Just checked a jp site on pistons and found that the e15 have the sama e76 mm diameter as a15 but lower piston height.
a14 67.5
a15 65
e15 62.5
could I just mill the block to suit these pistons???? that would lower my overall engine weight and give better stroke ratio

cant see how that would change stroke???

will this will bring problems of shortening pushrods and stuff? or not big enough diffrence

What I meant was piston and stroke ratio would be better and along with the less moving mass. 2.5mm less on the deck would need different pushrod length but i am wondering this as a way to get more out of the long stroke a15. Reducing reciprocating weight could have rpm advantages right??
Also the shorter deck with the shorter piston would make a more dynamic stroke??
This is out of my area help needed...

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dont understand how this changes stroke or ratio or anything it still gonna go up and down the same amount???

Are the E15 rod big ends anywhere near A15 in diameter and thickness? If so they could be used with E15 pistons possibly. This would give you a better rod ratio.

I see that too so it must just improve the overall reciprocating weight, the lighter the pistons the less stress overall and less important a kilo off the block if you deck it 2.5mm.
Sorry 2332 I dont know anything else bout the rods or e15 but would love to know as the e15 engined pulsars are everywhere here. In the end I might have to go for the matsuoka 78.5mm oversize pistons for the a15 but I really didnt want to slug my wallet that hard.

Rod-stroke ratio? OK, it gives you a one HP advantage at 8,000 rpm, and almost none at 6,000 rpm. Big deal.

Fitting e15 pistons into a A-engine won't change the rod or the stroke, so rod-stroke ratio remains unchanged. Unless you change the rods.

Unless the e15 pistons weigh less, it doesn't reduce the reciprocating mass either ... lower compression height doesn't necessarily mean lighter pistons.

These figures dont mean much to me
The figure that I would be looking for is the compression height of the piston (from gudgeon pin centre to top of piston). This should be 33 - 34mm appprox.

More info please D

can E15 or E13 Pistons b fitted in an A-12 on stock connecting rod and pin?

how much Compession Raio will they lower if they do fit in?
barpk

Sorry guys I dont have anymore info on these pistons or whether you could use the same e15 rods. Its a shame I cant find a site to check these other dimensions to see if any e15 stuff can go into the a15.
Your right dd shorter rods would do the real trick but maybe theyll pop pistons out the bottom of the bores If not it would be nice to lower the deck of the block about 2 cm!!! and make clearances for these shorter rods and pistons along with shorter pushrods and whatever else is needed. It would be nice to also adapt some kind of crank angle sensor get rid of the distributor, add electric fuel pump and then grind down the fuel pump, dizzy and power steering webbing safely to reduce a little engine weight without weakening it. The real thing Id love to see is a pic of 79mm bores to show how much meat is left in between the walls. Is it true the bores are offset to allow for this to be feasible after x-raying the block for clearances?? Feral any pics in your library of stuff?? has anyone ever contemplated or could it be possible to make a one piece sleeve kit grouping all four cylinders like that used on high hp alfa alloy motors instead of seperate sleeves to allow for an 82mm bore for the a15? or is it impossible? I think I better get off the turkish coffee and sweets and stop here too.