TexasTZ wrote:Where are you guys finding these pistons???

PLEASE someone share this info!

To be honest they are about as common as the original " hens teeth" and 'kin expensive if you do manage to find a set.

To the best of my knowledge.......

There were a few sets of cosworth made, over size pistons floating around a few years ago thanks to Mike Normans work (have a read here http://mngforce.typepad.com/nc450vdev/p ... ution.html) but there were not many and I suspect all are now in use.

JE did a (I think) +2mm over size piston making it a 433cc. Not sure if they still do them as I seem to remember they utilized the oversize rings from FZR400s ....which dried up (anyone please feel free to jump in and correct me here) plus, apparently, due to them being a bit heavier they put a lot of strain on the big ends / crank.

I am not sure what James has managed to find but the ones I got hold of we're allegedly a further development in Mike Norman piston design that he got manufactured by Omega pistons here in the UK complete with bespoke rings etc. The story there after seems a little fuzzy but I think a few extra sets were knocked out after Mikes order was fulfilled, that then came out of the back door of the factory and leached onto the market.

To be honest it is a lot quicker, easier and cheaper to just swap a tired engine for a replacement item. However, if you want to wring every bit of power out of an engine, or just want to do a total refurb on your old engine ( like me), you need to be in the right place at the right time ....and unfortunately have very deep pockets

TexasTZ wrote:Where are you guys finding these pistons???

PLEASE someone share this info!

Rumor has it that you can still buy the Omegas. Didn't realize they did a +1(414) in addition to the +2(428) oversize. I believe they require a minimum of 3 sets to have them made.

Since you're in the U.S., get a hold of Mike Norman and see if he is going to be placing an order soon. I may need a set as well if I can't salvage the cylinders in my cases.

NGneer wrote:
To be honest it is a lot quicker, easier and cheaper to just swap a tired engine for a replacement item.

Not for us US guys unfortunately. Shipping an engine from the UK(where most seem to be) is usually more expensive than buying the engine itself. On top of that you have no idea what you're getting until it shows up at your front door.

james66 wrote:Hi all

I need a set of crankcases bored for my +1mm pistons in the new engine im building
Does anyone know of any companies that are able to do the job properly + straight apart from tts?

Cheers
James

James,

Have you tried Southern Rebore Services? I have used them for other work, and they are reliable. Not too far from you either...

http://www.southern-rebore.co.uk/

kostritzer wrote:

NGneer wrote:
To be honest it is a lot quicker, easier and cheaper to just swap a tired engine for a replacement item.

Not for us US guys unfortunately. Shipping an engine from the UK(where most seem to be) is usually more expensive than buying the engine itself. On top of that you have no idea what you're getting until it shows up at your front door.

You can also buy engines from Japan too, with the yen being weak at the moment it's probably your cheaper option as the pound is quite strong.

I think the omegas were around 800 pounds, would be nice to start a group buy at some point.

krisztian_andre wrote:I think the omegas were around 800 pounds, would be nice to start a group buy at some point.

I think this has been tried. Way back - Mark (Csmj1) tried to organise a group buy and had all the people lined up, only to be let down (fobbed off) by Omega in the end.....if I remember correctly


[Edit] - I found my original post from when I was searching for oversize pistons (before I got hold of my Omegas) and this is a copy / past from that thread with some good gen...

"Mark (CMSMJ1) – started to organise a group buy of +1mm/+2mm from Omega/Accralite a couple of years ago (viewtopic.php?f=22&t=15106) but unfortunately that never seemed to come to fruition – Notably due to the company and not the collective 400GB will to get some oversize pistons made.

The only other options I am aware of to refresh the bores/pistons are:

Either the JE 433 big bore kit for (Approximately a +2.5mm bore, I think)

Or the beautiful, if expensive and rarely available, Cosworth Piston option utilizing +1 oversize FZR rings through G-force performance – Fair warning, this link contains engineering pornography - (viewtopic.php?f=22&t=7610)"