well I finally have an a-15 block and I waswondering what pistons are available for it, I need to go over size and I would lik eto raise the compression.

Any help would be great!

Thanks James

I read about using mazda uc pistons but was wondering if there was any thing available that didnt need modifing my parts suplier said they can get me .030" over sized but was wondering if i could go more and was wanting something with no dish or at least less dish, MY A12 pistons has flat tops, just wondering

There are some .040 on ebay now....

EBAY .040 pistons NOS

Mike

Mike I am wanting some that are flat top like my A-12 pistons put over sized.

By the way what is the maximum bore of an A-15 is it .060? I think that what i read

The largest 'factory' oversize is 1.5mm [which is close to 0.060"] however some racers run bore sizes out to 79mm, which is 3mm [0.118"] over
For street use, I would suggest the factory oversize is a practical limit.

where would 1.5mm over be available thru, and what about flat tops?

The UC pistons I used in mine needed some milling off the top to get the pin height right
They also need the small ends of the rods machined out to 20mm

They are flat tops once machined down



After I broke those I changed to another Mazda piston that needed no top machining
Pin height is 28.6 instead of 30mm so piston is 1.4mm down the bore
Less compression but might pay to calculate your own based on the head chamber volume anyway.
Still needs 20mm pins

The mazda is 77mm bore standard.

Theres also a Miata 1.6 piston from the 1.6 non turbo you could look at
But it needs more shaved off the top and will give over 11:1 compression when set up
Still 20mm pin size

Then theres the Subaru Justy 3 cylinder piston
But this needs the small end bushed down to 18mm I think. It also needs the block decked about 80 though. This might play havok with timing chains but not sure on this. Its 79mm bore too I think, bit big.

Thanks Dattoman, that gives me something to llok at, I was hoping I didnt have to modify that much but, maybe the only option, by the way what is a Mazda UC

The UC engine was used in RWD Mazda 323's in Australia

What cam specs would you sugest dattoman
?