273ci thoughts?

papabear said

I have a 67 273 now...you saying go with the sealed power pistons and my stock heads (freshened up of course) would work well?

Also, the 273 vs. 318 crank snout and relationship to my 904 trans...I'd be best running my 273 forged crank in the 318, no?

Click to expand...

The Sealed Power pistons will be just under 9:1 compression ratio only if you use the available .028 thick head gaskets. They will make a CR of 8.5:1 if the standard Felpro kit head gaskets is used. So they are low-to-moderate compression at best. They should balance with the 318 or 273 crank as-is .

The other disadvantage is the lack of eyebrows. You will have to stay modest on the cam lift and duration. But you would do anyway if you have that low-moderate compression and want spunky street performance with good low RPM torque.

The KB167 is going to give you a CR that is 0.6 point higher, all else being equal. That will make the engine behave very noticeably more torquey at low to mid RPM's. And now you have eyebrows and the compression to do a bigger cam without hurting the low RPM torque. The disadvantage is that the crank will need to be balanced to the lighter piston.

BTW, all of these CR numbers cited are with the small chambered heads, around 62 cc.