SSS Maniold and SU Carbs on my 620

[Northport Datsun]

I started this post to share my experience installing a SSS manifold and SU carbs on a L20B in my 1976 620. I've seen a few of these set ups and most involved additional cables to pull the throttle open from above the center of the manifold. I wanted a share a fairly clean installation that uses minimal parts and keeps it as close to stock as possible for reliability. This only requires two parts to be fabricated and no additional cables. It's also adjustable to get the right angle to rotate the throttle shaft fully and it retains the original tensioner to take up slack in the stock throttle cable.

 

https://lh4.googleusercontent.com/-3he3PNDrQTY/VMatUfA-wdI/AAAAAAAAA_0/es5-YES89L8/w473-h841-no/20140706_191225.jpg

 

My set up uses the stock cam and cable. I removed the cam that accepts the cable on the stock downdraft carb. It's a small half round cam with a groove in the center for the cable and it has the hole for attaching the end of the throttle cable too. Obviously, this was all stock so it mates perfectly together and it is reliable. 

 

I welded a nut on that cam and used a threaded bolt to attach it to the U shaped throttle shaft end on the Manifold. I welded the bolt on the U shaped throttle shaft end. If you use a threaded nut welded to the cam and thread it on to the bolt now welded to the throttle shaft, you can adjust the position of the cam to get the right angle for the throttle cable. You will do this adjustment at the end.

 

Cam on end of threaded bolt:

 

https://lh6.googleusercontent.com/-YZSkhii940w/VOEoG-3xPhI/AAAAAAAAEj0/XZDeLb-sx_Q/w473-h841-no/20150215_170401.jpg

 

Bolt welded to throttle shaft on the manifold:

 

https://lh4.googleusercontent.com/-2MAYqV3KWqY/VOEog5nx9gI/AAAAAAAAEj8/Qq9R_7-cNS8/w473-h841-no/20150215_170518.jpg

 

 

Now you need to make an L shaped bracket to hold your throttle cable in place. The bracket will mount to the manifold studs. You can lengthen these studs if necessary. I used 1/8th thick steel because I want no flex in my linkage. I cut the end that holds the cable off the stock bracket and welded it to the new L shaped bracket that bolts to the top studs on the intake manifold. The dimensions are not that complicated. Thread the throttle cable into the cam on the shaft and hold it in place. Take two measurements off the studs for the height and length of the bracket. Make one out of cardboard first if you have to and check the fit.  The next pictures are before after final assembly.

 

https://lh5.googleusercontent.com/-VbM0tZD-QOE/VMatYKwImlI/AAAAAAAABAY/XFwcIgF8J8I/w473-h841-no/20140704_113526.jpg

 

https://lh4.googleusercontent.com/-094k6jcEkzA/VOEn4ow8PUI/AAAAAAAAEjs/u927OA1VxMY/w473-h841-no/20150215_170243.jpg

 

 

Once these are complete, assemble everything together and adjust the cam so it is directly under and in-line with the cable (that's why you use a threaded bolt to attach to the throttle shaft on the manifold; now you can adjust it perfectly even if your bracket requires you move it a little). You can also adjust the cam clockwise and counter clockwise to accept the throttle cable and rotate perfectly.

 

It's optional to weld the cam to the shaft at the end so it can never fall out of adjustment. I did (as you can see), but make sure your happy with the position of the cam first. The cam should never leave the cable with slack, and it should rotate until the mechanical stop forces it to stop. Ensure you have full rotation before you weld it permanently to the shaft.

 

https://lh5.googleusercontent.com/-wa7780aVeHM/VMast8ULqYI/AAAAAAAAA5U/J2bpYWPdEL0/w473-h841-no/20141214_184959.jpg

[flatcat19]

Nice. 

 

This should be in the How-To section. 

[heretic]

GREAT write up. thanks for sharing.!!