piston to valve clearance with woods 777 in 103

[hi$toy]

just cleaned up set of late model 103 heads, ports cleaned up around valves , 3 angle valve job-stock valves, , heads cc at 86 per head, how much can i cut heads safely to get to 82 ccs, without running into clearance problems on 13  103 engine .030 headgskt, think .028 to .030 to get to 10.2  with Woods 777...

[Ohio HD]

Wood 777, intake TDC lift is 0.200", exhaust TDC lift is 0.187".

Add the 0.030" you want to remove from the heads, 0.200" + 0.030" = 0.230" and 0.187" + 0.030" = 0.217"

With the valve springs off, let the intake valve drop down the guide 0.230". I bet the valve doesn't even leave the combustion chamber. Do the same for the exhaust valve and use 0.217" down the guide.

Of course after the heads are cut you just use the TDC lifts of 0.200" and 0.187" without the 0.030" added to them.

You also have the head gasket as a buffer to the piston. 

[hi$toy]

so you are saying shouldnt see any problems at .030 removed? Using the stock pistons , they are .005 down

[Ohio HD]

I'm saying you should not have issues. But you should "always" check clearances when modifying a motor.

[hi$toy]

Thanks for the response, felt would be safe , thanks again

[kd]

Thanks for the response, felt would be safe , thanks again

You did see where Ohio said to "always check the clearances"?  That means when someone that doesn't have the engine history or on the bench says it "should" be OK, check it to confirm.

[hi$toy]

was planning to check, as pistons are 005 down front and rear, realize cam has tall TDC lift.

[Ohio HD]

This is a TC head with 0.025" removed from the head gasket surface. The intake valve is open 0.197". There's a mile before the valve even gets close to the head gasket surface, so it won't hit anything. But when you have the parts off the motor, I always check.



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[hi$toy]

thanks so much for input, was planning on cutting and rechecking ccs after first cut, and continue to get 82ccs,any other input is very welcome. The way I have it figured .028 off to max of .030 off gasket surface then use.030 headgasket..Have a Thunermax tuner as well as Rinehart Slimline headpipes and their 4inch slipons with competion  baffle and K&N type open filter , bike mad fair numbers as is , just trying to up compression to work better with current cams .Any and all advice is appreciated...