Originally Posted by Sbc10
What would be some good clearances for a derby motor? And kind of pistons with low expansion. Im building a 383 thanks for any help
we've built some successful ones using stock cast pistons.
some guys like to spend money on forged but that's up to you.
keep in mind, these things get HOT, and need to keep going, even if it is weakly.
we've done .008" extra clearance on the bores (i.e. 4." bore is honed to 4.008")
and .080" top and second ring gaps. no that's not a typo.
what often happens is these get so hot that the ring gap closes up and seizes in the bore. this huge gap helps that.
whatever engine you're running, find a cylinder head that is not crack prone.
if you have more questions feel free to send me a pm.