Blew the carb on my bronco...replace or rebuild?

[Rustytruck]

Your going to have an issue finding one with an automatic transmission kickdown set-up if they even exist. No doubt someone could build one cobbling parts from a 2150 2 barrel. I wish pony carbs were still around they could have helped you.

 

[blamejane]

Your going to have an issue finding one with an automatic transmission kickdown set-up if they even exist. No doubt someone could build one cobbling parts from a 2150 2 barrel. I wish pony carbs were still around they could have helped you.

Thanks Rustytruck. In fact I was just reading the bronco tech forum and see a few threads on the A/T kick down required. I agree on pony carbs, wish I could have just called 'em up and placed my order :-[

 

[broncodriver99]

Here is a good page explaining the applications for all of the 4100s.

http://www.mustangtek.com/4100/ford4100.html

I run a 4100 and it is a great carb. If you can't find one with the auto linkage the shafts from 2100s are interchangeable. Same carb family. Finding one in good shape is going to cost a little bit and is well worth it. I bought a couple of junkers before I found a good rebuildable core. Ended up picking up another good one just to have a spare.

 

[Rustytruck]

I run a 4100 and it is a great carb. If you can't find one with the auto linkage the shafts from 2100s are interchangeable. Same carb family. Finding one in good shape is going to cost a little bit and is well worth it. I bought a couple of junkers before I found a good rebuildable core. Ended up picking up another good one just to have a spare.

What jet sizes do you run in your carb. Primary/secondary? I am assuming at idle it just runs on the primary so they may be close to the stock 46F or 48F as used in the 2100?

 

[blamejane]

What jet sizes do you run in your carb. Primary/secondary? I am assuming at idle it just runs on the primary so they may be close to the stock 46F or 48F as used in the 2100?

Um...

4.3221.96.324.3334 +/- 4% of overall jet density ;D

Seriously I have no idea, but I can ask my mechanic later today when I'm back in town. Thanks RT

EDIT: Thanks for the link broncodriver99!

 

[broncodriver99]

What jet sizes do you run in your carb. Primary/secondary? I am assuming at idle it just runs on the primary so they may be close to the stock 46F or 48F as used in the 2100?

Honestly I can't remember. It has been on there for a couple of years now. For some reason 48 sounds familiar. I will have to check. My 302 is worn and tired so I didn't spend much time in the way of tuning, I just kept whatever was stock. I have an engine swap planned for this fall or winter and will spend some time getting the jetting where I want it.

 

[broncodriver99]

What jet sizes do you run in your carb. Primary/secondary? I am assuming at idle it just runs on the primary so they may be close to the stock 46F or 48F as used in the 2100?

I just pulled the lid on my spare which happens to be sitting by my desk. It has 48F Primary and 57F Secondaries. I ran this carb for a little while and it ran great. Only problem was if I got into it too hard and slammed the secondaries open they would stick. That was always fun when hitting a red light. I would have to shut off the truck and restart then it was fine. Something going on in the secondary's vacuum circuit. Guess I should get it figured out.

 

[broncodriver99]

I checked and my intake manifold has been replaced with Eddlebrock Performer 289.

That intake will likely give you vacuum leak issues with a 4100. The carb mounting pad on the aftermarket intakes are a little smaller than the factory intake that these carbs were designed for. With an aftermarket carb it isn't an issue as the base of the carb is solid and flat.The 4100 has a relieved webbed base. You either have to run a thin phenolic insert or there is a gasket kit that has a reinforcing plate in it that helps seal up the problem areas.

I chose to run a factory '66 Mustang cast iron intake and PCV spacer to eliminate any issue down the road.

 

[blamejane]

That intake will likely give you vacuum leak issues with a 4100. The carb mounting pad on the aftermarket intakes are a little smaller than the factory intake that these carbs were designed for. With an aftermarket carb it isn't an issue as the base of the carb is solid and flat.The 4100 has a relieved webbed base. You either have to run a thin phenolic insert or there is a gasket kit that has a reinforcing plate in it that helps seal up the problem areas.

I chose to run a factory '66 Mustang cast iron intake and PCV spacer to eliminate any issue down the road.

Thanks I was reading about the undercut on the Eddlebrock's and how it causes leaking when paired with the 4100. The spacer sounds like a solution (I read somewhere that 1/2" phenolic would be best) but I also read that another good choice is the Weiland 8124 intake. Not sure if I want to replace my intake at this time, so I'll probably go with the spacer.

Question: is the transmission kick down a rod that comes up and has a slight bend towards the driver side of the carb?

 

[blamejane]

Looking at that link from mustangtek I think this one might work. Only difference is the eBay item states the secondary jet sizes are 58F not the 57F broncodriver99 has.

Okay guys is there a "window" of sizes that will work or is this a hard number. School in session!

 

[jckkys]

The 4100 is probably the best carb you can get for an EB with either a 302 or 351. The 1.08" venturi version is the preferable size for these engines. The Edelbrock Performer intake has a skimpy gasket surface on the carb mounting pad. You would want a phenolic ported carb spacer to assure sealing and provide a PCV hose port like this;
http://www.ebay.com/itm/Trans-Dapt-...-Carb-Spacer-/271976801158?hash=item3f5314a38
I find better deals on 4100s by searching "Ford carburetor", because a search mentioning 4100 doubles or triples the starting price. Here's a good example;
http://www.ebay.com/itm/281775385670?_trksid=p2060353.m1438.l2648&ssPageName=STRK:MEBIDX:IT
The price is fair and it looks perfectly rebuildable. Kurt Praxl of KP Carbs worked with John Enyert "now deceased" at Pony Carbs. Kurt has taken over the business and rebuilds 4100s for I think $200. The auction I referenced is for manual transmissions, but I can give you a 2100 throttle shaft with the automatic kick down lever.

