360 sidepipe pistons

[tony27]

Are pistons available for 360s? I know OTZ has rings in 80, 80.25, 80.5 & 80.75 but don't show 360 pistons
Any possible sources that people can suggest?
Not sure what size bore the bike I have coming is but if possible I would prefer to keep it as a 360 rather than open it out to 380 when I rebuild the engine

[tony27]

Got the motor apart & the bore looks good so the piston or rings at minimum I need are 80.91mm for a 81mm bore. Piston appears to be a Kolbenschmidt

[tony27]

Was able to get the rings off the piston by sliding a feeler gauge under the end of the ring & sliding it as far around as possible, I then tapped the ring where it was clear of the groove with a lump of copper to help pull the ring clear of the groove on the other side of the feeler gauge, I then moved the feeler gauge further around & repeated, took about half an hour to get both out & the grooves clean. Need to see what the end gap is before deciding on whether to try & source a new piston kit or have the cylinder bored out to 82mm

[ralph311]

Not much help I know but my suggestion is contact OTZ and ask him if he has what you want. Guys like that have tons of stuff that never gets listed on the website simply because they've got better things to do.

[tony27]

Contacted Piotr when I first took the top end off & he wasn't able to help, probably going to have to ask Bertus if he has 1

[tony27]

Gerard Copping from CZStuff mentioned he had a 80.91mm piston kit which he sold me for a really good price. From what I understand it is a early Kolbenschmidt due to it having 2 cast iron dykes rings
The cylinder had been bored to use a used piston & needed to be honed out .05mm for the new piston, it has cleaned up nicely

[tony27]

Cylinder is back from honing to finished size & vapourblasting. Sanding & polishing the sidecovers at the moment, should be able to finish assembling the motor during the week & try to find what went wrong with the hybrid Suzuki ignition

Have 1 piece aluminium seal holders on both sides of the crank & will be picking up the clutch hub that I've had modified to help with the leakage problem that CZs are known for, will be interesting to see if it works

[FAT-TOY]

 
   Tony did you make your own alloy seal holders or buy them?   I am interested in making a set for my side piper, but I'd like to see a couple of photos before I start, to get an idea of the thickness etc and the size of the O ring used.
   I purchased an electronic ignition from Europe a while back and hope to fit it in the next week or so, along with a set of crank seals.  Hopefully I can make the seal holders while the motor is pulled down
               cheers mate.   Zane

[tony27]

I bought the ignition side holder this time from DIYvintagemoto but have the drawing from the motor in the background somewhere but I'll need to take a photo & upload it
This is the drawing for the clutch side holder, you'll need to measure what the distance is down to the bearing & make to suit. The original holders measure about 0.5mm more than will fit so they must sit proud & cause the steel plate to bend a bit.
O-ring size could easily be 3mm section, may make it easier to source in viton. Position isn't critical but groove dimensions are as the o-ring does the centering in the bore as well as sealing, I've done it like this so it comes out easier when needed but the OD would probably work at 51.90mm just as well


Just found the drawing for the ignition side, the DIYvintagemoto version doesn't have a o-ring & isn't radiused either which is just a looks thing. I'm just using the gasket out of the cometic gasket set on the sidepipe with sealant on the motor side of it

At the bottom of this drawing is the later type drain plug with the fine threads, I had a few made at the same time because they are something I haven't seen for sale & at least 1 of mine was heavily damaged from the wrong size socket of possibly adjustable spanner used previously

[OverTheHill]

Tony who do you use locally for boring or honing nowdays. Just handy info to have i'm that out of touch. Thanks Morley.
ps, jeez your Z's run big clearances or are my maths up the creek just doing it in my head--0.09mm clearance [3.6 thou], mind you most of ;my' jap stuff is probably looser lol. I'm still live in the couple of thou times but different piston material different clearances i suppose--like seizco which rattled till warmed up in my yam360 but then quietened & went for years with recommended double yam clearance by memory.

[FAT-TOY]

Thanks Tony, thats just what I wanted. Now to make time to get it all done.
   Cheers Zane

[tony27]

Morley, I normally use Phil at the engine rebuilders on west street. It doesn't seem to matter if the piston is cast of forged in the big CZ motors, they all run 0.09mm clearance on the 80-84mm bores
Glad to be of help Zane, actually thought the original drawings I'd done were lost so I've now taken photos just in case

Guess where I've been today

The original plastic fantastic F1 Suzuki, I found out today that there were 4 built with 1 being a road bike. There was only 1 of the aluminium monoque bikes built before that though