Now this to me seemed strange...BUT i was told by a top tuner the other day that the std mahle (£400 a set) are superior to the genuine cossie Racing pistons (£800 a set)...not doubting the person...but can anyone tell me how this could possibly be?

 

I would say road pistons for road use, race pistons for race use

 

what application are the pistons for ?

 

Overall..any application.

 

i was informed differently yesterday by 2 tuners/builders

 

Either will always be slightly compromised then......fit the right parts for the application

 

Billy the point is if you are gonna run a piston in a high power engine and its a choice between the 2....std all the way....apparently


(Not my engine BTW!...)

 

every tuna is gona have there own opinion, i would rather have cossie racing

 

Its not to do with the superior strength in the Underside of the piston is it????????

 

Essex...yes so would i...because if it costs more then surely its better?...LOL.

Its one of them things that no matter WHO it was that told me i just couldnt beleive it

 

IIRC the main differences are noise and lifespan (after a certain amount of heat cycles - compare road to track for example), so again I say it depends on application and - what your expectationsare / what you find acceptable - for the potential drawbacks of either.....

e.g. if you accept that with a given spec you'll have to rebuild/freshen up every 10k and you're happy with that....

 

My genuine racing pistons are very quiet and assumed they were a harder material so were stronger and last longer if you had det

 

Why put up with det' to start with and proper det at high rev's - even the Cossie pistons aren't gonna last enough to save an expensive rebuild

 

cosworth forged pistons all the way

i bought mine straight from cosworth them selves and saved a shit load of money

if i remember rite have to find the reciept out and take a look but what a work of art they are compared to manure (mahle)



grp a forged 7.2.1 cr and very light

 

Phil, I was told exactly the same thing by a very well
known tuner/engine builder..........

i.e. That standard Mahle pistons are a better choice for a
big power road going/occasional track-day YB engine build.

I of course queeried this, and he gave me some sound/proven
reasons to back up this choice - but I have forgotton them

I think it was to do with the hardness of the material..........

Hopefully Mike R can confirm this

 

Billy there are lots of factors which can cause det...just cause its set up proffesionally dont mean you wont get it.

xr4x4rs....same as mine in the Saff...3mm inlet 1.5mm exhaust cut outs

 

Sorry lad i just fell on the floor , how easy u r to convince pmsl

 

cool mate just out of interest whats the saf running? with these pistons

as im going to be aiming for 500 - 550 hopefully as long as its more than 400 id be happy



pm me if ya like mate save a good thread getting slated

 

Dont get that....i aint convinced thats the point although i have to respect who said it

 

xr4x4rs....i always get slated so whats new ....these are in the T38 greys hi comp motor running 2.4 bar spike and 2 bar held...must be 420 plus with big torque due to comp ratio..it scares me and yet i am building a 650plus engine They are 7.2-1 pistons like yours but as my block had wire rings machined out of it it brought the comp right up to my desired level

 

quote not doubting the person quote
sounds like u r to me ask karl
No dont
i recon you hit the nail on the head a PROPER FORGED piston will hold up better agains det but they all melt.
Look at the ring lands on a cosworth racing piston and on the mahles and note the difference.
Guess i wasted my money then lol

 

[quote="Bosch Man"] Same here Phil.........I wanted him to say "Mahle's are crap,
we wont be using them on your engine build"....BUT he said just
the opposite "you dont want genuine Cossie pistons"

I think Mike R can confirm/deny....trouble is he may have used up all his evening passes for this month

 

i'd say youve been misinformed and also ripped off if you bought them for that money

 

superior in what way though,well there quiter errrrrrrrrrrrr is that it ???????????

 

u lot will be urprised when u discover which tuner it is

 

and it is ?????????????????????

 

julian godfrey

 

who's he lol

 

Not surprised at all Ranj as Julian comes from a motorsport background - i.e. 80/90% of his work is on rally/rallycross/race engines....

And it was Harvey Gibb, with a similar motorsport/compitition customer base that told me the Mahles were a better choice on big power YB's........

 

I have Cosworth pistons in mine .5 oversize 7.2-1 comp
cost me £600 from Cosworth direct
they seem fine
I'm worried now there not made of chocolate are they then

 

so whats the REASON then?

 

Chris, thats the thing that confuses me to this day......

He said that the genuine Cosworth pistons are made of a
harder material........But there were reasons why this was'nt
such a good thing on a NON compitetion/race YB engine............
damn, wish I could recall the full explanation

 

I still reckon it's got something to do with heat cycles, expansion rates etc.

 

So far mine have done around 6k on a road car used every day in city and motorway traffic, with no problems. They are a little noisey when cold though, i tend to let it idle a while on cold starts.

 

UP for Mike R..............

Edited: he was on line a few mins ago

 

this is REALY WIERD as when i spoke to julian godfrey's yesterday , the nice lady mentioned using cosworth pistons as they are better (see the post about piston coatings) its all getting a bit confusing now

 

theres plenty of 500 bhp+ engines on mahles so they cant be bad.

 

i know which ones im using

 

I was under the impression that mahle's would last longer. cosworth racing might be better but wear out quicker??

either way

USE J.E or wiseco

 

I know for fact Cosworth tried there own piston in the Yb,cant remember what variant,probably early YBT build,but reverted back to mahle because they couldnt get it through durability testing with out failing,i think they kept cracking,cant remember now,over 10 years ago.