Author Topic: Measurements for RC distributor drive (Read 2254 times)

cbr954 · « **on:** August 26, 2014, 07:45:18 PM »

Does anyone have a drive for the RC distributor that would be willing to take some measurements for me? Something just isn't right with mine as it is too long to even mount the distributor. I need a couple measurements to try and help determine what the heck is going on. Any help would be greatly appreciated.

BPellerine · « **Reply #1 on:** August 27, 2014, 05:35:09 PM »

thought johnnycakes had two?bill

jaguar · « **Reply #2 on:** August 29, 2014, 03:27:00 PM »

I have one.
Whats up?

cbr954 · « **Reply #3 on:** August 29, 2014, 03:35:05 PM »

Dont know why but mine is about 1.4" too long. Mounted on the crank it is too long to allow the distributor housing to be bolted to cases. To start with looking for an overall length measurement of the drive.

jaguar · « **Reply #4 on:** August 29, 2014, 03:46:27 PM »

Okay, the drive is 60.7mm from the base(not the pin) to the end of the bolt that holds everything to the crank.
The gear is 16.5mm "deep"
The bolt/screw head is 2.3mm "deep"
When the drive gear is seated into the crank the shaft is a little less then 12mm deep inside measured from the end of the drive(with no gear on)

jaguar · « **Reply #5 on:** August 29, 2014, 03:50:17 PM »

cbr954 · « **Reply #6 on:** August 30, 2014, 04:59:45 PM »

Thank you jaguar. Just from the photo I can tell that mine is longer. Mine measures 66.19 to your 60.7, this is almost exactly what I had figured that this one had to be too long. I dont know why but mine must have been made for a custom set of cases that had been out of spec. I guess now I know what needs to be done though. Now to find a good machinest and I will be set. Thanks a ton for the info and picture.

jaguar · « **Reply #7 on:** August 30, 2014, 07:16:52 PM »

Sure it's a honda drive and not a kawi one?

cbr954 · « **Reply #8 on:** August 30, 2014, 08:21:59 PM »

I have seen a picture of the Kawi drive on here and the crank side is different unless I am missing something. It definitely fits the 750 crank, I have no experience with how the Kawi crank looks.

jonnycakes · « **Reply #9 on:** August 31, 2014, 03:31:14 AM »

Ive had both units on my engine, so maybe the drives got swapped. The drive I have on the bike right now is 2.291” long. I know the drive you have fits my mag and I know that the shorter drive works with my mag so it has to work with yours. Send the drive hub, gear and key….keep your nut, the nut I have is 1.33” long.

I’ll send you mine as soon as I get yours to swap…..as the bike is my daily rider.

cbr954 · « **Reply #10 on:** August 31, 2014, 10:28:10 AM »

Thanks Jonnycakes will do.

jaguar · « **Reply #11 on:** August 31, 2014, 10:56:08 AM »

I didnt know there was more then one drive size.

cbr954 · « **Reply #12 on:** August 31, 2014, 11:12:22 AM »

I didn't either. I will see once we get things swapped around.

jonnycakes · « **Reply #13 on:** September 04, 2014, 03:41:13 PM »

I'm guessing the longer ones are for the drives running a magneto. The Mag sits very close to the cylinder fins so.....

I never tried, but maybe you could not us the other RC drive units with a mag without it hitting the fins.

cbr954 · « **Reply #14 on:** September 04, 2014, 05:11:34 PM »

Hmm would be interesting to find out from other people running the mag if there setup is longer also.

jaguar · « **Reply #15 on:** September 04, 2014, 06:53:41 PM »

Odd. I was under the impression these were VW bodies(not the same rotation) and the same goes with the mags.

