[Formulajones]

Originally Posted by HWYSTR455

For me it was the opposite, the OE cranks are fine with the rope seals, only with the neoprene seals the hash marks required attention, or at least checked.

Depending on the brand aftermarket crank, where the hash marks are more pronounced, require attention, with neoprene seals, but I can't say for rope seals, because I personally have not tried a rope on an aftermarket crank.

I think Eagle cranks have serrations, and Ohio ones don't, but don't quote me on that.


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Yes I agree, OE cranks are fine with rope seals, as they have the serrations. It was my understanding as I was told, the serrations were there for that. So when ever I switch over to a conventional seal (meaning a lip seal) I would either dress those serrations or have the machine shop do it in advance knowing that's what the engine was going to get.

Those seals are designed to work on a smooth surface, as seen in other applications like axle seals, timing cover seals etc..... Doesn't take a lot of thought to figure out those serrations might not be a good idea when switching to a conventional seal. But some people feel otherwise.

Dad's is an Ohio Crank. It's a smooth surface. I have pictures of the crank but nothing that shows the seal area at the moment. Going to do the rear main in it soon. Going with the 2 piece BOP as that's what I've always used with excellent results. Not pulling the crank out of this one.

Oddly Bischoff had trouble with this rear main when building the engine, and the BOP seal was replaced 3 times while on the dyno. Within a couple pulls it would leak horribly (another reason everyone should dyno their engines) Turned out the MR1 block didn't have venting back there and oil was trapped in that area.
Tony relieved the block and cap around the seal and the rest of the dyno pulls went leak free. Been a few years now and it's leaking again. Don't know what his install procedures are so I'll be curious to see what I find when I pull it apart. I've got my suspicions.