Another Hilliard Flame clutch engagement thread

Working on tuning our Hilliard Flame for a blue slide cadet kart.

Do folks find that the Hilliard engagement chart is pretty accurate? I had my clutch set for 3200 engagement with 2 black and 2 yellow (trying to get close to 3000) but when I tested it by holding the tire gently and giving it some throttle on the stand it seemed to start engaging at 2900 RPM.

Are my springs bad? Or is there just some normal variability and you need to check where things actually are after tuning the clutch?

Our clutch is about 1 season old - should I get a new one? New shoes? it looks ok and is not galled but not sure about this.
 
The Hilliard engagement chart does not show clutch lock-up, only the chatter engagement where the shoes touch the drum.
With that said, the springs do fall off over time (and heat cycles.)
If you haven't already, replace the springs and see where that puts you.


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Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
Thanks guys.

If I put my finger on the rear tire like I am holding for a field goal, engagement will be when the tire pulls out from under my finger (not full lock up - that is higher, but when the clutch starts to pull?).

I want to try 2 heavy weights/shoe with white and black springs which would engage a blue slide LO206 at 3000 RPM which is slightly above max torque. I've heard the weights may prevent slipping at higher speeds and in any event give one more options for tuning. If we engage slightly above max torque the RPM will drop under the higher load putting the engine right on max torque (which I guess is about 2950 for blue slide) as lock up happens?
 

Jimbo

A trial w/o witnesses is like racin w/o tech
How it works on the track is what's important. Using you finger is not going to tell you what it is actually doing on the track.
You need some way to determine if you fine tuning actually makes you faster or slower.
Your method of measurement needs to be foolproof. A faulty data collection method is a sure way to go backwards.
 
Thanks Jimbo. I am just trying to see if my engagement matches the published data from Hilliard. My engagement speeds seem consistently low and I have older springs - I take my springs off when I clean the clutch and I have seen Brent from Hilliard say this puts the most stress on the springs - so maybe the springs are bad and need to be replaced? We use a MyChron 5 for lap times and I've thought about trying simulated rolling starts to see what is the fastest (roll in at 20 mph or whatever and hit the throttle and time it to a fixed point but this seems tricky to do.
 

Jimbo

A trial w/o witnesses is like racin w/o tech
You are correct. Very tricky to do.
I've done clutch testing on my dyno but i'm working on a better method.
 

paulkish

old fart
Thanks guys.

If I put my finger on the rear tire like I am holding for a field goal, engagement will be when the tire pulls out from under my finger (not full lock up - that is higher, but when the clutch starts to pull?).

I want to try 2 heavy weights/shoe with white and black springs which would engage a blue slide LO206 at 3000 RPM which is slightly above max torque. I've heard the weights may prevent slipping at higher speeds and in any event give one more options for tuning. If we engage slightly above max torque the RPM will drop under the higher load putting the engine right on max torque (which I guess is about 2950 for blue slide) as lock up happens?

I think the way you do it is fine, so long as you do it the same all the time and become skilled at checking it.

It's the same concept as it doesn't matter what kind of air gauge you use to check your tires so long as you always use the same gauge and check them the same way. Beyond that it's about you knowing how what you check in the pits relates to on track performance. The types of test doesn't matter what matters is accurate repeatability and being able to use the results of your testing.

The only draw back is when in conversation with others you will have to be able to relate and alter what you hear from others because how everyone tests things will vary. It's no different then dyno's and how they are used can vary.
 
Thanks that's really helpful. When cleaning the Hilliard clutches do folks remove the springs? I've been doing this but I've read that this can accelerate the aging of the springs (being spread by snap ring pliers). Is it necessary to remove the springs to get things clean?
 

fatboy1dh

Member
Nope. No need. If you’re feeling frisky, just spray the dust out with your air nozzle. Shoes surface and drum is what you need to focus on when cleaning/maintaining.
 
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