If you have an LS it's easier to stick a VTEC head on the block you already have. Putting in an entire GSR motor is a bit more involved. Also pretty expensive in comparison to just buying a VTEC head and slappin it on an LS block.

From an engine design standpoint the LS has a longer stroke which gets you more power lower in the revs. The block isn't really built to take the higher revs so if you truly want it to be reliable with extended high-RPM running you need to do some beefing up.

 

well my buddy has a 92 hatch with b18a bottoma and b16 head with type r pistons, cams and everyhting else, on slicks he run 13.1!!! not bad for a little hatch

 

lsvtec running for over a year but I have no Idea what HP.

 

i've heard of ls/vtecs making anywhere between 180 and 245 hp at the flywheel. where these numbers true? i have no clue.
remember, just because you've got a frankenstein motor doesn't mean you dont have to massage and build it to make good hp.

 

yea, theres a reason the LS block tops out at 7K RPM or whatever it does. It wasnt meant to be revved as high as a VTEC block. the R/S ratio isnt the greatest for high revving. so if youre gonna do it build up the block. If you dont wanna/dont have the money to upgrade the block, dont do it, or do it and use the LS ECU.

 

Rod/stroke ratio is a general figure that doesn't determine much at all. The B18C1 block has a 1.58 ratio, B18A and B18B are 1.54. The reason the B18C1 can rev higher is because it has a crank girdle and under-piston oil jets, not because it's got amazingly ideal geometry.

 

yeah i was thinking that it could rev higher because of the girdle and also the oil jets which the ls doesnt have

 

what would be the point of doing an lsvtec just to use an ls ecu?

 

doesnt determine much?? It determines how much stress is gonna be put on the cylinder walls and the rod itself., i think thats kinda important, especially when youre revving the hell out of it, i.e tapping the potential of a vtec head. As a general rule, (at least in hondas, i dont know too much about other engines) the bigger the engine gets, the worse the R/S it gets. Too low of an R/S (below 1.75 : 1) means the piston will be more slanted towards the horizontal during its stroke. Its like having sex sideways, youd want it to slide in smoothly (1.75 : 1 ) not scraping against the walls ( 1.54 : 1) she isnt comfortable cause shes gettin poked in the side (cylinder walls) you arent cofortable cause your d!cks ( rods ) bendin the wrong way haha i dont know why i just thought of that, i guess im just a horny bastard. I say just save yourself the trouble and buy a car thats already got VTEC. but thats not for everyone, so do what you want, just look into all the aspects of it before jumpin in head first.

 

just a temporary solution till you could afford (money wise and reliability wise ) to rev it higher.