Ski-Doo Snowmobiles Forum banner
1 - 15 of 15 Posts

·
Registered
Joined
·
395 Posts
Discussion Starter · #1 ·
I have a suzuki gsxr 750 engine and all electronics from a wrecked 2003 bike that I bought for parts for my race bikes and I was thinking Sunday night on my 6 hour drive home from upper Wi cable. I don't really think it would be all that tough. Replace primary and secondary with sprocket and chain. Motor mount and air shifter,cooling system,battery. I know that I would love to be able to shift my own gears.

I bet that thing would be deadly fast with 150hp and 6 speed!

What do you guys think possible or waste of time?
 

·
Registered
Joined
·
739 Posts
it would be an interesting concoction and open up doors for a whole nation of "wrencheads"
ckoz
 

·
Registered
Joined
·
93 Posts
Anything can be done, But really to use the gears would do no good as it would take so long to get going. The skidoo motors now make just about the same hp with out the switching of gears by the clutches used today, over all top speed yes i think it could be fast. This is where the testing of the 4stroke skidoos are! The good thing about the gsxr motor is they love to rev, I know with my Ninja once you hit 7500rpm through to the 16000rpm it pulls like a bat out of hell. Now not sure what this would do to the other moving parts on the skidoo. I think it would make a fun test in any case given you have the motor.

I would have to say with some gearing and a centrifical clutch it will do alot better. As I think you would go through alot of clutches using the stock clutch and Transmission. Not to mention a centrifical clutch allows the lag(before it grabs) to higher rpms.
 

·
Registered
Joined
·
395 Posts
Discussion Starter · #4 ·
I am curious How much does a 670 motor weigh? I don't really want to do a lot of modifications to the motor. I think I am first going to pull the 670 motor and clutches and see if I can drop in the gsxr's engine to see if it will even be able to fit. 1 if it's 2 tall and 2 if it will be possible to get the drive sprocket to allign up roughly with the drive shaft or jack shaft what ever they call that shaft that goes to the chain case smaller gear.
Other than that Ithink I would have everything I would need. I have a few race systems that I can cut that the coupling and then I would have to heat um up and bend um. Do you think I could still use the heat exchangers?

Any more Idea's before I start ripping into this project?

How much hp does a 700 or 800cc sled put out at clutch engagement 4,000-5,000 rpm .
 

·
Registered
Joined
·
93 Posts
I think the use of the heat exchanger my help with getting the engine to a good running temp, then you may need an alternative cooling system maybe even a small heater core from a car to help cooling. But for now try just the stock heat exchanger.

I know when I run my bike hard, when it is about 50deg out the bike will only reach a running temp of about 70-73deg which in my eyes is too cool. I find when I get the bike to a temp of 85-90deg the engine runs better, meaning more throttle response.

The next would be exhaust, like most sport bike the exhaust is in header form, which runs under the engine and exist out the right side this is a good thing if you have a spare to modify to run around the side.

The engine will have to sit a little lower in the sled that what a stock 700-800 sits, meaning you may have to cut abit. Which may cause a small problem. You may have to create a small caged drive/axle with the use of a bearing to move the sprocket closer to the point you wish to mount the chain/belt drive to.

I wish I were close to you in helping do this; I love mod just about anything I can get my hands on.
 

·
Registered
Joined
·
93 Posts
Oh forgot to mention, It is not the hp that is the factor but is the torq. Twins do not create as much torq that a 4 cylinder does, but mind you the twins create more at low rpm. where as the curve on a 4cylinder starts at 4500rpm and only with about 25-35hp until it hites about 7500 which it makes a big jump from about 70-80hp on up to the peak about 15000rpm at about 130-140 on the gsxr750engine
 

·
Registered
Joined
·
79 Posts
How many HP is a 670 anyway?

97mxz670 said:
I am curious How much does a 670 motor weigh? I don't really want to do a lot of modifications to the motor. I think I am first going to pull the 670 motor and clutches and see if I can drop in the gsxr's engine to see if it will even be able to fit. 1 if it's 2 tall and 2 if it will be possible to get the drive sprocket to allign up roughly with the drive shaft or jack shaft what ever they call that shaft that goes to the chain case smaller gear.
Other than that Ithink I would have everything I would need. I have a few race systems that I can cut that the coupling and then I would have to heat um up and bend um. Do you think I could still use the heat exchangers?

Any more Idea's before I start ripping into this project?

How much hp does a 700 or 800cc sled put out at clutch engagement 4,000-5,000 rpm .
[snapback]293864[/snapback]​
 

·
Registered
Joined
·
79 Posts

I have Seadoo HX that would go like hell with a 670 engine I bet. Its a 720 right now (85 HP) I bet she could be hopped up more though. Gotta be able to if you say a 670 is 117 HP...I gotta check out the spec on them both. I bet its the same crankcase..Interesting.. Is a 670 a twin or a triple?
Oh man this could get ugly! lol

MXZBULL said:
the 670 engine is [email protected] about 117hp if i remember.
[snapback]294435[/snapback]​
 

·
Registered
Joined
·
83 Posts
Sounds like alot of hassel, but would make a really great conversation piece.
A used mach motor warmed over a bit would give the same if not better performance, look at the rx-1, same thing but alot more work.
let us know if you go through with it or not, is sure sounds cool!
 

·
Registered
Joined
·
93 Posts
To start with a heat issue of this type of motor in a sled is not much of a issue, it will get hot, My bike has a 12.7:1 compression ratio. This in itself will create alot of heat. Now will just the heat exchanger cool it enough is the question. That is where a small heater core would help in cooling but not as much as what the rad would do as these motors do not like to run cold! For instance if i were to try to start my bike in the winter about -2deg it will just fart and burp. yes it will start but it does not like cold weather.
 

·
Registered
Joined
·
93 Posts
Here is a breif speed this bike does and ratios to gearing. The redline is a bit lower then the ninja @ 14500rpm. Thus find the proper set up and this machine will haul "edit for bad language".
Transmission Gear Teeth (Ratios)
6th (1.181:1)
5th (1.304:1)
4th (1.450:1)
3rd (1.681:1)
2nd (2.052:1)
1st (2.785:1)
Transmission Overall Ratios
6th (5.551:1)
5th (6.127:1)
4th (6.811:1)
3rd (7.900:1)
2nd (9.642:1)
1st (13.086:1)
Theoretical Speed in Gears at Redline
6th 185 mph
5th 168 mph
4th 151 mph
3rd 130 mph
2nd 107 mph
1st 79 mph
 

·
Registered
Joined
·
395 Posts
Discussion Starter · #14 ·
Well I tore out the 670 engine and tried to find a way to mount the 750 engine so it will not be off center. I cut out the engine mounts out of the 750's frame and I am going to see if I can find a way to tack them in and then I am going to decide from there if it's going to be worth while.
I love the idea of beaing able to do a few quick down shifts into a corner and side thru the corner with the thing screamin at redline.
I want to do it just because I can but I don't want to chop up the body of the sled to do it. My friend and I were sitting in the garage last night and were were thinking about exhaust and I found a old yoshi header and pipe that will work and we were thinking about a side exit for the exhaust. There are lots of idea's just have to find the time to do it or wait until the season is over.
Let me know if you guys have any more idea's or something we should do let me know.
 

·
Registered
Joined
·
93 Posts
What you might want to do is make a drive shaft that would connect to the out put of the trans, to make the engine centred in the sled. Couple of bearings will make it perfect, at which you can mount a chain or what ever setup you choose. search Dwarf Karts for setup.

I would still mount the exaust exit in the same place. Make sure the headerpipes are equal length.
 
1 - 15 of 15 Posts
Top