Originally posted by Top Gun 777
. But with longer strock and ROAR, IFMAR and efra ruls of 4.5 mm exhaust windows height-it will have tighter timing on transfer and exhuast (Stefan says windows look the same). So, without modding this will be more torq and less top end, but with better milage.
Uhm. Some interesting points that may shed some more light and some more Q's to put some life on this thread that I find very interesting.
1. EFRA doesn't limits Exhaust transfer height. Ran a sleeve on a very large track (Lostallo - Swiss) with more than 4.6mm of transfer height (low-end was completely killed, but talk about high speed -engine sound was wickening on all the backstraight-
).
2. That slightly longer stroke will be beneficial (IMHO) because the increased dwell time at TDC, powerband will be different from RS12/NS12, but I bet that new engine will be 'something boring' on high traction tracks due to their sweeter powerband and how develops the power (Attention to this...). Probably will not be soft at low-end and more like an electric motor like. Think on it like a truck engine with an almost flat torque curve.
3. Figuring a longer dwell time (uhm, a slightly longer conrod to round this will be perfect), engine will be slightly more fuel efficient, because it has more time to push the piston downwards, probably can authorize more static CR to make it more efficient.
4. Longer stroke means higher linear velocity of the piston and more inertia, so 'theorically' less ability to hold the high rpms that we're getting nowadays.
5. Trying to figure the timing of an engine who no one has seen it is futile, better to wait to see it and degree it. But much probably will be quite similar with more 'lobe centerline' on their distribution scheme talking in the '4 stroke jargon' - not much, but probably make a difference. On the .21's this made their magic and made it more controlable.