when i do my ls/vtec turbo, i wanna use the stock ls pistons for the time being for the low compression it will create(not sure what the compression will be, does anyone know what it will be)i was just curoius if anyone knew if i would run into any valve clearance problems, and if i can fit oil squirters, will there be any clearance problems with those. thanks

 

The valve reliefs on the pistons will not be large enough for the VTEC valves.

 

You will not run into clearance problems as long as you do not mill the head, or as long as you run gsr or b16 cams, ITR + cams could equal clearance problems, 9.6.1 compression ratio.

 

thanks

 

If you do run ITR cams with a stock LS bottom end, and do advance the timing on the cam gears (especially the intake side), then YES, your pistons will slap the valves... and will VERY LOUD also. I had my intake cam advanced 6 degrees (dyno tuned) with B16A cams and when I threw in the ITR cams, and "dry revved" it in the garage before taking it out (w/Mugen chip, VTEC will engage w/out a load on the motor), as soon as I went into VTEC, the valves were hitting the pistons, and it made a loud buzz/chatter sound. Took the cams out and put the B16A cams back in and no more problems. Didn't feel like making my cam gears back to zero.

When we took the head off about 8 months later, you could see some nice marks on the pistons from where the valves hit them... not just from the ITR cams, but from overall use. Be careful, there isn't as much clearance as most say there is (unless you have your cam gears set to zero, or something very low).

 

how about if i had jdm itr pistons in there and had ctr cams... and i might have advanced the timing a bit too much.. would it slap valves??

 

I think only if there is a lot of advance, but you should be fine!