My friend has a 85' prelude and he was wondering if a 91' si engine will be able to fit, what tranny to use and how much horsepower does it have. (the base engine is only rated a 100hp)

 

is your friends 85 the dual carb, or the 2.0 si? it will make a big difference in the amount of money and time he will have to spend putting in the newer motor.

 

it's the dual carb. i know that we might end up changing the whole fuel system because the 91 si engine is fuel injected

 

call place racing in california. they do these swaps in their sleep.

 

i have the exact car - the 85 prelude dual carb. the best thing to do with that car is to not do the engine swap, unless you plan on redoing almost the whole car - which you can do, but it will take the 91 si as a parts car - and why ruin that car just to make the 85 faster?

if you want that car to go faster, find someone who can make a custom "header" and exhaust with a better muffler, take all of the air box pieces off, except the metal cover over the filter, and get a k&n filter to put on the end of that metal cover (take the old one out and get rid of it) - you now have a "performance air intake", advance the timing a few degrees to give you more top end power, give it platinum plugs and performance wires to get as much fuel burning as possible, lighten the flywheel, and watch it go. you could easily get your car to push 140 horse with those mods - i believe that is about what i will be pushing with mine when i get the exhaust done.

if that doesn't interest you, then just sell the car and get an si that already has the 140 hp (the 91 si) and mod the hell out of that one!