XFlow compression piston clearance question

[RickC]

Hi all,

I'm rebuilding a Kent 1600 engine, I've had it bored to .060 Kent 234 camshaft, steel rocker gear (+.050), GT sized valves, lightened fly wheel, balanced, R6 throttle bodies etc.

I've just CC'd the combustion an found that my machinist has supplied 1300LC or 1600 pistons instead of 1300HC pistons which has left me wanting for compression.

I have ample valve clearance (4mm + exhaust), 6mm + inlet, 0.9 deck to piston clearance, I'm hoping getting the block decked to zero clearance with a 82.5mm gasket with minimum piston to head clearance
might save me the hassle of skimming and rebalancing pistons.

Does anyone know of a minimum safe piston to head clearance (max revs 7K)?

Does anyone know the minimum compression ration to get honest road performance out of a stage 2 type build?

Any other ideas/comments?
Thanks,
Rick

[mick32]

i have been down this road in the past with nasty results got too greedy with compression and it went bang on no3 cyl my advice to you is stick to between 10-10.5 for reliable results.40 to 60 thou can be decked from the block safely enough but as i said go easy on compression btw mine was 11.5 with a bp300 cam.

[Graham]

40 Thou, although you would probably get away with a bit less, 30 thou would be absolute rock bottom limit

[RickC]

Mick and Graham,

I can deck off .9mm to bring the block level with the pistons, a 82.5mm 1mm gasket should give me a CR of 10.4.

Thanks for your help.

I'll go searching for a gasket.

Cheers,
Rick

[fatboy slim]

cometic do an 83mm one @ 40 thou