Torque Converter selection help + general advice

[jacobf8]

Hello DIY Gokarts!!

I recently bought an off road gokart, it has a 15Hp 420cc Powerfist engine, a worn out centrifugal clutch and 16 in tires. The engine drive shaft is 1" diameter, and the same goes for the rear axle. I am looking to add a torque converter to the mix because I drive this on hilly terrain. I believe I require a 40 series Torque Converter, but I have not bought one before and Im relatively new to DIY so I think its best to consult the experts!

Where would you guys recommend I purchase a TC for someone who lives in ON, Canada? I dont mind buying from a store, or online. I just want it to be the correct size, and to not over pay.

I also have just a list of questions that I am hoping some of you can answer, because I have not been able to find answers online anywhere else.

Q1: Why do I not see much information about powerfist engines online? are they a "Clone" of another engine, is there anything I should be aware of regarding this brand/series.

Q2: How would I be able to ensure that the mounting bolt pattern for the TC drive side will fit the bolt pattern on my engine (please see photo)

Q3: Does the angle that you mount a TC matter relative to the angle from the engine's axle and the rear axle. In my head I feel like there are large moments that will be generated depending on how the TC is mounted.

Thank you in advance. Please see the photos attached

 

[Brianator]

Where abouts in Ontario do you hail from?

Yes all the Powerfist and ProPoint motors found at Princess Auto are clones, being a 420 I assume it's a clone of the Predator 420 which in fact based off a Honda GX390, Predators 212 is based off a GX200. Both are not exact clones but have alot a similarities and alot of parts interchange (but not all from what I've read here).

May I ask why you want to go with a TC when it's already setup for a clutch? 15hp on that light little kart outta scoot just the way it is (well, with a chain)!

I'm pretty sure all the Hondas, Predators and clones have the same bolt patterns for the gear reduction drives that some come with, small and big block. We've seen guys put 30 series TCs (made for small blocks) on big blocks with some modification but I don't believe they hold up very long...

TC back plates don't seem to care about how they're angled, mine is at the 2 o'clock position and I haven't had a problem yet.

Hope this helps some! Others should be along shortly

 

[jacobf8]

I am from Ottawa! The reason I want a TC is because from what I have read I dont think I will be operating my centrifugal clutch at an rpm where it is locked up the majority of the time. I want the flexibility to make it up hills without having to be driving my kart at high speed? I just got the feel that centrifugal clutch is better off on a real go kart track where your just holding it open. (Edit - Also I have 16in tires and I think its healthier for my kart to have the CVT which provides more low end torque)

Thank you for the answers to my questions! What do you mean by big block vs small block when your talking about Gokarts, the web generally talks about "Big block V8" and references car engines more.

Do you think that a TC will be overkill? Do you have any advice on what type of gear ratio I should use, or where I should purchase a TC in Ontario that wont break the budget?

 

[Brianator]

I have some family out that way!

You are right, based on your wants and needs a TC IS the way to go and 40 series is the best route, I don't have and experience with a 40 but they are designed to handle your power levels. I've noticed alot of members here seem against 40 series with a backplate, I'm not sure why but no doubt someone will chime in and fill that blank in! Lol. A regular 40 with a jackshaft is preferred but I don't think you have room for one and considering you kart looks light I don't see why one with a backplate wouldn't work but yet again let's let someone else speak up in regards to all that.

A 212 is a small block and a 420 a big block, they are physically different sizes.

A TC will be perfect for what you want to do. You'll have to shop around online to see what you can find depending on what you want to spend, there seems to be alot of places being out of stock on the units with backplates... we're kind of screwed for kart parts here in Canada too which can make it tough.

*edit** Where's 'sid! Help a fella out here would ya?! Lol

 

[mckutzy]

Oh, just to clarify about the 212cc clones...
They are typically sold here in Canada as their main brand RATO. They are rebranded and sold as predator brand in the US.
RATO motors are getting pretty difficult to get and the US Predators are almost impossible now..
If you're able to get one up here... your one of the lucky ones...

 

[Brianator]

They are typically sold here in Canada as their main brand RATO. They are rebranded and sold as predator brand in the US.

I did not know that! Looks like they've been discontinued (by Canadian Tire anyways).

 

[mckutzy]

I kick myself, I was only able to buy the one.. they had 3 at the time, from my local...

 

[landuse]

Welcome to the forum!

Yes, you will need a TC for the type of riding you would like to do...and yes, a CC is better for conditions where you will keep it engaged. Slipping CC's wear out real fast!

