Piston parts

[single-junk]

Not to familiar with the whole vintage Ducati parts scene yet..

Is there a good parts supplier available for piston rings, wrist pins, and clips?

Thanks

[ajleone]

Yes there is. Nigel Lacey:
http://www.laceyducati.com/ducati-parts/

Tony

[single-junk]

Thanks.. pretty incredible selection of parts!

[single-junk]

Been busy, so I finally got back to this..

Looking at the rings for sale, I keep seeing multiple sizes.. eg. 74.6mm, 74.8mm, 75.0mm

As I'm doing pretty much a stock engine rebuild, and my piston has 74.25 stamped on it, I'm assuming that's the size I'm going for right? (I'm thinking the rings are sized by the piston and not by the sleeve)

Sorry if this is a dumb question (kind of a newbie here) Is that corrrect?

Also, the clips for a 4 ring 250 piston are the 18mm x 1.5mm clips correct?


Thanks

[DewCatTea-Bob]

[quote= single-junk ...
" Looking at the rings for sale, I keep seeing multiple sizes.. eg. 74.6mm, 74.8mm, 75.0mm "

____ Those piston-sizes are same as Borgo-brand sizes, (which is the stock-brand that Ducati employed), and represent the 2nd; 3rd & 4th -(maximum Borgo) over-sized 250-pistion.



" my piston has 74.25 stamped on it, "

____ That is-not a std.Borgo-size, and is the 1st.oversize for piston-brands such as Asso.
(I still have that particular size of ring-sets in stock.)



" I'm assuming that's the size I'm going for right? "

____ Indeed so.
However if your 74.25mm ring-gap happens to be too-large outside of spec (within your cyl.bore), then the option of resizing a 74.4 or 74.5mm ring-set to better fit your cyl.sleeve-bore, is a possible solution.



" (I'm thinking the rings are sized by the piston and not by the sleeve) "

____ Those two fitment-concerns ought-to be the same, however it is the ring-gap which really matters most importantly, and therefore the p.rings should be sized for the cyl.bore -(sleeve-ID).



" the clips for a 4 ring 250 piston are the 18mm x 1.5mm clips correct? "

____ Seems right.
__ Also, the rings for a 4-ring piston ought-to be 2mm-thick for the comp.rings and 2.5mm thick for the two oil-rings.


Duke-Cheers,
-Bob

[LaceyDucati]

As Bob said, most likely it's an Asso Piston with that size and being four ring.

Only thing I would add is to check the ring grooves as often this is over looked. Had quite a few customers over the years trying to re ring worn out pistons

Ring side clearance should be 2 or 3 thou, if you've got 5 thou or more (with new rings) it's time for a new piston.

Circlips for all 175/200/250/350 original Borgo pistons (and Asso after market) are 18mm x 1.5mm. If there is no small slot in the pin bore leading to the groove you will need clips with ears or an ear to allow removal. You can of course carefully add a groove if all you can get plain type clips.

Regards Nigel

[single-junk]

As Bob said, most likely it's an Asso Piston with that size and being four ring.

Only thing I would add is to check the ring grooves as often this is over looked. Had quite a few customers over the years trying to re ring worn out pistons

Ring side clearance should be 2 or 3 thou, if you've got 5 thou or more (with new rings) it's time for a new piston.

Circlips for all 175/200/250/350 original Borgo pistons (and Asso after market) are 18mm x 1.5mm. If there is no small slot in the pin bore leading to the groove you will need clips with ears or an ear to allow removal. You can of course carefully add a groove if all you can get plain type clips.

Regards Nigel

Definitely an Asso, stamped next to the size.. didn't realize that was an after-market brand; good to know. So those rings are still available?

I'm presented me with another problem.. When I bought my 2 250's and my 160, someone had pulled the top end of each 250 engine apart, beat the hell out of one of the pistons with a hammer, and lost the rings and clips for both I've got to double-check to see if both pistons are the same; hopefully they are, saves me the pain in the a$$ finding out which piston belongs to which engine. Both are four ring pistons, so that gives me some hope.

[DewCatTea-Bob]

[quote= single-junk ...
" So those rings are still available? "

____ Seems that you must've overlooked MY previous post (above) !?
__ I also have a selection of NOS.ASSO-pistons left as well.



" someone had pulled the top end of each 250 engine apart,
I've got to double-check to see if both pistons are the same; hopefully they are, saves me the
finding out which piston belongs to which engine. Both are four ring pistons, "

____ Chances are that your other piston is made by the Borgo-brand.
__ Are both your 250-engines Monza or Scrambler models ?


Duke-Cheers,
-Bob

[Jordan]

Don't chuck 'em out.
I'm happy to receive any Ducati piston with worn ring grooves, as long as the skirt is serviceable.

[DewCatTea-Bob]

[quote= Jordan ...
" Don't chuck 'em out. "

____ I-myself have never thrown-away a used-piston that wasn't obviously damaged too much to be possibly used again. _ Thus I've accumulated a couple of dozen 250/350 examples, (mostly Borgo).


Duke-Cheers,
-Bob