Hey guys. I'm back, and dealing once again with my LN3 block/internals dressed as a Series 1 L67...

As we left off, my harmonic balancer keyway and key were really chewed up. This created like a 1'' timing offset (don't know how many degrees that is), making the engine feel like it had 30-40 hp or so. Don't know if it caused any other damage inside. Anyway, as I understand it, the issue is that an LN3'* rotating assembly is internally balanced, while the L67'* rotating assembly is externally balanced.

The L67 is not balanced without the harmonic balancer. Neither the rotating assembly nor the balancer are balanced by themselves, but are balanced with each other.

With this being known, my issue which lead to the eaten up keyway/key and the vibration at idle are due to the weight of the L67 balancer on the LN3'* rotating assembly.



The L67'* balancer is on the left, LN3 on the right. Notice the "hammerhead" weight of the L67 and how much bigger it is.

I spoke with the owner of Dale Manufacturing, a rebuilder of harmonic balancers and Corvair parts dealer (if you're into those...). I described my issue and what I wanted, pretty much that I wanted an L67 balancer than acted like an LN3'*. He couldn't like build me one, saying that they're pretty much a one piece assembly and are already difficult to rebuild. At any rate, we got talking about the "hammerhead", and how in theory, though not a precise operation, I could Dremel the L67'* hammerhead, make it about the size on the LN3'* by eyeballing it, and I would be set. The L67 balancer does have some holes drilled in it for added balancing, which I will take into consideration. It won't be precise at all but I'll be a lot better off than otherwise.

Any comments? Thanks guys.