Throttle body conversion kits

[carl]

I get a Summit Racing catalog in the mail occasionally and like to flip through it. I noticed with the one I got yesterday that four barrel conversion kits for hot rods are fairly common now and the Summit brand version is about $1,000 supposedly complete….just pull off you old carb and install the throttle body, hook up the provided sensor and off you go. Whether it's actually that simple, I don't know. You have to wonder how many folks here would be jerking around with installing the factory FI system on their 1300s or early 1500s or even playing with larger Webers on their carbed cars if they had access to something like the modern throttle body kits.

Yes, I know you can get DCOE, DCNF and DGV type throttle bodies but you have to make your own "kit" and the costs will ultimately be a lot more than $1,000. For someone like me it would be a useless endeavor.

 

[lookforjoe]

Can't visualize how that would interface with the runners/manifold on the X - got any pics or links to the product?

 

[Dan Sarandrea (Phila)]

I get a Summit Racing catalog in the mail occasionally and like to flip through it. I noticed with the one I got yesterday that four barrel conversion kits for hot rods are fairly common now and the Summit brand version is about $1,000 supposedly complete….just pull off you old carb and install the throttle body, hook up the provided sensor and off you go. Whether it's actually that simple, I don't know. You have to wonder how many folks here would be jerking around with installing the factory FI system on their 1300s or early 1500s or even playing with larger Webers on their carbed cars if they had access to something like the modern throttle body kits.

Yes, I know you can get DCOE, DCNF and DGV type throttle bodies but you have to make your own "kit" and the costs will ultimately be a lot more than $1,000. For someone like me it would be a useless endeavor.

These guys have a huge assortment of kits, but none that are specifically for the Weber series that came stock on carbed Exxies. I know very little about carbed Exxies so maybe the DGA/DGV kit they have could be adapted to a stock carbed manifold? They do have kits for side draft DCOEs, however---but I have to think that if you went to the trouble of doing a side draft setup on your X, you're probably not interested in FI .

 

[MikeHynes]

I get a Summit Racing catalog in the mail occasionally and like to flip through it. I noticed with the one I got yesterday that four barrel conversion kits for hot rods are fairly common now and the Summit brand version is about $1,000 supposedly complete….just pull off you old carb and install the throttle body, hook up the provided sensor and off you go. Whether it's actually that simple, I don't know. You have to wonder how many folks here would be jerking around with installing the factory FI system on their 1300s or early 1500s or even playing with larger Webers on their carbed cars if they had access to something like the modern throttle body kits.

Yes, I know you can get DCOE, DCNF and DGV type throttle bodies but you have to make your own "kit" and the costs will ultimately be a lot more than $1,000. For someone like me it would be a useless endeavor.

Surprised that you even though about this.
Carl, you can get a stock X FI system for a LOT less than $1,000. Most often it comes attached to a really rusty car. So, I believe that's why folks would convert to the stock FI system, it's a lot cheaper. When you have a donor car it's really easy to make the swap.
Another reason for making to stock system swap would be that you don't have to/can't spend a lot of time tuning it. No PC needed.
Of course if your goal is 200 HP, the stock swap won't help, but then again, most folks don't target 200 HP for their X. And if they do...$1,000 is chump change.

 

[gene cooley]

Holley has a replacement injector for the old 500CFM 2 barrel carbs. There are some people using these on engines near 2L but it still seems kind of big for our use.
If they came out with something around 350CFM it would help. Only drawback is a lack of ignition control (unless that's changed).
As noted, for what you get $1000 (or $850 many places) is a pretty good deal.

 

[JimD]

When you have a donor car it's really easy to make the swap.

Hi Mike,

I think this is true if you start with a 79 or 80 carb'd X, not a 74-78 1300. Or maybe if you are a very experienced mechanic. There are many subtle differences between 1300 series to 1500 series cars that will make you question why you ever started on this "easy" swap. It is a life lesson for me, I should have just replaced the carb on my 78. I would have been driving it for the last 8 years rather than having it mock me from the corner of the garage.

 

[lookforjoe]

I would have been driving it for the last 8 years rather than having it mock me from the corner of the garage.

 

[carl]

I have pulled many X FI systems off my projects and easily sold them. To a carb guy like me, the stock system is rather complicated in that there are a lot of components and they are all old to boot. A TB system seems very simple in comparison. I posted more for entertaining discussion purposes, I have no plans on converting myself. And of course the hot rod crowd will always have interesting, lesser expensive components since the potential customer base is so much larger.

 

[Dallarax19]

I keep eyeballing these:

I have no idea how well they work but they are a copy of the Jenvey design which information is available.

The Holley Sniper system is designed for engines with a 250hp or more. FITech has a not so great rep so I did not investigate their system too much. I keep tossing the idea around for replacing my Holley 390cfm 4160 on my Alpine but is only about 200 hp and I don't want that to turn it into a doctoral thesis on how to develop the sniper FI system for small engines. I have asked on the Holley forums who has had success using the sniper system with small displacement engines 2.7ltr and all I got was crickets.

 

[carl]

I think someone makes IDF throttle bodies too. Like you, I'm not curious about developing a kit, waiting for someone to market an "everything you need in a box" kit. I believe you can get DCOE kits with the TBs looking exactly like the carbs so when you open the hood to your XKE everyone will ooh and ahh and then realize not only are there triple Webers on your Jag they are really TBs.

 

[JimD]

It's my own damn fault Hussein. I didn't do enough due diligence before diving in. Then I let scope creep increase the overall difficulty. It is still a nice X, just not mobile yet.

 

[Kevin B (Asheville NC)]

I ran a GM throttle body setup on my 392 Cu In IH Scout II.

Ran like a champ.

 

[Dr.Jeff]

A TB system seems very simple in comparison.