I am going to link you to an ongoing thread that will give you a lot of info about the 40 series. Backplates are not recommended because they interfere with the true working of how the 40 series was meant to be run

https://www.diygokarts.com/vb/showthread.php?p=555631#post555631

 

[jacobf8]

Thanks for the info guys! I have doing some reading in the threads linked. I am wondering if you are able to let me know if this TC is a 40 series and if it will fit my setup.

https://www.princessauto.com/en/detail/1-in-bore-10-tooth-torque-converter-kit/A-p8404642e

If not, I am wondering what options I have for procuring the correct TC. If anyone can direct me to Canadian friendly sites that would be amazing.

 

[mckutzy]

Here in Canada were kinda screwed for parts like this...
Princess is about the only place we have..

 

[bob58o]

The reason I want a TC is because from what I have read I dont think I will be operating my centrifugal clutch at an rpm where it is locked up the majority of the time. I want the flexibility to make it up hills without having to be driving my kart at high speed? I just got the feel that centrifugal clutch is better off on a real go kart track where your just holding it open. (Edit - Also I have 16in tires and I think its healthier for my kart to have the CVT which provides more low end torque)

Do you think that a TC will be overkill? Do you have any advice on what type of gear ratio I should use, or where I should purchase a TC in Ontario that wont break the budget?

This guy gets it!!! It's rare to read such an educated post.

I think that link is a 30 series TC made for a 1" shaft. They are ok for smaller 8hp engines, not great for 420cc engines. They cost less than $75 shipped here in the States.
https://www.ebay.com/p/4013068245?i..._2h7zIpJ8Gg_MbK7ByXR4jS09M8wpJXhoC4qsQAvD_BwE
KartFab has some good guidelines for setting up gear ratios.
I want to say setting up a "big block" with a TC and you can probably shoot for 36-40mph at 3600 RPM.

With 16" Tires and a 40 series CVT (with 7.5" Driven unit -40D)....
as for sprocket ratio recommendations.

4.8 :1 sprocket ratio
11.7 :1 in "lowest" gear
4.8 :1 in "highest" gear
36mph at 3600 RPM
45mph at 4500 RPM

4.2 :1 sprocket ratio
10.2 :1 in "lowest" gear
4.2 :1 in "highest" gear
41 mph at 3600 RPM
51 mph at 4500 RPM

My larger buggy had a 420cc with 40 series TC and was geared to do 36 mph at 3600RPM, but if it was samller and I wanted more speed I would have gone for closer to 40 mph at 3600 RPM.

Here in Canada were kinda screwed for parts like this...
Princess is about the only place we have..

Is it expensive for a person like me to send stuff across the border? We can start a business where i buy Chinese crap from ebay and send it to you. You sell it and return barrels of syrup to me.

Not sure this will link to the correct item. This is a 1" driver and 3/4" driven. Meaning you need to add some pillow block bearings (or other type) and add a 3/4 jackshaft. Also need a belt and a sprocket for the jackshaft (with some lock collars).

They do sell 40 series with backplates included. They are pretty expensive. To correctly use it that way the driver unit must be mounted inboard.

 

[mckutzy]

Bob, it would be nice... but.... look it up... The Syrup Cartel....(Its actually a true thing, and for the most part legal.)

They would say....fugetaboutit.....

 

[bob58o]

Bob, it would be nice... but.... look it up... The Syrup Cartel....(Its actually a true thing, and for the most part legal.)

They would say....fugetaboutit.....

Long live the Queen.
One of my fav videos. Skip to 1:00
https://www.youtube.com/watch?v=1JPBdBIFGNQ

 

[mckutzy]

OH thats pretty funny.....
Good times...

 

[Brianator]

Is it expensive for a person like me to send stuff across the border? We can start a business where i buy Chinese crap from ebay and send it to you. You sell it and return barrels of syrup to me.

Maple syrup is expensive even here! I bet a gallon would cost more than a 40 series! No joke!

 

[mckutzy]

And Brian is east coaster...
Me.. it would be a real deal trying to get even a Litre let alone a gallon..

 

[Brianator]

And Brian is east coaster...
Me.. it would be a real deal trying to get even a Litre let alone a gallon..

Not excatley, we're considered central but Ontario is definitely the maple syrup hot spot! Lol. I could get some out your way easily enough if you want some! NS, NB, PEI and NFLD are all considered "east coast". Quebec is on their own since they wanted to leave Canada and held a referendum!