Inside Look: Jim Dimmerman’s SnoPro 1100 Triple

Hands down, this will be the coolest piece of Arctic Cat content you’ll see on the internet this week. I’m late to share this story, but last week, Jim Dimmerman unveiled a new Sno Pro project on his Facebook page which has consumed a fair amount of his free time (and cash) the last 5yrs.  

I can’t begin to explain the coolness of this custom project, and the rarity surrounding the 2003 Suzuki 1100cc, triple-cylinder prototype engine with electronic controlled Variable Exhaust Valves (VEV) it was built around.

Jim and I had a conversation earlier this week and he gave me the blessing to make a story out of his Facebook posts. Jim said his plan is to take the SnoPro to the Snowmobile Hall of Fame Legend Laps event and potentially bring it to TripleFest this winter for one radar run pass. -Kale

THE TRIPLE ENGINE THAT NEVER WAS

2003 Thundercat Suzuki triple,1100 cc, electronic controlled VEV (variable exhaust valves)

This engine was produced as a prototype at the same time as the concept of a new F7.

(That was in early 2000) Product planning and marketing decided to put their efforts into the F7 Firecat project and shelved this big triple forever.

Over 5 yrs ago, I made a call to Roger Skime about a project sled I had in mind. Initially it was going to be a trail version for the Ride With The Champs. As the years passed by from concepts to mock-up, I changed the design 3 times.

I knew about the 1100 triple that was sitting in the prototype engine room. I had a dream!

I convinced Roger I would build a sled worthy of this iconic piece and he said, “I have no doubt.”

Here’s my tribute to Team Arctic Snopro 1980 and some fun facts about the build.

The motor: Crankcase is based off the 800,900,1000 production motor, same balance shaft as the little brothers. The rods have larger wrist pins (800-900 had 20mm) (1000 had 22mm) (1100 has 24mm)

64.6 stroke same as 1000. 85mm bore 1099.7cc’s. Projected horsepower 180-190 w/muffler.

The cylinders are one off, not like the Tigershark watercraft, not like the 1000. The exhaust port is 3 ports with the variable valve controlling the port height. The port itself is significantly angled down. (The 800-1000 were 90*) The entire sleeve is proportionately larger and the crankcase base is bored larger to fit this cylinder. The reed cages are the same size as the 800-1000. The ignition is the 3D version used on 99-02 1000’s with the added servo control box for the valves. It’s a one off ignition.

No carburetor’s or exhaust were prototyped yet when the package was shelved, so the motor had never been run! I asked Greg Spaulding to draw me up specs for the pipes and had TJ Long from RPM concepts (formerly Larry Rugland Motorsports) roll and hand fit pipes to this chassis. I had Brad Hulings bore me a set of flatrack carbs to 42mm. The internals of the motor and cylinders are completely stock as prototyped. I am running the engine as a pre-mix with oil pump removed. 32:1 Blendzall and AV gas. I have NO extra parts. Satisfyingly, when the carburetors were primed, the motor started on the second pull!

THE MOCK-UP PROCESS

I thought I’d share some of the early stages of mock-up and ideas for livery (color and graphics) that came and went. The Porsche livery was my choice up until the very end (hence the bronze tunnel) but too many of my friends said I should make it look like an 80 sno pro. I agree it was the most iconic, so I went down that path with a little graphics ghosting twist.

The Hood: Kenny Halvorson created the tail and raw hoods (76 & 80). Bryan Mahler did all the glass work and transformed a 2cyl hood for a completely different bulkhead into the fine piece it is now! Brianna Ische worked her magic with the decals and nailed the look I wanted!

The Chassis: The bulkhead started life as a Mountain Cat with a 2cyl engine and dropped and rolled chaincase. I chose a 128-inch skidframe from a Firecat (speed and rolling resistance) and a Touring tunnel. It’s all put together with aluminum aircraft rivets, all hand bucked.

The triple exhaust pipes were all Tony TJ Long under the watchful eyes of Larry Rugland – What a masterpiece of pipe fabrication. I had to delete the radiator to make some room for the pipes. I initially tried to use the radiator, but when I went created some preliminary plumbing, the hoses were just too ugly and I would have had to change everything over to AN threaded fittings to make the hoses look sano, so I scrapped the radiator idea to give Tony more room for the pipes.

My leaf spring suspension retrofitted to 128-inch Firecat skidframe…

Here’s another speed secret – While I was at it, I had Brett Buer whittle me up some 7075 aluminum shafts for a Speed Run driveline. I coupled that with a titanium brake disc and special Wilwood brake pads. And of course, a trick plastic prototype chain case!