850 Pistons (again)

[gs.davies]

On my quest for a set of 850 Pistons that don't cost the earth I've turned up these. Does anyone know anything about them?

"I can supply you with 848cc pistons @ any size:

STD
+20
+30
+40
+60

The pistons are original fitment, 5 ring type, dished top, pinch bolt fit, 8.3:1 or 9.1:1 compression ratio versions."

I have asked for part numbers but I was unaware that there was a 9.1:1 850 piston..

[251 ENG]

Who is the manufacturer of these ?

[Spider]

I have a couple of suppliers for new after market 850 pistons, only 4 ring types though and in all the standard oversizes up to +0.060", however they are listed as 8.3:1 types.

I've also just looked across a variety of factory info (Metro and ST) re: the 9.1's and I can't find any reference to them. These do have me curious.

[Gareth Brandt]

8.9:1 for 8AH engine.......is this the automatic?

[Spider]

8.9:1 for 8AH engine.......is this the automatic?

Yes it is. I didn't think of looking there, we never had 850 Auto's here, only 998's.

Could be the higher comp pistons though.

[Macker2]

Are they something like these County Pistons that I got from Paul at Engine Tekniks in Westhoughton.

viewtopic.php?f=3&t=11989

I have them in my 850 but haven't fired it up yet.
Macker

[gs.davies]

I've asked for the part numbers - I already have 15037s at plus 40 in it. They're all showing stress fractures around the pin though.

It's either these which are on offer at a great price (compared to how much they're usually going for) or I build an 1100 and have some proper fun!

[nick rogers]

After discussions at Blyton, I wanted to let folks know that I have several sets of 15037's at different oversize. I will sort them out and photograph them and stick them on the For Sale section.