MSefi.com read only forum (Jan.15,2018)

I would like to replace the carb on a early 70's Datsun with a TBI/CFI throttle body but am not sure which cars had single injector or small two injector TBs that would be suitable. It would be going on a stock US L16 engine. Going this route for simplicity, having no access to milling equipment to make manifolds, fuel rails or adapters.

Which TBs would be suitable?

Thanks

What is the displacement? Is the motor fairly stock? What do think the HP is?

What size and shape is the mounting flange? Round? 2 rounds? If 2 rounds are the divided or open in the middle? A picture would be great to see what things are in the way.

Ford made a 1bbl for a couple of years that is fairly easy to mount. The GM's were physically much larger and tend to be harder to retro fit. I can find better picture and measurements of the ford one if you want.


You may be able to find small enough injectors to get a 2 bbl to work but they are going to be physically fairly large so mounting could be an issue, this is a holley that is the size of the big block chevy one. THe rest of the Gm ones have the same bore spacing, just smaller bores. Some of the Ford ones were slightly closer bores but like the rest a fairly large block to deal with. The carbon marks in the picture are the ports from a spread bore (Quadrajet) carb mount. Again I can give you better pictures and measurements if you want them.


If your engine is fairly small you may want to look into motorcycle/ atv/ snowmobile type of setups.

DWise wrote:I would like to replace the carb on a early 70's Datsun with a TBI/CFI throttle body but am not sure which cars had single injector or small two injector TBs that would be suitable. It would be going on a stock US L16 engine. Going this route for simplicity, having no access to milling equipment to make manifolds, fuel rails or adapters.

Which TBs would be suitable?

Thanks

1600cc 4 cylinder stock about 100 horsepower. Will take a picture of the engine in a couple of days.


What vehicles did the Ford units come on?

The most common place to find the Ford one is on an 85 Tempo. The may have been on them a year or so in either direction. It was also a rare option on the early Taurus around that same time. I have never seen on on anything other than an 85 tempo but that could just be what happens to be in the yards around here. I have seen them on Ebay from time to time.

Pictures, finally. It shows the Datsun side of a Weber/Datsun adapter.
Bolt spacing is 1.75 X 3.125.



With a throat opening of 2.5 by 1.125 (approx). What is the throttle plate spacing/sizes on the Tempo/Topaz unit?

Dave

I will try to go get some pics and measurements soon. The flange is sort of an oval with 2 mounting holes and it has a single round bore.

Is the hole in the intake rectangle(ish) like that adapter? If it is I would look at those motorcycle atv type of throttle bodies. I have seen some that interlock together so the linkage would not be a problem and use bosch type multiport injectors. You would then just have to make the 2 bore holes in a flat plate to mount them. I dont remember the details, I think they may have been off a polaris? The project I have the fords for is a mustang with an inline 6 that has the intake integrated and cast as part of the head so there is not much you can do with it.

The opening in the manifold is shaped like the adapter, as the carb is a progressive two barrel, like half a Q-jet.

Air inlet OD is 3.6"x 2.7"
Throttle bore 1.685"
Mounting holes on flange 3.0"
Unit is about 5" tall

Thanks for the pictures. They are a big help.

Dave

I would grab a TBI off a 80's Chrysler with a 2.2/2.5L 4cyl car. They are cheap, reliable and easy to find. You would still have to fab up your own adapter, but I think this would be easier than a ford unit.

Daytona, do you have more specifics on that unit? I looked at a few cars and they were either MP or still had carbs.

Thinking seriously about one of these Tempo TBI units for my Spitfire. Single-barrel, two-bolt mounting should be a breeze to install on a stock Spit manifold. Anybody got more tech info on them? Specifically...

Any problem mounting it at 90 degrees (onto a side-draft manifold)? I can't think of any reason there would be.

Is this a typical 12 psi TBI injector? Internally regulated, or do I need to regulate down to 12 psi?

Injector specs and other stuff I'd need to configure the MS?