Thread:

clearance

Yep, it only has to clear. But it has to clear all the time, under all conditions. But it only has to clear by .0001 I had a small block Ford yeeeeears ago, that would never let carbon built under the quench pad. Never hit. Just never developed carbon either. May have after some long term street driving. But the first time it went to red line, it was gone. I hve no idea how close it was coming. But it wasn't clearing by much.

You really shouldn't blame TRW/SP for the interference on the pistons. You have to remember, they are built to be .020+ IN THE HOLE.

Cut the deck of the block till the piston is .025 out of the hole. Now cut the flat of the piston area to where it is 0 deck. Now stick cylinder head on and cut piston dome to where it clears any part of the cylinder head. Check P/V clearance and maybe cut the valve pockets to where you have .125 on exhaust side and .100 on intake.
Now use .040 gasket.
Done that many times and never touched anything at 8000.
Anyone else that crazy?
LOL

Oh yeah....steel rod only. LOL

Originally Posted by Fiat48

Cut the deck of the block till the piston is .025 out of the hole. Now cut the flat of the piston area to where it is 0 deck. Now stick cylinder head on and cut piston dome to where it clears any part of the cylinder head. Check P/V clearance and maybe cut the valve pockets to where you have .125 on exhaust side and .100 on intake.
Now use .040 gasket.
Done that many times and never touched anything at 8000.
Anyone else that crazy?
LOL

Oh yeah....steel rod only. LOL

Plenty of room.. I'm currently running .068 with aluminum rods and less than .125" on the exhaust and all is good at 8400..

Originally Posted by Wicked Performance Boats

No . Problem is exhaust side of top of piston catches edge of combustion chamber in open chambered head 119 cc. So i need to die grind a little clearance in one spot on each chamber. I think Sealed Powered had these 12.5 to 1 pistons made in China. Piston to wall clearance is .005. My thought was .040 clearance minimium. Thanks for the imput. Pat

Curious on how you determined this? With or without gasket?

Originally Posted by Wicked Performance Boats

No . Problem is exhaust side of top of piston catches edge of combustion chamber in open chambered head 119 cc. So i need to die grind a little clearance in one spot on each chamber. I think Sealed Powered had these 12.5 to 1 pistons made in China. Piston to wall clearance is .005. My thought was .040 clearance minimium. Thanks for the imput. Pat

Actually India. After they closed the Maulden (spelling) MO plant down they shipped it over to India.

Originally Posted by Fiat48

Cut the deck of the block till the piston is .025 out of the hole. Now cut the flat of the piston area to where it is 0 deck. Now stick cylinder head on and cut piston dome to where it clears any part of the cylinder head. Check P/V clearance and maybe cut the valve pockets to where you have .125 on exhaust side and .100 on intake.
Now use .040 gasket.
Done that many times and never touched anything at 8000.
Anyone else that crazy?
LOL

Oh yeah....steel rod only. LOL

oh yeah, always ordered j&e's with blob dome and hand fit them to combustion chamber and cut my own pockets. just lay uh head up there, get out the old prussin blue and get on it, bam 16 or so hours later you got some HIGH compression pistons...lmao thank god for digitizing the chamber.......