80smetalfan

I might be able to get a Weiand 142 for my 350. I'd love to bolt it on, but I'm curious as to if my C/R would be unacceptable on pump gas, if it would blow up etc. Setup in sig. Pistons are 15cc dished.

Edit: It's only $500, so I'm very tempted!

80smetalfan

TTT

Anyone?

80smetalfan

This is probably obvious, and I've got some 350 heads in case it's too much, but anyone, can I get away with the 305s?

kevinc

Sure thing, pop on the blower and have fun, no way you'll ever blow the engine, guaranteed or your money refunded.

DuronClocker

iTrader: (1)

What's your compression ratio? Head gasket bore/thickness? Piston down bore? etc.

How much boost do you plan on running? Do you have forged pistons at least? Forged rods and crank are never a bad idea for boost either...

80smetalfan

80smetalfan

Standard gasket thickness from an average Fel-Pro gasket, with the 350 bore.

The rest is fairly obvious. 58cc heads on a bone stock 010 350 with 15cc dishes on the pistons.

Weiand offers no information in terms of boost, but I do know it's a 142, which I thought some of you might be more familiar with. I believe it's about 6 psi from what I've heard, and it's obviously a roots setup.

So again I pose the question. Will it work on the 58cc heads, or will I need to switch some 64cc heads back on?

kevinc

'

Yup, still good to go. Bolt it up and report back.

DuronClocker

iTrader: (1)

Like I asked, how far in the hole is the piston? Height from flat part of piston (not bottom of dish) to the block's deck. Need to know if the block has been decked before or not.

As it is right now, without knowing the piston down bore distance, your compression can be from 9.22 to 9.96 or so. If I had to guess at a number, I'd say its .025" down and your compression will be 9.5:1.

If you used L98 heads with a 64cc chamber, you'd be perfect for boost. Again, with my guess of a .025" in the hole, you'll be right around 9:1. I just hope that bottom end is built right or you're going to be shattering rods or breaking rod caps and throwing rods.

Please measure this value and get back to us though. Or you could just take the advice above and bolt it on, but use a bigger pulley, and rev it to the moon and report back with findings.

80smetalfan

Nope. Stock casting and internals are untouched. Just the way she came out of the factory.

80smetalfan

Don't bother replying in this thread again.

kevinc

Since you're not serious about this...you won't bother calculating your static compression ratio...won't bother researching the blower to see how much boost it can generate...I'm encouraged to poke fun at ya.

A quick google search of weiand 142 returned this among other useful items:

http://www.holley.com/HolleyNews/article.asp?ID=14
And since this isn't even a third-gen FBody you're talking about, you're pretty much fair game for picking on. There are G-Body sites out there, ya know.

80smetalfan

Well, I most likely will buy the blower, because I find it hard to turn one down for $500. I know a few of the variables behind calculating compression (chamber size, deck height, bore, etc.), but I figured since this is the general tech part of the site, I would post the parts of the build like everyone else who asks about compression, and let people who know this stuff better than I do at this point, figure it out.

I did guesstimate 6 lbs, which one can work with.

As far as the G-body thing, ya I know . I was a proud owner of a 3rd gen until this week, and I will have one again. And my drive and powertrain both can be found inside of an 3rd gen f-body (though with the 350 it would have to be swapped in for that casting to appear, but it happens), so it's relevant.

I'm kind of an ugly duckling on the various g-body boards. The monte guys don't like the fact that it's a Cutlass on a Monte board. The Olds crowd gets absolutely enraged when I post on their boards because it's a Chevy-powered Olds, which they cannot see the logic behing doing (they will argue built SBO 307 >swapped SBC 350, seriously!) And I'm very familiar with these boards, so I usually give it a shot. Besides, I'm sure this wouldn't be an issue if I had TPI and I asked about a centrifugal .

But anyways, thanks for the constructive response and the info on the S/C.

I DO know that with the 350 heads the motor made the stock compression rating of 8.x to 1 with the dished pistons, and that if I put them back on and add 6 lbs, it won't just blow up the first time I fire it up. My block is comprable to an L98s, and I see L98 owners with 9.3-1 throw on 6 lb blowers all day long. It WILL blow up eventually, but it can live comfortably for a while, as I'd imagine 6 lbs would put me somewhere in the mid 9.x-1 range. So the debate with the 350 heads is nonexistant, and not part of the question.

I was just curious as to whether I could get away with keeping freshly rebuilt and home ported 305s on, if for nothing else because of the fact that they don't use oil, like my 350s.