Can anyone tell me if these are S&S pistons? I can't find any mark except the .030.

I went to order rings but they're different on the S&S than other big-bore pistons.

 

Probably not.. SnS does not mark oversize on the tops of the pistons.. The vibra-etch it in the bottom near the piston boss. At least that the way they been doing it for the last 20 years on the pistons I've seen/used..

You might want to include year and model HD (shovel?).. Size of piston also.. You might be able to get a ring set from Hastings.

 

they are just cast,OEM type aftermarket pistons.drag,cci,midwest,mid usa will all have rings,measure to see if its 74" or 80" & I can get you a part #

 

S&S does not stamp those in that location, not even back in the TRW days.
Scott

 

Bugger! I called the previous owner. He assured me that they're S&S pistons. There's only one Hastings ring set for big-bore, .030" over rings for S&S so I ordered them. Maybe they'll match up anyway.

 

when you say "big bore",have you measured these?? I don't know of any cast,aftermarket 3.625" pistons (BTW,.030 isn't considered big bore)if they measure around 3.467",their 74" (.030 over),if the measure around 3.530",their 80" (.030 over) and if they measure around 3.655",their 3 5/8 big bore (.030),but im really doubting their 3 5/8

 

I dropped the jugs off at the machine shop for honing. I asked them to verify my measurements because my bore gauge is kind of cheap. He checked them at 3.657". That's both cylinders, top and bottom. You could still see the hone marks from the previous build less than 1,200 miles before. I had measured 3.665". It's a good thing I asked. 0.008" is substantial.

Big-bore is 3-5/8" or 3.625". Thirty over would be 3.655" so I"m pretty sure that's what I have.

The bike is a 1983 FXWG with the S&S stroker kit. The jugs are Zodiac Enterprises Limited. It took me a while to identify those.

This is my first HD experience so I'm a little fuzzy on terminology. I just recently learned that the oil reservoir is a "bag" not a tank.

 

I called S&S tech. He agreed that they generally stamp the overage on the bottom inside of the piston. He also told me that I should be able to find a part number. I couldn't see anything, even with a little flashlight. Then I tried taking pictures. This was kind of amazing:

 

Wow,those are some very old pistons

 

Frank, the previous owner, put a Phase 3 primary on it. As near as I can figure, that company sold out in the early '80's. The transmission is a '91 5-speed. It was several years in the making and it sat for nearly 20 years until I got it. I believe this is what's commonly called a "barn-find."