Will milling 243 heads on an Ls1, 30 thousanths cause any Ptv issues? Thanks

 

This depends on what camshaft and head gasket you plan on running with this setup. Also if larger valves are being used in the 243s that should be a consideration as well. If it is a completely stock LS1, and stock 243s milled 30 you shouldn't have a problem with clearance. Checking PTV before final installation is always the recommended way though.



Aaron@ThompsonMotorsports

 

Also it's duration not lift that can cause PTV issues. Full lift is when the piston is far away to that is a non-issue. It's when it starts to open or close that can cause problems. I agree you should always check and it's pretty easy with clay and calipers. I ran a .030" milled 243 head with a 228/232 .612/.600 111 lsa cam with plenty of clearance but sometimes cams are ground a little wrong or the timing set is slightly different (degreeing the cam is a good idea too) and why every PTV should be checked even if it worked for someone else.

 

https://ls1tech.com/forums/generatio...alculator.html

Handy tool if you have enough information to plug into it

 

I see in your other post that you are thinking of running the 228 cam and you asked about PTV clearance with milled 243's. I actually had Texas speed do a .030 mill and port with bigger valves etc using a stock GM MLS Gasket. I haven't had any PTV issues, they milled and set up the heads to work with the 228 cam. BUT as previously stated every cam is different and claying the motor is simple.