Ideas for a vintage racing sled??

[Smokin'Gun]

Im puttin together a vintage snowmobile to race at the great eastern whiteout vintage show next february and i need some of you snowmobile guys ideas of what i should do to it to make it a winner. Most of the sleds are just things people put together to race because the race is an oval track with water, mud and slush on it. Right now i have a 1972 18" chassis with a good track and double link chaincase and a 1972 440 motor. Im going to do the twin-carb conversion and if i can find the right intake boots im going to put mikuni carbs on it because tillotsons are a bitch to tune right, im going to have a friend that builds pipes build me a set of race pipes, im going to re-gear the chaincase for acceleration, put a comet 108 clutch on it and tune it up nice, cut the head to raise compression, have the cylinders ported, and balance the crank. Im also going to take the big 6 gallon fuel tank out and put a 2 gallon tank in and figure out a way to widen the ski-stance wether it be the bolt on wideners or to actually cut the chassis up and widen it which would be alot better than a bolt on. My question is how much should i cut the head down so the motor is still good and reliable because anyone that runs these old sleds knows that they arent too reliable to begin with but i really dont care if i have to run race gas or not as long as the sled will be reliable enough to race and ride without having to rebuild it preferably at all. Also i need to know the names of a few good shops that could port the cylinders around western massachusetts if anyone knows some please tell me. Im also thinking about doing some wiseco pistons but this race is just for kicks so im not big on spending a ton of money on a race that has no prize but a trophy just for fun but ya kno you gotta win.

[flotek]

to take a vintage design no ones sure of and just start saying numbers& shaving may be very bad, your going to have know a few thing first, porting, how muchand what porting and how extensive this is going to be, fuel choice,ignition timing, and this especially **** current squish band clearance when its assembled WITH gaskets***. without that your gonna wad your sled motor . oh yeahdefinitly get flatslide mikunis, not round slides PM me ill help you through it

[Smokin'Gun]

Im keepin the tillotsons and I know how to build a rock solid motor but I know nothing about doing the porting work and head milling. I found out that AAEN does vintage race porting for $155 a cylinder and vintage head milling for $55 a head which is somewhat steep to me but its also worth it because they know their stuff theyve been doing it for 30 years. The timing and everything else is no big deal to me Ive been setting up ignitions since i was 10 years old on those snowmobiles. I really wanna get the pipes made up.

[rivet]

HOw long is the race? Is the course rough or smooth? What kind of racing? Flat out? To make decisions on what to modiify we nead to know how the sled will be used.

[369DuneBunny]

are old josnson sleds and good....

[rivet]

For boat anchers! Well to be fair the small rampages and such were at least under 350lbs with 25hp while the other models werre 700lbs and propelled by 30hp. Not race sleds

[369DuneBunny]

that and was supposed to be "any"
there's a couple for sale on here that look like they are from way back, that's why i was wondering?

[Smokin'Gun]

Originally Posted by rivet

For boat anchers! Well to be fair the small rampages and such were at least under 350lbs with 25hp while the other models werre 700lbs and propelled by 30hp. Not race sleds

Im talkin a vintage sled with 100+hp. They dont have much hp stock but theyre held back alot with shitty ports, bad carb setups and can exhaust. Oh and the race is usually 1/2 - 1 mile oval track that is somewhat smooth. The last race that i went to is 5/8 milel ong.

[flotek]

2 stroke engine performance has made huge leaps and bounds since the days when they thought a 2 stroke pipe should be similar in design to a 4 stroke pipe and crude intake and smal l poorly placed and sized ports made narrow low power dogs , id do some extreme porting find bigger dual carbs and plenty of compression

[Smokin'Gun]

Yea I got dual AAEN pipes that i found at a used parts shop, milled the head down raised the compression to 185psi per cyl., had it ported to hell, found some NOS wiseco high comp. pistons and i had a guy cryogenically freeze the pistons and cut ports in them, balanced the crank, lightened the flywheel, put a NOS comet race clutch on it, got bigger mikuni carbs and im probably forgetting something but thats the gist of it. Its going on in a pro-stock oval chassis that im getting from a friend soon. My guess is anywhere from 95-110hp its only a 250cc twin cylinder f/a motor (change of plans) and the motor made 80hp stock. I gotta get the chassis and stuff so hopefully ill be racing next season with it.