hi all, i'm busy with my a15, got it bored out 60 thou (1.50) mazda e5 pistons with modified gudging pins to match. must get the block decked and was wondering if i should deck the pistons to flat top as well, question is if the pistons will work flat top or is going to need a valve relieve in the pistons? any advice please? i'm using an h75 head which is match ported to twin su manifold, 2mm shaved off the head.

would depend on the lift of your cam,
you'll need to assemble it and measure the clearance anyway...

i'm using the standard a14 bottom end atm with standard pistons. cam is a tr68 290 degree duration, 11.5mm valve lift

With 2mm off the head and flat tops at 0 deck height ,with that cam ,ide say yes get the fly cut

What's the ccs of the head ? And how far down the bore will the Mazda pistons sit at tdc ?

the pistons atm looks alot like normal a14 pistons with a small dish, at tdc the pistons is 1.5mm from the top of the block

what made you use mazda e5 pistons. e3 is a full flat top with a +0.76mm dome in centre. what comp are you chasing.taking 1.5mm off deck is alot to take off + 2mm off head(pushrod adjustment maybe a problem). cheers

jess you are learning well(for a bright sparky)HAHA.

A15 and A14 use different pistons, though both are the same diameter. If you make the Mazda pistons work with the A14, then they won't be right for the A15.

Mazda pistons give the A15 some zoom-zoom.

the a14 bottom end is standard in the ute atm, i'm using new pistons for the a15. i bought the a15 with mazda pistons fitted already as it was used fr turbo but one piston was damaged. had to put bigger pistons and mazda was the best option at this stage as the conrods was already modifed for it. i took it in saturday to get the block decked with the pistons but it will not be flat top pistons as the e5 pistons has a pop up centre and will only be milled to where the centre of the pistons is fluch with the deck.

So your A14 was fitted with A15 pistons that were machined to work with an A14?