i have an 87 indy sport that i have restored to great condition but now i need more go. i can do about 60 on a good day :( it is a great sled and i just rebuilt the suspension and lots of the sled. WHAT IS THE BIGGEST ENGINE THAT WILL FIT THE CHASSIS. i am willing to do some custom work if i have to but are there any engines besides a 340 that will be a direct fit?

If it's a fan cooled chassis you can get up to a 440 in there.
If it's a liquid cooled chassis you could stuff up to a 600 or 800 triple in there.
You could convert it to liquid but I don't think it would be worth the time and effort.
Just trade it up for something faster,I have a 500 lc Indy and on our local trail system it can run with anybody ;)

thanks man. i think i will get a new sled but i was just curious to see how much i could stuff into that sport because it practically weighs nothing!!!i love it. it is so reliable that is why i want to keep it. i think im gonna get a custom indy storm with a 500 motor. should be pretty cool. how much do you think a decent 440 would cost me?? i have only been into sledding for a few years.

o yeah one more thing, what would i have to go through to stuff a 440 in there? how much custom work? would i be a direct fit? and one more thing does the new engine have to be the same year as the sled?
Thanks alot i apreciate any help!

If your swapping 340 for 440 it should be pretty much a bolt in.
Round here that motor would be about 4oo to 5oo bucks for a nice one ;)

I believe you could also bolt in a Indy Trail engine, which is 488 cc fan from 86 up to 2000 (where they gave it a 550 fan.) The 83-85's had a 440. I used to have an 85 with the 440 and it was basically bulletproof. Rode nicely for an older sled too. Good luck SWRules

could the new 550 fan speak byu in that chasis??