Board index Flathead Power-Technical Questions, Answers, and Suggestions General Whatever-Technical Reading Standard Crank Shaft

Reading Standard Crank Shaft

Pretty much anything not covered by the topics above. Short lived production bikes or vehicles, Electrical, Tires, Paint, Brakes, etc. Use this for tech questions, and "Shoot the Bull" for general conversation, no tech.
Post Sat May 27, 2017 6:14 am

Posts: 49
From what I've read. You have to consider the rev range, you are going to run in when choosing a balance factor. Up to 50% for race engines.. higher percentage for lugging street motors. That's my interpretation of it. Shoot me down if I am wrong.

Post Sat May 27, 2017 7:37 am

Posts: 3321
Location: Central Illinois, USA
Jack!

If you have the original wheels, rods, and at least a piston, pin and rings, then you can back-calculate the original factor.

Please remember that engine balancing isn't about running "smooth", its about keeping the motor from tearing itself apart.
And the means of holding it with the frame is critical to the choice of factor.

Many of us have lost a top motormount bolt, and sensed it by bad vibrations.
That's because the motor was suddenly out of balance for its frame!

Somewhere in the "Theory" section of http://virtualindian.org/1techflywheel.htm, Matt Elvenkemper explains that motors with a low balance factor vibrate up and down a lot, and vibrate fore and aft a little. So Sport Scouts enjoyed a much, much higher factor (82%) than Chiefs (64%) because of their support plates to their cases. VLs are reported as low as 46%, but OHVs often back-calculate to ~57%.

How is the Reading Standard held in its frame?

.....Cotten

Post Sat May 27, 2017 9:49 am

Posts: 116
Dusty, Thank you for the understandable explanation of the Indian balance method. I had read about it before in a description that went on for 2 pages & made little sense to me. I now see how simple it is.


Cotton & Indian 45, This will definitely be a low speed engine, probably used at a few shows & back roads. I do not see the Cannonball in my future!

I have the last used rods, wheels & piston assemblies but the pistons are aluminum & the rods have been drilled & lightened to the point they bent from the torque. There is evidence that the bike was raced at some point. The original pistons would have been cast iron. It does not look like the flywheels have been altered to suit. I feel that main bearing misalignment and/or poor balance led to the broken flywheel. I think reverse engineering the balance factor is probably not a sound idea on this one.
009.JPG


The engine has 4 mounting bolts on the crankcase & no upper mount. The engine also forms part of the frame structure.
005.JPG


Given the direction of vibration theory & the low speed engine theory, should I be aiming for a higher balance factor?

It would be possible to balance the individual wheels with the bob weight & balance factor method then check the assembly with the Indian method.

Jack
You do not have the required permissions to view the files attached to this post.

Post Sat May 27, 2017 10:35 am

Posts: 3321
Location: Central Illinois, USA
Its anybody's guess, Jack!

Total flymass is independent of factor, of course, but I would keep the flywheels 'beefy' if possible.

The extra mass dampens the internal push-and-pull;
Factor is very forgiving, with later machines, anyway. And they had much heavier flywheels than the "window" design.

....Cotten
PS: Remember the "Magnacycle"? Wonder what factor they used... Or should have!

Post Sat May 27, 2017 10:22 pm

Posts: 1200
Location: Ojo Caliente,NM,USA
Jack,
Sorry I been putting you off but I been off doing important stuff. Last day of Red River is Monday so I'll get down there Tuesday. Less of course Pablo hollers and says meet me at!
Heres proof I'm doing it on a Scout
Image
Cotten,
The Gorilla Glued Durable Float is still holding, I even quit carrying a spare this year.
Dusty

Post Sat May 27, 2017 10:22 pm

Posts: 1200
Location: Ojo Caliente,NM,USA
Jack,
Sorry I been putting you off but I been off doing important stuff. Last day of Red River is Monday so I'll get down there Tuesday. Less of course Pablo hollers and says meet me at!
Heres proof I'm doing it on a Scout
Image
Cotten,
The Gorilla Glued Durable Float is still holding, I even quit carrying a spare this year.
Dusty

Post Sun May 28, 2017 8:14 am

Posts: 116
Sure looks like a fun place to be - I wish it was about 1900 miles closer to here!

Jack

Post Tue May 30, 2017 7:26 pm

Posts: 1200
Location: Ojo Caliente,NM,USA
Jack,
I only have 1 27B181 retainer but i do have 50 Std rollers from Eastern. If you want them let me know.
Dusty

Post Tue May 30, 2017 10:44 pm

Posts: 116
Dusty,
I do need the rollers for sure. I will PM you on them.

The flywheels are now turned to size. I allowed a bit on width in case the saw ran & then the steel supplier allowed even more for the same reason. I have a very large quantity of blue swarf in my shop right now!

Jack
You do not have the required permissions to view the files attached to this post.

Post Wed May 31, 2017 2:48 pm
Pa Site Admin

Posts: 6055
Location: Ohio USA

You do nice work Jack !!

Post Sun Jun 04, 2017 12:30 am
GuS

Posts: 408
Location: Bergen, Norway
Agree!!, and please keep posting. Im exited to see the continuation of your project.
GuS

Post Sun Jun 04, 2017 6:40 pm

Posts: 116
Thank you for the encouragement.

Not too much progress other than the rod bearing question. I now have a NOS set of roller retainers & thanks to Dusty Dave, a set of known quality, standard rollers are on the way. The new style bearings I have look good but I can see the stamped retainers have many areas that could fracture if the metallurgy was not right on. More concerning is that the rollers vary about .0005 in diameter from smallest to largest. That does not sound like much but certainly not the best way to start out. I may have the races touched up on a Sunnen hone to make sure they are round as well.

002.JPG


Jack
You do not have the required permissions to view the files attached to this post.

Post Mon Jun 05, 2017 6:43 am

Posts: 3321
Location: Central Illinois, USA
Jack!

A half-thou is plenty enough error to cause premature failures, without a doubt.
I need to find my stock, measure them, and probably sort them for dedication to other applications.

A Sunnen can be rigged to line-hone the assembled cases by taking a worn-out stone holder, and affixing a nylon 'pad' to it.
It can then be ground to approximate the height of the other stone on a two-stone mandrel. That way you can cut only one side at at time, and swap the stone and pad to hone from the opposite side to avoid "bell-mouthing" or tapering.

This allows for one main to be different from the other, when necessary.

....Cotten
You do not have the required permissions to view the files attached to this post.

Post Fri Jun 09, 2017 9:18 pm

Posts: 1200
Location: Ojo Caliente,NM,USA
Jack,
Did the rollers get there?
Dave

Post Sat Jun 10, 2017 9:13 am

Posts: 116
Dave,

No sign of them yet, but the mail is often slow.

Thank you,
Jack

Post Thu Jun 22, 2017 6:40 pm

Posts: 116
Dave,

The rollers arrived today! They look great - thank you so much.
I can now go forward with all of the pieces in hand for the crankshaft.

Jack

Post Thu Jun 22, 2017 7:34 pm

Posts: 1200
Location: Ojo Caliente,NM,USA
Damn two weeks! At least I didn't have to find the tracking number, I remember putting it in a safe place.
Dusty

Previous

Return to General Whatever-Technical