ATR BBBB Pistons please

Post by **Drax** » Mon Nov 17, 2014 11:12 pm

Vtecmec wrote:I think the A's have no marks, but the B's are stamped.

all h22 and a7 pistons ive handled, both A and B pistons were stamped

CrankmasterII wrote:FWIW I measured AAAA pistons at 86.1mm

ok, i need the BBBB ones now to see if i need a much more precise measuring tool to find the difference

Therealjj91 · Post by **Therealjj91** » Tue Nov 18, 2014 4:43 pm

I found some BB pistons on eBay but the guy doesn't know what the comp ratio is

is there anyway to tell? He didn't even know if they came out a black or red top engine.

Post by **Drax** » Tue Nov 18, 2014 4:59 pm

Therealjj91 wrote:I found some BB pistons on eBay but the guy doesn't know what the comp ratio is is there anyway to tell? He didn't even know if they came out a black or red top engine.

do they have PDE marked on the piston & rod side? if so, they are ATR pistons.

if they have P13 on the piston/rod side they are standard H22 pistons

Therealjj91 · Post by **Therealjj91** » Tue Nov 18, 2014 5:47 pm

Ahh no they have p13 written on them

Therealjj91 · Post by **Therealjj91** » Wed Nov 19, 2014 3:30 pm

I'm having real trouble finding some ATR Pistons so if I was to go for the Mahle gold series pistons 11.5:1 which are designed to go in our standard cylinders, would these fit on standard conrods and do these come in AA and BB sizes? Thanks.

Therealjj91 · Post by **Therealjj91** » Wed Nov 19, 2014 6:39 pm

It turns out they use the standard rods but I can't find out about AA or BB? Does anyone know?

Therealjj91 · Post by **Therealjj91** » Thu Nov 20, 2014 10:40 am

Anyone?

Post by **Drax** » Thu Nov 20, 2014 11:39 am

I don't know anything about Mahle gold series pistons but @NafemanNathan or @Merlin may know

Post by **4thgenphil** » Thu Nov 20, 2014 12:07 pm

Therealjj91 wrote:I'm having real trouble finding some ATR Pistons so if I was to go for the Mahle gold series pistons 11.5:1 which are designed to go in our standard cylinders, would these fit on standard conrods and do these come in AA and BB sizes? Thanks.

they can be made to fit, not actually sure how but atr rods would be easier to fit them as well as for atr pistons.

how mega desperate are you for them? i have a few sets of pistons so i can have a dig through but i will need a set replacing.

i may have another set of rods aswell

Post by **NafemanNathan** » Thu Nov 20, 2014 12:26 pm

Mahles only come in the one size, there's no AA BB about them. I think it's wise to have your block checked prior to fitting Mahles incase your bores are too worn. Otherwise you stand a chance of clattering/loosing compression. Chances are the block will be fine. I think Rich of PAW has mentioned it on the forum before, so might be worth a search.

I actually have a brand new set of Mahle 11.5:1 pistons I need to move on, so give me a shout if you decide to go that way.