Need oversize pistons for my CSL

[Wes]

So after a trip to the engine works turns out my CSL motor will need a re-bore and oversize pistons as the clearance is presently 10k of an inch (speck is 2k of an inch).
Seem to remember somebody on here saying they had some oversize pistons kicking around they wanted to offload.

 

[m5bb]

I have a friend that has some Alpina pistons. Not sure of the size? What size will your new bore be and what do the top of your current pistons look like?
Flat or with dimples for valves. What compression are you expecting?
I have CP pistons in an S38 motor in my M5 that are 94mm. They are well made and readily available.

 

[Wes]

I don't know the diameter we will re-bore to yet as I need to find pistons first.
At present everything in my motor is factory specs with piano top pistons.

 

[tferrer]

If push comes to shove, J&E can make whatever size and features you want. Pretty popular in the porsche world. They've been at it for ever.

Home | JE Pistons

Shop Forged Racing Pistons AUTOMOTIVE Domestic, European, Sport Compact, Drag, Circle Track POWERSPORTS Dirt Bike, Street, UTV, ATV, V-Twin, Snowmobile Over

www.jepistons.com

 

[Wes]

Jaymic have also given me some options.

 

[HB Chris]

Euro coupes are 9.0:1 with piano tops, US got flat top 8.0:1.

 

[Wes]

Correct. So I need to source oversize piano tops..

 

[Marc-M]

Hello

I did post on the blog a few weeks ago about my pistons....
is cheaper to get them made that buy them .... a odd situation indeed.
i used
Performance Unlimited
3 Chessingham Park
Dunnington
York
North Yorkshire
YO19 5SE
England
Tel +44 (0) 1904 489332
Fax +44 (0) 1904 488355
www.performanceunlimited.co.uk

and they have done a lot of these - but i guess you will find someone in Austriala

copy of email

Hi Marc
We have your piston sample. We have supplied 5 sets of custom pistons for this engine in the past, 2 sets made at JE and 3 sets at CP. The dome on the CLS factory piston is a cast dome, i.e. not machined. The factory dome can not be accurately copied as the dome casting is not accurate and the cutters would have to be made to the dome contours. Below is a CAD model of the CP piston we have previously supplied. This piston can supplied for 90mm bore and have also supplied for 89.75mm bore

These pistons are £8xx + VAT with pins, locks and rings per 6cyl set. Lead time in manufacture at JE is 4 weeks, CP is 6 weeks. Skirt coating adds 1 week to the lead time.

If required add £1xx + VAT per 6cyl for skirt coating.

these are the pistons when they came

you can see the black coating on the skirt - these reduce any noise sound when cold, as forged have bigger clearance as they expand more when hot ( or so i have been told)

So you can get any size you wish......

hope it helps

Marc

 

[Wes]

This is very helpful.
So what did it actually cost for a new set? Am I reading it right at 800 pounds?

 

[tferrer]

If J&E made them then you can probably go directly to them. I would imagine they save the patterns for something like that.

 

[Marc-M]

This is very helpful.
So what did it actually cost for a new set? Am I reading it right at 800 pounds?

Hi - top end of £800.00 and mid £100s for the coating for all 6- you will probs have someone in Aus who will sell them...

Mine are CP

normal size is 89.22 - mine are 90 bore - but the do do 89.75....

these guys may help

CP Pistons Catalogue

Australian online store selling genuine Spool conrods, crankshafts and performance parts worldwide.

www.spoolimports.com

 

[Marc-M]

Hi - top end of £800.00 and mid £100s for the coating for all 6- you will probs have someone in Aus who will sell them...

normal size is 89.22 - mine are 90 bore - but the do do 89.75.... still only works out at £175 ish each... bargin!!!!!

 

[paul]

Wes....I had my pistons custom made by Ross in CA ........Race Max Direct in Sydney are the importers (cost $1465 Delivered) They were flat top though. I am not sure if they deal direct with the public....I actually had my engine re builder do all the negotiating.