Board index Flathead Power-Technical Questions, Answers, and Suggestions K-Models Early flywheels

Early flywheels

Moderators: Curt!, Pa

Post Wed Jun 15, 2011 1:00 pm

Posts: 67
I'm trying to true a set of early K Model press together flywheels, and I've got a problem with parallelism. The center shafts are .005" out, and the wedge/clamp/hammer technique produces no results. Is there a trick, or should I simply hit the wheels harder?

Post Wed Jun 15, 2011 1:35 pm
Pa Site Admin

Posts: 5806
Location: Ohio USA

Disassemble...look for burs and high spots and then lap the tapers in before assembly, then re-try truing them.

Post Thu Jun 16, 2011 5:29 am

Posts: 67
Early flywheels don't have tapers.

Post Thu Jun 16, 2011 6:53 am

Posts: 587
Location: Crewe, Great Britain

Hi Larry,

Wedge and hammer techniques won't work with parallel interference fits when they are fully seated... I seem to remember the K pin interference is around 6 thou. At 1 ton effort per thou, that's around 6 tons...

You'll need a holding fixture that will ensure crank wheels are dead parallel before pressing them on the last shaft. See some H-D alloy XR manuals for illustrations and adapt the technique to your K Model.

An early Iron Sportster crank, same stroke but tapers and nuts..., can be made to fit in the K cases, but some machining around the cam bore locations is required...

Patrick

Post Thu Jun 16, 2011 6:57 am
Pa Site Admin

Posts: 5806
Location: Ohio USA

Oops !! :oops: Shows how long it has been since I was into a K model bottom end. I still recomend checking for burs or distortion in the shafts or bores though, The amount of out of alignment points my opinion that direction.

Post Thu Jun 16, 2011 6:59 am
Pa Site Admin

Posts: 5806
Location: Ohio USA

Seems I replied just about the same time as you did Patrick. :lol: Great explanation Bro !! :D

Post Thu Jun 16, 2011 9:40 am

Posts: 67
Thank you both for the advice. The wheels were already assembled, limiting my choices. A steel wedge and a BFH brought the shafts to about .001". Next time I'll use a little less force and a little more finesse.


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