Hilliard Flame Engagement

ricmcdade

Member
New to the L206 after many years of 2 stroke Karting. Road racing only! Dennis Scott motor and couldn’t ask for a better guy. Dyno shows peak torque at 3800. First race out, was told by a fellow competitor to go with 4 black springs- clutch came in about 4000 and seem to be too far past peak torque and The “pull” was slow compared to others. Second race out, went to 2 black, 2 white, and was better, but came in about 3400 and seemed to struggle to get to the 3800 range, where it seem to accelerate decent. I guess my first question, is what peak torque average are you guys seeing on the dyno? I then went to the Hilliard engagement chart. I noticed that the chart was “when shoe first touches drum- Not Lock Up!” I then got a hold of Brent at Hilliard, and found out that it is approx 400 RPM from the time the shoe touches the drum to “full lock up”. If we assume the 3800 peak torque is correct, and try 2 black to white- at 3400, which with the 400rpm for full lock up, I would think that there has to be some “drag/pull” on the motor In between the two, therefore your actually pulling on the motor way before peak torque. I have went to 4 black and 1 heavy weight per shoe for the next race, thinking that “starts” engagement at 3600 and your right in that peak torque range as the clutch goes from “touching drum to lock up”. Am I thinking Right? Third Question- has anyone tried this Hilliard Sanding Drum to “profile” shoes? And?
As Always- Thanks!!
 
I've always understood lockup to mean when the clutch and the axle, divided by the gear ratio, are turning the same RPM.

I've always understood that stall means when the clutch is slipping at the engine is not gaining RPM.

I've always believed that the clutch should engage and stall at peak torque. Most charts that I have seen, of stock clone engines, had the engine reaching peak torque between 32 and 3600 RPM. That could veri.

The dyno is a very good way to verify those numbers but, a bathroom scale between a strong wall and the front of your kart is another way. Slip the clutch where you get the maximum reading on the scale.
 
We road race the CIK LO206 Sprint class. What we do is no added weight, with 2 white and 2 black springs. I believe that's the recommended starting point most folks will suggest. It has always worked well for us. We've tried several combinations of whites and blacks, and always go back to the 2 white, 2 black combo. And as you know, in road racing they sit on the clutch for quite a while on the starts. After the start, the clutch does nothing.
Clark Gaynor Sr.
 
New to the L206 after many years of 2 stroke Karting. Road racing only! Dennis Scott motor and couldn’t ask for a better guy. Dyno shows peak torque at 3800. First race out, was told by a fellow competitor to go with 4 black springs- clutch came in about 4000 and seem to be too far past peak torque and The “pull” was slow compared to others. Second race out, went to 2 black, 2 white, and was better, but came in about 3400 and seemed to struggle to get to the 3800 range, where it seem to accelerate decent. I guess my first question, is what peak torque average are you guys seeing on the dyno? I then went to the Hilliard engagement chart. I noticed that the chart was “when shoe first touches drum- Not Lock Up!” I then got a hold of Brent at Hilliard, and found out that it is approx 400 RPM from the time the shoe touches the drum to “full lock up”. If we assume the 3800 peak torque is correct, and try 2 black to white- at 3400, which with the 400rpm for full lock up, I would think that there has to be some “drag/pull” on the motor In between the two, therefore your actually pulling on the motor way before peak torque. I have went to 4 black and 1 heavy weight per shoe for the next race, thinking that “starts” engagement at 3600 and your right in that peak torque range as the clutch goes from “touching drum to lock up”. Am I thinking Right? Third Question- has anyone tried this Hilliard Sanding Drum to “profile” shoes? And?
As Always- Thanks!!
You can try 4 blacks with weights, but I'm thinking that you'll come back to 2 black and 2 white springs with no weights. Yes, you are understanding the engagement (chatter and lock up) correctly. Personally, I think the chart can be off by more than 400 in some instances, and it's rare that you see the clutch only slip 400 rpm between chatter engagement and full lock up.
Aside from that, what Brett told you is spot on.
I had the same conversation with him several years ago when looking at his charts.
Now, your peak torque from Dennis is a good bit higher than what we are seeing on our LO206s, and that may attribute to the higher engagement you are desiring. Follow his advice, as he is the one that dyno'd it and his carb set up, ign. timing, etc may vary from ours, and that's the difference in rpm of his peak torque to ours.
Keep in mind that the torque curve is very flat on these engines, and the clutch engage is not as critical as some make it out to be. Not that it doesn't matter, but within that flat torque curve, the engine really doesn't care at what rpm you bring the clutch in. Now, the course lay-out may further dictate which end of that torque plateau you will want to be on.


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🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
From a non-motor builder, Dyno's are nice (have one) BUT, TRACK TESTING and the STOP WATCH tells you what you need!!! Myself and both my kids who are known across the country in road racing come from 2-cycles. I myself got into what is called B&S ANIMAL SPORTSMAN (laydown) several years ago when KART introduced this class as it was hard to keep 3- 2-cycle karts going let alone the funds it took. As for LO206, we got into this class 3 years ago when Lindsay was asked to drive a kart for someone. She has been in 3 different chassis such as the Intreped, Rocket and currently in a Margay Brava and wins or runs up front. We run the Hillard Flame clutch. I did a track test with it along with the Stinger last year and as far as performance gain, NONE!! I do like the Hillard as it's easier for this old man to work on it. We mainly run the all black springs (no weights). Depending on the track, we will run 1/2 black, 1/2 white (no weights). Why this someone asks, it's due to that some tracks we need hooked up earlier. The key to engagement is that I want the motor and clutch to come together smoothly. Hooked up to soon and you are bogged down and now it takes TIME for the motor to catch up. Clutch slipping to long and now your spending TIME for the clutch to catch up. Hint: TIME is seconds lost to the competitors!! Let's say that you have this PERFECT but still not fast!! How about the chassis set-up?? Camber, Castor, Toe, F/R weight differential, air pressure, kart free rolling?? Then as for #1, DRIVER!! Do they understand what their feeling, seeing and listening to from what the kart, motor, clutch is telling them while on the track?? It doesn't matter in my mind rather it's a stock 4 stroke or a 2 cycle open if these are not in sync!!!
 
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