car transmission in go kart?

[Swabbster]

i has looking around on youtube and i found a video of a homemade 3 wheeled go kart, the guy used a honda clone and a pulley belt tensioner sutup going into a old car transmission, i am planing out the build of my buggy and id really like reverse, and gears, a bike motor has gears but no reverse, one question if i used a snowmobile motor and to to shift let off the gas and shifted would that **** the transmission? have torque applied to it, id assume not, the reason im asking is because the clutch will not fulley dissengage, it would not be hard to install it and setup jackshafts because in the end you have 3-5 forward and reverse, and reverse is needed for trail riding, has anyone here tried this before? getting the shifter setup may be a challenge, at this point its just an idea

 

[fowler]

It wouldn't be too hard to do
Just some expensive machining To be done

But it really isn't worth it
Car gear boxes are power hungry
U will lose a noticeable amount of power running one

It would only be worth it if u were running 200hp up

Because of my latitude I know little about sleds but surly like quads most would have reverse Anyway

 

[Doc Sprocket]

Way, waaaay too big and heavy. Maybe look into race-prepping a good mower transmission.

 

[fowler]

If u are using a bike or snow mobile engine I'd be looking for a FNR box

U can get boxes that are for industrial motors to run accessories like a grain auger
They usually have just forward and reverse they have big heavy gears made for a lot if torque and they are usually in a metal box and weight around 7kg

U could make an ally box to put the gears in and lose a bit of weight
The only concern with a mower tranny would be can it handle 70+hp

Basically u will pay big for reverse

 

[r97]

If you want ideas for reverse, look over at minibuggy.net, lots of discussion over there. People have used car transmissions, but as fowler said, they need big power. I'm planning to make my own reverse gearbox, but if you want to do the same be sure you know a machinist, and be prepared to drop some dough on it.

I think a decent sized motorcycle engine would rip a lawn mower trans to shreds. If you really wanted to use one you would probably want a small-ish snowmobile engine.

 

[fowler]

well a mower trans is for s 15 to 30hp motor and takes very little torque

u are putting anywhere from 40 to 200hp though it at at least 7000rmpm and alot of torque

when are u going to start this buggy r97
sounds like u have some wicked deals going or u have 10 grand in the piggy bank

 

[Swabbster]

well i was looking at a 3 speed transmission at my school, its about 2 1/2 feet long, but the tail is what makes it long, it is removable and i could get a back plate machined for it, then i have a four long transmission, i can get both input and output shafts machined down to 3/4 or 1 inch keyed, my mechanics teacher told me i should find a small car like a 3 cylinder (FWD) engine trans and cv's what do you guys thing, most (FWD) engines and trans are cable shift, so i could re mount the shifter beside the seat,

 

[r97]

well a mower trans is for s 15 to 30hp motor and takes very little torque

u are putting anywhere from 40 to 200hp though it at at least 7000rmpm and alot of torque

when are u going to start this buggy r97
sounds like u have some wicked deals going or u have 10 grand in the piggy bank

I have started it, I'm finishing the CAD model, and putting the engine back together. I got all the necessary gears for very little, and I will be casting aluminum cases. I live near the sea, so there are a lot of machinists around (for boats). Many of the shops are a one man show, and the people are pretty cool, so I'm sure they would take me under their wing a bit in their spare time. It will be a slow process, but that can be a good thing. No ten grand in the bank, my buggy is being put together one part at a time.

 

[AusArrow]

Has anyone considered using a Harley transmission in a kart, chain driven off the engine and are cheap

 

[Swabbster]

Has anyone considered using a Harley transmission in a kart, chain driven off the engine and are cheap

would it have reverse, Harley as in Harley Davidson?

 

[GregMartin]

If u are using a bike or snow mobile engine I'd be looking for a FNR box

U can get boxes that are for industrial motors to run accessories like a grain auger
They usually have just forward and reverse they have big heavy gears made for a lot if torque and they are usually in a metal box and weight around 7kg

U could make an ally box to put the gears in and lose a bit of weight
The only concern with a mower tranny would be can it handle 70+hp

Basically u will pay big for reverse

There are also forward and reverse boxes that are used in motor sport. There are various classes of racing cars around the would that use motorbike engines and gearboxes they almost always have a F/R box in the drive train.

 

[Doc Sprocket]

The Harley box suggested by AusArrow, it's not likely to be "cheap". If it were, it would be a very common thing to do. Same for the F-N-R race boxes mentioned by Greg.

I suggested a mower transmission because they are inexpensive ($100-$200) for an already race-prepped brand new Peerless 700) and are used in some racing events. Sure- you're probably best not to feed 'em more than maybe 30 or so HP, but I did not see a reference to engine size. If I missed it, I apologize.

A transaxle from a small FWD car is STILL going to be a large, heavy bit of kit. Yes, it can be made to work, but, it's very much like killing a fly with an RPG. The fly may well end up dead, but so will the whole village. As much as I like to over-engineer things, some concepts go well beyond prudent.

Honestly, If we're talking maybe 40-100HP range, your best bet IMO is to source either an ATV or snowmobile with reverse, and take what you need. The components are pre-engineered for compatibility and suitability already.

 

[GregMartin]

I looked at using a ride on mower Spicer transaxle at one point but I was worried that it wouldn't take the RPM because it was filled with grease and not hypod oil so I looked no further. If there are oil filled ones out then I recon they would work quite well.

 

[Doc Sprocket]

I looked at using a ride on mower Spicer transaxle at one point but I was worried that it wouldn't take the RPM because it was filled with grease and not hypod oil so I looked no further. If there are oil filled ones out then I recon they would work quite well.

This is why I specifically said, "Race prepped mower transmission. I am not speaking of a factory-stock unit, and for that matter, not a transaxle, either. A transmission.

 

[GregMartin]

This is why I specifically said, "Race prepped mower transmission. I am not speaking of a factory-stock unit, and for that matter, not a transaxle, either. A transmission.

I think you have me confused with someone who is disagreeing with you!

 

[Swabbster]

i have a peerless transaxle from 82 and it looks pretty beefy, i was wondering about modifying it like build a new case or something so i can run bearings rather than bushings, and just have f-n-r, do you guys think it is worth it to setup reverse? i guess i could just find a big opening, or electric reverse, possibly make a electric starter for it so i could fire it up backwards?

 

[Doc Sprocket]

It's up to you. I found that I miss reverse a lot less than I thought I would. For a kart, I wouldn't bother. If I was building a trail buggy, ATV, or UTV, I would have reverse.

Definitely NOT worth the incredible effort required to engineer a new case.

 

[GregMartin]

I just saw a post from FatCat about a F-N-R box advertised on bmikarts web site for $245.
http://www.bmikarts.com/item/Comet-Forward--Reverse-Gearbox-800350-3191

 

[r97]

That box is only rated to hold up to a 16hp industrial engine running a CVT... most bike engines will rip it to shreds.

 

[GregMartin]

That box is only rated to hold up to a 16hp industrial engine running a CVT... most bike engines will rip it to shreds.

Yep you get what you paid for!