madcossy

has anyone had woosner pistons fitted in a cosworth and did they still get piston slap from cold

JTECH James

iTrader: (13)

they are crap mate,

they change shape after a few miles...

madcossy

what pistons would you recomend

Dicko&Vacant

iTrader: (3)

i had them mate lasted 5k miles and died

so as above they are shite

JTECH James

iTrader: (13)

im having cp ones made, but je, cosworth, or the good old mahle if your not going for big power...

jacko

dicko what was the tolarence you had on them

madcossy

im only running 420 just dont like piston slap do you know how much the je pistons are mate

JTECH James

iTrader: (13)

i think they are generally around 600 ish, all the good ones seem a similar price

Nash

iTrader: (3)

I have Wossners in mine, and the car developed piston slap after around 3k miles. This got worse and worse and when i took the car off the road it sounded like a tank on start up untill it was warm, even when warm you could still hear it a little bit.

Jay,

iTrader: (4)

je pistons are 480 a set

Nash

iTrader: (3)

Is that direct Jay?

Jay,

iTrader: (4)

yes mate no point in paying inflated prices if you can build your own engine

Nash

iTrader: (3)

Cool cheers mate

m_nettleship

i had woosner pistons fine with me, but depends whos built it i suppose.

Turbo Zetec

iTrader: (1)

its nothing to do with who builds it, its the materials or machining of the pistons... we had a harley engine in at work wich had them fitted and one had shrunk 4 thou!

jacko

they are suposed to have 4 thou clearance when setup

simon170

Just of interest, do forged pistons come with a guidence of what the bore gap should be at the time of install (during break in) and what they should be once broken in?

Was told this and not sure if it was true...

Thanks.

jacko

wossner specify a 4 thou gap for install

Nash

iTrader: (3)

Wossner told me what to get my block bored to and said to follow this exactly. I did the engine was fine untill about the 3k mark when it started to get piston slap, this has gradually got worse the more i drop the car.

Now if an engine is built wrong the slap would be there from day one, not appear 3k miles down the road. There have been to many people running Wossners and have had the same problems to blame it on the people who built the engines, Like has allready been said they shrink.

Dicko&Vacant

iTrader: (3)

mine was exactly the same mate

Jacko - mine was done to the bore tolerances stated with the pistons.

Turbo Zetec

iTrader: (1)

i didn't say it had 4 thou clearance, i said it had shrunk 4 thou... which would then mean 8 thou clearance

RWD Pete

Bought some genuine cosworth low comps for Ł620 and they appear to befine, makes sense buying pistons from the original engine designers eh?

JTECH James

iTrader: (13)

yeah....and there oil pumps eh

Dicko&Vacant

iTrader: (3)

pmsl. Actually that could well have been another contributing cause to my engine failure,the brand new cosworth oil pump i bought

RWD Pete

shit better take them out

JTECH James

iTrader: (13)

just hope they had a "good" day when they made yours....

tbh, you must be on a winner, if it had been a "bad" day, they probably wouldnt have fitted down a round bore

RWD Pete

Theres always that but then my local machine shop has a square boring machine according to some folk

JTECH James

iTrader: (13)

that may be a good match then

simon170

Glad I read this, nearly bought a set!

pa_sjo

So i'm assuming that all these people that have measured 'shrunk' pistons did so in identical conditions, with the pistons at exactly the same temperature before and after?

And that whoever built the engine acclimatised the block with the pistons for the measurements & machining? (including actually measuring the piston to bore the block, rather than bore the block to a given size without measuring)?

m_nettleship

hmmm, but i also no hundreds of engines with these pistons and all good.

pa_sjo

Exactly.. nothing like a bandwagon eh.

TiB

iTrader: (1)

Just go for 4x4 mahles.. absolutely fine to over 500bhp...

Just get your machine shop to adjust them to the correct compression ratio (assuming your running 2wd engine now)..

Buy the pistons, measure them, THEN get the block bored to the manufacturers stated clearence (2thou from memory) and get them to check it all with you there as it appears not many machine shops can get tollerences dead right

Mike Rainbird

iTrader: (3)

Mark Shead, Martin at Reyland, Harvey at SCS, Tomas at TG Racing and myself all use CP pistons, I think that is all you need to know...

johnnycos

Bummer i've got these in my engine done 1300 miles so far and not had a problem YET!!!!Lets hope it stays that way, also built the engine myself!!!

madcossy

have you hadit tuned yet mine were quiet until i done running in miles and had it tuned

madcossy

where can i get cp pistons and how much do they cost

johnnycos

Nah not had it tuned yet, still in 2 mind weather or not to go with the greys(already have) or go with the greens now!!!!

Mike Rainbird

iTrader: (3)

Any of the above places. Cost depends on spec, as they can build them to your exact requirements, but let me know what you want, and I can price them up for you. Normal sizes / cr are kept in stock.

m_nettleship

I would also go 4 these mike says, All im saying is woosner pistons didnt give me any trouble and no other cars i no.