Wonder about superchargers

[launieg]

I know little to nothing about superchargers. What are the critical parameters for matching them up with engines? Locally, these two are for sale. The first is from a Buick 3800, and the second is claimed to be new and good for a multitude of vehicles, including Fiat.

[maytag]

well, I'll wonder along w/ ya.

I would think the first one (from the Buick) would be difficult to make work. There's some fab problems in cvreating a plenum that it would fit to. Beyond that; I'd think you'd really need to underdrive the thing, as it was originally designed to work with TWICE the volume of our motors. (3.8L)

The sceond looks like an easier package to make work, logistically speaking. Any idea what sort of volume it's built for?

[BigShirl]

The second one is a unit off of a 2.3l v6 Mazda Millenia with the "Miller Cycle" engine...

[maytag]

it would seem that a "vortech-type" supercharger could be more readily adapted to our motors than the traditional roots-type you've got there.

[Fonz]

I think you would be the first to tackle this monster.

[pope]

The first one is an Eaton Supercharger. Used on Pontiacs and Buick 3800 V-6's. It is a big one for a Spider, but it could work. The neck on that one is too long and would have to be switched out for a shorter 2-3" version. Not too familiar with the second version.

You might be better off finding one in a pic yard off of a 2.0 to 2.5 l engine.

[mdrburchette]

That first one is what's on my mother's Park Avenue Ultra. What a blast that old granny car is to drive! It'll burn rubber from a dead stop like nobody's business. Keep us informed on what you do.

[So Cal Mark]

that first one would be tough to adapt, since it's designed to fit down into the V of the V6.

[launieg]

Thanks for the comments. I'm really just thinking out loud at this stage. The second supercharger does look like it might be appropriate, but the fellow would want too much money for it. I can keep an eye out for a used one though.

Also, I would need to lower the compression to use a supercharger. Any ideas how I would lower the compression on a 2 litre? A thick head gasket? I imagine that is the solution.

There's a wonderful (but very old) writeup about superchargers at:

http://www.fefcholden.org.au/techinfo/s ... index.html

Very detailed and old, but very interesting nevertheless. His discussion about a "hot" engine (cams, etc.) versus supercharging is extremely interesting.

[pope]

If your running an 81, you dont need to lower the compression as it is already at 8.1:1
That is low compression. I think the compression used on the factory Fiat Spider Super was 7.6, but nothing wrong with 8.1

You real problem is having cast pistons and not forged rods and pistons. You would need to switch them out.

You cant have a HOT engine, unless you get rid of the Bosch Fuel Injection system, pistons and switch cam shafts.

[maytag]

I still think that if you're going to go with a supercharger, the ease of adaptation of a Vortech-type unit can't be beat.
Think of it as a "Belt-driven-turbo", to get a visual.
(Note: it is NOT a turbo. Don;t let the snail-shape of the prop-housing distract you)

see a cutaway-view of one, below:


the benefits are they're easy to build bracketing for, and adapt to most belt-drives. You can drive them at nearly ANY ratio you want, by simple pulley-sizing, and they're easily adaptable to intercooling, etc etc etc.
you just can't beat 'em.

and I absolutely agree with what Pope said in the previous post: your compression ratio is fine for forced induction, but cast pistons are not. (and just as an aside: you don't want to decrease your compression ratio by adding gasket thickness when you're doing it to allow for higher cylinder pressures. that's going the wrong way! )

[launieg]

I see, the 8.1:1 ratio is low enough.

you don't want to decrease your compression ratio by adding gasket thickness when you're doing it to allow for higher cylinder pressures. that's going the wrong way!

By this I assume you are saying that a thicker gasket will be more likely to blow? I understood that some people (when the compression is too high for a supercharger) use a thick copper gasket. Of course, I now realize that there is no need to lower the compression, so this is a moot question.

So what vehicles (of any make) use a Vortech unit? Has anyone fitted one to a spider? It seems to me that it would increase performance significantly, without the sum of hassles for a multitude of other mods for just a little gain. It looks to me like the fellows "down under" like to supercharge the coupes, or am I misinformed?

[maytag]

By this I assume you are saying that a thicker gasket will be more likely to blow? I understood that some people (when the compression is too high for a supercharger) use a thick copper gasket. Of course, I now realize that there is no need to lower the compression, so this is a moot question.

So what vehicles (of any make) use a Vortech unit? Has anyone fitted one to a spider? It seems to me that it would increase performance significantly, without the sum of hassles for a multitude of other mods for just a little gain. It looks to me like the fellows "down under" like to supercharge the coupes, or am I misinformed?

Many (most?) engine builders who deal with very high cylinder pressures (either via forced induction or NOS) will "o-ring" the cylinder; machining a groove around each jug, then fitting a small copper wire into that groove, which then mates into a groove just like it in the head.

I can't think off the top of my head of any vehicles using a unit like this from the factory, but they were used like CRAZY on the ford modular motors in the aftermarket.
a quick search on ebay brings-up 167 hits, with this one being the cheapest, currently:
http://cgi.ebay.com/ebaymotors/97-03-Fo ... ccessories

[pastaroni34]

Member Scotti on the turbo124 forum put a Vortech supercharger on his Fiat engine. All the details are in his post: Vortech V9 124 Install Its a pretty detailed write-up.

Wire-ringing or o-ringing is not really necessary for low boost applications. A good (Goetze brand) stock head gasket can seal safely to about 18psi via forced induction. This is assuming though that you're not detonating, then all bets are off.

[launieg]

Thank you for the link to Scotti's build up. Very interesting reading with plenty of photos. I'm only part way through the thread and will enjoy the rest of it. It's great stuff to think about. I'll look forward to finding out what his results were.