Hello, the title summarizes it. I have an 3970010 engine that came with my '69 K5 that doesn't run and I've been picking off all the performance parts that the previous owner put on it. Today I pulled the aftermarket roller rockers, push rods, and then the rest of the head assemblies. I was initially told that one of the pistons exploded when the new build on the engine had only 500 miles, but when the heads came off the piston was intact in the cylinder that had no compression and was full of oil/coolant. The exhaust valve however for that cylinder is stuck in the open position which I believe is the cause for no compression.
This leads me to believe that there may be hope of resurrecting this engine with the ready-to-bolt on 64cc heads I have on hand...
What confuses me though is that I noticed that each head that came off the engine has a completely different casting #:
One is 333882 which I researched has 1.94 intake valve, 1.50 exhaust valve made '70-'80, 76cc chambers.
The other is 3998993 which I researched has 1.94 intake valve, 1.50 exhaust valve made '68-'79, 76cc chambers.
Is this mixing of different castings of cylinder heads something that is commonly done as long as the specs match as I listed above or at least possible to do in an engine build without creating serious problems?
I ask because The heads are clean and appear in good shape aside from the one stuck valve, so before I offer them to a friend I want to make sure I'm not setting him up for failure on his build.
This leads me to believe that there may be hope of resurrecting this engine with the ready-to-bolt on 64cc heads I have on hand...
What confuses me though is that I noticed that each head that came off the engine has a completely different casting #:
One is 333882 which I researched has 1.94 intake valve, 1.50 exhaust valve made '70-'80, 76cc chambers.
The other is 3998993 which I researched has 1.94 intake valve, 1.50 exhaust valve made '68-'79, 76cc chambers.
Is this mixing of different castings of cylinder heads something that is commonly done as long as the specs match as I listed above or at least possible to do in an engine build without creating serious problems?
I ask because The heads are clean and appear in good shape aside from the one stuck valve, so before I offer them to a friend I want to make sure I'm not setting him up for failure on his build.
