Switch from Cannon to Harada Triple Manifold

[Rio24 7]

@duffman here's a link if you have a throttle cable set up https://www.rhdjapan.com/kameari-intake-manifold-kit-l-type-44mm-l6-wire-type.html

[Rio24 7]

@Mike W  thanks for that info.  I have already switched to cable setup and rebuilt all carbs completely.  My issue only happens when its really hot out or I get stuck in traffic. Was your issue was always or got worse under certain conditions?

[duffman 36]

Thanks, Rio24, comes out to about $490 delivered to me, not bad.  Appreciate the info!

 

[Mike W 135]

Here's a link to the same person in Japan that I bought mine from 4-5 years ago:

https://www.ebay.com/itm/Datsun-240Z-260z-280z-Harada-Intake-manifold-for-triple-Mikuni-Webers/283568679779?hash=item420602ab63:g:upIAAOSwVvBdRLCj

@Rio24

I do not recall that my issue was worse with heat soak.  It seemed to happen all of the time so perhaps you are dealing with something a little different.

Mike.

[duffman 36]

Seems to be about $100 cheaper going through RHD, then going through eBay; $491 vs $591, delivered.

Edited August 8, 2019 by duffman

[Perfect240Z 3]

I just wanted to add on here, a couple years back I came upon my 72 JCR which had triple Weber’s with a cannon intake. The car would not idle really at all and carbs also needing rebuilt. But I just wanted to add after I removed the carbs I took the manifold off and saw the linkage was bent in the middle and rusted. I had to cut the main rod for the linkage to remove everything, and after looking around I was almost going to use my new harada that I’ve been saving for my other Z. I found out that there’s a company that makes a thicker rod and linkage set up for this issue and is way cheaper. My car now has this linkage with rebuilt Weber’s and a cannon intake and it idles just fine. Just search pierce manifolds and it will come up.?

[Perfect240Z 3]

Here’s a link for the idle of the Z with now on a cannon and new linkage

 

 

[duffman 36]

Thanks, Perfect240Z, good to know!  Talked to Mike at Pierce Manifolds about their intake manifold, and it seems to be an improvement over the Cannon intake.  

FYI, for those triple Weber fans, Pierce Manifolds is working on a customized emulsion tube specifically for the L24 thru L28 engine, it is going to dyno at Rebello this week, I think.  Would be available in a few weeks, if the results come out as expected.  Supposed to be better suited for our engines and a better balance of performance and  economy.

[Rio24 7]

No way!   Please keep us posted on that @duffman

[Perfect240Z 3]

I think I heard of someone who was making custom emulsion tubes for Weber’s. I’ll have to ask about it if they’re local and if they’re the same person with pierce since they're local.

Edited August 8, 2019 by Perfect240Z

[240260280 2,156 1 Vehicles]

200sx throttle cable conversion:

 

https://www.zcar.com/forum/10-70-83-tech-discussion-forum/54528-cable-throttle-linkage.html#post482558

[Rio24 7]

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 36]

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 7]

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