hi guys, just out of interest, is it necessary when rebuilding a YB to used pistons
with the valve cut outs, i know cut outs would be needed when runnind big cams etc
but using std cams with a new rebuilt engine should one be using pistons with cut outs???
cheers.........

 

I would do this because even with totally standard engines sometimes the valves hit the pistons.

 

pistons only normally hit the valves if the engine isnt timed up correctly, the head is too thin or you rev the bollox off it

most cossie's have had valve to piston contact - but this is normally due to neglect rather than anything else

if you;re going for big power than yes i would get them; if its standard then i wouldnt bother

 

As said if keeping std cams etc then not needed, thoyugh clipping can still occur very gently, especially as valve springs get tired.
I would personally though just for peace of mind, a good safeguard for future mods as well, as most people will want more power at some point!!.
tabetha