shoe clutches question
- Thread starter bhill
- Start date
CarlsonMotorsports
Site Supporter
Noram GE series clutches come with either "light" - 150gm shoes, or "heavy" - 200gm shoes.
They can be used in many applications, but the combination of shoe weight and springs make a huge difference in engagement.
-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
29 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
They can be used in many applications, but the combination of shoe weight and springs make a huge difference in engagement.
-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
29 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
racinnut15xm
Member
Anyway to tell by just looking at the shoes which you have? Measurements wider at some point?
flattop1
Dawg 89
https://www.noramclutch.com/go-kart-clutch/noram/ge/
this is a picture of the heavy shoe.
this is a picture of the heavy shoe.
racinnut15xm
Member
Looks like I've got heavy's. So Orange or green should help me get away from engaging at idle and a lot closer to the peak torque. This red plate clone I had doesn't seem to like to idle below 2000, really likes closer to 2200 and the clutch is really engaging at that point.
CarlsonMotorsports
Site Supporter
Orange or green will be Waaaaaaaaaay too high. If the clutch is clean and serviced recently, you would want black or possibly red springs with a red plate clone.
Make sure that the hub driving dogs are PULLING the shoes also. Having the shoes reversed (for inboard/outboard orientation) will be pushing the shoes and cause you all sorts of problems.
Make sure that the hub driving dogs are PULLING the shoes also. Having the shoes reversed (for inboard/outboard orientation) will be pushing the shoes and cause you all sorts of problems.
racinnut15xm
Member
I read a few posts where people talked about aiming for max torq. Where do most red plate clones hit max torque? Maybe the springs are old or shoes are wore down. Thats why i'm trying to find measurements for some of the stuff so i can check it all out and determine if something is wrong or its acting like it should and i just need to move up in RPM. Thanks for the help guys.
racinnut15xm
Member
- - - Updated - - -
Looks like i have it setup to pull like you mentioned and its "chattering" about 1900/1950 like the red spring chart says so my logic says i need to go up. I will take the advice and go up only a little instead of jumping to a orange or green. Since it looks like you guys are saying i can mix and match colors maybe a red and a blue 2240? or red and white 2185? Is that how it works just add them together divide by 2?
CarlsonMotorsports
Site Supporter
Yea, I wouldn't mix spring colors when you've got only two springs on this style clutch.
It will cause a very long slip and build a ton of heat = not good.
Yes, you want clutch engagement at peak torque for your engine (which I suspect is around 2800-3000 rpm depending on set-up.)
White springs will engage the clutch around 3800 rpm.
Red springs will engage around 3400.
Black springs will engage around 3000. (just going off of memory)
I made a real nice chart many years ago when we blueprinted these clutches. I don't think it's on our website, I probably posted it on this site before the big crash of several year back.
The orientation of the shoes in the pictures that you posted are exactly what I would suggest for running inboard (chain closest to the engine.)
The bronze bushing on smaller tooth drivers have a habit of seizing. Make sure that you have plenty of endplay, plenty of high temp grease, and maintenance it often. We actually hone that busing slightly to give it more clearance than the factory gives them.
Trial and error - you've got this.
Springs are cheap and all it will cost you beyond that is some time.
If you've got a Mychron with replay, you will be able to visually see the clutch engagement/lock-up during testing.
All the best!
It will cause a very long slip and build a ton of heat = not good.
Yes, you want clutch engagement at peak torque for your engine (which I suspect is around 2800-3000 rpm depending on set-up.)
White springs will engage the clutch around 3800 rpm.
Red springs will engage around 3400.
Black springs will engage around 3000. (just going off of memory)
I made a real nice chart many years ago when we blueprinted these clutches. I don't think it's on our website, I probably posted it on this site before the big crash of several year back.
The orientation of the shoes in the pictures that you posted are exactly what I would suggest for running inboard (chain closest to the engine.)
The bronze bushing on smaller tooth drivers have a habit of seizing. Make sure that you have plenty of endplay, plenty of high temp grease, and maintenance it often. We actually hone that busing slightly to give it more clearance than the factory gives them.
Trial and error - you've got this.
Springs are cheap and all it will cost you beyond that is some time.
If you've got a Mychron with replay, you will be able to visually see the clutch engagement/lock-up during testing.
All the best!
racinnut15xm
Member
On the bushing/grease part. This was the 2nd night on the clutch since we took it apart and checked it. First night we only ran hot laps/heat/feature. 2nd night we did 2 hot lap sessions, 2 heats 2 features. I was surprised how little grease remained after I took it off. Thanks for the tips.
flattop1
Dawg 89
Those rpm's are way off the factory chart .
maybe that's full lock up?
CarlsonMotorsports
Site Supporter
Tony,
The chart that I've seen most people go off of for Noram GE clutches is what I call "chatter engagement." That's where the shoes just start to touch the drum. Certainly not the engagement that will move the kart, or even turn the tires with your hand on them.
This is typical of how the chain saw industry looks at clutching as well.
For karting, we are more interested in 1:1 lock-up (or as close as you can get to that.)
Yes, the numbers I gave are for full lock-up.
Everything in between the chatter engagement and the full lock-up I suppose could be considered "engagement" as well, but if it's not moving the kart forward, we typically disregard it.
From a standing start, (engine and clutch both warm) if you watch on a replay tach, you will see the rpm increase: 2400, 2600, 2800, 3000, 3200, 3400, 3600, 3800, 3000 3200...That very first time that the rpm drops is the engagement rpm we are interested in. Now, you will often see several drops after that first one....this is mostly chatter, or engagement rebound. Some clutch chatter is to be expected (some designs do it more than others - this is a reason most like heavier weights and springs to limit chatter.) If you've got a lot of chatter, it might well be an indication of need for maintenance of the clutch. But it's that very first drop that is what we're looking for.
Hope that helps.
The chart that I've seen most people go off of for Noram GE clutches is what I call "chatter engagement." That's where the shoes just start to touch the drum. Certainly not the engagement that will move the kart, or even turn the tires with your hand on them.
This is typical of how the chain saw industry looks at clutching as well.
For karting, we are more interested in 1:1 lock-up (or as close as you can get to that.)
Yes, the numbers I gave are for full lock-up.
Everything in between the chatter engagement and the full lock-up I suppose could be considered "engagement" as well, but if it's not moving the kart forward, we typically disregard it.
From a standing start, (engine and clutch both warm) if you watch on a replay tach, you will see the rpm increase: 2400, 2600, 2800, 3000, 3200, 3400, 3600, 3800, 3000 3200...That very first time that the rpm drops is the engagement rpm we are interested in. Now, you will often see several drops after that first one....this is mostly chatter, or engagement rebound. Some clutch chatter is to be expected (some designs do it more than others - this is a reason most like heavier weights and springs to limit chatter.) If you've got a lot of chatter, it might well be an indication of need for maintenance of the clutch. But it's that very first drop that is what we're looking for.
Hope that helps.
racinnut15xm
Member
Just to report back after a couple more trips. New red springs and greasing it after every night of racing and it seems to be acting much better. Plugs on this thing only last about a night with all the black soot, i will blast them and re-use.