crank shaft compatibility
 

hi will a ej 25 crank shaft fit in ej 20 engine cases and use the ej 20 rods and pistons
thanks guys for any help

Yes the 79 mm 2.5 will fit, but your pistons need to be a different pin height due to the extra stroke.

Crank shaft comparability
 

Hi thanks for the reply. Can I get forged piston that would fit and H section rods.or would I have to get the engine rebored for a larger piston.
. Thanks in advance.

You would be better to get the next size up piston & start with a fresh, correct bore clearance, you can get a std length forged rods & compatable piston, most reputable piston makers do stroker pistons to suit.

hi thanks for that been having look and im thinking of going to a 93 piston with H beam rods but is the ej25 crank needed or can i stick with the el20 crank because the stroke is longer on the ej25 crank about 4 mm if im right all im wondering is the ej 20 strong enough .thanks for your help

You can use either crank, but the 2.5 will give you a 2.1 engine with matching pistons, 2.0 crank will still be 2.0, with correct pistons, seeing as you have a 2.5 crank, rods & pistons are still going to cost with either crank, but at least you will get an extra 100 cc with extra torque & spool up.

thanks for the reply im going to go go with what you have said .just one more thing as im having the cases machined for the 93 pistons should have them machined for bigger head bolts if so what size .
thanks again for all your advice

I presume you have the exact pistons you are using being machined to the block, for measurement accuracy, you can stay with 11mm studs, unless your going for big power build.

Crank shaft comparability
 

Yea I intend to take the cases and piston .I was hoping to at some stage coax a bit more power out of the engine but nothing to big so what do you think regards pete