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Mike9311

Joined: 14 Dec 2004
Posts: 1786
Location: Chicago-ish

Posted: Fri Dec 13, 2024 9:24 am Post subject:

morghen wrote:

So the holes in the cam lobes are for rotational balancing?
Mike, I think you should start the Franco gear thread

Mike9311 wrote:

morghen wrote:

Whoah whoah, wait..whats the story behind that cam gear?

I knew someone would ask

Apologies in advance for topic drift

This was done many years ago. Asymmetrically lightened cam gear. At the time an attempt was made to have it offset the camshaft unbalance. Something done much easier today with scanning and much improved modeling. Certainly could be done more "cleanly" today. The process helped on a work project afterward for a 15000 rpm spindle design and build. Even that would be easier today. Looking at the gear I was so wrong with my guessing lol

The camshaft and cam gear are balanced. I mentioned it before but sometimes my madness goes unnoticed. Two plane balancing on outer cam journals with gear installed. The holes are actually drill dimples (not through the gear) to correct the remaining imbalance in the design attempt of the gear lightening. Did something related to this previously on a Ducati

Also, if you look really close at the cam lobes on the right side, they have holes. Everything on this particular NA is extra balanced. Engine, clutch, flywheel etc.

Yes, exactly, while combined with the gear balancing as a matched balanced set. Not what I was hoping for with all the small corrections on the gear. Seems easier now for me to figure out if there is another attempt

I might do that

_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

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