We're boring the block to 4.040" because of skirt to wall damage.

Was thinking of running a SRP-139629 piston, which is for a 3.75" stroke crank. http://www.flatlanderracing.com/srpsbclowcomp.html

Run a 5.850" H beam rod, with a 3.480" stroke steel crank. The compression distance on the piston is 1.425".

I think that will work, and would make a 9.1:1 compression ratio motor.

Can someone check my math?

-- Joe

 

That will put the piston surface at 9.015" from the crank centerline..... in a zero-decked block, .015" out of the hole.

Only you can determine whether that will work in your specific block.

 

What is the formula you used for this? I was figuring dead even on a 9" block, so I made a math mistake .. ?

Without buying these pistons and rods, how can I measure the block deck height from crank centerline? LIke what tool specifically?

I measured the installed height of my old pistons. At TDC, with a 3.480 stroke cast crank, 5.7" ibeam rod, and compression distance of 1.563", the piston was .025" in the hole. So I'm sorta guessing the block is fairly stock height.

??

-- Joe

 

3.48/2+5.85+1.425=9.015

 

Ahh. I'm retarded.

What piston would you use for a 6" rod (if I decide to go that route) ?

-- Joe

 

Competition Products has lots of flattops and domes(hyper+forged) for a 3.48"/6" rod combo. I didn't see any dished or more than -4cc for releifs. I'm just assuming that you wanted a dished piston looking at the link in the first post is for a -16cc dish.

 

Thats the problem. Noone seems to have a thick deck dish around -16cc. I want a 9:1ish compression ratio for boost.



-- Joe

 

Thicker head gaskets or larger cylinder head chambers.

 

This CPW is with Stek... if you only need a little more clearance, get a thicker head gasket if that will do the trick. Getting different heads just because of this seems like a pretty drastic change to me though.

 

Destroys the whole idea of utilizing quench area.

Think I'll go with the SRP 383 piston and the 5.850 rod. My deck is tall enough, infact, i'd take about .010 out so the pistons about .005 in the hole. Should work perrrrrfect.

-- Joe