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Datsun 240Z Restoration: Carbs’ Return

March 12, 2012 by Matt

Datsun 240Z SU Carbs Carburetors Carburettors Hitachi S30 Refurbished Rebuilt ZTherapy

The Z’s SU carbs returned from their visit to ZTherapy today, and I couldn’t be more pleased with them.

They’re clean as a whistle, and the action of every shaft and linkage is buttery smooth. The founder of ZTherapy had rebuilt them in the late ’90s, fitting them with the company’s signature ball-bearing throttle shafts in an effort to cure tune-distorting vacuum leaks; however, the seals failed and the founder’s remanufacturing process removed too much material from the aluminum bodies of the carbs for them to be refitted with new bearings. ZTherapy’s current owner was forced to use new cores during this latest rebuild, and he cleaned them, replacing all gaskets and rubber in the process too.

Datsun 240Z SU Carbs Carburetors Carburettors Hitachi S30 Refurbished Rebuilt ZTherapy

The icing on the cake was the presence of the mid-production-style knurled mixture adjustment knobs, shown above. Early Z SUs were fitted with knob without knurls, making it difficult to count turns when tuning, and late-model SUs had thin, notched discs, hard to grasp when rooting around under the carb bodies. I requested the knurled knobs, but ZTherapy declined to fit them, as they (understandably) like to keep the cores together and avoid mixing and matching parts. But then they did it anyway, a fact that really made my evening.

Datsun 240Z SU Carbs Carburetors Carburettors Hitachi S30 Refurbished Rebuilt ZTherapy

A view of the sealed (outer) end of the throttle shaft. A ball bearing resides under here. The new owner’s machining process removes much less material from the carb body, making for a much tighter fit around the throttle shaft, greatly reducing the chance the dust shields or retaining clips will work their way loose.

In other Z news, the wheels have been cleaned and fitted with the BF Goodrich Radial T/As, sized 225/60-14. Pictures forthcoming.

Editor’s note: This post is Part 10 of an ongoing series chronicling my efforts toward the restoration of my 1972 Datsun 240Z, originally my father’s. Read the other installments here:

Filed under: 240Z Restoration, Datsun, Project Cars, Technical, Tinkering

4 Comments

  1. John D says:

    Awesome!

  2. frank says:

    HI THERE LOOKING FOR CARBS SU HS6 3 BOLT REBUILDING 67 VOLVO P 1800S CAR WITH A B18 ENGINE NEED CARBS CAN YOU HELP ME

    • Matt says:

      Hi Frank. Please turn off your caps lock key. Did you read the article? There’s a link to a SU carb rebuilding outfit that could help you.

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