Hi guys, like the title says I want your opinion on what you think is wrong with my sbc. I would also like a few ideas on how to go back together with it. The motor has started knocking when it warms up. I haven't taken the time to tear it down and see what is wrong yet. Here is a little history on the motor. The motor is in my 68 Camaro. My dad and I built it several years ago. It was the first motor that we ever built together. It is a 377, which is a 400 block with a 350 crank using main bearing spacers. It has GM pink rods, hyper pistons, 490 lift hyd. comp cam, hv oil pump, vortec heads, edelbrock air gap intake, 750 holley dp. It is a pretty basic setup. The thing has very few miles on it, probably less than 200. It was running great until a while back when I might have ran it a little too hard for a little too long. I had an allergic reaction to some food I ate and had to get to an eppy pen fast! I turned a 35 min drive into a 17 min drive. But anyway, I never noticed anything that evening, but the next morning I took the car down the road and the oil pressure dropped and it started knocking when it got up to operating temp. I brought it back to my shop and pulled the oil filter and drain plug and to my surprise I didn't find any metal in it. When It cools down the oil pressure is back up and it sounds great. I have pulled the motor, now I just have to get time to tear it down and see what is wrong. I have ran across 400 blocks that cracked around the cam journals, have any of you ran into this problem? Since it is going to be torn down, how would you go back with it? Keep the 377, make a 406, stroke the bad boy, or give it a little BOOST?

 

The bigger you go with the engine the larger the turbo you will need. What is your horsepower goal for your engine?.

 

Not knowing how the engine was assembled (brg clearances.. ect) i'd look at the mains, and spacers first. I have built a few 377's over the years, and although never had a main bearing problem, never cared for the spacer deal.

 

91turboterror, I don't really have any goals for it other than being a fun street motor. I have other plans for the camaro, so it will probably be going in my 61 Chevy Apachie. They are heavy old trucks, so the more torque the better. If something is wrong with the block I will probably put a 496 big block in the truck.

 

Mnlx, I have never liked the idea of spacers either. I can't remember exactly what the specs were on the bearing tolerances, but I do remember they were well within specs using plasti-gauge. I did take a few minutes in between working on customers vehicles to pull the pan and a couple of main bearings. The mains bearings looked great. I pulled a couple of rods, and it was the same story with them. It will probably be tomorrow before I get a chance to tear it down completely. I will let you guys know what I find.