SBC 350/Weiand 144 build opinions

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I have a stock bottom end 350. Originally a vortec 880 block. Fairly low mileage deal with cross hatching still in the cylinder walls. Bores measure out and should be fine with a ball hone. Low buck type of a deal reusing the stock crank, rods and pistons. All bearings looked good but I’m going to hand polish the crank, replace all bearings and rings.

The cam will be a Summit Racing “hot cam”hydraulic roller. 218/227 Dur., 112 LSA + 1, .525/.520 1.5 Ratio. Along with Summits LS7 hydraulic roller lifters.

The heads I have now are some Flotek 200cc runner 64cc chambered heads. The only thing I’m concerned with is getting the Weiand 144 intake to seal up with the larger ports? Not sure that will even be an issue, though.

I can never seem to find an exact answer but I believe the stock Vortec 350 pistons are -12 cc dished. With a deck height if .025 and a .026 head gasket (I never have luck with the shim .015 gasket.) that brings the compression to ~9.3:1.

The cam specs may be a little big for the lower compression but I plan to run about 5psi with the Weiand 144.

This is in a 91 single cab s10 with a 700r4 and 3.08 gears. The idea was to build a similar truck to my 95’ single cab Silverado with a 383/177 combo.

Or I could keep everything else the same, but scratch the small blower and just build a flat top 10.5:1 350.

Thoughts?

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Posted by jose-lopez (Questions: 2, Answers: 1)
Asked on August 24, 2023 2:32 pm
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A blower motor really needs forged pistons, they can be a life saver if tge engine goes into detonation. Otherwise a detonation sensor and retard system can offer protection without taking the engine apart.

Need the cam part number. Blower cams tend to be a little different in that they cut back on overlap as the blower pressure is doing that work done in an NA engine by the overlap cycle.

Running a wider gap on the rings is a good idea, keeps them from running out of gap when your foot weighs down the pedal.

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Posted by VW-Guy (Questions: 1, Answers: 2)
Answered on September 13, 2023 9:48 am
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I have the B&M Power Charger 250 blower with Brodix Track One heads. We had to add material to the intake to enlarge the ports to match up to the Brodix heads. I think we added about .250" of material to the valve cover side at each runner set. I ported and gasket matched the intake the intake gaskets and heads, sanded and polished the outer intake runners, you can't even tell we welded on them.

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Posted by pootie (Questions: 1, Answers: 2)
Answered on August 28, 2023 12:31 pm