So the drive works with either a distributor or a mag, but not both?
Meaning the longer drive the OP was talking about having works with a "deeper" or "wider" drive housing?

jonnycakes · « **Reply #16 on:** September 05, 2014, 03:36:53 AM »

My drive for the mag is deeper.

sohc boy · « **Reply #17 on:** September 05, 2014, 05:44:19 AM »

Quote from: jaguar on August 31, 2014, 10:56:08 AM

I didnt know there was more then one drive size.

yes ,same here , plenty of clearance still with mag ,Vertex is slightly smaller , same drive , mag or Dizzy , right rotation ,(anti clock rotation )

jaguar · « **Reply #18 on:** September 05, 2014, 05:57:46 AM »

I guess it would stand to reason that if the mag drives where larger a mag drive would be able to run a dizzy but a dizzy drive couldn't run a mag.

So the OP has a mag drive and dizzy case?

BPellerine · « **Reply #19 on:** September 05, 2014, 05:20:30 PM »

off topic but that is a nice race bike sohc boy!bill

sohc boy · « **Reply #20 on:** September 05, 2014, 09:13:19 PM »

Many thanks Bill .......took mine off , yes , 60mm

jaguar · « **Reply #21 on:** September 06, 2014, 05:31:45 AM »

Quote from: sohc boy on September 05, 2014, 09:13:19 PM

Many thanks Bill .......took mine off , yes , 60mm

And still fits the mag. Interesting.
Then I wonder why the two sizes.

BLUE71TURBO · « **Reply #22 on:** September 07, 2014, 01:01:27 AM »

All R.C. angle drives can use a distributor or a magneto. The base is a VW design. The original setup came with a Mallory duel point VW distributor. You could also get a magneto for more money. Either way the distributor or magneto had to be setup to run counter clockwise. The distributor weights, plate and point's cam were reversed. The magneto had to be setup " phased " for reverse rotation.

Here is a Mallory super mag III that i have with a VW base drive. In order for me to use it with the R.C. drive i have it will have to be phased for reverse rotation. Also the magnets have to be changed because they are too powerful for the R.C gear drive. It will need to be converted to a super mag II.

Here is my KZ R.C. angle drive setup......

And the gear drive shaft " KZ " with the gear. " DO NOT LOOSE THE GEAR ! " as they are rare as a DODO bird !

They are not an off the shelf part !

A JOE HUNT magneto with the VW drive base.....

BLUE71TURBO · « **Reply #23 on:** September 07, 2014, 01:14:41 AM »

Hey CBR954, Here is a bunch more info to help ya out. I spent a lot of time researching to find out how much $$$$ it would take to some new gears made. Very costly just to have the gear " reversed engineered ".

http://forums.sohc4.net/index.php?topic=107887.msg1208999#msg1208999

cbr954 · « **Reply #24 on:** September 07, 2014, 07:13:29 AM »

Yup I followed that thread while it was going on. I still dont see how suck a little gear would cost that much to design other then the fact that no one really wants to do it. Maybe someday the original design papers will show up in someones collection. We know for sure now that there are two different length drives for the sohc...for whatever reason. I had the long one and Monday I should have the shorter one which will be the correct length. I am thinking somewhere along the line it must have been a special made part but Jonnycakes was very helpful and swapped drives with me.

cbr954 · « **Reply #25 on:** September 08, 2014, 05:13:32 PM »

Just a follow up...I got the shorter drive from Jonnycakes today and it fit like it should. The nut now engages the advancer stud on the crankshaft. And everything else looks like it should work now. For what ever reason there definitely are two different lengths of drives for the sohc.

BPellerine · « **Reply #26 on:** September 09, 2014, 01:50:47 PM »

so you will get to see that dist in action!hope you get the same feeling I did when I got my ard on and running,pure joy!bill

cbr954 · « **Reply #27 on:** September 13, 2014, 04:16:08 PM »

Got it installed and running.

BPellerine · « **Reply #28 on:** September 13, 2014, 06:46:07 PM »

now get ready for the what is it questions when you take the bike out!haha bill

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Author Topic: Measurements for RC distributor drive (Read 2254 times)