I just recieved my new set of speedpro pistons from summit...the 11.98 special and as sofakingdom said their compression distance is 1.540 so they are going back...

I am looking at these to replace them

Product Line:Keith Black Silv-O-Lite Claimer PistonsBore (in):4.000 in.Bore (mm):101.600mmPiston Material:Hypereutectic aluminumPiston StyleomeCompression Distance (in):1.565 in.Dome Height (in):0.150 in.Piston Head Volume (cc):-4.00ccValve Reliefs:TwoWrist Pin Style:Press fitPin Diameter (in):0.927 in.Top Ring Thickness:5/64 in.Second Ring Thickness:5/64 in.Oil Ring Thickness:3/16 in.Quantity:Sold as a set of 8.Notes:Gram weight of piston and pin 537/132g.


so my questions are..
1 will the dome height of .150 be a problem with 76cc heads casting number 369? as in clearance? the CR would be about 9.9:1 with a shim gasket
and 9.4:1 with a .039 gasket

2 can you reuse press fit connecting rods or will the wrist pins be sloppy?

the only requirements for this motor is it has to run on 93 octane

would the .039 head gasket give the the clearance and the CR to run 93?

 

I don't understand, why are you returning the speedpro pistons to buy inferior pop up domes?
Domes with big smogger heads (are 369's smoggers? Just my wild guess here...), is a bad idea.

You can reuse press fit rods.

You can go for the 9.4:1, but you'd have a .060" quench, with domes and smogger heads. It would probably be fine on 93 octane, but i'm still lost on why you're returning the speedpros..? Are they pop ups as well?

Oh, claimers are meant to be the cheapest piston money can buy really. Are you sure that's what you want?

 

i was hoping to raise the compression as the speed pro pistons i would need to use a shim gasket with a thickness of .015 to get 9:1 CR i am trying to get away from the shim gasket and still raise the compression

and i dont really want to zero deck the block as i might change to vortec heads in the future

 

KBs, like many piston sets, come with new wrist pins. Yes, you can reuse your press-fit rods.

You might want to try a smaller dome and a thinner gasket to hit your target compression ratio. GMPP sells a set of .028" composite head gaskets for a 350 block (4" bore) that work just great- used them several times now myself, if you don't want to use steel shims.

 

Run this by me again please? I missed the reasoning?

Why not 0 deck to your flat tops (speed pros), and run the 76 cc heads with a .028" gasket. You'd be in the low 9's. Then when you go vortecs, use a normal .041" gasket. Perfect quench, just barely at 10:1 - perfect and perfect. This is the recipe for success. zero decking and flat tops go hand in hand with a 64cc head, and have for a long time. Port open the chamber a tad (deshroud the valves a bit) if you want more volume.

Pop-ups are bad for flame travel etc. And why would you want domes if you're using the vortecs in the future?

 

i am sorry i should have clariffied i didnt really want to have the block decked because the machine shop was screwing me around with my crank they wanted my flywheel with the crank to "stand it up" for "storage" and it had taken me a while to find a shop equiped to balance a crank around here

 

What? Ok, i'm even more lost now. Why don't you want to deck the block?
Can't find a competent machine shop to deck the block?