quote:
Originally posted by jack deryke:
I don't recommend this, as there are surprisingly few machine shops around that can reliably bore lifter holes correctly, then install & ream bushings so the lifters run properly. Remember, you have 16 chances to do it wrong. There are multiple angles involved as the stock lifter bores are slightly tipped backwards to preload the cam that way, and the lifter bores are slightly higher than true centerline, to ensure the lifters rotate for long-term durablity. Sure, on race-only blocks, it's successfully done. But those blocks are forever dedicated to racing with frequent teardowns, roller lifters forever, etc
The commonly avaliable oil restrictor kits (les than $20) only limit oil flowing to the 8 lifters on the left side of the block, and do nothing for the oversized oil passages that intersect all 16 lifters. Each hole is nearly 1/2" dia where it should be 0.050 or smaller. Restrictor kits in the lifter bore for the left side bank of bores probably shouldn't be used with hydraulic lifters, especially the fast-bleed types that need more oil to work properly. I wrote a recent article for the POCA news that mapped all the oil passages in a 351-C, and to call it 'severely twisted' is a mild understatement.One quote by a noted motor journalist in 1972 said, "... Sherlock Holmes himself would be baffled by the oiling in a 351-C..."
Jack, i fully agree with you on both points, but if you have a (very) good adres for a machine shop, than it would be no problem at all.
I've seen this several times, and not even one time i saw a failure.
I only added 2 options wich will work, it's up to the car owner what he prefers, i will warn for consequenses (like you wrote) next time.
Paul.