Chaparral2f Posted November 28, 2002 Share Posted November 28, 2002 I have a 350 truck engine,(#14010207)with stock dished pistons, and 76cc heads (#462624) If I change the heads to corvette aluminum, (#10088113) with 58cc chambers how much my compression ratio will raise? Will the stock dish work with these heads? Thanks Quote Link to comment Share on other sites More sharing options...
DavyZ Posted November 29, 2002 Share Posted November 29, 2002 In the far recesses of my mind I remember somewhere that it will raise your compression from somewhere in the realm between 1 to 2 points. That means if you are making a pathetic 8:1 compression with the stock pistons, you will be getting someplace between 9:1 to 10:1 compression, which is really ideal for the street and pump gas. Hopefully someone who knows for sure will chime in to make sure I am not leading you astray. I think the question you raise about "will the stck dish work with these heads" is asking about valve to piston clearance? Yes? If so, that has more to do with the lift of your cam then anything else. Under .500 inches and you should be ok. If your heads are properly setup, you'll be fine over that. Again, hopefully a truly educated person will chime in. If the question does not ask about that, then the simple answer is 'yes' they will work fine. Davy Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 29, 2002 Share Posted November 29, 2002 Your stock cast iron heads appear to be universal/generic according to Moretec meaning that just about any valve size up to a combination of 2.02/1.60 could be in there.I am chiming in but not an expert about these matters like Mike C or Greiman etc. I would agree with Davy that 9.1 or 10.00 with the dished pistons sounds reasonable considering the chambers are 76 cc. I f you have not pulled the heads .. you can always hope that they are not door stops ...OEM 4 Barrel carb?? Quote Link to comment Share on other sites More sharing options...
Chaparral2f Posted November 29, 2002 Author Share Posted November 29, 2002 This is IMO the best sight on the Net! I want @400 hp/390lb-ft torque:I know this thing is gonna have a really choppy idle, but that's OK with me. Comp Cam Magnum 292 Hyd (244 duration,.501 lift,110*lobe seperation.) Pete Jackson gear drive. Victor jr intake. 750 Holley double pumper.(No webers this millinium) 1-3/4" headers. Vertex Magneto Any Sugesstions? Thanx, Joe Quote Link to comment Share on other sites More sharing options...
Guest Z-rific Posted November 29, 2002 Share Posted November 29, 2002 2 or 4 bolt mains? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 29, 2002 Share Posted November 29, 2002 Your aluminum heads should have 1.94/1.5 valves with angle plugs. Your truck engine should be a 4 bolt main.Your cam selection will require an after market torque converter. With the mid size valves in the aluminum block, you may want to consider a 270H or 280H series Comp Cam. Foreseeing no clearance valve/piston clearance problems.. go for a 58cc 2.02/1.60 head with the 292H cam,750/victor/1 3/4 headers. Lately there has been some 383 cast "internally balanced" stroker cranks (Scat) being offered that will accept the stock 5.7 rods or 6 inch aftermarket rods and aftermarket .030 hypereutectic cast pistons (Keith Black/Silvolite) that can be selectively tailored in the 9 to 13 compression ratios.The crank and pistons can be had for a little over $400.00 if a person gets on top of the eBay listings.The new internal balanced stroker cranks take some of the cost out of obtaining 400 ci hardware (damper and flywheel *****Yeah I know the parts are not forged and this is beer budget but not everyone is not that anxious to be competitive at the track weekly grinding metal together. Quote Link to comment Share on other sites More sharing options...
Mike C Posted November 30, 2002 Share Posted November 30, 2002 The 58cc 'vette heads on the truck motor should net about 10.0:1 with the dished pistons. 12cc is about 1 pt. in general. 76 to 64 would get you about 9.5 and 64 to 58 should bump it to about 10. If it is a used short block in only fair condition, the added compression will do it in pretty quickly. The Vortecs flow better but require a different intake depending on what you already have, and their 9.5:1 should be more friendly at the pump. Quote Link to comment Share on other sites More sharing options...
Chaparral2f Posted November 30, 2002 Author Share Posted November 30, 2002 Actually, the engine I am putting together is stolen from the "John Lingenfelter On Modifying Small-block Chevy Engines" book. (Page 155 to be exact). I wasn't worried so much about clearances as I was about compression ratios with stock pistons. AS to ging to a 280H cam, I think it would cost me about 40hp and 20lb torque. kthis may not sound like much, but I am going to be hauling around a z31 that is heavier than an early Z. I may go for a bigger crank, But my beer budget is getting down to the foam on the sice of the glass. Check out this link, there is some really outragous classifieds. www.RaceMedia.com Quote Link to comment Share on other sites More sharing options...
denny411 Posted November 30, 2002 Share Posted November 30, 2002 If you are planning to run 400 or more HP, I would strongly recomend having the rotating assembly balanced. It`s a good idea on any engine, but as HP#`s climb it`s even more crucial. Quote Link to comment Share on other sites More sharing options...
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