The Stovebolt Site Forums The Shop Area Engine Shop Has anyone supercharged a 350ci?

I was toying with idea of putting a supercharger on my 60 C10 that has a mildly built 350 in it. I'm not sure if I'm going to do it, I just wanted peoples thoughts on this. The truck is pretty fast already, I just thought it would be a cool thing to do. Any thoughts appreciated. If someone has done this how do you like it and was it worth it? I can buy a Weiand supercharger for around $1,800.
Joe

The cost of the supercharger will only be the beginning. To make the engine live with the extra power, you'll need to build it from the ground up with heavy-duty parts. H-beam connecting rods, a forged crankshaft, and forged, low-compression pistons, plus a different camshaft will be a bare minumum. If I were building one of my customers a blower engine, I'd estimate the cost at around $7,000.00, minimum.
Jerry

Thanks Jerry,
I guess I'll forget that idea. The motor was built by the PO so I'm not really sure what was done to it internally. If I ever need to rebuild it then maybe I would consider it. I would hate to ruin the engine I have now, I don't even know the compression ratio.
Thanks again,
Joe

To add to that, you would also need to build the rest of the drivetrain to handle the power, plus improvements to the braking system (no good going fast if you can't stop).

I generally agree with posts above for safe advice, but if you want to gamble a bit, then there may be some options.

What compression ratio is the motor today?
How much boost do you want to add?
Are you willing to have to run a bit of race/high octane (100+) fuel?

If you keep boost levels moderate, compression ratio is fairly low to start with, and run pump premium, depending on availability of higher octane gas... mix some of that in then you can do so, get some decent gains in performance. In the mean time you can be building a motor that you can turn up the boost levels and make a rocket ship out of your ride.

A blower or a turbo? I would think a turbo would work, probably less money and more power at the same time. If you don't get crazy with the power I don't think you would have too much of a problem with your engine. You can't run much compression with a turbo though. 8:1 is a pretty good place to start.

The Weiand unit mentioned in the first post is a slightly upgraded version of the Detroit Diesel blower. It produces massive gains in horsepower and torque, but it takes lots of power just to turn it. The most common failure when it's coupled up to a stock-type crankshaft is that the crank snout gets twisted off trying to turn the blower. The slightest hint of detonation on a blower engine will launch the blower through the hood from an intake manifold explosion, so the compression ratio and ignition timing must be perfect. Fun at the drag strip, but totally impractical on the street.
Jerry

My question is why is this subject even being discussed here? There is a Hi Performance Forum here for this stuff, isn't there?

I mean every little thing that doesn't precisely fit into General Truck Talk gets buried in the Greasy Spoon so why are we discussing superchargers here?

Thanks for all the information, I didn't realize how much there is to take into account. My truck is a nice driver so for now I'm going to leave it alone. It's not like I'm going to be racing it or taking it to a drag strip.
Joe

Czechman: it was posted here and I do not take offense at an off topic question occasionally. Some think everything has to be put into neat little pigeonholes just because we have them. That is great if the topic is the main discussion but what is the harm in having an OT question once in a while in any forum. None that I can see. I've even had some of my own replies deleted. I would only do that for crude or blatantly offensive language but never because I didn't personally like it or where it is posted. It's America and free speech is about the only thing we have left so say it if you believe it.

Besides, it is the duty of every inline lover to convert as many of these bent motor guys as we can, HA. Sixbangersrule!

cal55,

A friend of mine has a automotive machine shop. He drives a '96 Suburban that has a blown 350 in it. It drives the same and sounds the same.

Weiand makes the 142 supercharger (blower) that can be stuck on a stock 350 and driven away. The $7000 dollar blower motor is something else, it's a race engine. There are probably hundreds of stock SBC's equipped with blowers used as daily drivers running around all over the country, so it can easily be done.

Stuart

Thanks Stuart,
That's the one I was looking at the Weiand 142. The company that's selling it for $1,760. is SRS out of Ohio. I will call them for more information if I decide to pursue this. If I can just bolt it on and drive I might do it. It's suppose to give you an 25-40% increase in hp. I'm guessing mines around 300hp now, but I never had it dynoed. I just thought it would be a fun thing to do. If I put this in the wrong forum my apologies, and thanks 53moneypit for giving me a break.

Joe

Those little 142 blowers will not put out enough boost to hurt a stock 350. It takes manifold pressure of 13 to 15 lbs. to put a hurt on a stock engine, the 142 blower only makes about 5 to 6 lbs.

Thanks chevman32, that's good to hear. The owner of the company emailed me about it and it's a woman which kind of suprised me.
Here's what she wrote.

Hi, thanks for your question, My name is Kelly, Im the owner of SRS. I drive a 500 inch dart with an 871 blower with 9 lbsof boost. Ill answer you question for you in 2 ways.

1. Running a blower is a very general term, since you can run diffeent levels of boost. Generally speaking, boost up to 5 lbs. on a stock motor ( cast crank and cast pistons) is ok and will not require any mods except for retarding the timing a degree or two to help prevent detonation. Also adding a higher octane fuel will do the same job ( like Sunoco 94)

2. Have the compression checked if your unsure and make sure it's not above 135 psi or so, if it is, you may want to run a timing box like the msd btm box. if you motor is around 10:1 then you wont have any problem, ill assume that a 12 only comes with a 4 or 5 lbs pulley. If you get above 6 lbs or so, you begin to run into problems with fuel octane being too low and, too much timing advance causing heat whih could melt a Piston. If you plan on running more that 6-7 lbs of boost, you will want to run a steel ( forged) crank and forged pistons with a compression ratio of less than 9:1

I hope that helps, you can expect around 4% per pound of boost gain. So 4 lbs will give you a 16% boost in hp

Good Luck
Kelly Waddell