Broken Main Bolt. How to fix?
Thread Starter
Race Director
Joined: Apr 2003
Posts: 19,351
Likes: 654
From: Tampa, Florida
First, I'd like to thank everyone for their advice. Depending on each individuals circumstances any of the suggestions would be most suitable.
My circumstances are more 'shade tree' mechanic than anything else. I have a variety of tools, jackstands, a good jack and reasonable mechanical skills. Based on that I decided to pull the cap and see if I could remove it by hand. There was a small nub extending out of the block but I couldn't get enough torque with my pliers.
I shielded the crank/rods and Dremeled a slot in the broken bolt. After tapping my screwdriver into the slot all it took was 1 good twist and the bolt came right out.
The main caps and cap bolts appear to factory GM, they dont have washers and are as pictured in post #15. Shank length of the short outer bolts is 2-1/16" +/-.
I'm off to the speed shop for some bolts. I'll post another update later.
Thanks for the help and tips,
Jim
My circumstances are more 'shade tree' mechanic than anything else. I have a variety of tools, jackstands, a good jack and reasonable mechanical skills. Based on that I decided to pull the cap and see if I could remove it by hand. There was a small nub extending out of the block but I couldn't get enough torque with my pliers.
I shielded the crank/rods and Dremeled a slot in the broken bolt. After tapping my screwdriver into the slot all it took was 1 good twist and the bolt came right out.
The main caps and cap bolts appear to factory GM, they dont have washers and are as pictured in post #15. Shank length of the short outer bolts is 2-1/16" +/-.
I'm off to the speed shop for some bolts. I'll post another update later.
Thanks for the help and tips,
Jim
Thread Starter
Race Director
Joined: Apr 2003
Posts: 19,351
Likes: 654
From: Tampa, Florida
Everything worked out. My local speed shop didnt have a set of bolts for a 4-bolt main SBC so I grabbed a single bolt.
Before installing the bolt I made some measurements to make sure 'bottoming out' wasn't issue. I put it all back together and double checked the torque on the other bolts. I bought a new oil pump and pickup only to find out the pickup was the wrong shape so I thoroughly cleaned out the old one, set its depth and had it tack welded at the local muffler shop. The rear main seal (blue Felpro double lip offset) and oil pan gasket (1 piece Felpro) installation went OK.
As a side note to set the oil pump pickup depth I installed the pump with the pickup set intentionaly low. As I set the pan into place it pushed the pickup. I figured once the gasket was in place I had at least the gaskets thickness in clearance. I removed the pump and pushed up the pickup by hand another 3/8" or so and then had it tack welded.
Before installing the bolt I made some measurements to make sure 'bottoming out' wasn't issue. I put it all back together and double checked the torque on the other bolts. I bought a new oil pump and pickup only to find out the pickup was the wrong shape so I thoroughly cleaned out the old one, set its depth and had it tack welded at the local muffler shop. The rear main seal (blue Felpro double lip offset) and oil pan gasket (1 piece Felpro) installation went OK.
As a side note to set the oil pump pickup depth I installed the pump with the pickup set intentionaly low. As I set the pan into place it pushed the pickup. I figured once the gasket was in place I had at least the gaskets thickness in clearance. I removed the pump and pushed up the pickup by hand another 3/8" or so and then had it tack welded.
