Time to build a Shark

[Ameritude]

Hey fellas, its been a while since I've been on the site, but I figured now is as good a time as any to bring this up. (Please move the topic if it doesn't fit this board). as the title states, I have come to the realization, that I want to compete at the highest level of vintage racing and to do so, I am going to build a IFS replica shark over the next 2 years. i am in the beginning stages, starting with research, I have also reached out to Kawasaki Development for any details they could possibly give me, they got back to me this morning with little to no info, but still cool that I received a response. I have decided to develop my own hood due to seeing little imperfections within others designs and I will be modeling the entire snowmobile in CAD within the next couple months. My request is this I need pictures, I have basically all the ones I can find on the internet but i need some more if they exist. i am taking measurements off of the pictures and using that to piece together this machine. i have an appointment setup with a gentleman i know, for Friday, to measure a 1975 sno-jet thunder jet tunnel (was supposedly used to create the sharks back in the day). basically any details that you guys might have, i would be so so grateful for. I will Keep Yall updated as i go, i am super excited for this challenge!

[Interceptor398]

Greg Lahr  aka Sprocket is the guy to ask questions of.

[sprocket]

Why not just buy a hood and modify it to your likings. If you are going to race it I would not recommend building a sno jet tunnel more headaches than you’ll need. Figure out what track & suspension rear you want to use. Make a tunnel out of .050” thick aluminum you can buy or make the rolled edges on the running boards pretty easy. As for the front end ifs I’d talk with Wahl brothers racing the factory Kawasaki is not safe

[sprocket]

Racing an IFS Kawasaki are you going for more original because you should look up the classes you plan on racing to see what is allowed I know at Eagle River Derby track Wisconsin they eliminated the 440 IFS & the IFSX 440 class due to not enough entries.
I would also contact with someone from ISR to find out if you can even race it. I went more rounds with them then I’d like to take about especially Eagle River and that was with my first build of the Kawasaki sno pro shark leaf spring 440 l/c super mod class I never got the opportunity to race there because they needed measurements from the factory specs which nobody has, even if I presented to them my prints it still did not hold up water. Their super mod rules are up for talk in April 2025 not sure about the IFS classes you’ll have to contact them. Before contacting them I’d read the rules first they are found on the ISR vintage ice oval page then if you have more questions then write them down when you call. I was just told a month ago it’s better to have it in writing than just showing up to race. I know the leaf spring super mod class allows you to go upto 40” c/c with the carbides. On the IFS & IFSX classes 45” c/c on carbide. I was gonna say with the tunnel I would build it 16 1/2 inches wide and 9” deep or measure up what an Intruder tunnel depth is. Having a tapered tunnel is not easy peazy because everything will need to be custom made because the tracks do stretch.

[Ameritude]

To start, thankyou very very much for the information, I appreciate the response immensely. the reason I'm going to take measurements of the Sno jet tunnel, is for the modeling side of it. I figured the process of bringing the shark to legal with the ISR/eagle river team would be a challenge, therefore I want as much modeling of the exact measurements, of the original sled as possible. I have gathered every picture I can find on the internet and between them all, I believe I will be able to reference dimensions that i know, with ones that I don't and create a full set of build plans, every single part included. I have a background in engineering and cad, and with that im hoping to get accuracy to 98% or higher. (just to throw this in here, any pictures that y'all might have, can help immensely with this). To answer the question about the hood, in my opinion, the designs that I've found, already made, are too far off to modify to perfection. this is not meant to be take as an insult to the designers who have done it, they are beautiful hoods no doubt, with design keys that are master class, I am simply too picky. I have built fiberglass molds in the past, by 3d printing every section and gluing it together, and i plan to do the same for this. I want to start by recreating an exact (to my ability) dimensionally accurate, model of the sled. I feel as this will be the best chance I have of getting into the big leagues with it. I plan to design both the ifs sled and leaf spring sled in this way, and if i can manage to get the prints approved to the correct governing body's, than i can possibly sell them as such, allowing more people to bring these sleds to life. that last part is a stretch and a long way off in the future, past the building and testing phase, but it would be very cool indeed.

[Ameritude]

I have much to learn about everything involved in this process, I hope I'm not coming across as a snob, as I'm fully aware, my knowledge is slim compared to some. if anyone has any references to original documents, context, design, notes, anything from the source, I would be immensely grateful, and very little will deter me. the worst that comes out of this will be a set of plans for replica sharks that wont be ISR approved. The best would be the contrary, either way, I'm young enough, to be dumb enough, to go for it lol.

Thankyou - Parker

[gixxer6]

I look forward to seeing another Shark build!  Sorry, I have nothing to contribute other than to say Good Luck!   

