valve reliefs on ls/vtec...help

[Jszy]

I have read in write up on building the ls/vtec that you have to use different pistons then the stock b18a pistons, because the valve reliefs are too small for the vtec head. Does anyone know if this is true. Is it not possible to simply put the stock b16a head onto the stock b18a block? (not concerning dowel pins and things like that)

[Beyond Imagination]

i've never heard that before.
here's a good writeup on the ls/vtec
http://www.c-speedracing.com/howto/lsvtec/lsvtec.php

[Jszy]

Yea I have seen that one before...thats prolly the best one out there.

Oh, and I just read somewhere that the valve reliefs are only a problem if the cams are upgraded to a bigger lobe. Then, when the valves are pushed open further by the bigger lobes, it becomes a problem.

[jcrx]

The B18A1 has 31mm intake and 28mm exhaust vavles, the B16A has 33mm intake and 28mm exhaust vavles, with a stock headgasket, and stock cams you shouldn't run into any problems. You should clay the motor anyway to remove any doubts. If you are running an aggressive lobe you could have some contact.

[Jszy]

I dont plan on upgrading cams or anything like yet. I am not building the internals yet for financial reasons, so I have no intentions of upgrading the valvetrain. I wont be able to rev past the stock blocks 6800 redline anyway.