 

[broncodriver99]

Looking at that link from mustangtek I think this one might work. Only difference is the eBay item states the secondary jet sizes are 58F not the 57F broncodriver99 has.

Okay guys is there a "window" of sizes that will work or is this a hard number. School in session!

There is a range. The secondary jets set your fuel ratio whenever there is enough load to bring the secondary venturis into play, generally climbing a hill or wide open throttle. There will be an ideal jet for your particular engine as too large would cause a rich condition and too small would cause a lean condition. Either condition would hinder performance.

 

[jckkys]

The Weiand 8124 is a taller intake than the Edelbrock Performer, with a similar carb mounting pad that has little gasket surface. There would be no advantage over the Edelbrock. Tuning a 4100 is the same as tuning a vacuum secondary Holley. It even uses the same springs to time the secondary opening. The jets are selected the same way but the thread is a larger size so jets don't interchange with Holleys. The power valves ARE interchangeable with Holleys and are selected the same way. A knowledgeable 4100 tuner like Kurt would know how to set up a 4100 for a 302. Sometimes a carb calibrated for a larger displacement engine has an off idle flat spot when run on a smaller engine. I'm sure Kurt would make the changes needed to correct this.

 

[blamejane]

The 4100 is probably the best carb you can get for an EB with either a 302 or 351. The 1.08" venturi version is the preferable size for these engines. The Edelbrock Performer intake has a skimpy gasket surface on the carb mounting pad. You would want a phenolic ported carb spacer to assure sealing and provide a PCV hose port like this;
http://www.ebay.com/itm/Trans-Dapt-...-Carb-Spacer-/271976801158?hash=item3f5314a38
I find better deals on 4100s by searching "Ford carburetor", because a search mentioning 4100 doubles or triples the starting price. Here's a good example;
http://www.ebay.com/itm/281775385670?_trksid=p2060353.m1438.l2648&ssPageName=STRK:MEBIDX:IT
The price is fair and it looks perfectly rebuildable. Kurt Praxl of KP Carbs worked with John Enyert "now deceased" at Pony Carbs. Kurt has taken over the business and rebuilds 4100s for I think $200. The auction I referenced is for manual transmissions, but I can give you a 2100 throttle shaft with the automatic kick down lever.

Thanks for the information and the links, really appreciate the help. I checked out the listing for the rebuild on eBay and it seems these sellers are missing out by not referencing the 4100.

The Weiand 8124 is a taller intake than the Edelbrock Performer, with a similar carb mounting pad that has little gasket surface. There would be no advantage over the Edelbrock. Tuning a 4100 is the same as tuning a vacuum secondary Holley. It even uses the same springs to time the secondary opening. The jets are selected the same way but the thread is a larger size so jets don't interchange with Holleys. The power valves ARE interchangeable with Holleys and are selected the same way. A knowledgeable 4100 tuner like Kurt would know how to set up a 4100 for a 302. Sometimes a carb calibrated for a larger displacement engine has an off idle flat spot when run on a smaller engine. I'm sure Kurt would make the changes needed to correct this.

Okay scratch the weiland, I'm sticking with the Performer.

 

[blamejane]

I think I'm narrowing this down a little. Looks like my best bet is a 1966 series carb from a Mustang/Fairlane because it includes the kick down and linkage ball.

C6ZF-B
----------
66 289 Mustang, Fairlane (exc/TE) <-- not sure what that means
1.08 venturi 4V
Auto
480 CFM

C6ZF-E
----------
66 289 Mustang, Falcon(w/MT & TE) <-- again not sure what that means
1.08 venturi 4V
Auto
480 CFM
California Emission

So here's the kicker: Dad purchased this new in California does this mean I. So do I need to consider the Cal emissions into the equation? However this is not the original engine, it's a rebuilt 302. Transmission is a rebuilt as well. So does this negate Cal emissions from the equation? All of the smog has been removed.

 

[broncodriver99]

TE stands for Thermactor Emissions. It was an air injection scheme that was used to help control emissions in certain areas. You don't have to worry about the CA emissions either. They likely were just set up to run leaner that the 49 state carbs. There is nothing different about the engine itself.

As long as whichever carb you find has the second lever on the throttle linkage you should be good to go.

 

[blamejane]

TE stands for Thermactor Emissions. It was an air injection scheme that was used to help control emissions in certain areas. You don't have to worry about the CA emissions either. They likely were just set up to run leaner that the 49 state carbs. There is nothing different about the engine itself.

As long as whichever carb you find has the second lever on the throttle linkage you should be good to go.

This is starting to make sense guys...thanks for the help.

Okay I found two that I'm almost certain will work. Here they are:

1st choice:
C5ZF-F

specs and photos found here: C5ZF-F

2nd choice:
C6ZF-E

specs and photos here: C6ZF-E

Don't be haters about the price...it's my bronco ;D

 

[broncodriver99]

This is starting to make sense guys...thanks for the help.

Okay I found two that I'm almost certain will work. Here they are:

1st choice:
C5ZF-F

specs and photos found here: C5ZF-F

2nd choice:
C6ZF-E

specs and photos here: C6ZF-E

Don't be haters about the price...it's my bronco ;D

Neither one of those has the kick down linkage.

 

[broncodriver99]

Here is a picture of the linkage you need for the kick down lever, and a picture of the post that the linkage goes on.

 

[blamejane]

Good thing I posted. Thanks broncodriver99.

EDIT: I see the 2nd lever now. That's all good, but it looks like I'm going to have to get one rebuilt. I'm certainly not deterred. Might even rebuild it myself. At the very least I can buy a good back-up and try my hand at it.