Trying to get information on ports on the carb and where the vac lines go to and what are they hooked to. I know this old stuff to most 300 builders, but it is all new to me, thanks for any and all information.

1st picture, the vac port from the carb base runs to or feeds what?

2nd picture, Vac tube coming from the air cleaner area runs to or feeds what?

3rd picture Caped port from the choke base goes to where? Or does it stay caped?
Tee port from the caped base goes to where or does it stay open?


https://image.ibb.co/n4hP1b/300_Motor_26.jpg
https://image.ibb.co/jtCrgb/300_Motor_27.jpg
https://image.ibb.co/gk0Bgb/300_Motor_25.jpg

 

The vacuum nipple on the carb base is for your vacuum advance.

The one one from the air cleaner area is the choke stove air inlet.

The one on the choke housing is for the choke stove.

Both of the choke stove ones went down to the passenger side exhaust manifold on the V8 the carb came off from. Check out post # 5 in this thread for a picture of a manifold with the hook ups for that. https://www.ford-trucks.com/forums/1...-to-choke.html

 

fordman75 -- As the EFI exhaust manifolds are not set up for this stove heat to the choke manifold can the current choke be converted to an electric unit? I hope their is a way as I don't like the looks of the heat tubes running from carb to exhaust manifold. This motor may be going in a 29 fenderless roadster and I want the motor looking sharp. thanks tom

 

I don't see why you couldn't convert it. I usually go to the other extreme on mine. I convert them all to manual choke. I like to control the choke.

 

Maybe that is the way to go as I really won't need it that much at my place in Southern, CA about 10 miles from the beach. Is there a part that you can install in place of the OEM spring unit or do you just make the bracket for the cable control? Thanks Tom

 

There are a few ways you can convert it to manual choke.

1. There is the kind of cheap auto parts store set up that uses the stock choke parts but just converts the plastic cover. They don't look as good as option 2. but are cheaper and they work.

These kits run around $10.00-$20.00. I know Dorman offers one of these kits. The part # is: 55101.

https://www.summitracing.com/parts/r...SABEgLwevD_BwE



2. Is change out the whole choke assembly for the factory manual choke parts. This is the way I prefer on my carbs. You can either look for a used Autolite 2100 2V carb with the factory manual choke. This is what I usually do but I'm also somewhat of a Autolite carb hoarder. These are getting harder to find since most where the same style choke yours has. I have a few but I'm still looking for more for my own projects

There is also a company that sells kits to do this with all new reproduction parts. But I feel they are way too expensive. The kit runs right around $70.00. https://www.mustangsetc.com/hi-po-ma...onversion-kit/


Here's a website that covers the install of the stock style kit. It does clean up the looks of the side of the carb.



3. Is to make up something yourself that will work.

 

fordman75 -- As this motor will be on a run stand for a while I think #1 will work fine and I will be able to run cable from my start/stop control panel to the choke.

As an intake setup for a future motor I want to take my lower EFI intake section and build a 2x2 plenum intake with dual 2100 1.08 autolite carbs. I may run this setup on the 300 nostalgia race motor for a while as we get the car dialed in.

I had a pair of 2100 1.08 on a home built intake on my nostalgia front motor dragster that had a little 194" Chevy inline 6. They worked out great and as FrenchTownFlyer told me they are easy to work on. I still have two units on the shelf. They are getting a bit hard to find.

Thanks for the help. Tom

 

Yep it should work fine.

The EFI lower with a fabricated plenum should perform really well too. The nice thing about making your own plenum is you can modify it's shape/size to tune how it will run on your engine. And the 1.08's are about the best all around size to use. I can't wait to see how your engine turns out.

I'm building my own 2-2V intake and header for my 300. It's going in a van so the aftermarket intakes don't fit all that well. I was planning on running dual 1.02's on mine. But my build is going to be a little wilder then my original plans. So I'm thinking I may need bigger carbs. Yea the carbs are getting slightly harder to find. At least the cheap ones are. I use to pick these up for $5-$15. Now a really cheap one is $25. Most are in the $40-$100 range. I think I've got around 20 of them right now. The 1.08's are the most common. They were the ones that came on the 289 & 302's. The hardest to find are the 0.98's and the 1.33's. Right now I've got one or two of the 0.98's, two or three of the 1.01's. And the rest of mine are the 1.02's. I'm going to start picking up all the larger sizes. That way I can try them all on the 300 and see which performs the best for my needs. Like I said I've got a small Autolite 2100 hoarding problem.

 

AUTOLITE CARBS = most under appreciated and overlooked carbs by the hot rod fraternity.

 

FTF -- As you know I am going to run this first mild 300 build with a dual port 4v intake with a 1.08 4100 autolite that I have.

On the motor for the nostalgia altered (about 250-275 HP) I will put together a home built intake with the lower EFI section I have and weld up a 2x2 plenum to run the two 1.08 autolite I have on the shelf. Will not start on this motor until summer.

On the 2x2 home built intake with two 1.08 autolite I ran on my 194" Chevy (bored to 210") nostalgia dragster I just made a plenum that looked nice in size with those carbs and did not really look into a proper size.

Is there a volume size that the plenum should be? Do you have some starting measurements for the L-W-H.

 

I'm not able to measure mine at this time, but for a strip engine I would shoot for around 200 cubic inches. On a street driven car I think about 50% - 60% of displacement is a good compromise between acceptable throttle response and maximum volumetric efficiency in the upper reaches of the power band.

You will note that the Clifford 2 x 4 intake had much less plenum volume under the carbs than that which suggests to me that Clifford kinda felt that most of the customers in the market for the 2 x 4 intake probably intended to run them on a street driven car. For a pure drag car a better manifold design could be made. But for starters that 2 x 4 is a good place to start. Compare that to a H&M 4V intake, which has living-room sized volume and was intended to be a purely hi-RPM race piece.

 

 

FTF -- Thanks for the reply. The race motor is down the road a bit, but I like to work on the drawing for a setup with my EFI lower intake and my two 1.08. I may even build the plenum for 3 1.08 (start with two & add third as I build more HP into the motor.).

What kind of HP would I need to take advantage of 3 1.08's? As I don't want to get to wild with the motor (250-275 HP) maybe two is all I need?

 

I have a lot of experience with the good ol' 4100. After many tries with them, I gave up b/c of their age. That usually meant countless rebuilds during which parts got swapped. Swapped venturi clusters and other parts=crappy running, ie., rich, lean, etc. There is no catalog for the serial #s under the v.clusters. So one never knows if what you have was designed for the carb you have. Like GM with quadrajets, Ford tailored the 4100 for just about every engine. Even the 1.08, which is a 485 cfm, was made by Ford to be used on big blocks.

Just looking at yours, I see you are missing a part on the air horn crucial to a good idle. You see those two screws on the side of the choke flap housing? Someone filled the passage with what looks like JB weld. There is supposed to be what looks like a mouth harp there. It is a hot run air bleed that opens during hot running, and bumps the idle up a bit to prevent stalling.

The annular discharge is a great system. Holley paid to use it, and built their own model, iirc it was the Holley 4010. It didn't look like a Holley and flopped. Now Summit has resurrected it, and created a Holley/Autolite hybrid, with holley acc. pump, choke, jets, etc. It comes in both a 600 and 500 cfm.

I'd ck mustang tek dot com, and run your carb's #'s. That will tell you what the base at least came off. They are in front of the throttle, on the base of the carb. Bite my tongue. Scratch what I said about mustang tek site. It's been undated and they did away with all the codes. The info on that nearly 50 year old carb is fading fast. Anyway, good luck.

I think the two 2100's idea would be great.