SDPC sells new L98 shortblocks for $1135.95. L98 shortblocks have dish pistons w/4 VR's (-11cc). With stock 64cc heads, I'd have a 9.1:1 CR, not bad. With the 67cc S/R Torquers, I'd have about 8.8:1 CR; great if somebody has 3K they want to toss me for a SC...

Should I tear down the L98 shortblock to put flat-tops in, mill the heads, or just get a ZZ4 shortblock w/the better crank and flat tops already in there?? Keep in mind this is on paper, and isn't costing me any time or money right now so I'm open for all suggestions. Thanks in advance.

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-Jason M. 1991 Camaro Z28

 

Also, how do the new Trick Flow heads compare to the Torquers. I'm aware that aluminum dissipates heat faster.

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-Jason M. 1991 Camaro Z28

 

Jason, how did you get your c/r to come out to 9.1/1 with -11cc on the pistons and a combustion chamber of 64cc? Are you figuring it with a .041" thick head gasket and a deck height of -.020" . If you run a .020" thick gasket it will put you at 9.6/1cr. or you could use a set of 305 torquer heads with the 58cc combustion chambers. Either way you can get your compression up without to much trouble.

Steve

[This message has been edited by steve8586iroc (edited June 18, 2001).]

 

I was actually just using the figures on the SDPC website. It says 9.1:1 w/ 64cc, 8.4:1 w/ 76cc. I never really bothered doing the math myself. Thanks for the heads up bro!

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-Jason M. 1991 Camaro Z28

 

I'd wonder if the cost of milling the heads, then maybe having to mill the intake to match, would be better spent towards a better set of heads you can run as is?

This is my current contemplation too....the topend of my motor is apart and I would rather run cast iron heads, the SR's seemed like a decent choice for me too, but the 67?cc chambers has me looking elsewhere.

 

It is inexpensive to have the heads milled, it doesn't take much to go from 67cc to 64cc. I am in the process of having an engine built with the 67cc S/R Torquers, milled to 64cc. This engine has flat-top pistons (not sure of the gasket thickness), should be around 9.3 to 1 compression. I went with cast iron instead of aluminum for my street car, a better choice for a daily driver. Also, I recommend gasket matching the ports and cleaning up any rough casting.

Good luck!

 

Mike,

Do you have the stock -11cc dish pistons? If so, that would result in an 8.8:1 CR with a .041" gasket and a -.025" deck height which I believe is about accurate on stock engines. If you use the ZZ4 hyperu pistons, or any flat top with -4cc valve reliefs for that matter, CR jumps to 9.4:1. I'm probably going to get the ZZ4 shortblock and use the 67cc S/R's.

I realize you don't have the luxury of ripping your bottom end apart now for flat tops, so it may be in your best interest to keep looking for heads, but don't forget it isn't too hard to have them and the intake milled. The only thing I don't like about milling is that then you need shims under the dist, you need shorter pushrods to maintain the correct valvetrain geom. etc etc. I understand you wanting to do it the right way. Good luck bro, and thanks for the insight.

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-Jason M. 1991 Camaro Z28

 

Mike,

Just calculated again, with a -.025" deck height, 67cc chambers, and -11cc pistons BUT now with a .015" gasket, the CR is about 9.3. Not sounding too bad now.

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-Jason M. 1991 Camaro Z28

 

Jason,

I'd think about the only way to get a .015 headgasket would be to use a full copper?

Also, I think the SR's w/67cc CC's only comin in 2.02/1.6 valves? That was another reason I was looking also..plus the other parts involved too (which I hadn't thought of until now that you mentioned it).

I wonder if the 58cc heads (1.94's/1.5's) have enough meat to open up to 63/64cc's and keep a decent chamber shape and I wonder if they flow well enough for a 350 without having to go crazy with the diegrinder?

My bottom end has about 110K on it and I still have good oil pressure and don't use any oil, so I'm not ready to go through the whole shortblock yet, just pep it up some.

I may end up doing some work on my stock heads then send them to the shop to get redone, for now....

If only money came as quick as ideas, huh?