HarleyTechTalk

Does anyone know the rod length on one of these cranks?

What year?  If you search your thread title on here you will find quiet a few discussions.

I believe he's looking for the Milwaukee 8 SE 4.625 flywheels. TC SE 4.625 wheels had 7.575" rods.

Quote from: rigidthumper on November 07, 2023, 09:02:30 AMI believe he's looking for the Milwaukee 8 SE 4.625 flywheels

Yes, that's the info I am looking for.

    I should have realized that as it is posted in the M8 page.

SE catalog shows the same 4.310" cylinders for the 128 (4.375" stroke), 131 (4.5" stroke), and 135 (4.625" stroke) engines, but different pistons: so it would make sense that since they changed the pin height from 1.143" for 128 pistons, to 1.080" for 131 pistons, they would change the pin height to 1.018" for the 135 pistons. Anybody have a set of 135 pistons they can measure (#21900164)?

S&S instructions 510-0727 04-20-2020 state that their 4 5/8 m8 flywheels have 7.953 length rods.

Ok, so if we look at a piston with 1.080" compression height, rod length of 7.953, cylinder length of 4.840, 4-5/8 stroke, 0.020 thick base gasket, we get an estimated piston depth in the cylinder of 0.015. So that all seems to be very possible. As Rigidthumper said, a measure of the 135" piston would help nail down the setup info.

Quote from: hrdtail78 on November 12, 2023, 04:58:18 AMS&S instructions 510-0727 04-20-2020 state that their 4 5/8 m8 flywheels have 7.953 length rods.

Yes. But to use those wheels without S&S pistons require a change to the longer OE M8 rods.
If the SE wheels have the 8.10" rods that would take that move out of the equation.
As Robin and Bryan said, compression height of the 135 pistons would help answer the question.

Thanks guys, and if anyone finds out let me know.

I would doubt if this were not a direct replacement.   But IDK.  Call S&S.

You may very well have it Jason. I didn't think to use a 0.010" base gasket. That gets the pistons to 0.005" in the hole based on 1.080" piston compression height and the 7.953" rod length.


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Quote from: Durwood on November 08, 2023, 08:40:05 AM

Quote from: rigidthumper on November 07, 2023, 09:02:30 AMI believe he's looking for the Milwaukee 8 SE 4.625 flywheels

Yes, that's the info I am looking for.

As per GRC and Suburban Speed, the Milwaukee 8 SE 4.625 flywheel rod length is 8.015.
GRC had one disassembled when I called asking about it and measured them.

The Suburban Speed, Man O' War 135 kit, includes H-beam Carrillo rods.