Author Topic: Invader upgrade  (Read 5622 times)

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mswyka

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Re: Invader upgrade
« Reply #15 on: March 23, 2015, 10:43:55 AM »
One of the pieces of data we have is the table that Bob published in the 2012 Kawasaki Calendar.  That chart lists the 340 at 53.5 HP and the 440 at 67, 68 or 70  depending on the year - 78, 79 or 80.  That would make sense, since they run the same rpms, it really comes down to the mass of fuel and air that can be pushed through the cylinders.  All other things being roughly equal, that becomes the difference in volume of the cylinders.  Curiously enough, this chart shows the 440 intruder at about the same HP, but the stock Intruder runs the same gears as the 440 Invader.
Intruders:  1978, 1979, 1980, 1981 Custom
Invaders:  1979 340, 1980 440, 1980 440 TOC Custom
Projects:  1979 Invader 340, 1980 Invader 340, 1979 Intruder 440, 1982 Intruder 440, 1980 Drifter 340 F/C, 1972 Panther 303 ...

Tory944

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Re: Invader upgrade
« Reply #16 on: March 23, 2015, 11:42:13 AM »
Unfortunately, back in my service days in the Air Force...  there wasn't any snowmobiling to watch at Travis A.F.B in California!  I used to take the hour drive to Lake Tahoe (beautiful area) and check out all the snowmobile rentals in winter.  It was always raining where I was stationed, but I still read snowmobile magazines!  LOL.  1995 era. ;)

I had a Liquifire shipped to the barracks for me to work on in my spare time...  guaranteed I was the only guy in my building with a Liquifire chassis stuffed in my closet.  When it came time for inspections I made damn sure my locker was locked!!!   :o
Torys Vintage Sleds
Website:  torysvintagesleds.com

rminier

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Re: Invader upgrade
« Reply #17 on: March 23, 2015, 11:44:24 AM »
  That makes some sense regarding the Intruder gears matching the 440 Invader. If the Invader achieved 88 mph at 8000 RPM with those gears, the Intruder, with it's power peak at 7000 RPM, would achieve 77 mph with those same gears...sounds reasonable. Surprised the HP was really that high from an Intruder.
  I was almost sure the 340 Invader was under 56 HP. Back in the late 70's the cross country racing circuit at the time had a 56 HP limit. I distinctly remember John Deere had a "cross-country" kit available for their 440 Liquifire. It was a de-tune kit, designed to drop the 440 down to the 56 HP limit...if I remember correctly, it included different cylinders, heads, and clutch parts to work with the new de-tuned motor. JD didn't have any 340 Liquifires from 1980 and up...maybe a couple prototypes....so they had to de-tune their 440.
  I thought the 340 Invader was good to go for that 56 HP rule. Jay Sperry certainly didn't do too badly with one in either the 77-78 season or the next year. I think he finished 2nd in total points, kinda a lone wolf effort against scads of Polaris TXLs, and others...
  Yamaha's first SRV came out mid season as an 80 1/2 model, and they participated with it for 2 or 3 years on the CC circuit because it came stock with 56 HP. About 1983 ?? the rules must have changed, because Yamaha upped the HP to about 60 for the SRV motor.
   Then Kawi, Deere, Scorpion, Arctic Cat bailed or went bankrupt...and the darned TXL Indy's ruled the CC races :'( :'( :'(
75 SnoJet Astro SS, 79 Kawasaki Invader 440 (two of them), 81 Scorpion Sidewinder, 82 Blizzard 9500, 83 Yamaha Vmax 540, 97 MXZ 670....and holding...for now.

bhurlin

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Re: Invader upgrade
« Reply #18 on: July 16, 2018, 10:49:34 AM »
There are a couple of things to get the speed out of the 340.

Just to understand the 340 was 56 hp stock. The rules stated that you had to have 55 hp to participate in the cross country. Kawasaki made a kit that consisted of a new pipe and some clutch weights that were available. It should be noted that you can add the intruder pipe for 2 additional horsepower.

Each pipe was good for about 2 mph. On a hard packed mile, you could hit 82 with stock gearing and pipe. The 55 mph pipe would drop 2 mph and the intruder pipe would add 2 mph up to 84 mph.

To get additional speed you had to add rpms. The way to do this is to tighten up the rear spring, I increased the rates to bring you up to 8800 RPM. The best gearing was to increase final drive gearing to improve off the line as well as the additional RPM's to pull on the top end. My racing top speed was 92 MPH with the 340. It would beat the Kawasaki reps 4/6 LTD on the top end. He wanted to buy my sled which I refused.

Sunday racing with this sled would bring Monday morning sales results at the dealership!!!

rminier

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Re: Invader upgrade
« Reply #19 on: July 16, 2018, 03:28:31 PM »
 Very cool information.. 8)
Welcome to the site.
Please share more sometime.
Did you ever try the Winnipeg to St. Paul race?
75 SnoJet Astro SS, 79 Kawasaki Invader 440 (two of them), 81 Scorpion Sidewinder, 82 Blizzard 9500, 83 Yamaha Vmax 540, 97 MXZ 670....and holding...for now.

rminier

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Re: Invader upgrade
« Reply #20 on: July 16, 2018, 03:52:29 PM »
 I believe this is the 1978 Winnipeg to St. Paul race:
# 49 Robert Heinen, Avon, MN
# 147 Dave Corbett, Winnipeg

75 SnoJet Astro SS, 79 Kawasaki Invader 440 (two of them), 81 Scorpion Sidewinder, 82 Blizzard 9500, 83 Yamaha Vmax 540, 97 MXZ 670....and holding...for now.