/c??

[img]/wwwthreads_images/icons/smile.gif[/img] Superchargers are directly connected to the drive system and only have a limited ability to get an increase in RPM quickly. Like the old McCulloch kits which had a split pulley on the blower drive which opened up when the intake manifold vacuum dropped. The smaller pulley gave the blower more RPM and the engine got a boost of air, BUT....it did take power to turn th e blower. A turbo is a more flexible system, uses waste energy from the exhaust, has the ability to increase RPM without a corresponding increase in crankshaft RPM. Just the hot gasses from a throttle increase give it more spin. Superchargers were the thing in the old days, and it was partly because without space age ceramics, nothing could stand the exhaust heat. A P-51 Mustang fighter from WWII had a TWO-STAGE supercharger which gave it a 0 to 11,000 feet range, and then 11,001 feet on up to 20,000 plus when the second wheel cut in. It was a hard plane to beat.[img]/wwwthreads_images/icons/crazy.gif[/img] The two-stroke Jimmy Diesels have a Roots-Type blower which is used in a very different fashion, and is technically NOT a supercharger....SUPER=on top of...CHARGER=filler. The Jimmy blower actually helps scavenge exhaust gasses, AND recharges the cylinders since there ARE no intake valves. The blower does it from the bottom as the piston drops to bottom dead center and exposes a row of holes in the cylinder wall. Quite a system.....been around since the thirties...went to WWII in MANY applications. I saw a Jimmy that was so old that it had a centrifugal blower on the flywheel!...a pre-war engine.[img]/wwwthreads_images/icons/crazy.gif[/img]

CJDave
I never believe any statistics unless my moonguys [img]/wwwthreads_images/icons/crazy.gif[/img][img]/wwwthreads_images/icons/wink.gif[/img] made 'em up themselves.
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post #4 of (permalink) Old 03-24-2000, 11:21 PM
 
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Re: Hey CJDave...why no s/c??

CJ Dave is correct.
The Old P-38's and P-51's were hard to beat, and all because of the GE superchargers...
The Germans were relying on nitrous oxide, and out planes could just flat whoop ass in a straight up fight over even the largest nitrous injected German engine...

(P-38's were my favorite!)
--------------------------------

There are at least a dozen aftermarket makers of superchargers out there.
Eaton has 500,000 superchargers out there on STOCK passenger vehicles sense 92.
With half a million out there, I don't know why more of the Do It Yourselfers haven't latched on to them...
The are small, powerful, easy to drive, and fit modern engines.
The latest advent of by pass valves makes the low end problem moot, and the Eatons can be had in the salvage yards for a little bit of nothing...
(I bought three in the last month from salvage yards, and never paid more than $300 for any one of them)

The Eaton lineup...
The M-45, 45 cu.in., has 6 ribs in the case. Used on Honda cars.
The M-62, 62 cu.in., has 8 ribs in the case. Used on 92 to 95 GM V-6 engines.
(mostly Buick 3.8L.)
The M-90, 90 cu.in., has 8 ribs in the case. Used on 92 to 95 Ford V-6 engines.
(Thunderbird Super Coupes)
The M-112, 112 cu.in., has 11 ribs. Used experimentally on both Ford and GM engines, and produced by Magunson for racing applications.

Look for the fourth generation design of Eaton supercharger to show up in mass...
it has 'Delta' or 'Involute' rotor design that has a 60 degree twist and acrylic coating.
Look for, and collect the vacuum canister at the rear right of the supercharger. It is the 'bypass' control. It equalizes the blower and manifold pressure at high vacuum levels.
It takes away most of the parasitic drag a blower has at low boost situations...
---------------------------------

The basic blower types I know of and have worked with,
Centrifugal, (McCulloch, Paxton, others)
Roots, 2 lobe, straight, (53 series GM, Pepco, Penco, Weiand, Wade, B&M, others)
Roots, 3 lobe, straight, (KF, Fageol, Magunson, Weiand, others)
Roots, 3 lobe, twist, (GM 71 series, BDS, Dyers, Weiand, Mooneyham, Hampton, Littlefield, and a host of others...)
Vane, (Judson is the only one I know of.)
Whipple/ Lysholm Screw, (Lysholm, BDS)
Axial Flow, (Latham)
Wankel Rotary, (Holley, Wankel)
Wankel/ Holley Vane, (Wankel, Holley)
----------------------------------

The Mechanically driven supercharger has one real draw back...
By the time it's made small enough and turned fast enough to do real good at very low RPM, it's operational efficiency is lacking at higher rpm.
If it is larger, and geared more toward higher rpm, it is very inefficient, and even a blockage in the intake tract.

