Roosie

iTrader: (8)

just been speaking to my engine builder and he said he never builds any cossies with offset gusgeon pins as they wear the pistons quicker and saps the power?
he said only good thing about offset pin is o reduce noise thats it.

is this true?

richard_syko

99.99999999999999999999999999% of pistons have off set gudgeon pins

col cos1

iTrader: (5)

2wd dont have them

jonnyboy

genuine cosworth pistons have offset pins to reduce piston slap.

BigErn

thought 2wd didnt and 4x4 did?

PeterLucas

2wd dont have them.

I thought they helped with the thrust angle reducing wear!

Roosie

iTrader: (8)

i have a 2wd so if im getting forged pistons i wanted to use 4wd offset ones but if its true that you lose power because of the offset i will get 2wd forged ones

col cos1

iTrader: (5)

i have cosworth racing pistons and they are 2wd spec,so dont have offset pin

big_wig_074

do you REALLY think itll lose any noticeable power?with ALL the people out there running big power 4wd engines?

CossieRich

iTrader: (1)

how much power we talking about. 2 horses or less

Roosie

iTrader: (8)

why do they give you the option of 2wd or 4wd pistons if the 2wd give piston slap. they might aswell sell ust 4wd spec without the slap to everyone

big_wig_074

4wd pistons in a 2wd motor reduce the compression ratio to about 7.8:1 IIRC

MikeR

Who do you use Dave Walker ?

Mike

JamesH

iTrader: (21)

I thought they'd stopped making 2wd pistons!

jonnyboy

i ran 7.5 to 1 4wd ones so mine did along with thicker top ring lands iirc

Simmo

iTrader: (20)

Same here James!!!

Karl

Roosie, I suggest you change engine builders then, as his advice is completely wrong in respect of a normal YB engine. Having an offset pin reduces piston wear due to reduced piston rock at low rpm, and hence reduces noise! It won't make the slightest bit of difference in power either! Your engine builder is a clown to suggest running centre pin pistons in a YB!

Edited to add, there are some minor benefits to centre pin pistons for engines of 10K rpm upwards, which rather rules out 99.9% of YB's!

the original

yeah as all the replies above. So Roosie was it Walker or was it Damico?

Roosie

iTrader: (8)

Damico Scrote

tabetha

Edit,
Dave Walker does ZERO engine building, and does NOT offer advice as he does NOT deal with that side of engines, just mapping etc.
BOTH 2wd and 4wd pistons have offset, just diffferent amounts.
tabetha

MikeR

What tuner is that Roosie, l only know Dave Walker when l lived in Elveden,

Mike

Dan

He mentioned Damico above Mike

Nice advice Karl, clears it up spot on if you ask me!

Roosie

iTrader: (8)

I say hes my engine builder realasticly hes not he just done bits and peices
Impulse developments have been doing my headwork lately and i cant fault the service from Adrian, and when it comes to mapping and tuning advice its Dave Walker @ Emerald when i do get a chance for mapping. I Think i will knock Damico on the head completely tbh this would be the 2nd bit of bad advice ive had lately

Dan

Literally, do it with a gudgeon pin!

JamesH

iTrader: (21)