Newbie Needs Advice

[12348910]

”He was a person who worked on and loved machines all his life. Little did he know one would be the cause of his death, but if he had known, we are sure he would have chosen no other way to go. However, we all agree it would have been nice if it could have come at least 40 years later."

Sounds like me but I know I’m gonna die doing something like that

 

[Whitetrashrocker]

You can go fast with no brakes, but you can go faster with brakes.

What are you going to do about power delivery. Your gonna need a jackshaft.

 

[Speedster]

Your gonna need a jackshaft.

Do what?

You can go fast with no brakes, but you can go faster with brakes.

I am definitely going to put brakes.

 

[Speedster]

Ok, how about one of these: BMI karts axle kit and 2 of these: BMI hubs
Whitetrashrocker, you were correct I could get the same kit and axle cheaper at BMI karts. But while I was looking for that, I saw that one kit with the brakes, and realized I needed those. So I went with the other kit.

 

[Whitetrashrocker]

How are you gonna connect the engine to the axle?

Engine pto gets the driver half of the cvt. The axle has the big sprocket.
There a part in the middle. The driven half of the cvt and a small sprocket. These will need to be on a shaft of their own. A jackshaft.
The cvt halves will need to be spaced at a fixed distance from each other. The chain side of that will need to be adjustable for various reasons. Chain stretch, sprocket size change...

Have you been reading up on steering geometry?
How about the length/width ratio?
Seat, steering wheel, pedals, linkages, lights ,stereo?

 

[Speedster]

Seat, steering wheel, pedals, linkages, lights

I was gonna fabricate all those. Except for the cables. Believe me, I can do it.

stereo?

No kidding, I was gonna come up with a radio system.

Have you been reading up on steering geometry?

A little, I'm gonna do a lot more.

How about the length/width ratio?

I printed out a picture of the GoPowerSports American Express 2.0, and made a scale drawing. Whatever the ratio is on that is what I will have.

How are you gonna connect the engine to the axle?

I thought this is how it works, please correct me if I am wrong.: The engine turns the driver in the torque convertor, the belt on that turns the driven, the driven turns a gear, the gear turns the chain, the chain turns the axle. (on the house that Jack built)

 

[Whitetrashrocker]

Sounds like you have it almost figured out.
Yes you have the drive line in the right working order. I was getting at, how do you keep the cvt at a stationary distance while having the chain side adjustable while having a stationary axle.

 

[Speedster]

Sounds like you have it almost figured out.
Yes you have the drive line in the right working order. I was getting at, how do you keep the cvt at a stationary distance while having the chain side adjustable while having a stationary axle.

CVT mounts to the engine, which will slide to adjust the chain length. I think? Alternatively, I was considering fabricating a chain tensioner.

 

[Whitetrashrocker]

If I remember right. The 30 has a back plate. The 40 doesn't, just 2 pulley halves.

Here is some pics of mine.
This holds the driven and the drive at a fixed distance. Then the whole assembly, with engine slides to tension the chain.
Keep in mind that if your using a 8 or 11hp engine you have a big block and not a small block like the 212. Different mounting plate size.

 

[Speedster]

If I remember right. The 30 has a back plate. The 40 doesn't, just 2 pulley halves.

Here is some pics of mine.
This holds the driven and the drive at a fixed distance. Then the whole assembly, with engine slides to tension the chain.
Keep in mind that if your using a 8 or 11hp engine you have a big block and not a small block like the 212. Different mounting plate size. View attachment 147291View attachment 147292View attachment 147293View attachment 147294View attachment 147295

Thanks man! Here is the one I am gonna get, it comes with a backplate, so I think it should work great. And it says that it is for 8-16hp engines, so it should be fine with the big block. And if the holes don't line up, I can slap it on the drill press.

 

[Whitetrashrocker]

Looks like that should work. I'm. not a parts surfer so I'm sure there lots I don't know.

 

[Rat]

If I remember right. The 30 has a back plate. The 40 doesn't, just 2 pulley halves.

Here is some pics of mine.
This holds the driven and the drive at a fixed distance. Then the whole assembly, with engine slides to tension the chain.
Keep in mind that if your using a 8 or 11hp engine you have a big block and not a small block like the 212. Different mounting plate size.

If you can find a full 40 series kit (rediculously priced) then they have a cast aluminum backplate just like a 30 series... might even be the same one IDK.

THEN there is of course the jackshaft engine mount variety Which give you a little bit of adjustability on the belt if I'm not mistaken and as usual the chain tension as well.

 

[Speedster]

If you can find a full 40 series kit (rediculously priced) then they have a cast aluminum backplate just like a 30 series... might even be the same one IDK.

THEN there is of course the jackshaft engine mount variety Which give you a little bit of adjustability on the belt if I'm not mistaken and as usual the chain tension as well.

So the other kinds are lower priced? 'Cause I thought the price of the full one is kinda high.

 

[Rat]

So the other kinds are lower priced? 'Cause I thought the price of the full one is kinda high.

Idk for sure, 40 series in general is more than double the cost of a 30 series on average. A 30 series can handle a fair bit more than it's recommended 8hp limit... some guys use them on 12hp engines without issue.

It's near impossible to find a 30 series for 1" shaft, and almost as difficult to find a 40 series for 3/4" shaft... both do exsist




Somewhere

 

[Speedster]

40 series in general is more than double the cost of a 30 series on average.

Yeah, I found that out.

some guys use them on 12hp engines without issue.

I still think I will go with a 40 series, just to be sure.

 

[Speedster]

How do you all think my acceleration will be? 11hp engine, 18 inch wheels, 40 series torque convertor, and probably like 250lbs total, rider included.

 

[Whitetrashrocker]

Depends on your gearing.
You could gear it to do 100mph. But you would need a push start, cause it wouldn't pull it self at that gearing.
Or you could gear it to pull a semi, but would never get anywhere at a snails pace.

Normal gearing will definitely put a smile on your face. Don't worry, once you get going you will always want to go faster.

 

[Rat]

How do you all think my acceleration will be? 11hp engine, 18 inch wheels, 40 series torque convertor, and probably like 250lbs total, rider included.

Wheel size isn't useful information anyway, now in the event you meant the rolling diameter of the [drive] tires inflated then 5.5:1 is the absolute highest, but it may well be really hard on the belt and cause engagement shuddering of the driver clutch (scary AF feeling especially on 2 wheels) so ideally you'll want 6:1 (The golden ratio of Karting) that 12t would need a 72t on the axle to achieve 6:1

For the sake of experience and experiments I recommend going with a split sprocket set up, make it easy to swap gearing until you're happy without being forced to disconnect everything and knock bearings out of seat.

 

[Denny]

That axle kit is the one you want. Just step up to an #40 chain it’s stronger. Excellent! Your 40 series choice is a good one too. Stick to the 6:1 ratio or 5.4:1 at the highest. Once you get the CVT kit get the number off the belt and replace it with a Genuine Comet belt. I’m glad to see you learning! And yes, brakes are handy to have and drum brakes do work good.

 

[Speedster]

that 12t would need a 72t on the axle to achieve 6:1

I just checked, and I am a lucky dog. The kit that I have in my cart at BMI karts has a 72t sprocket. Which relieves me the necessity of more searching.