Parts

[wyatt emp]

Need a set of JD STD pistons, rings, and wrist pins. Any sugestions?

[Chris Haynes]

I'd like to know where you found Std. bore cylinders.

[harleytoprock]

I used Harley flathead pistons made by Eastern MC in my 27JD. You can't get them from Chuck's kickstart.

[harleytoprock]

I should also mention that the skirts on the Harley flathead pistons were a little too long and hit the crankcase baffles. You can trim the bottom of the pistons. In my case the baffles were pretty broke up so I just removed the remaining baffle reminants. I used the cast iron oil control rings that came with the pistons and it runs great.

[gww]

afternoon, may try Eastern M/C Parts in Blackville S.C. or V-Twin in NY
taiwan made UL pistons that you ll need to trim 150 thou. off the bottoms. then you ll need to decide whether or not to run the expander ring under the oil ring. good luck.

[wyatt emp]

It's a mutt. Cant find a frame # under all the paint. The gear side case is a 26 and the sproket side is a 27, so I guess motor parts from 26 to 28 will all fit?

[wyatt emp]

What are the pros and cons on the expander?

[harleytoprock]

The expander is a good thing. It helps support the piston to prevent rocking in the bore. A taper ground piston gets its support at the bottom front and rear. The expander helps central the piston at the top. No real cons with the expander.

[Steve Slocombe]

Yes the JD, VL, VLH and ULH all had 3.422" original standard bore so the same pistons can be made to fit all these models. Harley called these 3 7/16" bore and the repro piston manufacturers then made theirs to this exact size, so they come out 0.0155" bigger than the Harley originals.