i'm planning on running a +5 crank after this winter. i planned to take a CP 11:1 piston and have it cut down to 10.5:1 but i'm wondering if, with the +5 crank, i just leave the 11:1 could i still run 93 octane pump gas? i will also be running a KDS racing CNC ported head, +2 valves, RJ cam, and i already have a +3 TB and barker duals. do you guys think i should still have the piston milled down or will it be ok? and i'm just curious is there enough valve releif in a CP 11:1 for +2 valves and a RJ cam?
I am running a +5 crank w/ KDS 11:1, which is corrected deck height, on pump gas. I am 1200 elev. where I ride. Have had no problems I don't know about the reliefs in the CP. You could alweays put it together and then clay it to make sure, should always check valve clearance anyway.
is there anybody that i could ask about the valve releifs in this piston? would kenny at KDS racing know for sure?
If it is a off the shelf CP piston then the exhaust valve reliefs need to be deepened by .030" or better. They get close with cams larger than a HCIII.
Basically running the same set up as tonto and I run 87-91.
ok so i should get the valve releifs in my piston cut down some but the compression will be ok for pump gas? am i understanding this right? i do alot of trail riding if that makes a difference.
I thought Kenny sold pistons as well.
well i got ahold of kenny yesterday and he told me that i would be fine running this CP piston without needing the valve releifs cut back into it. now i'm curious if it matters that i'm running a +5 crank i forgot to mention that to him again. so with the +5 crank will i need to worry about getting the valve reliefs cut deeper in a 11:1 CP piston?