Superchargers are still one of the best Horse Power gains for the buck spent you can make.
Superchargers are no more difficult to rebuild than a differential, and no harder to install in kit form than installing wheel bearings.
They are simple, powerful, dependable, reliable and offer higher horse power gains cheaper than any other form of bolt on item.
---------------------------------

My first cylinder supercharging was done with a turbocharger, but I have worked for supercharger companies, and I have worked for companies that tested every conceivable turbo charger in production, and I have a healthy respect for the roots type super charger.
It is relatively inexpensive, very available, and easy to install and operate.
----------------------------------







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post #5 of (permalink) Old 03-25-2000, 01:24 AM
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Re: Hey CJDave...why no s/c??

hey farmjeep
super M supercharged? do u do tractor pulling?? what or who has the super charger for the M ARe u running in a stock class?? if u are running a s/c??
Andy

post #6 of (permalink) Old 03-25-2000, 08:18 AM
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Re: Hey CJDave...why no s/c??

[img]/wwwthreads_images/icons/laugh.gif[/img] Farmjeep has to run in the "reserve" moonguy[img]/wwwthreads_images/icons/wink.gif[/img][img]/wwwthreads_images/icons/wink.gif[/img][img]/wwwthreads_images/icons/smile.gif[/img]class since his crew chief is a moonguy[img]/wwwthreads_images/icons/wink.gif[/img] and that puts the rest of the tractor guys at a disadvantage. Farmjeep can only attend the tractor pulls sponsored by a major beer company to assure an adequate supply for his extensive, corn-fed moonguy[img]/wwwthreads_images/icons/wink.gif[/img][img]/wwwthreads_images/icons/wink.gif[/img][img]/wwwthreads_images/icons/smile.gif[/img][img]/wwwthreads_images/icons/wink.gif[/img][img]/wwwthreads_images/icons/smile.gif[/img][img]/wwwthreads_images/icons/smile.gif[/img][img]/wwwthreads_images/icons/smile.gif[/img][img]/wwwthreads_images/icons/crazy.gif[/img][img]/wwwthreads_images/icons/cool.gif[/img][img]/wwwthreads_images/icons/wink.gif[/img]crew. Luckily, he doesn't need a stretched Suburban to haul them, but uses a 1950's vintage John Deere ear corn trailer and piles them in there like so many beach balls. Hey.....it isn't easy being the caretaker of so many moonguys[img]/wwwthreads_images/icons/wink.gif[/img][img]/wwwthreads_images/icons/wink.gif[/img], no matter what they say.[img]/wwwthreads_images/icons/crazy.gif[/img]

CJDave
I never believe any statistics unless my moonguys [img]/wwwthreads_images/icons/crazy.gif[/img][img]/wwwthreads_images/icons/wink.gif[/img] made 'em up themselves.
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post #7 of (permalink) Old 03-25-2000, 10:47 AM
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Re: Hey CJDave...why no s/c??

No, the M was ordered with the supercharger. It was the first tractor we ever ordered. (My grandpa bought a few off the lot before it) but then he signed the papers to order the Super M with custom features (two hydraulic outlets, 10" belt drive, live PTO, deluxe seat, supercharger w/ hd air cleaner). We still have her. She really zings.

Trying to come up with a witty line to end all of my posts...
post #8 of (permalink) Old 03-25-2000, 10:51 AM
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Re: Hey CJDave...why no s/c??

Hey Dave, you missed bashful [img]/wwwthreads_images/icons/blush.gif[/img] when you pictured my moonguy pit crew and boy is he angry now! [img]/wwwthreads_images/icons/mad.gif[/img] I've never seen him that red before! Thanks for the explanation gentlemen. I knew you guys would have the answers.

Deano
p.s. the moonguy with the shades on doesn't have them on because he's cool. At the last tractor pull, someone told him that the whiskey he was drinking was made from corn, so he decided to do his part to help out American farmers by creating demand for corn...

Trying to come up with a witty line to end all of my posts...
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