We have a go-kart that had an after market sprocket and clutch put on in replacement of a torque converter. the bore of the shaft is 1". I'm not sure what specifics are important when shopping for torque converters, or the best place to buy one. We can post pictures/ measurements to help with the search. All responses are appreciated, thanks in advance for your time.
need to know what kind of torque converter to buy and the best place to buy
- Thread starter boatman
- Start date
Smerft85
Member
Posting pictures would be best, wouldn't know what t/c to recommend without knowing engine size at minimum. T/c's are pretty reasonable on Amazon, as for the belt it will depend on distance between the pullies, size of gullies, and which converter you end up with. A 30 series is rated up to 8hp, and with a 1" shaft I'll bet you are 9hp or better, putting you into 40 series territory most likely, and they are a bit more money. There are 1" 30 series, but I wouldn't go over a 9hp with one.
This
I'm running a predator 212 cc. I can post more pictures when I get off work.
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Smerft85
Member
Predator 212 has a 3/4" shaft and the cheapest 30 series t/c on Amazon will suit just fine. You can get them as a complete kit anywhere between $60 and $100 each, they will have a belt but buy a quality back-up.
As for that jackshaft it looks like you have a 1" diameter spacer in front of the sprocket meant to take up the space of the driven pulley, back the nut off and see if I'm right please. Unless you need the gear reduction the jackshaft gives you, you may be able to get a 30 series with the backing plate and bypass the jackshaft altogether, then we are probably looking at a 10t #40 chain on the t/c and would need to know about your axle sprocket and tire size to get the gearing right, from the picture it looks like the axle sprocket is a #40, and the jackshaft almost looks like #35 chain, but may be the picture.
As for that jackshaft it looks like you have a 1" diameter spacer in front of the sprocket meant to take up the space of the driven pulley, back the nut off and see if I'm right please. Unless you need the gear reduction the jackshaft gives you, you may be able to get a 30 series with the backing plate and bypass the jackshaft altogether, then we are probably looking at a 10t #40 chain on the t/c and would need to know about your axle sprocket and tire size to get the gearing right, from the picture it looks like the axle sprocket is a #40, and the jackshaft almost looks like #35 chain, but may be the picture.
I already have the jackshaft taken apart and will send pictures of it as soon as I get home. Forgive me and my stupid questions, I am very ignorant as far as mechanical things go. will I have to do anything different with the lower chain? what is the best way to measure the axle sprocket? I assume that, like car tires, the size will be on the sidewall? Thanks, by the way, you have been a tremendous help already.
Bansil
Painter of gnomes....
Should/may have tooth count, if not a magic marker and count teeth
I apologize if I'm not using the correct terminology(corrections are always welcome). The jackshaft is 9 1/2" in length with 1/2" bore on the small end and 3/4" on the bigger end. The sprocket that appears to be permanently attached to the jack shaft has 10 teeth and the "pitch" (distance from tooth to tooth) is 1/2". The sprocket that slides on to the shaft has 21 teeth and the "pitch" is 3/8, the slide on socket is 5/8" - 11/16" thick. The clutch has 12 teeth and the pitch is 3/8" as well. The chain running from clutch to slide on sprocket is a #35 chain. The chain running from attached sprocket to the lowest sprocket is a #40 chain. The two spacers and nut on the end of shaft all have 5/8" interior diameter if I am measuring correctly. One spacer is 1 1/4" in length, the other is 9/16" in length. I'm not seeing tire sizes that I'm accustomed to, but I took clear pictures of both front and rear tires.
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Smerft85
Member
When you can get a count of teeth on the axle sprocket. You confirmed my thoughts on the two chain sizes used. To try to explain as simple as possible, everything related to the #35 chain will be extra parts to sit on the shelf forever once you get the torque converter. Since you have a jackshaft already, you should order the 30 series pullies only, forget about the backer plate. Make sure the driver pulley is for a 3/4" shaft, and if your 3/4" measurement is correct on the jackshaft in front of the 10t #40 sprocket, get a 3/4" driven pulley. Once you have them mounted you will measure center to center of the pulleys, and need to know the diameter of the driven to order the correct belt. I believe bmikarts.com and gopowersports.com are both sources that can help you acquire the correct belt. Your driven and driver pullies will take the place of your clutch, the #35 sprocket and the #35 chain, all your #40 stuff will likely stay how it is, but get that tooth count to make sure. With those tires a 6:1 should work well with a t/c so youd need a 60t axle sprocket, 68t would give better torque and less top end having a 6.8:1 ratio based on sprockets alone.
Which sprocket do you need a tooth count on, the lower #40 sprocket (has the most teeth of all my sprockets)? As far as the gear ratios go, I don't know anything about proper gear ratios, do you have any good guides for explanation? We will be driving this kart on an off road track through the woods that we cleared, not sure if that has any bearing on the gear ratio. Also are these the correct parts to order? https://www.amazon.com/Torque-Converter-Clutch-Driver-Replacement/dp/B076BSL5W3 ,https://www.amazon.com/BLAST-Diamet...en+pulley&qid=1588736026&s=automotive&sr=1-16
The first link is just for a driver pulley, the second looks like the driven pulley.
Smerft85
Member
Those would be correct, I forgot to ask if the shaft on your jackshaft is keyed? Yes the sprocket that is attached directly to the axle is the one I'm curious about, should be the largest and have the most teeth. With the approximate tire size I figure a 6:1 will do decent, if you are a heavier rider, say around the 200 mark, maybe bump up to a 68t axle sprocket, but I have a feeling if you have 60 teeth on that big sprocket you'll be just fine with the t/c. Any less teeth than that and you start running to high of a ratio, making acceleration weaker, but top speed greater, after a long while, also can wear parts faster if geared too high.
Tyre size is just measured from the ground to the top of the tyre (the diameter)
So, that lower sprocket has 60 teeth. Is it necessary for us to get a 68 tooth sprocket? We will commonly have riders weighing up to 250. Also will I need to change out any parts or simply leave the #40 chain and sprockets and replace the clutch and #35 sprocket?
Smerft85
Member
I'd try the 60t out before going to a 68t, partially because the diameter of a 68t is considerably larger than the 60t. If you are going with a t/c, order those pullies you asked about and run the #40 chain and sprockets that are already there. All your #35 stuff comes off. If the 60t doesn't get it moving off the line then I'd consider the 68t, or a 9t sprocket on the driven pulley, either way will give you a lower ratio, the 9t will be a bit more subtle on changing torque, but also wont drop your top speed as much as the 68t axle sprocket.
For now, run what ya brung with a t/c in place of the #35 stuff, it may be just right. T/c units offer a bit of flexibility in your gear ratio so with the 60/10/converter setup it may be a nice sweet spot for torque and speed, just right on both.
For now, run what ya brung with a t/c in place of the #35 stuff, it may be just right. T/c units offer a bit of flexibility in your gear ratio so with the 60/10/converter setup it may be a nice sweet spot for torque and speed, just right on both.