tinamcjittles
ello m8
Looks like it should be flying! You going to put a wing on the front or rear for extra downforce?
Building a Race Kart
- Thread starter Mammoth
- Start date
- Status
Flyinhillbilly
The great cornholio
That's looking good, nice work.
Mammoth
Active member
The wing will be on top of the roll cage just like a full size sprint car. I will get some more pics when I get it back on.
The steering wheel was 13" which is way bigger than it needed to be so I got a 10-3/4" to take its place. The new one is about half the weight.
Then made the windshield fit around it.
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It's a snug cockpit.
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The steering wheel was 13" which is way bigger than it needed to be so I got a 10-3/4" to take its place. The new one is about half the weight.
Then made the windshield fit around it.
It's a snug cockpit.
Mammoth
Active member
Had to angle the plumbing straight back to lower the reservoir.
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Then made a bump over it.
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Made a spoiler to help push down on the rear tires.
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Took a whole week off from work. My first real time off in 6 years, and I've been working on this around the clock.
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Then made a bump over it.
Made a spoiler to help push down on the rear tires.
Took a whole week off from work. My first real time off in 6 years, and I've been working on this around the clock.
Mammoth
Active member
Made this fitting for the pulse pump..
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Shaped a steel brake line from the fitting to the pulse pump. This solid steel line will help keep the fuel pressure high unlike rubber hoses which will expand each pulse. The last thing I want to do is run it lean on fuel.
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Shortened the clutch handel to match the size of the steering wheel.
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Made a chain tensioner bolt.
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Ballanced the tires.
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Ended up putting about an ounce on each tire.
These karts have a tendency to snap the right front spindles off during races. You can probably see why.
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Added some strength and then had it cryofroze.
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Shaped a steel brake line from the fitting to the pulse pump. This solid steel line will help keep the fuel pressure high unlike rubber hoses which will expand each pulse. The last thing I want to do is run it lean on fuel.
Shortened the clutch handel to match the size of the steering wheel.
Made a chain tensioner bolt.
Ballanced the tires.
Ended up putting about an ounce on each tire.
These karts have a tendency to snap the right front spindles off during races. You can probably see why.
Added some strength and then had it cryofroze.
Flyinhillbilly
The great cornholio
Oh baby!!!
Are those threaded 22's?
If so where did you get them and for how much?
PM me if you like.
Are those threaded 22's?
If so where did you get them and for how much?
PM me if you like.
Mammoth
Active member
Would you believe I've been working every weekend for 3 months on the left side air box, and it's still not done.
It's close though.
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It's close though.
Mammoth
Active member
Ended up going round and round on the electronics. After major testing of three stators, two coils and two cdi boxes all that was happening was weak spark. Three quick pops from of the engine and then it would die.
With the limited info on the web about this motor I had all my friends scratching there heads on what the problem was.
I contacted opfermanmotors and he sent me some pics of his electronics on one of his bikes.
Low and behold they showed the solution. The coils I had were the wrong ones.
After installing the correct one it still wouldn't fire.
With some time thinking about the problem it became apparent I made an error.
The pulse pump that I plumed into the carburetor intake mount was on the wrong side of the reed cage. With it like this it won't pump fuel strong enough. Face palm.
The solution was to drill and tap a hole for a fitting on the engine side of the reed cage.
After this was done it fired up, and so the tuning began.
I rushed to get it ready for the track. Had 2 hours in the mourning to get the carb diled in. Which consisted of finding a quiet spot on the street, and ripping it back and fourth getting all the sputters out. Kept a close eye on the temperatures by using a mychron 5.
It was doing 86 mph at 6900 rpm, and 200* temperature. This was without the body and wing.
Then ran to the track.
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With the limited info on the web about this motor I had all my friends scratching there heads on what the problem was.
I contacted opfermanmotors and he sent me some pics of his electronics on one of his bikes.
Low and behold they showed the solution. The coils I had were the wrong ones.
After installing the correct one it still wouldn't fire.
With some time thinking about the problem it became apparent I made an error.
The pulse pump that I plumed into the carburetor intake mount was on the wrong side of the reed cage. With it like this it won't pump fuel strong enough. Face palm.
The solution was to drill and tap a hole for a fitting on the engine side of the reed cage.
After this was done it fired up, and so the tuning began.
I rushed to get it ready for the track. Had 2 hours in the mourning to get the carb diled in. Which consisted of finding a quiet spot on the street, and ripping it back and fourth getting all the sputters out. Kept a close eye on the temperatures by using a mychron 5.