[sprocket]

The original sharks were a titanium cleated track with their own slide suspension 103” I believe. ISR will not allow that track you need to use a rubber track. Al Enno’s sharks are damn near perfect clones including his hood give him a call he probably would sell you a complete sled ready to go. Buy his and change a few things and write down on your cad with all the measurements would be a lot easier to do then starting from pics off the internet. Everything thing that the factory race team told us at Waconia Mn show was all the sharks were aluminum chassis’s and no steel components. The radiators they used were from a kx 125 dirt bike very crude compared to what you can buy now. They made 6 total all started out as leaf spring sleds mid season 5 were turned into an ifs trailing arm. You will run into another problem ISR will not let you run aluminum leaf springs on your skis. Some of the sleds had their gas tank up front where mid season were put on the tunnel. The tunnel that they used was a Sno jet Thinderjet the bulk head they custom made it. ISR will not let you run the trailing arms either its not safe. Safety is key the rules also state a battery tail light, closed in back panel all the clutch guards are mandatory to be closed off including belting on it. It’s nice you want to make one and make the prints I’m trying to help you a few of us has been down this road before and I’m here to tell you it’s down right frustrating because you can be a 100% legal to their rules to have them tell you can’t race it here. The guys from Kawasaki that raced and put these together are great people reaching out to them might be tough. Gregg Channel raced them and very knowledgeable about the sleds. The welder is still around not sure if he remembers all of it just like the others including Jacques but again what was isn’t legal to race now and that’s a fact.

[sprocket]

You are going to run into a problem with the engines. Most of them don’t exist. So you’ll have to do what I did to be somewhat close to original. The Kawasaki group told us they used the T7 bottom ends with cylinders that look like the 550 except the exhaust port runs Horizontally not vertical also the heads were individual dual plug you would have to have them made because they don’t exist,. They ran a belt drive external pump off the engine. Not one engine had oil injection so that throws out the Invader engine. The chain case they used was a sno jet with a plastic cover the brakes they used were Kelsey Hase. The clutches were Kawasaki because they had to run what came from the factory where ISR rules state any clutching same goes for the chain case. Any mod pipes with a silencer on it. If you have any of the sno pro books the Kawasaki shark sat really low & wide to the ground. Another thing is ISR will not allow offsetting in a super mod leaf spring class, the IFS class it is allowed how much they had idk. Also from the tunnel to the front those sleds in length were 7’-8’ at most

[sprocket]

If ISR would allow you to run any Kawasaki engine that would be great as long as it fits the rules you should be ok. In IFSX class you can run any engine only that class though. I know for a fact these sleds will not fit in a super stock class or a stock class only a mod or ifs, IFSX class

[Interceptor398]

Greg and his Shark at Waconia 2010

[Ameritude]

the information you packed into those two short posts was incredible, thankyou Sprocket! i messaged back and forth with Al and got a gist of what he was all about, maybe it was the disconnect caused by digital messaging, but he seemed to take offense to the idea that i wanted to make something that he had already made, either way, he was very knowledgeable and i respect his work a ton. He also heavily informed me that all of his chassis are perfectly legal and run at eagle river just fine... i don't know where the confusion on that is coming from, but that is neither here nor there. from what you were mentioning about trailing arm suspension, im a bit confused. From my research there isn't anything within the isr rules that prohibits that type of suspension and from researching recent years of people within the classes, there seems to be multiple sled with that style of suspension, i am probably missing something but i cant figure out what it is lol. I want to race in either "IFS sno-pro" or "IFS sno-pro X" just matters which one i can fit. as for motor, both of those classes allow for any motor, they are basically just cc limited, however, the coolness of this project imo comes from the "Kawasaki" name, thus i will be developing and building some 8 port motors for the sleds (if i can find some more cylinders) I recently designed and built a motor dyno, so this summer will be filled with testing and development on those motors, aiming for 115hp at-least, we will see what happens. From some people that ive talked to, i got some images of the original cylinders and some measurements too, they were 8 port and the crankcases look very interesting, a bit different the t7s i thought, but it might have been perspective. So far i have 7 or so different objects on the sleds, that i know the exact dimensions of. With these, i can calculate the distance away from the snowmobile that the picture was taken and use that measurement to figure out the dimensions of most other things within the pictures. what ive been looking for the most is a picture that includes the front of the hood and the tunnel all in one, with that i can pull a ton of measurements from the hood and start that design process. My goal is to create some blueprints that are to the exact dimensions of the sled, so that i can modify the chassis to my liking, modernization and safety, that fit within the rules based off of the "original" dimensions. in your opinion Sprocket, would you put the gas tank at the front of the sled or the middle? i was thinking middle for weight distribution and impact safety. thankyou again for all of your help ive been learning a ton over the last week or so.