1972 Bellcrank differences

[JoelH]

I've been trying to smooth out my touchy carb linkage in my 1972 240Z. It's build date is 8/72. There are two bellcranks used in the 1972 and from a parts supplier where I've attached pictures it appears there is a different bellcrank after 6/72.

The earlier one looks like this:

http://www.zcarsource.com/content/p/9/pid/53387/catid/7643_7653/Carburetor_Linkage__Bell_Crank_70_6_72__with_used_bushings_

And the later one looks like this:

http://www.zcarsource.com/content/p/9/pid/53388/catid/7643_7653/Carburetor_Linkage__Bell_Crank_7_72_78__with_used_bushings_

My linkage looks like the earlier model. I ordered a bellcrank from ZBarn and he sent me the later one. Could it be I have the wrong one in the car causing my touchy accelerator? The pictures I've seen with the later bellcrank seem to have a shorter post it sits on. Mine seems to be proper for the post or longer than the short post.

I probably need to get the earlier one but just wondered if the build dates are correct for this bellcrank and if they are interchangeable? Does anyone with the newer one have a short post or does your post stick up higher than the top of the bellcrank?

[beandip]

I have the first one with the longer tube. The problem of a touchy throttle is with either of these . It is the geometry of the levers having to overcome the resistance of movement.

Drivers have been dealing with this for years . Some have found relief by removing one of the levers and repositioning it. Before you do this check the pivots on the balance tube. Where he linkage rod passes through. I find when my throttle feels sticky if I lube these two places it helps a lot.

Gary

[soundmasterg]

Gary, maybe you can show me these two places at our next meet so Ic an try to fix my issues on my '72? Going to be there at PIR on wednesday?

Greg

[JoelH]

I had planned to reposition the arm with this bellcrank. I wanted to save my original. I'm not sure where the point is you are talking about. Anyone with a picture?

[bob m]

Joelh

I have an early 72z and bought a carb set and bell crank from a 260z. The later bell crank is shorter and I can not use it. If it works for you send me a PM and I will send it to you, gratis.

Bob M

[JoelH]

Thanks for the offer Bob, that's very generous of you but I already have the later (shorter) bellcrank that I received today. Unfortunately, even though my production date is later, I need the longer one.

Thanks again!

[JoelH]

Just an update -

It may help others who have the "throttle lag" "aggresive throttle" etc. My 72 had the seemingly common problem of when you are in second gear and turning a corner, give it gas - delay - then BAM it jerks you back in the seat.

I used this: http://www.classiczcars.com/forums/attachment.php?attachmentid=23568&d=1212283739 procedure with a spare bellcrank and it fixed my problem! I'm letting it set up with JB Weld for a good bond right now but before that I screwed it together and tested it on lots of neighborhood roads in the 20-30 mph range. I made a bunch of turns and I'd say the jerk is gone.

Thanks to whomever came up with this fix!

[TrumpetRhapsody]

Can you elaborate on that procedure?

I have early 240z carbs on my 260z, and the low end throttle is like an on off switch.

[JoelH]

You mean how to do the mod or what the problem is like? The link describes the procedure as good as I can. Only other thing you would need to do is adjust the linkage rod parallel to the firewall to fit the new angle.

[TrumpetRhapsody]

The procedure specifically... I assume it's similar to this one, but the link you provided seems a bit vague (top vs bottom... etc).

Might you be able to snap a picture of your completed modification?

[JoelH]

They're one in the same. I'll try to snap a picture tomorrow after the JB Weld dries.

[JoelH]

Here's some pictures of he bellcrank (modified) and stock. I also made a pic of the screws I used.

One problem I encountered was reinstallation on the shaft. By adding the washer I brought the height of the bellcrank up above the c-clip groove. I have a very small amount of space (maybe a thin washer's worth) above the bellcrank where the shaft potrudes. How can I secure the bellcrank to the shaft? It can easily be pulled off by hand without the clip and I'm afraid due to road vibrations, bumps etc it will pop off. Even if the whole bellcrank doesn't pop off the bushing could come out and it would wobble.

Any ideas?