383 grind rods down to clear?
TECH Apprentice
Joined: May 2009
Posts: 323
Likes: 2
From: NW AR
I ran .380 camshaft lift on 1.6 rockers .600 lift, on a 3.875" crankshaft. 6" Rods, ARP2000 bolts. The reason he "massaged" the shoulder of the rod is that it is easier to do versus putting the block upside down on a milling machine and properly notching the bottom of the cylinders.
It really isn't the worst thing I've heard of a shop doing, but it still sucks that it happened.
It really isn't the worst thing I've heard of a shop doing, but it still sucks that it happened.
The bolt heads are what hit the block near the pan rails. That requires notching the block. I have seen the bolt heads beveled for clearance. As long as the socket still gets a good hold, that is no problem. The rods will hit the camshaft at the other end of the bolt, if you failed to order "stroker rods" which have the shoulder of the rod machined and that end of that one bolt in each rod shortened. Most I have had were machined so the end of the bolt was flush with the flat that was machined on the rod when torqued. That end is for camshaft clearance. Cam lift has pretty much zero to do with those four rods hitting the camshaft. Duration, which lobe profile is used, and how much the cam is advanced. Advance is the big one. More cam is advanced, the worse the rods will hit. Intake lobes are what will hit. I always advance the cam four degrees further than I'm going to run it to make sure they still clear, because it's a little tougher to acurately measure the clearance there.
My 383's rods weren some I already had, and were bought for a 350", so were not profiled for a stroker crank, so I profiled them on my belt sander. I did all eight rods to maintain balance. They look fine, all weighed the same. Many 8000 RPM + passes, still in the engine. Zero issues.
My 383's rods weren some I already had, and were bought for a 350", so were not profiled for a stroker crank, so I profiled them on my belt sander. I did all eight rods to maintain balance. They look fine, all weighed the same. Many 8000 RPM + passes, still in the engine. Zero issues.
