Oversize Pistons

[Mark Halligan]

Hi!

Think there is some debate about the OE fitment whether it was Mahle or KS or a bit of both. I have heard that German companies had to source stuff from different suppliers.
Perhaps those who have paid close attention can tell us.

Hi Robin

I think Steve H or Aelred know the answer to this one, I think I remember Steve telling me about the differences between the KS and Mahle pistons that he saw.

[Doug_RS2]

i know someone who has 528 bhp rs 500 cossie and he said he uses audi rs2 pistons

The problem with those are you have to have standard bore (which is no use when you have scored bores) or you buy new oversized ones from mahle that are approx 800 GBP a set - if you are going for big power you should be going for lower compression anyway.

My JE pistons still had the sharp edge on them and I just pulled them and they are fine.

The cosworth pistons sound intersting.

[CR500Dom]

The Cosworth pistons are not YB (Sierra Cosworth) pistons.

They are custom forged pistons to whatever spec you want and whatever Diameter.

You can have fully forged or the latest F1 type Slipper pistons, they are designed to suit the application Be that a NA screamer or a 3 bar boosted Turbo alky motor

Have a look on the site and see the detail they go into on the piston enquiry page
Seriously, I put JE pistons in My Ducati before I did some work at cosworth and realised the extent of the piston catalogue they have, for instance, for my Engine, they had drawings and designs for 8 different pistons supplied to different tuners specs

Quality between Cosworth and JE....... I fitted JE and was happy with them, but next time I would go with Cosworth no question.... the quality really is second to none

HTH
Dom

[Rsmotor]

what about wiseco pistons? i`m going to use those for my 550 bhp application with
8,5-1 comp

[Billman]

I whant someone to built me pistons in order to use them with a Diesel Block and Crank, Long Sten Parner Rods with 23mm for pin, 8.5 : 1 CR and so that they dont interfear with the valves in case of a belt problem! Who can tell me what should i tell the manufacturer??

[Jon441cc]

The Cosworth pistons are not YB (Sierra Cosworth) pistons.

They are custom forged pistons to whatever spec you want and whatever Diameter.

You can have fully forged or the latest F1 type Slipper pistons, they are designed to suit the application Be that a NA screamer or a 3 bar boosted Turbo alky motor

Have a look on the site and see the detail they go into on the piston enquiry page
Seriously, I put JE pistons in My Ducati before I did some work at cosworth and realised the extent of the piston catalogue they have, for instance, for my Engine, they had drawings and designs for 8 different pistons supplied to different tuners specs

Quality between Cosworth and JE....... I fitted JE and was happy with them, but next time I would go with Cosworth no question.... the quality really is second to none

HTH
Dom

I've just had a look on the cosworth website about there custom pistons + perforance parts and i can't get over the quality, when i take the plunge and have my ABY rebuilt i'm going to Seriously consider the cosworth pistons, Like you say Dom i can't believe anyone hasn't gone with them already must be because there associated with Ford


''all customer pistons go through the same shop as the F1 pistons''

[Billman]

Actually now, Cosworth belogs to Audi! Did till the beginning of 2005 at least!

And how much does these Cosworth cost?? How much does the Rods cost also??

[Jon441cc]

I am amazed no one has talked to Cosworth

Not that they advertise the fact but they probably have a fully forged piston for the 5 pot already.

If not they can do you whatever you want.....

Minimum order size is 8 pistons normally so 2 sets and you could have a fully forged F1 spec slipper piston for whatever C/R you need..... and the best bit is, they normally work out about £80-£100 a peice with rings

Seriously, some of you big HP guys should talk to them, Having worked there and got to know the Piston guy Julian very well, I can honestly say, you will not buy better quality pistons anywhere, and all customer pistons go through the same shop as the F1 pistons They do Pistons for Jun in Japan and their mega HP Skylines and Evos, Race bikes, cars, MXers, etc they have Forge tools for pretty much any incremental bore size you could wish for as well

https://www.cosworth.com

You wont regret it
HTH
Dom

Actually now, Cosworth belogs to Audi! Did till the beginning of 2005 at least!

And how much does these Cosworth cost?? How much does the Rods cost also??

Oh really Dom said the custom pistons should cost around £100 each including the rings. Not sure about the rods

[CR500Dom]

Cosworth dont belong to Audi and never have...

Cosworth Technology was owned by Audi, which was the Road car/OEM side of the business. It was they who designed and developed the RS6
This was sold to Mahle last year and is now called Mahle Technology

Good company to work for, I have been lucky enough on 2 occasions so far.

Cosworth Racing was owned by Ford, but was sold to Forsythe about the same time as Cos tech was sold.
This is now just Cosworth.
Cosworth do the Customer Race engines, F1/ Indy/CArt/WRC engines as well Pistons.
They also do the new Duratech engines for Caterham.
I worked on that project, doing the Inlet manifold and engine installation, which is how I came to be sat next to Julian and his Desktop stack of Pistons

They were looking at doing Forged rods and Cranks too, they certainly have the Machinery for this, as they do it on the race engines.
I think Duratech rods are listed at £600 set or something, so presumably they have started doing them.

I dont have the facilities, but someone like Doug, Lee or Mihnea should talk to them.
If you had 3 or 4 sets done it would be very cost effective

They dont advertise what they do, their policy is to wait untill someone wants something, rather than telling the world whats available from their back catalogue

You would be amazed if you knew what they had pistons for, and what is currently running with Cosworth pistons in it

No affiliation other than an engineer who has worked there and seen what they do, I would always go back there as a customer now
HTH
Dom

[ridgeracer]

didnt Cosworth do much of the work on the V6 2.7 RS4 engine also ?

[Billman]

i think they designed the Heads!

[CR500Dom]

Cosworth Technology WAS owned by Audi.

They did most of the recent VW/Audi petrol engines

5 cylinder VR5 replacement
V10 Gallardo
V6 and V8
RS4
RS6 was done completely in house

Not the same company that does the pistons though
They are next door and share a carpark though thats as far as it goes for collaboration

[auditude]

I whant someone to built me pistons in order to use them with a Diesel Block and Crank, Long Sten Parner Rods with 23mm for pin, 8.5 : 1 CR and so that they dont interfear with the valves in case of a belt problem! Who can tell me what should i tell the manufacturer??

Sounds good. I'll take 5 of those as well. Maybe without the non-interference requirement for me, if it would increase the potential for detonation. Should we get them a conservative overbore while we're doing it?

[Billman]

Sounds good. I'll take 5 of those as well. Maybe without the non-interference requirement for me, if it would increase the potential for detonation. Should we get them a conservative overbore while we're doing it?

The non-interferenece thing has nothing to do with detonation! The CR has to do!
Thing is, who can provide us this info??

[CR500Dom]

You will have to Draw it out and do the Maths

If you have everything there you just need to measure it properly