What is the diameter of the throttle shaft on a SU carb?

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111jag
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What is the diameter of the throttle shaft on a SU carb?

Post by 111jag »

Looking into buying reamers (they are very cheap like $30 Cdn for eight of them), and bushings for the carbs on my 67. I'm going to rebush them myself. "They" say they should be replaced every 40K miles. Mine is at 50k. Was wondering what size of bushing and what is the diameter of the shaft? Will the shaft have wear as well, if so where is the best place to buy them? I will use Joes technique of not drilling right through. Has anybody tried this? I'm also looking for bushings with bearings that should never wear. I hear they are for racing. Anybody know of a place I could buy them or should I just stick to brass? In the process of taking the carbs apart. Will let you know how it goes.

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Linda
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Re: What is the diameter of the throttle shaft on a SU carb?

Post by Linda »

Hope you can take pics of your process and tools that you are using
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Cyclewrks
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Re: What is the diameter of the throttle shaft on a SU carb?

Post by Cyclewrks »

I rebushed a set of SSS carbs on my 510 years ago and used a kit I got from Moss Motors. Think it was for one of the big Healeys but don’t remember exactly. It had both a bushing and a rubber seal for both sides. It did require resizing the holes in the carbs so they would fit.
"Life is not a journey to the grave intent to arrive safely in a pretty, well preserved body-but rather arriving in a broadside skid, thoroughly used up, totally worn out and loudly proclaiming "Damn, what a friggin ride!"- Anon
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jrusso07
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Re: What is the diameter of the throttle shaft on a SU carb?

Post by jrusso07 »

Here are some measurements on a USED and possibly worn shaft.

Calipers are not calibrated to traceable standard.

The 8.80mm is the minor diameter
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CSP311
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Re: What is the diameter of the throttle shaft on a SU carb?

Post by CSP311 »

I know you said you want to do this yourself, but for info;

https://www.ztherapy.com/

They replace with a roller bearing for the z car hitachi su type carb. They say they can do roadster carbs...
1965 Nissan Silvia (CSP311) for total restoration
1978 260Z finally on the road (Rebello 3.2L)

111jag
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Re: What is the diameter of the throttle shaft on a SU carb?

Post by 111jag »

I haven't taken the shaft out yet but did a quick mesurement. The shaft is 5/16" diametre and the outside diametre of the bushing looks like it is 7/16"? Is this correct? Is that the type of bushing I should buy? I was thinking of machining a stainless steel shaft to fit. Has anybody done that? And I read that you can drill a pin hole perpendicular to the shaft and oil it every once in a while so it stays lubricated and it should never wear? By the way I live in eastern Canada. With exchange, shipping and everything it would be close to $1000 CDN to get them done. I can't see paying that.

111jag
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Re: What is the diameter of the throttle shaft on a SU carb?

Post by 111jag »

Ok, I took the shaft out. The dimensions are different than the previous post. Here are the pics of the shaft for a 67 Datsun 1600. Does the difference warrant a new shaft? Also, the bushings look like they are steel. I have read that they may not need to be replaced as they wouldn't wear as much as the brass? Anybody agree. The only way I will know is by ordering a new shaft and seeing what the play is like? Also, they say that I should get a new throttle valve? Is this necessary? The original one looks like it seals pretty good and actually would be a better fit than a new one.
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