It was doing 86 mph at 6900 rpm, and 200* temperature. This was without the body and wing.
Then ran to the track.
Mammoth
Active member
Ive never raced before so it was a bit frantic to get signed in and figure out what to do.
Worked feverishly to get the body and wing on in time for heat races.
When it was all together I rolled it out of the trailer in order to warm it up and thats when people started to notice something was different here.
I fired it up in the pit lane with lots of people staring. Yep its an oddball to them.
Missed the heat race in all the staging mayhem, but I got to run in the first qualifying race.
As soon as I got on the track and hit the first turn with some speed I realized the steering wheel took a tremendous effort to move.
The faster I went the harder it was to turn. I guess all the work done to the skid pan and wing were creating lots of downforce which was acting against the caster setting.
I musseled through the whole race keeping it straight with no spinouts, and by the time I got back to the pits I couldn't even lift my arms.
Had one other issue where my leg was burning because the radiator hose was so close.
With the body being on, and pushing it hard the engine got hotter then the test in the streets. 246* degrees which is too hot to be running a two stroke.
The whole purpose of getting it on the track that day was to figure out what it would do.
Even though I qualified for the next race the info collected was enough to call it a day.
Now theres a long list of things to adjust in order to make it fast on the track.
Here is how the pulse pump got hooked up.
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Here is how the water temperature sensor is hooked up for the mychron.
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Here is how the exhaust gas temperature sensor is hooked up.
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Worked feverishly to get the body and wing on in time for heat races.
When it was all together I rolled it out of the trailer in order to warm it up and thats when people started to notice something was different here.
I fired it up in the pit lane with lots of people staring. Yep its an oddball to them.
Missed the heat race in all the staging mayhem, but I got to run in the first qualifying race.
As soon as I got on the track and hit the first turn with some speed I realized the steering wheel took a tremendous effort to move.
The faster I went the harder it was to turn. I guess all the work done to the skid pan and wing were creating lots of downforce which was acting against the caster setting.
I musseled through the whole race keeping it straight with no spinouts, and by the time I got back to the pits I couldn't even lift my arms.
Had one other issue where my leg was burning because the radiator hose was so close.
With the body being on, and pushing it hard the engine got hotter then the test in the streets. 246* degrees which is too hot to be running a two stroke.
The whole purpose of getting it on the track that day was to figure out what it would do.
Even though I qualified for the next race the info collected was enough to call it a day.
Now theres a long list of things to adjust in order to make it fast on the track.
Here is how the pulse pump got hooked up.
Here is how the water temperature sensor is hooked up for the mychron.
Here is how the exhaust gas temperature sensor is hooked up.
Mammoth
Active member
I raced it again last week, and I could go on an on about the challanges me and my friends are overcoming, but I don't know how interested you guys are with that stuff so I will just write about some of the more noteable things.
The competition is quite fierce out there. Guys are willing to push all they got to win.
I've only done about 20 laps so far, and have passed by several wrecked karts that fell out of the front.
After the second race there was some signs of trouble with the engine so I did a full inspection.
As it turns out the cylinder wall started flaking off for some reason.
When I pulled the head off there were signs that it had been run lean at one point. The top of the piston had a little melt mark on the edge which caused one of the two rings to jam up.
This must have happened early on when there was fuel pump issues, because I had been running it real rich the whole time to avoid problems like this while were figuring the kart out.
Exhaust gas temps were alway around 700* degrees which means it's real rich. It could probably go as high as 1100* if it doesn't over heat first.
The whole time on the track it must have been running with only one piston ring, and the kart was holding ground.
The cylinder was sent off to get replated. Hopefully I will get back on the track soon.
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The competition is quite fierce out there. Guys are willing to push all they got to win.
I've only done about 20 laps so far, and have passed by several wrecked karts that fell out of the front.
After the second race there was some signs of trouble with the engine so I did a full inspection.
As it turns out the cylinder wall started flaking off for some reason.
When I pulled the head off there were signs that it had been run lean at one point. The top of the piston had a little melt mark on the edge which caused one of the two rings to jam up.
This must have happened early on when there was fuel pump issues, because I had been running it real rich the whole time to avoid problems like this while were figuring the kart out.
Exhaust gas temps were alway around 700* degrees which means it's real rich. It could probably go as high as 1100* if it doesn't over heat first.
The whole time on the track it must have been running with only one piston ring, and the kart was holding ground.
