Belt Drive Meditations

[Sheik Yerbouti]

Well, I've pretty much determined that I am going to just buy a clutch from max torque that works with the Honda engine, and I am going to retrofit a GEBE driver on there some way. I've been bouncing some ideas around in my head, but can't say anything definite until I get the actual clutch in my hands. I figure with access to CNCs and welders, I can do pretty much anything.

Are any of the Max Torque clutches capable of working well with the Honda engine, ocscully? You were able to talk to them moreso than myself, so I was wondering if you might know. Which would be easier to retrofit for the driver? A V belt or a sprocket clutch?

 

[ocscully]

Jon,

below is the answer to my first contact with the folks at Max-Torque. I would recommend at this point that what you do is phone Jim Donavan Sr. at max torque and talk with him. I guess at this point if I were you I'd buy a clutch from him that had a bell with a driver of the type I would use for a fall back system (what I would use if I find I can't make the GEBE driver work) and then also purchase an extra clutch bell to do my custom work on. I'm pretty sure he will be able to fix you up with the items you need. I think the problem you are going to be dealing with is the OD (outside diameter) of the driver vs. the ID (inside diameter) of the driver bore that you need to fit the Honda crankshaft. I'v done som calculations based on the tech. info. available at the Pfeifier Industries web site and I come up with the OD of a
5mm pitch 14t driver to be .875 (7/8) in. When you subtract the ID of .625
(5/8) in. for the bore that dosen't leave much meat on the driver. A 15t driver I calculate the OD to be .938 in. which still dosen't leave much meat in the body of the driver. Any way call Jim Donavan at max Torque and talk things thru with him and see just what he has to say and what he recommends.

ocscully

(e-mail from Jim Donavan)
you would deal direct with us because the clutch is a special. I already make some clutches for that engine and because of the short crankshaft it is a little of a challenge. Also the high idle of the engine to engage the clutch as not to bog down the engine is a little tricky. The 5mm pitch that we have in stock without getting into a special is 23 tooth pulley and it will handle a belt 25mm wide or 1".

My son's company, Pfeifer Industries makes the various 5mm pitch pulleys we use as well as the larger and smaller tooth pulleys. The reason we use a 23 tooth pulley is the original design was for a 3/4" crankshaft.

Do you plan on inboard mounting the clutch or outboard mount? The reason I ask is that you want the belt tight so I would like to see the pressure of the belt on the crankshaft not on the clutch sleeve that will be past the end of the crank. We have made a special crankshaft extension to help support the clutch but because the bolt is only a 1/4 - 28 it doesn't impress me that much for strength.

The price of the clutch is $88.00. Give me a call and we can discuss pros and cons.



James F. Donovan
Max-Torque, LTD.
2180 Corporate Lane
Naperville, IL 60563
Phone: (630) 369-9600

 

[Sheik Yerbouti]

Dang. This is getting worse and worse. I might throw in the towel, but I really hate the prospect of a noise gearbox.

Edit: I might contact GEBE regarding the price of their centrifugal Robin 33.5cc clutch and go that way instead. Then I would have a clutch inherently ready to accept GEBE drivers.

 

[ocscully]

Maybe a Dax Titan?

Dang. This is getting worse and worse. I might throw in the towel, but I really hate the prospect of a noise gearbox.

Edit: I might contact GEBE regarding the price of their centrifugal Robin 33.5cc clutch and go that way instead. Then I would have a clutch inherently ready to accept GEBE drivers.

Jon,

I'm going to throw another option into the mix for you to check out and consider. Look into the Dax Titan engine. I believe it comes with the same mounting flange and clutch as the Subaru 4-stroke and 2-stroke engines come with? So maybe the GEBE housing and clutch bell will bolt directly to it? The Titan is only $180.00 and includes the clutch. Just a thought.

ocscully

 

[Sheik Yerbouti]

Jon,

I'm going to throw another option into the mix for you to check out and consider. Look into the Dax Titan engine. I believe it comes with the same mounting flange and clutch as the Subaru 4-stroke and 2-stroke engines come with? So maybe the GEBE housing and clutch bell will bolt directly to it? The Titan is only $180.00 and includes the clutch. Just a thought.

ocscully

Good thinking!

I'll contact GEBE and see what they'll charge for the clutch. Thanks again.

 

[stude13]

man is this interesting or what? most is over my head but when (not if) you guys figure this out and patent or whatever a kit you will be thousandaires many times over. bona fortuna. mitch