[Neophyte]

I can get hold of a 4-71 GMC blower for a decent price. In my part of the world they are quite scarce 2nd hand. I haven't gone and checked it out yet but what I do know is that I'll need to have pulleys made for it and I'll need a manifold. The guys selling is upgrading to a 6-71.

The engine I want to put it on is a 350 SBC TBI motor, .020 over with flat-tops and a Crane cam 272/282. Can't remember the .050 duration off-hand though.

To use the blower I thought of getting heads from a 400 SBC due to bigger chambers and ports. This way I hope to lower the c/r enough to use a max of 6lbs boost. I'll then most probably also use a carb or two instead of the TBI. I do however have an aftermarket programmable ECU if I decide to stay with injection.

My questions are as follows:
1. What is the minimum approximate width of the drive belt?
2. Does the belt have to be toothed or can it be ribbed (like on a serpentine belt)?
3. What kind of drive ratio must I use to get the 5-6 lbs of boost?
4. Will the cam I've got be enough?

[BOBCRMAN@aol.com]

The only years that 400 heads had bigger chambers are the 70-71 with the 1.60 exhaust. After that Chevrolet just used the 350 production head with steam holes drilled in them. Ports are more or less all the same.

Way back when we used to drivethese things with three V-belts so a serpentine type belt of an inch or so should be usable if you are going for six lbs boost.

As for pulley ratios and availability. Try someone in the business like Dyers.

A blower motor isn't all that picky about camshaft. All you need to do is vary the boost and the fuel/air mix gets packed in there!

[paulo]

Hey SA. Keep the fuel injection system.The best aftermarket recurving is made right in your country.Look for Unichip from Dastek. Paulo

[Neophyte]

BOBCRMAN, Thanks. I'll definitely need better head than the TBI ones I've got now. I'll have to see what I can't scratch out under the bushes over here...lol. If that the case with the belt I'm gonna see if the standard serp belt will fit as I'm not gonna be using the p/steering pump. Does Dyers have some web-site?

Paulo, I actually bought the engine for my 53 Chevy without the original ecu. When the V8 shops import them that unfortunately doesn't come with from the states. I actually bought a setup called Mr. Turbo which is quite adjustable. And I can adjust myself from my laptop if I want.

[BOBCRMAN@aol.com]

TRY www.dyersblowers.com

[Neophyte]

Cool, thanks!

[Neophyte]

BOBCRMAN,

I don't suppose the standard serpentine belt of 9/16" would be enough or could it?

[BOBCRMAN@aol.com]

I would go at least an inch wide. Try some of the truck type belts and pulleys.