Datsun 240Z Restoration: Carbs’ Return
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.
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.
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:
- Part 23: Gutting the Interior
- Part 22: The Teardown Begins
- Part 21: …And the Engine Comes Out
- Part 20: Treasure Hunting
- Part 19: Beginnings
- Part 18: VIN Discoveries
- Part 17: The Bad News
- Part 16: On The Road
- Part 15: Getting It Back On The Road
- Part 14: It Lives!
- Part 13: Restoring the Fuel System, Part I
- Part 12: Meat on the Wheels
- Part 11: Inspiration (Sort Of)
- Part 9: First Triad Z Club Meet
- Part 8: Wheel Work
- Part 7: Tactical Changes
- Part 6: Little Things
- Part 5: Coming Home
- Part 4: The Rollout
- Part 3: Confessions of a Poor Car Enthusiast
- Part 2: Opening the Tomb
- Part 1: Projecting Forward
Awesome!
Can’t wait to get ’em on. :)
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
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.
Is there a real way to set-up the float level on a 1973 Datsun 240 Z, SU carbs ?
Thanks
The ZTherapy video does a great job of explaining:
http://ztherapy.com/products/videos/just_SU.htm
I have an old VHS copy that I’ve watched several times. It’s great! (no affiliation)
HITACHI SU.seeking after market thottle shaft (the BAR piece that joins the carbs, AT THE ADJUSTERS. THE PIECES ON MY 72 IS SLOPPY! WILL NOT ADJUST NOR TIGHTEN UP. ENDS WORN.
I have one OF THE REALLY GREAT AFTER MARKET IMPROVMENT ONES on my 73 Z rather than the original.
IT CAME WITH THE CAR SO I HAVE NO CLUE WHO SUPPLIES THIS BETTER FIX TO SLOPPY THROTTLE SHAFT.