Ironhead crankshaft width ironhead

[daniel91]

What should be the width of the crankshaft? I have a lot of clearance on the connecting rod. In the photos, the pin is still unscrewed.

[kitabel]

the pin is still unscrewed

???????????

[daniel91]

I mean it is not tightened with the correct torque. After tightening, it can have a smaller width.

[Hopper]

You have to have the nuts tightened up to 150 ft lb and there should be .005 to .015" clearance between the rod end and the flywheel.

The wheels will come in some as you tighten the nuts up.

[thefrenchowl]

I measured 3 of my rear con rods' width, all between 1.490 and 1.492 which gives 8 to 10 thou less than 1"1/2.

By the time you tighten your crank nuts to the required torque, it should shrink your 1"533 width to 1"1/2 or there about...

Patrick

[daniel91]

Thanks for help. After tightening is still 0.9 mm of endplay. I checked on the new and the old pin. It's the same gap. I need extra thick washers. I wonder if wide crankshaft will fit into case without a problem. Modern motors with pressed pin require high accuracy. Repair manual always shows this value. Unfortunately not Harley. Probably that difference doesn't matter much. I recently repaired a ktm mx engine where 0.2mm washer caused crankshaft not rotate.

[Ferrous Head]

So, your at 0.035 " which is technically 0.020 " wide.

There are thrust washers on the flywheels and these may be worn. That would account for the extra width. If the se wheels came out of an engine and you replaced the big end bearing because it was shot/worn that would be a good explanation for worn thrust washers.
If that's the problem over all width won't be affected. That is, you won't have a problem when you check the crank end float.

[needspeed]

Originally Posted by daniel91

.. I wonder if wide crankshaft will fit into case without a problem. Modern motors with pressed pin require high accuracy. Repair manual always shows this value. Unfortunately not Harley. Probably that difference doesn't matter much. I recently repaired a ktm mx engine where 0.2mm washer caused crankshaft not rotate..

You should have no worries about fitting the crankshaft in the cases. The fit is not that precise. Comparing these old Harley flywheel assemblies to other engines and designs is just a cause for consternation.

The distance that the sprocket shaft is drawn into the taper in the left flywheel will also have an affect on the centering of the crank in the case. There's no specification in the manual for that. Just a torque value.

Are you rebuilding with the same rods and flywheels that came from a running engine?

[daniel91]

The flywheels and connecting rod come from different engines don't come from a running engine. That's why I wasn't sure if everything was ok. I'm preparing an emergency set of crankshaft and bearings. Once I rebuild my sportster crankshaft. I didn't think about it at the time. I know I could have done better. Now I have time and more knowledge. Old engines are full of surprises and details matter. Especially when you're trying to make something out of scrap metal.

[Iron Mike]

“Running” engines do not necessarily contain components that are still in “service wear limits”.
Sounds like you have a handle on things, but be sure to measure all components involved.