Originally Posted by Biscuit6447
I Am getting my block from the machine shop tomorrow, and i am going to put together the crank and check to see if tolerences are within spec. Al parts are forged, crank is a large journal GM 327 crank, it was just ground .010/.010 under. The block had studs put in and got line honed.
This motor will see 7600rpm ever so often, and at least 6000 quite often. What are all the tolerances that i need to check? Does anyone have a link or something for a list of specs for a performance build?
Cam is isky cam 3000-7600 oval track. I am planning on getting some rhs proaction 200cc heads, forged KB pistons, and scat i-beam rods.
Typically, I find that the high side of factory spec's are good. Circle track engine's tend to get hot so the high end of the spec leaves some room for growth. I, also, build these with a high volume pump or a big block pump, there are those who would argue that it's not required and just as many that think it is, so while this isn't much help, you gotta make up your own mind. I like a circle track engine with a high on and just off idle oil pressure to cover what I think are those moments when you get the revs too low and the loads on the crank too high.
I would recommend you pay a lot of attention to the lube system, especially if you have to run a wet sump. You've got to keep the oil where the pick up is or the pick up where the oil is. You need a good windage tray to let the oil settle and de-aerate and a scraper or kick-out pan on the right side to catch the oil whipping along with the crank and peel it back to the pan, this is needed whether a wet or dry sump is used.