Not to nitpick, but the flat tops are still SU's. Hope they work out this summer!

Well, actually all the datsun carbs are Hitachis. They were made under license from the British company that makes SUs.

We tear down enough of both to go on to say that it's our feeling that Hitachi did a better job building them than did the Brits. FWIW Castings, machine work, etc.....

Any updates on your successes or lackthereof? I just bought a '73 240 with flat tops, and am basically planning on cleaning them up and trying to run them (it's been sitting for years, they're pretty scummy), however the last owner was given some Z parts by an acquaintance of his and threw 'em in with the car, including a pair of earlier carbs which seem to be remarkably cleaner (and better devices, if I can believe most of what I've read on the net). However, not sure if all the linkages and such line up enough to be able to do a swap, and if I'm not mistaken it'd require a new intake manifold as well, kind of expensive if I don't have to.

Hey Rich, logon to zcar.com and PM "Tony D". He loves flat tops and knows how to make them work very well. Tell him I sent you.

Hi Rich: good for you, I have a 260 and although I have not even attempted to clean my carbs or make any adjustments on them, I am as determined as you to keep them, my thought, if these carbs were not good enough, why mass produced them, right? keep us posted I can use any other tips you may have.

George

...my thought, if these carbs were not good enough, why mass produced them, right?

Because they had to meet emissions regulations. When you compare the round tops side by side to the flat tops, you'll see just how complex the flat tops are. Other than the few gurus who like them, they really are crap. Many dealers were swapping them out when the cars were brand new due to all the problems they had.

Just because something was mass produced, doesn't mean it was any good. AMC was in business for years and everything they built was junk. :sick:

Captain Zeros,

Wow, all the way over in Independence?? If you were closer I'd say give us a call and come by the shop. I just bet you we could answer all them little nagging questions.....

Hey Rich, logon to zcar.com and PM "Tony D". He loves flat tops and knows how to make them work very well. Tell him I sent you.

Why go over to Zcar.com? You can find Tony D here.

Ahh. Thanks SteveJ. I've never seen him hanging out here.

I think that's in part because there are fewer people talking out of their pie holes around here (and the Ignore feature works, too;)).Heck, even Bubbles didn't hang out here long. I have also noticed that we don't get the school break crowd around here.

Rich,

Go to Steve J's reply and click on "Xenon S30"

click on "Reference" "Other Guides" "1973-240Z/1974 260Z Fuel System Modification Plus Manual".

This is a reference about the Flattop carburetors.

Also as Jeff mentioned, check with Tony D.

Dave Ruiz

Well, actually all the datsun carbs are Hitachis. They were made under license from the British company that makes SUs.

We tear down enough of both to go on to say that it's our feeling that Hitachi did a better job building them than did the Brits. FWIW Castings, machine work, etc.....

Technically you are right, as SU stands for the brand "Skinner's Union" however, like Kleenex, I'd argue SU's now refer to the type of carb rather than the brand.

I just wanted to be clear that the flat-tops are essentially the same style carb as the round tops. They're both Skinner's Union type Hitachi's.

Captain Zeros,

Wow, all the way over in Independence?? If you were closer I'd say give us a call and come by the shop. I just bet you we could answer all them little nagging questions.....

I've had the car less than a week, just got the air-cleaner off yesterday (it was running into the brake master cylinder :stupid:)

First thing I did when I found I had an extra set of carbs not on the car was google around for information, and ran across z-therapy.... looked around the site and went "WHOA, SALEM! COOL!"

Nagging questions are gonna come after I try and get the car running, right now I'm still in learning and diagnosing mode

Edited April 13, 201014 yr by Captain_Zeros