I wonder what other ice racers do for carb heat. This might be a case where a simple glowplug setup run off a tool battery might do the trick.
You should send a petition to ROK USA to make the Florida Winter Tour up north, where the it’s actually winter and the tracks are on ice 
2 Likes
That thought crossed my mind when we were going to be at the stadium at the state fair
1 Like
Warm air intake mod. It works, but not sturdy enough to survive the wrath of Karting yet. The temps down at near -30 with windchill are challenging to say the least.
2 Likes
You know you are all mad, correct?
1 Like
You should talk to Prokart’s turbo engine that should keep the intake air nice and warm.
1 Like
Funny you should mention that. I asked Scotty if we could put one of our 460’s on the dyno.
Sounds like you’re from MN then?
Made a gif…
6 Likes
Yes sir. Maple Grove track is like 5 min away.
1 Like
Griiiiiiiiiiiiiip. Sort of.
It’s actually hard to say where we are on jetting given head temps are at.
In general it seemed like the air screw was against the stop with the stock GX 390 jet of .018", and our motors are 460 so probably not a surprise there. For the kart I’m focusing on I went from .018" pilot to 021" (Drilled it out) that seemed to help with idle once I worked the engine hard and got temps into the 225 range. That kart also has added shrouding to the fins to reduce the amount of -30F air crossing them.
There’s a lot of variables… Hoping we are close between raised pilot jet, warm air intake and some shrouding.
1 Like
I was thinking you would need something to help hold the heat in the cylinder a bit too. Can you go a step further and maybe wrap some kind of insulating material around the cylinder? Not sure how much heat is lost through the fins versus out the exhaust. At such low extremes, you might get sufficient cooling just from heat venting through the exhaust and the very cold air coming into the intake.
It might be one of those things that once the engines get warmed up, you will have to leave them running constantly to keep them near ideal operating temp.
1 Like
Q: Say, do you know where I can get a block heater for my kart engine?
A: Air or water cooled?
LOL
1 Like
I think this is about as clogged as an idle circuit can be. This is from last night before we made changes. Air temp about -20 F
This seems to have fixed things…
Removing the crankcase breather from the airbox, Going from 0.018 to 0.021 on the idle jet
Feeding the carb a little warm air
Blocking cooling air from some fins…
…we’re looking good.
Insulation for the block, or even removing the fan are not off the cards yet. The crankcase breather would probably stop freezing up if we kept more heat in the block.
3 Likes
Quick update off the top of my scattered brain.
This project is going to kill me. Uncovered a few things. One being the brand new carbs have a smaller idle passage compared to the old ones. I haven’t compared the jets yet. Between keeping temps in range and going back to an old carb, idle tuning issues seem to be solved.
Now experiencing shutdown after sustained periods of high loads. Slow driver 6mins, fast driver three mins. At this point fuel delivery to the carb is the only remaining suspect. Moved fuel pump temporarily to the head and that seemed to solve it… then the spark plug cap cracked, causing running issues and we called it a night.
Hopefully we’ll have it all figured out today to put on the other karts.
.
5 Likes
It’s a shame you’re one of the first to do this, because there’s a lack of information, but I’m sure you’ll figure it out. Best of luck, can’t wait to get down there
1 Like
Yooooo thats awesome congrats! Wish I could go up there
1 Like
Awesome!!! I really hope this works for you. It’s such a cool (literally) idea.
1 Like
Finally some video of the actual karts. It was challenging to find time to shoot with everything else going on, but here’s some “expressions” as the pros would say.
8 Likes