im running a stock LS1 bottom end (crank/pistons/rods) and:

comp cams - XER287HR-12 -238/240 -605,609 112LSA
trickflow 215 CNC heads
YellaTerra 1.7 adjustable rockers

my problem is with this cam installed 110deg intake center line.....

i only have 55thou piston to intake valve clearance

any suggestions/thoughts on this?....cam phasing?.....

 

It will be tight. You better check it. Any tighter then .060 you better cut it!

 

You will need to cut valve releafs in the pistions, you need a .100" clearance on the intake valve, and .080" on the exhaust valve.

 

how bout retarding the cam a bit?

 

Exactly what he said!

 

It's usually 80int and 100 exh.

 

OP what head gasket is that with, if its a thin gasket go with stock to get an extra .011-.013

 

you want at least 80 on the intake and 100-110 on the exhaust.Just flycut it so you dont have to worry about it

 

many poeple running big cams run those tolerances. Ask for MS4 clearance around, it is about the same.
besides flycutting, you could also sink your valves a bit.

proper way is to flycut and mill head.

 

thanks for the replys guys...it seems retarding the cam only compromises the exhaust valve clearance...i have tried 8,6 and 4deg retarded to check the clearances....so far 4 degrees has given me the most for both inlet and exhaust....

will try 2deg tommorow but i may end up having to fly cut as some of you have said already..

thanks,
douglas