what was done to this crank?

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hi all,

i purchased on old merc c service section 2 engine this summer and i'm beginning to restore it. i took the crank out and found some interesting machining that had been done on the throws. the ends have been beveled and i've seen that before. by the way the beveling was done very well. now for the big question, what was done to the flat part of the throws???? you can see on the pictures that there was a groove or a trough milled in it. my question is what was the reason for doing it.


i would also like to know who raced the engine. here is what i've been told. jack kugler had it for a while and never ran it. he cannot remember who he bought it from. however he said it won the nationals when they were in california. may have won both the hydro and the runabout c service classes. he was not sure. any help out here? that is all i know. if the owner who raced this engine has any pictures of him/her running it i would like some copies to use in my display. i do intend to run it at a vintage race one day.

i've also included a picture of the exhaust side of the block and a muffler that was on it. i don't know if the muffler was on it when it was raced, but it did have a bunch of castor on it.

any help would be great.


frank
collector of old things that were new when i raced