The cylinder was sent off to get replated. Hopefully I will get back on the track soon.
Ebrownie
Member
Man that engine looks awesome, I just saw this thread today. Just out of curiousity, where did you send your cylinder? I have a CR80 that needs a replate. I have looked at a few different places but I was wondering if you have any good or bad experiences with them.
Whitetrashrocker
Inmate #952016
**** yeah we're interested!
Got any vids to share?
Got any vids to share?
Flyinhillbilly
The great cornholio
It really is amazing how hard guys will push to win a $10 trophy. I've spent a small fortune winning a room full of cheap trophys. Sure was fun though.
Bubba_Z
Bubba_Z
Okay.....those tires...those wheels.....Please, Please, what are they??? Source?
Mammoth
Active member
The cylinder is getting nickel silicon carbide plated at Langcourt Performance in Alabama. My friend has been using their services since 1980 with no real problems. Just tell them the piston to cylinder wall clearance you want and they can do it.
I do have some videos, but nothing too impressive. As soon as I get some good footage spliced together I will share.
This track is the best oval I've seen so far. Its an 1/8 mile banked clay oval with lots of grip. Real fast times can be put down.
Even though no money is given out for winning this is a place where people can make a name for themselves.
Ive seen many people get big sponsors and move up in the race world. Many of them go on to full sized sprint cars.
Kyle Larson learned to race hear then he worked his way up to Nascar which he continues to do well in.
Thats the main reason people really push the limits at this track.
The tires and wheels were purchased from QRC in Red Bluff CA.
They are pretty standard in this type of racing. I'm running Burris tires, some people use Hoosier.
I went with the widest wheel I could to prevent side wall flex which will help get more traction.
They just got done racing tonight without me because the cylinder just had to fall apart. Oh well hopefully it will be ready soon.
I do have some videos, but nothing too impressive. As soon as I get some good footage spliced together I will share.
This track is the best oval I've seen so far. Its an 1/8 mile banked clay oval with lots of grip. Real fast times can be put down.
Even though no money is given out for winning this is a place where people can make a name for themselves.
Ive seen many people get big sponsors and move up in the race world. Many of them go on to full sized sprint cars.
Kyle Larson learned to race hear then he worked his way up to Nascar which he continues to do well in.
Thats the main reason people really push the limits at this track.
The tires and wheels were purchased from QRC in Red Bluff CA.
They are pretty standard in this type of racing. I'm running Burris tires, some people use Hoosier.
I went with the widest wheel I could to prevent side wall flex which will help get more traction.
They just got done racing tonight without me because the cylinder just had to fall apart. Oh well hopefully it will be ready soon.
Mammoth
Active member
Im still trying hard on this race project although its not been easy. Lots of set backs.
After getting the cylinder replated I redid the ceramic coating in the exhaust port which included baking it on. After baking a bubble appeared under the nickel silicon coating on the cylinder. I guess there was a contaminate causing this. So I had to send it back which took another two weeks.
Got it back together the day of a race. Fired it up to tune it in and the clutch locked up. Took it apart and found the thrust bearing had fallen apart.
Two weeks later after getting it back together was a day of a race and I only had enough time to do a quick couple of laps up and down the street to break it in, then rush to the track.
It ran the best yet right up until the piston wedged solid in the cylinder. Not enough break in time was the cause. I though this might happen, but I pushed it anyways.
Back to the plater it went for the third time only as it turns out the plater had closed its doors to business, so I had to find someone else.
After getting it back together it hasn't been easy to tune back in. Got it running semi good so I took it to the track and it ran bad.
Tough times.
After getting the cylinder replated I redid the ceramic coating in the exhaust port which included baking it on. After baking a bubble appeared under the nickel silicon coating on the cylinder. I guess there was a contaminate causing this. So I had to send it back which took another two weeks.
Got it back together the day of a race. Fired it up to tune it in and the clutch locked up. Took it apart and found the thrust bearing had fallen apart.
Two weeks later after getting it back together was a day of a race and I only had enough time to do a quick couple of laps up and down the street to break it in, then rush to the track.
It ran the best yet right up until the piston wedged solid in the cylinder. Not enough break in time was the cause. I though this might happen, but I pushed it anyways.
Back to the plater it went for the third time only as it turns out the plater had closed its doors to business, so I had to find someone else.
After getting it back together it hasn't been easy to tune back in. Got it running semi good so I took it to the track and it ran bad.
Tough times.
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