ditchdigger
ditchdigger Reader
5/23/09 10:32 p.m.

The 1950's design of my Fiat's Cylinder head makes port injection an impossibility. The tiny 30mm single barrel weber is really choking the motor and since I have a nice new Megasquirt unit and wideband O2 sitting next to me why bother with carbs I wont ever be happy with.

So I have to find a smallish TBI setup. Off the top of my head I can think of late 80's ford tempo, Some 2.2 dodges from the same era, The 3 cyl Geo and the dual point honda setup. The problem is I have no experience with any of these cars. I need the throttle body to be pretty short and have an injector that will be able to fuel about 75 horsepower.

I could waste hours in the junkyard popping hoods looking for an appropriate setup. Anyone have any ideas?

erohslc
erohslc New Reader
5/23/09 10:44 p.m.

I've a friend who put a TBI setup on his 1500 Spitfire with Megasquirt. ISTR he used the Ford stuff, and it was not a major challenge to do it with basic hand tools. Not sure if the TB will fit, depends on how much room you have. But as an alternative, consider a single regular (port) injector, with flow enough for 75 HP. Find a 300 HP 4 banger application, and then use one of those. Or go to one of the injector vendor sites, and use the online calculator. You ought to be able to mount the single port injector somewhere right after the TB.

What about a manifold? Sounds like you are planning to hog out the hole where the Weber now sits. 300 mm is about 1.2". What about something from a motorcycle?

Carter

Trans_Maro
Trans_Maro Reader
5/23/09 11:09 p.m.

The Tempo TBI is nice and small. The Delphi one from the iron duke is almost too big to be practical.

Have you checked out TWM throttle bodies? They're weber patterned TBI's, big $$$ but bolt-on for weber equipped cars.

Shawn

ValuePack
ValuePack HalfDork
5/23/09 11:13 p.m.

B12 Sentra comes to mind(didn't know they were TBI 'til I bought one). Happy hunting!

kevinSC1
kevinSC1 New Reader
5/23/09 11:36 p.m.

My '84 Cavalier had a TBI setup. That was in my pre-"car guy" days, so I can't tell you anything about it.

jpod999
jpod999 Reader
5/24/09 12:22 a.m.

Starquests are TBI, but those are probably to big for your needs.

suprf1y
suprf1y Reader
5/24/09 10:01 a.m.

Metro TBI's were 36mm, and 38 mm. I think the change to 36 was in 94, but the 4 cyl probably still had the 38 I think I have a 93, 4cyl TBI if you want it. I can take a pic, and some measurements if you want. It will easily support 70hp.

ditchdigger
ditchdigger Reader
5/24/09 12:31 p.m.

I would love a pic.

I fully expect to have to make my own manifold, nothing new there, and actually that is my favorite part

The intake port on the head makes most tractors look well designed. This is the old motor I yanked. The intake port is the triangleish shaped hole in the middle. Photobucket

There is only about 8 inches from the top of the motor to the top of the engine bay. A sidedraft type of setup would work pretty well.

patgizz
patgizz GRM+ Memberand Dork
5/24/09 1:37 p.m.

i have one off a 3.1 gm v6 minivan you can have for shipping cost to play with. its a small 2bbl/2 injector unit and it was like 120-130hp.

how about a single throttle body off a crossfire camaro/firebird/corvette?

ScottRA21
ScottRA21 New Reader
5/24/09 1:40 p.m.

I think you need to swap out that tractor engine...heh

Otherwise, Jenvey makes weber compatible carbs: DCOE, IDF, IDA and DCNF flanges.But those all start at 40mm.

They do have some simple 2 bolt throttlebodies starting down at 30mm.

Cheapest option: Bike throttlebodies.

suprf1y
suprf1y Reader
5/24/09 3:22 p.m.

The top is about 5" diameter. From the mounting flange to the top of the air cleaner stud is about 6.5" I didn't measure the bore, but I'm pretty sure its 38mm. There is an internal pressure regulator (about 10 psi IIRC), and I should also have a fuel pump too, if you want it.

mad_machine
mad_machine GRM+ Memberand SuperDork
5/24/09 3:38 p.m.

can you go "sidedraft" and use a modified webber carb?

Taiden
Taiden New Reader
5/24/09 4:10 p.m.

The Ford Focus SPI was throttle body injected as far as I know.. and the throttle body was pretty compact afaik.

Edit, how do you feel about drilling and tapping the two runners and using a fuel-rail-less setup?

Luke

Trans_Maro
Trans_Maro Reader
5/24/09 4:41 p.m.

You should be able to "go sidedraught" with pretty much any TBI unit. It's not like they've got floats or anything.

If you want something to mess around with, I think have a couple single Rochester TBI's from a crossfire kicking around, I also have a Ford TBI from a 302 (these are great, they're Holley 2300 pattern).

I can send them to you for whatever the shipping cost is.

Shawn

Raze
Raze Reader
5/24/09 4:54 p.m.

would prolly be too big, but Cadillacs had TBI on the first couple years of the 4.5L V8

MadScientistMatt
MadScientistMatt HalfDork
5/24/09 5:30 p.m.
Taiden wrote: The Ford Focus SPI was throttle body injected as far as I know.. and the throttle body was pretty compact afaik. Edit, how do you feel about drilling and tapping the two runners and using a fuel-rail-less setup? Luke

Pretty sure all Foci were multiport, but the earlier 1.9 version of the SPI / CVH engine found in Escorts sometimes came with a TBI.

dean1484
dean1484 GRM+ Memberand Dork
5/24/09 7:44 p.m.

87 ford escort has tbi.

Taiden
Taiden New Reader
5/24/09 8:52 p.m.
MadScientistMatt wrote:
Taiden wrote: The Ford Focus SPI was throttle body injected as far as I know.. and the throttle body was pretty compact afaik. Edit, how do you feel about drilling and tapping the two runners and using a fuel-rail-less setup? Luke
Pretty sure all Foci were multiport, but the earlier 1.9 version of the SPI / CVH engine found in Escorts sometimes came with a TBI.

I just did the research. You speak the truth!

That_Renault_Guy
That_Renault_Guy GRM+ Memberand HalfDork
5/26/09 3:14 p.m.

49 state AMC/Renault Alliance/Encore/GTA all have TBI (California cars had Bosch L-Jetronic).

dennisg
dennisg New Reader
7/25/09 8:41 p.m.
ditchdigger wrote: The intake port on the head makes most tractors look well designed. This is the old motor I yanked. The intake port is the triangleish shaped hole in the middle.

It has 4 studs. That is really good. I'm making do with a design with only one stud per port, and fighting sealing problems. dennis

Dusterbd13
Dusterbd13 New Reader
7/25/09 8:59 p.m.

think about a TBI from an s10 with a 2.8. self contained regulator, injectors can support about 120 horse at teh fluwheel. small, dual throttle bores with really good venturi effect, cable operated, and a three bolt mounting flange. could probably be strapped to you manifold weith a simple adapter. and the best part is they are only 4 inches high, common as dirt, and about as cheap. all the sensors are self contained in the TBI, and you can easily adapt the s10 harness into anything, even with the s10 PCM.

hope that helps. michael

ditchdigger
ditchdigger Reader
7/25/09 11:16 p.m.

Turns out the Suzuki swift 1.3 unit is a good fit. cold idle boost, coolant temp sensor, fuel pressure regulator all built in to a unit smaller than a weber DFEV. Even the coolant lines point to the proper points on the head.

Fit_Is_Slo
Fit_Is_Slo New Reader
7/25/09 11:20 p.m.

Base nissan pulsars have tbi's

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