WITH THE BIG DISC CASE THERE IS LESS RESTRICTION. YOU LOSE YOUR OIL INJECTION, BUT 48MM ROUND SLIDES ARE NOT A PROBLEM. THEY ALSO HAVE A BIG BORE 740 THAT USES ALUMINUM SLEEVES AND NICKICIL PLATING. THEIR STROKER MOTOR IS AN 800CC. I DON'T THINK THE CRANK SHOP HAS A WEB SITE THOUGH.
HEY KRUSTY. AREN'T YOU RUNNING A BIG BORE 95 OR 96 MACH 1? DID YOU PUT IN THE BRASS INSERT? I'M ASSUMING YOU BORED .080" OUT OF YOUR 44MM ROUNDSLIDES. DO YOU KNOW ANYONE RUNNING THE CRANK SHOP BIG RV CASE?
Ya, bored 44's in 95 Mach 1. Yes to the brass plate. My motor guy has a big plate but says is isn't worth the hassle to install. If your willing to mix gas, I'm sure you could gain more than 6-7 hp a lot cheaper. Ported case, billet or shorty RV cover, 46's, 150-80 timing, 13-1 comp. The injection cover is the bottle neck. So was the airbox in my case. Don't know about the S chassis. If your serious about keeping your rotary motor
you should look into the 740. $1200.00 is halfway there. (in Canada anyway)
KRUSTY- WHAT DO YOU MEAN YOUR MOTOR GUY HAS THE BIG PLATE? DO YOU MEAN THE CRANK SHOP BIG RV CASE? OR DO YOU MEAN THE SHORTY OIL INJECTION ROTARY VALVE COVER? OUR IMPROVED 670 MOTOR USES A HOGGED OUT RV COVER FROM A 76 RV FREE AIR. IT WORKS GREAT. WE OPENED IT UP TO 44MM. THE CARBS SIT NICE AND LEVEL IN THE CHASSIS. THERE'S NO ROOM FOR K&N FILTERS THOUGH. THEY WOULD RUB ON THE TUNNEL. THE JUGS WERE PORTED BY FAST AND WE DID THE TUNNEL PORTING. WE'RE RUNNING FAST TWIN ELIMINATORS AND THEY SPIN ABOUT 8500 R.P.M. BEING A MACHINIST AND A GEARHEAD GO HAND IN HAND.
We have made a big disc from a stock case. You weld both sides of the case and remachine it to a big disc intake. the only thing we got from the Crank Shop was the big RV valve.Those valves are a 1/2" bigger in diameter which allows better tunnel porting.If any one needs more info e-mail me. We also make the intake for this mod.
Hey Krusty I have a stock pipe 670 stock bore, 46 mill carbs made 144hp 94ftlb, intrested in clutch set-up's I'm very close to a good trail/lake race set-up now, but intrested in what other guy's are running to doo some comparing. Thanks
mr 670; I'm now a 740 big bore. I've been dialing in mag arms for the last two seasons. Major pin wieght and soft springs up front. Shallow cams with light tension on th secondary. Alot of testing but once dialed in
. I can give you multipile mag set ups to try. Let me know.
1 - 12 of 12 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
A forum community dedicated to snowmobile owners and enthusiasts. Come join the discussion about performance, troubleshooting, trails, maintenance, riding tips, modifications, classifieds, accessories, and more!