Hi all!

I have a 1970 Fiat 850 sports coupe that I have been attempting to rebuild in the last year. This is my first rebuild, so its quite the learning process! I had my engine resleeved/bored/honed to +1.0mm oversize (to make it 66mm) to fit the pistons/ring set that I had purchased (brand was kolbenschmidt.) This was all well and good, the pistons fit like a glove, so I compressed the piston rings, and slotted them into the cylinders assuming that the rings would have previously been cut to roughly the right size for the cylinder. You know what they say about assuming, so I broke two rings because the rings were too tight. So now I need new rings, but the piston/ring set that I purchased is not a standard size, and I cannot find the correct sized rings anywhere.

Does anyone have any idea at all about where you could purchase 65 +1.0mm rings for a 903cc 100 GBC.000 engine?

Cheers for looking

Not sure what country you reside in Maxie but I would concentrate on eBay. USA eBay probably. There are these in Australia. http://www.ebay.com.au/itm/271261936855?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

I'm in Australia (Adelaide) and these are the right rings, but they are just the standard diameter (65mm) whereas I'm looking for the 66mm . This is the dilemma that has been plaguing the rebuild for the last few months; they just can't be sourced from anywhere. The largest that I can find are 65.6mm.

Do you think that the 65.6mm would be too small to use? I'm unsure of whether you have to trim them that much the ensure that the ring gaps are up to standard

Maxie I noticed the flag after I posted. There has to be rings available in that size. The same engine is still in production in other cars like the Yugo 45/Zastava Koral etc. If you use Facebook I would suggest joining the "Fiat 850 Community". This is a fairly active page with a lot of Europeans and some Argentinians etc. The Seat 850 also has the same engine. Ask for info on that page.

Maxie,
You might like to contact Chris Obert in the USA. This is from the yahoo forum.
Hard to find engine parts back in stock
Posted by: [email protected]
Date: Fri Dec 5, 2014 6:00 pm ((PST))


Please note that this is a posting from a vendor.

I recently got a shipment in that was full of hard to find pistons and bearings for 850s.
65 mm flat top pistons in standard, and oversizes in 0.4 mm, 0.6 mm, 0.8 mm, & 1.0 mm
Early main bearings up to block #2103165 in standard, and undersizes in 0.010", 0.020", 0.030", & 0.040"
Late 903 cc main bearings after #2103166 in standard, and undersizes in 0.010", 0.020", 0.030", 0.040", 0.050" & 0.060"
Rod bearings in standard, and undersizes in 0.010", 0.020", 0.030", 0.040", 0.050" & 0.060"
Cam bushing sets in standard, and undersizes in 0.010", 0.020", 0.030", & 0.040"

Got a tired motor? Now you can't blame lack of availability of parts. But if you are like me, lack of time and money is what's going to hold you back.
I also stock most everything else you might need to maintain or restore your Fiat 850, or 850 based car.

Chris Obert

Yeah, That's the bloke I ended up going with, worked a treat as well. The engine is all back together, going to put it back in the shell today. Wish me luck!