Snowmobile Fanatics banner

1 - 7 of 7 Posts

·
Registered
Joined
·
110 Posts
Discussion Starter #1
My fiend and I have this old 75 scorpion whip, which has an all aluminum frame in the front, and a fairly light rearend. The motor and body are shot, but we have a spare 440 motor that runs and we are into painting/making body parts. We are thinking of making a race sled out of it. We want to get the most possible power out of the engine without any expensive mods like porting or clutches. Here are the ideas so far about the sled-

1. No mufflers, straight dual pipes out the side.
2. All aluminum frame
3. Possibly plastic/aluminum skis
4. A custom made hood to be aerodynamic
5. Aluminum track suspension
6. Studded track (to put that power to the ground)
7. Comet 94c clutch with about 5000 engagement (I already have that)
8. Dual 34mm carbs (already have those too)
9. A fan blower hooked up to the carbs (my friend's idea)
OR a hood scoop (my idea)

Please give me any and all input and or ideas on this guys! Thanks, Ed
 

·
Registered
Joined
·
510 Posts
you cant have straight pipes like auto exhaust pipe. they must be tuned expansion chamber designed for that engine. ditch the hood idea too hard to make a hood and expensive. ditch the aluminum suspension idea unless you own a machine/ metal fab shop and have the skills.
def stud the track. clutch and carbs are good idea.
blower idea wont do anything. hood scoop is good if it feeds cold air to carbs.

basically the whip isnt a very high performance model by the way what engine is the 440? fan cooled im assuming? its foolish to think you can substantially increase the performance of that sled with little to no monitary input.
 

·
Registered
Joined
·
67 Posts
NEVER run strait pipes you lose power and wash the pistons out very rapidly like in a day. Scorpions are sweet. i would say port it shave the heads, put some really heavy clutch springs in it and dump the air box. use octain booster and high octain fuel.
Even better if you could get a deal, use a free-air or a liquid cooled engine.
good lick let us know how you make out.
 

·
Registered
Joined
·
1,013 Posts
I would use a Chaparral Chasis. They are SUPER LIGHT!!! A free air engine would be better than a fan, i think a liquid would be too much work/weight. My dad has a Chaparral all striped down, no hood, pan, seat, etc(for racing)... I can pick the front and back up very very easily with one hand. 102c clutch would work much better.
 

·
Registered
Joined
·
110 Posts
Discussion Starter #5
Why no straight pipes? Can't I just jet the carb wayy rich to compensate? Not trying to say you are wrong I am just wondering why....
 

·
Registered
Joined
·
1,669 Posts
Originally posted by firepower14
[br]Why no straight pipes? Can't I just jet the carb wayy rich to compensate? Not trying to say you are wrong I am just wondering why....
If you understand the principles behind a twostroke engine, you will understand why you NEED a pipe. I relize that chainsaws and weedwackers are not piped, but they have a specific muffler for that model. Your 440 was designed to be run with some sort of backpressure that will keep the piston from running too lean. I have a .gif file here that I would attach, but i cant that illustrates the importance of the tuned pipe
 

·
Registered
Joined
·
1 Posts
My fiend and I have this old 75 scorpion whip, which has an all aluminum frame in the front, and a fairly light rearend. The motor and body are shot, but we have a spare 440 motor that runs and we are into painting/making body parts. We are thinking of making a race sled out of it. We want to get the most possible power out of the engine without any expensive mods like porting or clutches. Here are the ideas so far about the sled-

1. No mufflers, straight dual pipes out the side.
2. All aluminum frame
3. Possibly plastic/aluminum skis
4. A custom made hood to be aerodynamic
5. Aluminum track suspension
6. Studded track (to put that power to the ground)
7. Comet 94c clutch with about 5000 engagement (I already have that)
8. Dual 34mm carbs (already have those too)
9. A fan blower hooked up to the carbs (my friend's idea)
OR a hood scoop (my idea)

Please give me any and all input and or ideas on this guys! Thanks, Ed
Do it! When I was a kid after I wore my 76 whip out, I stripped it down bought skidoo‘s new Rotax engine at the time and installed it.I was told that the scorpion frames were one of the lightest frames to use for drag sleds. You brought back a lot of good memories of doing that project
 
1 - 7 of 7 Posts
Top