Gear drive harmonics

[dreracecar]

Cant understand with the 100's and 100's of units sold for the last 30+ years why you are the only one having issues.

[Draw 3D]

Cant understand with the 100's and 100's of units sold for the last 30+ years why you are the only one having issues.

I don't think the gear drive is the culprit, the manufacturing of the gears should make everything pretty concentric, I'm in belief that the harmonics were already there but the roller  chain absorbed most of it, how do the bearings look?

[George]

Well if Milodon has provided instructions on making a gear backlash adjustment and others have done it . I'm pretty sure I'm NOT the only one but I'll make another post when we get it figured out. Thank you.

[George]

Problem identified ! The gear drive idler gear and the blower pulley hub were not happy with each other. We have it apart checking everything . The hub OD will be turned down to give the gear more room. Glad we only made a few runs. Could have been real bad ! George

[Paul New]

So you have BBC snout and you didn't turn the end of the hub down I forgot about that

[George]

Actually have a SBC snout and made a hub with a BBC OD and double keyed . The fact the Donovan idler is forward of the crank gear was miscalculated . The hub had a chamfer but needed more. The idler gear was chewing on the back side of the softer hub. Really not too much damage . Live and learn. Check --- double check and check again. Thanks. George


Actually made 5 runs with this problem. The car was .2 slower than last year and lost 10 mph. I had made a few changes over the winter but I think we found a BIG HP loss today!

Next crank is going to be a BBC snout.