[PONTIAC DUDE]

George, George, George.

Build it fast, build it right, build a Pontiac.

http://PontiacDude.cc

[GTOGEORGE]

Dude,

Buddy, pal I wasn't talking about you. I know you beat your cars up all the time. It was just a general question.

It's like I said before I hear'em I just don't see'em. Of course I do limit myself to 500 miles.

[Tom Vaught]

Quote:

"Thanks for all your help. I guess that i will tear down the engine again and put in dished pistons. But also have any of you guys ever run a centrifical supercharger. Are they any better or worse than the other designs."

And thank you for the questions.

Try and stay around 8.5 to 8.75 if you have a
centrifugal supercharger that can make 20 psi of
boost with a good (320 cfm head). If you go to 8.0 you will lose about 75 hp over 8.75 comp
ratio if you spin the blower at the same pressure
ratio (boost). (Been there with Jimmy's engine).

I personally make my living working for Ford as their Supercharger/Turbocharger Engineer so I think I can say that between that and some race team experiences with a couple of fast Ford guys I know something about centrifugal superchargers.
I know a little bit about Turbos too.

A centrifugal supercharger makes compression inside the compressor housing, flow goes up by the square of the rpm of the unit, and the basic
unit is vastly lighter than most roots style units
for the same airflow/pressure ratios.

The biggest advantage of a roots style unit is
boost at low rpm vs a centrifugal and turbo type
supercharger which need rpm to function properly.

The visual image of a roots style unit with twin carbs will impress most non racers. A turbo on
the other hand for average power looks whimpy by
comparison. There are issues with turbos on the
street as you must create a complete package of
parts: (camshaft, compression ratio, manifolds,
plumbing (oil, water, air, and exhaust), along
with matching the parts for the application. Much
easier with a centrifugal supercharger, a bonnet,
a properly calibrated carb, low compression ratio,
basic camshaft, and a good fuel system. 600-800
hp fairly easy to come by. Making 2000 hp is
possible with a pair of centrifugal superchargers
but the fast turbo guys have done it with one
turbo. Some people like Marty Palbykin have been
involved with engines at close to 3000 hp in a
couple of Tractor puller and Boat classes.

Tom V.

I have personally worked with only one Tractor
puller guy and he was Canadian National Champion
some 20 years ago. I think he never went any farther as Jim Brady's brother used to whip his
a$$ most times. Francis Argenbright was National
Champion several times.

[Torment]

Unless I de-tune for 10's the track officials have a habit of kicking me out So I spend the majority of my time cruising....I will give out useful info when I can. What about you George? What's your story?

The secret to happiness is not getting what you want but rather, wanting what you have.