Differnce between efra and ifmar engine?
 

Can anyone explain the difference between an efra legal and ifmar legal engine. I think it has something to do with the crackshaft hole.
Which one has more power or rpm? What the difference regarding power and rpm?

Can I use an sirio .12 evo 2 efra crackshaft in a sirio .12 evo 2 ifmar engine? If so, how should i retune the engine? leaning or richen the HSN?

efra cranks are limitted to a 6mm crank hole, whereas ifmar crank afaik isnt limited at all.

yes you can use a evo2 efra crank in the ifmar evo2 motor if you wish, they all start life as the efra type then have a sleeve pushed into them to restrict them back apparently. as for retune, i'd probly say motor would need to be run a leaner to negate for the smaller crank hole.

I think its 7mm isnt it? Also the hole from the crank must be unbroken by the turbo scoop

Cheers

So do u just remove the sleeve to make it to the ifmar's version?

hey ziggy,

i measured the crank inlet of my mega zx12 motor when i first got it to check insides before running in and measured the crank inlet to be 6mm. So i just assumed, and i was sure someone else also told me a while back it was a max 6mm for efra crank hole, but i could be wrong.

you must be right about the crank hole not allowed to be unbroken by the scoop, as the little scoop if you'd call it that, that it does have is only really a little mark or slight swirl on the counter balance.

hendrikcls,
i dont think you will be able to get the sleeve out, most likely one metal was heated and the other cooled then slid in making impossible to seperate once united. your best bet would be to purchase a ifmar crank if your worried about it, you will get good performance by tuning your motor right with the efra crank then having an ifmar one and being off on tuning, this is just how i would feel about the situation.