Project---Split cable pull linkage

slowtwitch · Post by **slowtwitch** » Sun Apr 01, 2007 4:06 am

doc wrote:slowtwitch,

Most interested to see pics of your final setup with DTM. Please post when you can.

doc

Doc, I'm hoping to have a working setup by the end of the week. I'll definitely post some pics.

pete

914fan · Post by **914fan** » Wed Apr 04, 2007 1:22 pm

what are "MC throttle linkage bits"? Where can I get them?

speedy57tub · Post by **speedy57tub** » Wed Apr 04, 2007 4:01 pm

Mmmmmm, over a decade ago, I tried a similar approach with bad results. As soon as the engine warmed up the carburetors went out of synch.

This was due most likely to thermal expansion.

My design was somewhat crude because I was just trying out an idea. Now, revisiting the idea....well, it could be done succesfully if you design it well and try to address the heat expansion issues. Good luck and let us know how it all turns out....I hope it works out well.

Post by **Piledriver** » Wed Apr 04, 2007 7:53 pm

914fan wrote:what are "MC throttle linkage bits"? Where can I get them?

Any MC junkyard

(MC== MotorCycle)

Post by **Piledriver** » Wed Apr 04, 2007 7:56 pm

speedy57tub wrote:Mmmmmm, over a decade ago, I tried a similar approach with bad results. As soon as the engine warmed up the carburetors went out of synch. This was due most likely to thermal expansion. My design was somewhat crude because I was just trying out an idea. Now, revisiting the idea....well, it could be done succesfully if you design it well and try to address the heat expansion issues. Good luck and let us know how it all turns out....I hope it works out well.

I made sure the output cables were ~exactly the same length... So they would stretch the same etc.

Heat expansion would have ~zero effect, the carbs would have to move ~ 6 inches each before I would have run out of slack... Motor movement, no effect, etc. Sheathed cables are very nice in many ways.

I put ~60K miles on this rig before I converted to CIS for other reasons.

914fan · Post by **914fan** » Tue Apr 10, 2007 8:49 am

does any body know where ther is an MC junk yard in orange county? say from Long beach to san clemente.

Post by **Piledriver** » Tue Apr 10, 2007 10:37 am

Try "motorcycle salvage", or "used motorcycle parts" in the yellow pages.(dead tree or online version)

slowtwitch · Post by **slowtwitch** » Tue Apr 17, 2007 4:00 pm

Well, I finally was able to do some work on this project. Here is my prototype. I used the inner cables off my bike, because they where already prestretched

Don't pay no mind to the cable on the bottom wheel. I haven't drilled any holes in the DTM for it.

There's a ball bearing between those two pulleys on the right.

Works kinda neat, I can adjust the cable length by turning the threaded nut. I even tried it mounted in reverse, with all the linkage behind the shroud.

Looks different when there is no linkage staring at you, but, kinda of tuff to adjust the carbs, with the adjusting screws inboard

I don't know if there will be a problem with heat expansion, I'll have to build an engine to find that out

If things work out, I'm planning on casting most of the parts, instead on machining them from stock.

Oh, sorry about the dusty shroud, it has since been cleaned up and ready for paint.

Now to work on that EDIS pulley project.......build a couple of engines, get the bug back together and that infamous Honey Do List

pete

speedy57tub · Post by **speedy57tub** » Tue Apr 17, 2007 7:57 pm

Looks great...I hope it works out for you.

Post by **Piledriver** » Tue Apr 17, 2007 11:35 pm

The central pulley shaft would be a great place for a TPS sensor stub/mount option for the dual TB FI guys.
(Assuming you plan on production)

The slack in the cable sheaths allows the motor to grow some w/o changing the sync.
(do try to keep the cables the same length if possible)

slowtwitch · Post by **slowtwitch** » Wed Apr 18, 2007 6:56 am

Piledriver wrote:The central pulley shaft would be a great place for a TPS sensor stub/mount option for the dual TB FI guys.

Pile, I was thinking of that myself. I'll post a pic later (at work now), of what I have. I just went with the carb setup first, because, I don't have a complete FI setup, yet

pete

Post by **Piledriver** » Wed Apr 18, 2007 6:18 pm

I just took another look at the pics, from an "artistic" standpoint, rather than just from an engineering standpoint...

I must say you managed to make a throttle linkage look absolutely badass! Congrats!

Steve Arndt · Post by **Steve Arndt** » Thu Apr 19, 2007 8:03 am

I agree. The machine work looks great.

RG64 · Post by **RG64** » Mon Apr 23, 2007 5:10 pm

Any more progress on your set up Pete? Nice job BTW!

Rick

slowtwitch · Post by **slowtwitch** » Mon Apr 23, 2007 6:23 pm

RG64 wrote:Any more progress on your set up Pete? Nice job BTW!

Rick

Rick, I'm still working on some final touches. I made up a center wheel setup with a tps mounted on it.

I'll have some pics in a couple of days, my son borrowed the camera.

I'm also going to do a little testing, to see how much heat effects the cables. I'm thinking of a heat gun and some dial indicators, to see what happens.

I'm also talking to some people about carbon fiber, as a cable. No heat or stretching problems

I'll keep you posted

pete