For small blocks. How is this achieved? Without going with closed chamber. This is for 10.5:1 91oct E10. Thanks.

Quench pad pistons and lots of GOOD machining and measuring. You'd have to equalize all the "open" area of the chamber (probably have to machine them) and then cut the quench pads of the Pistons to give you your .040".

Have a piston recommendation (stock stroke 360)? Who does your machining? Kens? Comp?

No I don't have a piston for you to use but I'm sure some of the SB guru's will have some recommendations. I used Millar Racing Engines in Winkler for a 440 I had rebuilt as a teen and it was a good engine. He has a pretty good rep to this day, maybe give him a call. Are you in Manitoba?

Yeah, peg. Winkler's a bit of a drive.

There's a local BB guru (Mike Arsenault) who uses Competion Engine for his machine work. Mike builds some pretty stout BB's. He's got a 70 Satellite with a 588 B1MC that runs high 9's

Yahhhhh I know MIke. I'll go see the boys at Comp 2morrow. Thanks a bunch.

When I did it, I hand ground all of the chambers to the same depth, then cut the deck a TON to get the pistons .070 out of the hole. It is a long time consuming project to hand grind each piston to clear the edge of the chamber from there!

Yeah KB has the rough cut pistons. Toooo much work for this cat.
I think a cam in the 108ish LS & 236ish @ .050 should be enough
to get by on 91 on the street. Thanks guys.

get some KB 372 pistons in the OS your block requires. narrow the rods to 1" for them (it says required with them). machine open chambered head recesses just enough to get em equal/level. As said carefull measureing/machining of piston plateau keeping in mind gasket choice to get the SCR range you are after for .035-.040 quench. You'd need to bore to size then mockup the 4 corners & rock the pistons & check heights plus square decking the block. Need a good machine shop that will work with you. with 91 you will need quench & 040 is the very max.

It Takes some work but like said it can be done a few different ways. One I remember doing had the block decked enough to have a KB107 come out of the hole, then clearanced for the head. I did the same on my old 340 with the KB243. It required some more work for clearance because it was a 4.100 bore.

I took the easier way on this 360, KB107, Zero Deck, Edelbrock RPM heads milled a little, and a Fel Pro 1008. 11:1 91 Octane 500HP(11.16@119.5@3525lbs)

Yeah I was thinking about it. The KB373 pistons @ .005 below deck, with a .040" compressed gasket should give me .040" quench. Correct?

the quench plateau is .085" above the piston perimeter. you'd want .035-.040" between that flat and the head flat

Then get a set of closed chamber heads if you aren't interested in doing the job right.

Getting .040 quench is not a throw it together task with as cast iron heads .

read post #2087607 Johnny-be-bad But as per usual your right.. I'll do the quench pistons the right way.

you mean this ??



It makes no sense if you have an OPEN chamber head ????

was talking about the .085" quench pad on top of the piston.

.005 below deck + .085 quench pad - .040 gasket should be .040 quench.. no?

Mr. Bush would say.....Fuzzy Math.

It depends on how recessed the open area of your chamber is. Say it's .100", you have a .040" head gasket and the pistons are at zero deck, You'd need your quench pad to be .100" to get a .040" quench.