440 halfpipe

[PARTYVULTURE]

I have a 1987 js440 it has a straight 15 impeller with kerker short body pipe running 150 compression.
My question is has anybody put a half pipe on a 440? How did it work? Do you think there would be any bottom end gains from running a factory halfpipe on the 440 as opposed to the kerker short body. I have one to use and put on it so i was just wondering if anyone had done this and what happened. Any info would be appreciated.

[restosud]

put it on,it works well and much better than any short body pipe.

[BLRider]

Even a stock 550JetPower pipe will have good bottom end on your 440.

[Bob Gruen]

The idea behind the short body / high RPM pipe on a 440 was that back in the day the racers would spin the 440 motor to higher RPMs to get horsepower out of it. This was possible because the 440 pistons were a lot lighter than 550 pistons, and they used the same crankshafts. Spinning a motor at high RPMs makes for a lot of maintenance and engine rebuilds, so less than ideal for a recreational ski...

The longer track of the Jet Power / half pipe combo will make more power lower in the powerband. But, if a used Jet Power system is around $100, and a half pipe is around $150, you might be better off finding a good piston port 550 motor to drop in...

Bob

[PARTYVULTURE]

awesome thank you for the info, i love knowing how things work. and i already have a jet power sittin on a shelf not being used and same with a half pipe so i figured why not if it will help out bottom end i also have a coffman full pipe on the shelf, but i think ill try out the half pipe and see if that works thank for the info and input