I get what you are saying Carl. I'm also surprised there have not been more "generic" components developed to replace common carbs with a "all-in-one FI" unit, like they have for V8's. Those V8 kits are a great product for the targeted application. For import applications the Weber type side draft throttle bodies are only one piece to a much larger puzzle, but they are a start...especially if you already have a side draft carb setup. The 'Holly Weber' progressive two barrel (down draft) carb has been a huge seller for decades to replace stock carbs. They have manifold adapters for just about any import car out there. So why not do the same with a self contained EFI that replaces that carb? It would not be a high performance setup like the independant TB's are, but it would run much more efficiently than the carb.

I keep eyeballing these

they are a copy of the Jenvey design

I spotted those on eBay. Really great price for what they are. However it still leaves you with a LOT more needed to assemble a complete system. But it's a good start. I have a feeling this would be the least expensive part of it though.

 

[Dr.Jeff]

There are many subtle differences between 1300 series to 1500 series cars that will make you question why you ever started on this "easy" swap.

Jim, I've never really thought about it - in a nutshell what have been the biggest obstacles to putting the late FI system onto a 1300? Honestly I would have assumed the same as you, it seems a fairly straightforward thing.

 

[MikeHynes]

Holley has a replacement injector for the old 500CFM 2 barrel carbs. There are some people using these on engines near 2L but it still seems kind of big for our use.
If they came out with something around 350CFM it would help. Only drawback is a lack of ignition control (unless that's changed).
As noted, for what you get $1000 (or $850 many places) is a pretty good deal.

I'm not sure about a 350 CFM Holley System, but they did make a 300 CFM system a long time ago. Here's the one I have. Seems WAY too big for a Fiat engine to me, but I don't know.

 

[Dr.Jeff]

Well I just looked closer at the site Don referenced...

These guys have a huge assortment of kits, but none that are specifically for the Weber series that came stock on carbed Exxies.

They do have a unit for the Weber DGV, as I suggested a moment ago.

I bet this could be adapted for the SOHC;
https://www.classicfuelinjection.co...ucts_id=262&osCsid=bv2tp7mt9phuq8383qqa2c7ch3

 

[MikeHynes]

Hi Mike,

I think this is true if you start with a 79 or 80 carb'd X, not a 74-78 1300. Or maybe if you are a very experienced mechanic. There are many subtle differences between 1300 series to 1500 series cars that will make you question why you ever started on this "easy" swap. It is a life lesson for me, I should have just replaced the carb on my 78. I would have been driving it for the last 8 years rather than having it mock me from the corner of the garage.

Sorry to hear that you ran into trouble. What kind of issues did you have? I don't use the AUX air valve (never needed it) so that simplifies things a bit. Did you have a donor car to start with?

 

[gene cooley]

I'm not sure about a 350 CFM Holley System, but they did make a 300 CFM system a long time ago. Here's the one I have. Seems WAY too big for a Fiat engine to me, but I don't know.
View attachment 21363
View attachment 21364

That looks like the tb with injectors that was on the '84 Corvette with the "Crossfire" injection. They used 2 of them for 5.7L. If it is the same (or similar) each tb was providing fuel/air for about 100+/- hp. It may not be the same. These were before port injection became popular and there were a variety of bore sizes.
Did you ever get a chance to try it out or was it a replacement part for something?

Correction: I believe the Corvette had 2 single barrel throttle bodies, not (2) 2 barrel.

 

[JimD]

Sorry to hear that you ran into trouble. What kind of issues did you have? I don't use the AUX air valve (never needed it) so that simplifies things a bit. Did you have a donor car to start with?

Hi Mike,

Well, there is a thread on the project here. In a nutshell, things went pretty smoothly the first year or two while pulling the old engine, cleaning things up, building up the new 1500, etc. I even got the engine in the car and started mounting everything to it. So I was looking at the FI linkage and the existing carb accel cable end and I said "Hmmmm, well that ain't gonna work". This is the point of the story where the village idiot gets sad, because he just realized he is the village idiot and not the class clown. It is a subtle difference.

Let's continue: So the accel set up doesn't look workable at all with the new FI linkage. Fortunately I was heading for FFO soon and tracked down Madd Matt for some advice. He told me that the 1300 and 1500 accel pedal, cable and linkage were different and I would need to swap in the 1500 accel gear. I wasn't happy that I had that I had to pull the interior apart, but when I got home I gathered the parts and got to work. I got the old cable pulled, the new pedal assembly installed and grabbed the new cable. As you probably know, but I didn't, the 1500 cable will not fit into the 1300 cable guide tube that lives in the center tunnel. Right about here is where I yelled a few expletives, literally gave the guide tube the finger, cursed my decision to start this swap and then shoved the car into the corner and stacked boxes on it. It sat for a couple years, then I worked on it some more. Then it sat for a couple more years and then a couple more. It still sits in the corner and really makes a wonderful shelf.

There are other differences like various studs in the bay for mounting carb gear are shorter than the same stud in an FI car. The accel pedal issue was the back breaker for me though. I thought I was nearly done and then, nope.

Just for reference, this is the X:

At least it isn't getting rusty.

 

[Dr.Jeff]

Jim, I feel for you. There are plenty of times I give the finger and yell obscenities at a part I'm working one. Often wonder what someone would think if they saw me doing that, but it feels good at the time.

I'm actually about to do a FI swap into a '79 carb X. I've never had a 1300 so I don't know how different they are compared to the carb '79. But the '79 also has a different (carb) throttle cable and linkage compared to the '85 FI stuff I'll be putting in. I have not looked too close at it yet so don't know what will be needed. But I'm wondering if you could use the 1300 carb throttle pedal and cable, but make some sort of adapter around the rocker cover part of it (at the engine)...to connect the 1300 stuff to the FI stuff?