Ice racing in the middle of summer !!!!!

[TecateDan]

Okay more like armchair ice racing in the summer. You guys who know me know I've built a couple of machines on the site now. I'm going to be building a motor for a project that a fellow member will be building. It's an older air cooled 250r that will be built for Ice racing. High compression with race gas only. My question for people out there is what range port / pipeing is best for ice racing. I was thinking that more of a Low end woods or mx combo but not big into ice racing so looking to here what people are running.

[eddie pettengil]

What kind of ice racing will he / she be doing ? Will they be racing with quads or just trikes ?

Our Ice racing tracks in NH/ME have different layouts and multiple motors would be nice. I run a ESR310 with trx9 port. Its great on the 1/4 mile oval or on any track design with lots of momentum. When we get on the tight road course or small oval tracks its a major problem.

I would not do a bottom end port. You want something that gets tire spin with a snap of the throttle but also have some pull. Even on the tight tracks you usually have enough rpm to make a bottom end motor useless.

What I want when racing is a motor that gets the tires spinning instantly. Once the trike gets sideways I back off the throttle for traction and then rely on the pull of the motor.

[fastatc70]

We run a tight track in MA. I have found a motor with a lot of pull good mid range / top. If the track is full I run close to the snow on the outside line for the first couple of laps to get a good position.

I raced a banshee 370 long rod in 3rd gear in the corners and 4th on the straights. I have never run a three wheeler in a ice race. Hope this helps.

[Dirtcrasher]

They seem to want a strong mid with a great pull on top. Eddie knows his chit.......

[eddie pettengil]

Here is my short track motor, completely stock, reeds, carb but has a bottom end port with the atc5 esr pipe. Anything bigger than a track this size its completely useless. This motor spins the tire with a crack of the throttle but barely gains speed down the straights. This was my first time on a dirt track with the trike. The track was major tacky and I was running American Racers tires and had to much traction. I know its not ice racing but its as close as you will get.

http://www.youtube.com/watch?v=yJqhF7ippew

[TecateDan]

I'll have to double check what he has in mind. I'l assuming since he live in NH and heads north that a lot of the stuff will be of the faster nature. THanks for the info and feel free to send more


What kind of ice racing will he / she be doing ? Will they be racing with quads or just trikes ?

Our Ice racing tracks in NH/ME have different layouts and multiple motors would be nice. I run a ESR310 with trx9 port. Its great on the 1/4 mile oval or on any track design with lots of momentum. When we get on the tight road course or small oval tracks its a major problem.

I would not do a bottom end port. You want something that gets tire spin with a snap of the throttle but also have some pull. Even on the tight tracks you usually have enough rpm to make a bottom end motor useless.

What I want when racing is a motor that gets the tires spinning instantly. Once the trike gets sideways I back off the throttle for traction and then rely on the pull of the motor.

[Jason Hall]

I didn't watch the video, but wonder if a sprocket change would help your engine on a longer track. IMO you want power everywhere on the ice. I like the term Derrick Adams uses when racing. It is (Where Ever You Ain't) lol. So another words, if you are in the heat of the battle it would be nice to have low end power to cut inside, and mid / top end power to carry momentum on the outside. I know from Experiance that the air cooled R has a Very nice smooth wide power spread. IMO it would be best to make more power through that nice wide power range. So I would suggest making the exhaust port bigger all the way around slightly, and not raise or widen it that much. Open the intake up as much as you can. IMO you don't always need to go nuts on port timing to make a 2 stroke Run!! Attention to detail in every turn and bend the air / fuel makes will make more power in the stock rpm range. A bigger carb is a must with a air cooler, so I would look for a 36mm PWK. If you want more top end pull play with the flywheel lol. It's amazing what adding weight and taking it away will do for your power curve.

[TecateDan]

Thanks Jason! I'm thinking of maybe going 300CC if I can find a kit for hte 81 and as you mentioned Just massageing the ports so everything flows really nice and Smooth. I'm usually not a huge fan of changing the porting that much either so glad to here I'm not the only one. Will have the head milled, squish set and re-cc'd for race gas. Prob go 38mm kiehin AS for a carb. and not sure about pipe. More than likely will have the guy who built my drag pipe for the 500 build an inframe pipe for mid to high power. Dependibility is always key for me so this motor will running well is the most important