Flywheel Bolts FYI

New 347 Stroker build. Engine has been broken in. Drive train only, no body yet. Was running the engine about a week ago and noticed a steady stream of oil coming from the bellhousing/flex plate. Figured it was a real main seal failure. Pulled transmission/clutch/flywheel. Inspected and could not see any issues with the seal. So off to the internet I went. Finally realized what had happened. Since this is my first 302 engine, I did not realize that the flywheel bolts are through bolts. The threads go all the way into the block. I did not seal the bolts when they were installed. So I am posting for anyone that may not have known this.

Some cranks are through hole, others are blind holes. I think all the aftermarket cranks are through hole.

A steady stream of oil is a lot, I don't think you could get that much through the threads and under the heads of the bolts. That would have completely soaked the flywheel everything inside the bellhousing with massive amounts of oil.

Broncobowsher said:

Some cranks are through hole, others are blind holes. I think all the aftermarket cranks are through hole.

A steady stream of oil is a lot, I don't think you could get that much through the threads and under the heads of the bolts. That would have completely soaked the flywheel everything inside the bellhousing with massive amounts of oil.

Click to expand...

I agree. I think I had light leakage from the bolts. After inspecting further, all the oil was running down the inside (engine side) of the flex plate. Not a drop on the transmission side of the flex plate. The stains and oil marks on the flex plate start right at the line of where the engine block meets the oil pan. I think I have a leak or leaks from the oil pan gasket.