Switch from Cannon to Harada Triple Manifold

[Rio24]

On 8/8/2019 at 10:02 AM, Mike W said:

@Rio24

Yes I had a rather severe return to idle issue with my old Cannon manifold and it certainly contributed to the problem, but the manifold itself was not the only issue.

The main issue with the Cannon wrt this problem is that the 3 heim joints do not line up and I found on my setup that this misalignment caused excessive friction and a very slow return to idle.  I had to use rather heave return springs which really impacted the drivability of the car and so I needed to find a better solution.

I ended up eliminating the center joint but doing this made the main throttle rod less stable and so I ended up going with larger heim joints and a heftier throttle rod.  This change definitely helped the return to idle but did not eliminate it completely.  

The final solution to this, at least in my situation, was to replace the old worn OEM throttle linkage with a throttle cable.  I used a universal throttle cable from Lokar and in the end this solved the return to idle problem.  I was also able to change the return springs to something lighter and this really helped with the drivability.  

When I went to the Harada, I was able to eliminate all of the return springs except for the one that was integrated into the Harada.  It really cleaned up the engine bay and also helped with drivability.  You can also adjust the spring rate on the Harada and dial it in so it works in your setup.

I would say that the biggest change to this problem was going away from the OEM stock linkage and replacing it with the throttle cable.  I fought the OEM linkage for years and wish I had made the change to the cable long before I did.

In any case, I hope that helps.  If you have any other questions just let me know.

Mike.

Hello @MikeW  could you share you were you got your t-cable from?  I just install the harada you recommended.  I don't have that return idle problem anymore and in super happy, but my pedal feels really stiff and hard to press. I'm using the crank that comes with the intake and a lokar cable.  Feel so stiff that cable may break.  How does you pedal feel? Can you make some suggestions?

[Duffman]

I have stuck with the Cannon intake, so far, and have switched from the standard shepard's hook setup to the Lokar cable arrangement.  The linkage is so much better, but I still battle a sticking idle issue.  I have gone from the standard 3 terminal rod holder arrangement and downsized to a 2 terminal approach (see pics).  I have made sure that each carb closes independently and smoothly, and have installed the stronger throttle plate return springs in each carb.  I tried going to a 3/8" throttle rod (from standard 5/16"), but had sticking issues on the linkage rod end bearings, so went back to the smaller rod, but with a shorter length (ok, I hear the jokes coming ...).   You can see the arrangement in the pics.  Bottom line, still having idle sticking issues.  Should I try to have the linkage to each carb attach on the same side, would that make any difference?  Any other thoughts and suggestions?  Love the Lokar cable solution, much better than the shepard's hook setup!!

[Rio24]

looking good @duffman.  yeah i popped for the this intake. Thanks for the pictures  i may have to go that way