Well this post disappeared somewhere in the new forum and old forum so i am reposting...basically i need to know if there is a difference between an on-road and off-road engine. i have an extra novamega .21 from my serpent and wanted to know if it would fit in my ofna GT LX kause i am sure it is more powerfull than the stock 3port force.21. If this will not work anyone looking to trade an offroad engine for an on road one

i dont think there is a real difference the main difference is in power on road has more rpms usually and off road has more torque and arent as high reving, somebody write something if i am wrong this is just a guesss

intake and exhaust timing of the engines will be different.
off road engine will deliver max more torque at low rev and on-road engine at very high rev.
on road engine in off-road car will not deliver its max potential coz off-road cars normally need/use lower rpm (unless u r running on large flat/high speed track)
having said that.. you can always play with pipe length to make the engine deliver more grunt at lower rpm.

and I think the nova will out perform the 3 port force engine any time ... even in off road application.

eons ago I've used RB C3 on-road engine in my turbo inferno for high speed races (flat dirt track) with good result... until i broke my suspension arms in the final