Dual HPMX Throttle Linkage

[tartan18]

I bought two HPMX carbs and now need to figure out how to hook up the throttle linkage. As I understand there are two options ... One is to use a bellcrank on the cam box and the other is to mount a T bracket on the driver's side fender wall. Please share (with pictures) how you have hooked up the linkage and what parts you used and where you sourced them (with vendor and parts numbers). Your help will be greatly appreciated.

Jim
Corvallis, OR

[RoyBatty]

What are your fabrication capabilities?
If you have the ability to weld at all, you can fabricate the brackets and the bellcrank to make a linkage that works smoother than the factory solid bellcrank linkage. And will prevent the hippity-hop action that can happen with the solid linkage. I'll go out and try to get some detail shots now.
I see that you have a 75 Spider, if that is what your installing the HPMXs' to, you have another option also.
You can removed the cable drum from your stock carb and with a little modification you can install it to your rear carb to drive both carbs thru the way they are joined at the center.
I did this on my 75 Spider about two years ago and have had no issues with synch of the carbs in spite of what some "experts" warned me of. So to begin with, I'll see if my images from the Spider can help.
I think this would be the easiest way for you to do this, unless for some reason you don't have the factory cable and drum setup.
As you can see, the only fabrication required is to cut and weld the cable bracket that secures the carburetor end of the cable. This was made from a piece of 1/2" angle steel that I cut, welded and bent as required.
Works great, last long time.

[tartan18]

My mechanical (fabrication) ability is seriously challenged. I don't weld and the extent of my metal working is a bench vice, a 5# hammer and a small sawzall. I hope there is a kit of some kind that I can simply bolt on. I am willing to richly compensate for something that will work.

[RoyBatty]

I can duplicate my bracket for you.
Want to give it a shot?

[tartan18]

Hi Roy ... thanks for the help. Alas, when I upgraded from the stock ADFA to the DFEV the cable drum was sold with my old ADFA. I do have both types of accelerator cables however -- not being sure which one I would need. I'm still trying to figure out how to link both HPMX's together -- my new carbs don't have a ball stud like I see in your picture.

Yep ... my car is a 1975 with the 1800 engine. If you could fabricate that bracket for me I would be very grateful.

Jim ...

[RoyBatty]

The bracket I show in the images above will only help if you can use the stock cable with the stock drum.
Can you find another drum some where?
Pierce Manifolds sells the needed parts to join your carbs at the center.
See this link, give them a call and tell them what you're doing. http://www.piercemanifolds.com/category_s/223.htm
You will probably have to carefully use a dremel to trim the shafts where the carb links mate up to get the needed clearance. What manifold are you using?
Did you source your carbs from Mark Allison?
Also, check out this site, http://www.kendickson.com/car/idf/idf/index.html

Otherwise your choices are to use the stock style bellcrank on the cam cover pulled by a longer cable.
Or to have someone fabricate something similar to what I did for my Coupe.
Yes I know my welds look terrible, but nothing is going to break from my bellcrank or brackets.

[tartan18]

Roy, Yes, I did get my new carbs and intake manifold from Mark Allison. Here are two pictures of what I have:






Before I get too deep into this and take up more of your time (and kind offer to fab something for me) I will contact Mark tomorrow and see what he suggests.

Jim ...

[RoyBatty]

Will your carbs fit on the manifold add they are currently configured with the center linkages?

[So Cal Mark]

the carbs are already linked together, you only need to attach the cable to one of the levers. I use a T bracket bolted to two middle carb studs, not to the fender. I prefer to have the cable pull the linkage in the middle, not on the end of the carbs, but that's just my preference

[RoyBatty]

Your cable bracket is ready.

[tartan18]

Tom ... you even painted it. Wow! You ARE the MAN !! I am impressed and very thankful for your help. Let me know the cost of your time, materials and postage.

[RoyBatty]

Hey Jim,
I was unable to get to the post office to mail the bracket today.
I picked up some prop balance work after hours and can't afford to let that go.
I'll send it off tomorrow.
When you install it, call me if you have any questions.

[tartan18]

No problem. Happy to hear that you picked up some extra business.

[tartan18]

Received the bracket in today's mail. I test fitted it and everything seems to be correct. It will be a bit of a while before I get the intake side installed as I have to finish up running new hard fuel lines and re-install the steering box. Thank YOU so much. You've made a friend for life

[RoyBatty]

Stop typing and get to fixing.