autolite 1100 or holley/motorcraft 1940?

Hello all,

I have a 1966 200 with 69 head, 68 dizzy(dual advance)/ autolite 1100 (no SCV) Clay smith 264/264 @108, base timing at 13*



the throttle linkage is not holding the throttle plate closed on the 1100/ I used a spring for a seat track to have enough pull to hold the plate in the fully closed position. With that the idle set screw seems to be too short to get the idle correct? there is slop/plat between the shaft for the throttle plate and lever to the linkage?

I am having dificulties with my 1100 and have decided to get a rebuilt holley 1940. I got a good price on the 1940 from a local builder and hope to have it next week for installation.

The 1100 has a problem of continuing to flood from the overflow pipe. I have set the float a hair lower than spec to try to stem the problem. I checked the brass float for leaks in hot water before installation, no tiny bubbles observed. The plastic arm that controlls the overflow from the accel. pump has a broken tab and does not stay on at times. the housing was hammered shut so I cant remove the broken plastic rod.



I put a .69 jet in the 1100 instead of the .54 jet it had

I'm getting the holly/ motorcraft 1940 after talking to the guy at the carb shop. I'm keeping the autolite too, but I want to ue the easiest carb for the car.

I'm looking for any input for the 1940 for set up and any input on the throttle linkage. Once I get the 1940 I'll fill in the blanks for the exact specs.

Wes

HOwdy Wes:

Where to start? What trans is in the car? Are you using the hot air choke system?

From your description it sounds like the 1100 you are using is pretty beat. Is it the original '66 carb? You said it had NO SCV. Do you know what year it is from? Did it come with the '69 head? What does the Throttle bore measure?

The Holley #1940 carbs were used as a service replacement on a variety of engines after Autolite went out of business. So more information is needed on what this 1940 was made to replace.

FYI- The hot air choke was a bad idea for both the 1100 and the 1940 because it let hot, unfiltered air into the carbs. And both carbs were susceptable to dirt contamination. Both also had a weak accelerator pump.

How much did you have the '69 head milled for this engine? With that cam you could likely use more initial advance. What is the elevation at your locale?

A #69f jet very likely to be too, TOO big for an 1100 for this engine combo. What do your plugs look like?

On tuning a 1940 for this application; first verify what you have; jet size and application. Then set up with a basic vacuum guage tune of the low speed idle screw. Check for leaks and verify that full throttle is being achieved when the go pedal is floored.

Your engine combo could benefit from a carb with more cfm. An Autolite 1101 from a '69 Mustang 250 would really wake it up. The Autolite 1101 is rated at 215 cfm compared to 185 for a '66 200, or 150 cfm for a 1968 & '69 1100. They were rated at 150 cfm (No SCV) and designed to go with the dual advance distributor of those years.

Let us know more details and keep it coming.

Adios, David

sorry, yes it's a c4
Location: central NJ

The 1100 is what came with the car, a hodge podge of 67-69 parts(likely a junkyard swap years ago) As far as I can tell It is a 68-69 set up

the dizzy is the 68'

the carb is a non scv 68-69(?) it has the 1.1 venturi and came with a .54 jet. The block on this car was damaged, so I found a donor 66 engine that had a bad head, I got the 69 head redone. ( new valves, hardened seats, sleight shave to surface, the machine shop did not give a spec on how much was cut. My guess, .025-.050" (using fel-pro head gasket-est. .045 crushed thickness)

The 1100 has been a pain from day one. I have not been able to get the engine to fully run since getting it back together. I had about 5 minutes of it running with the choke held open and tried to get some of the timing quirks worked out. Then it got cold and now is a pain again.

I went to a local carb shop and the guy there recomended the motorcraft/holley1940 as a more reliable carb. They are currently working on a 1940 they had on the shelf to get it ready for my application. I do not have any other specs as of yet on the 1940.

Wes

Wes, who suggested a cam with a 108 L/C??? If you have a stock stall speed converter you will hate your combination.
Even with distributor recurve & using manifold vacuum for the vacuum advance you will hate it.
The Clay Smith for you would be with a 112 L/C.

Howdy Back Wes:

Yes, the '68 - '69 1100s are down sized from previous 200 1100s. Did you commit to the Holley 1940. A couple of other options to consider are the 1969 250 1101 for a direct swap on your 250 head. Other good choices, but will require some adaptation are the Carter RBS, used on 250 engines from 1970 to 1974. They are rated at 210 cfm. The other is the Carter YF which first appeared on 200s in 1970. The big rub with them is that you will have to do major adapting to use the stock type mechanical throttle linkage or switch over to a throttle cable setup. The Carter YF is rated at 197 cfm. So, if you're looking for an easy upgrade in performance I'd be on the lookout for an 1101. It is even stock appearing.

At seal level stock jetting should be about right.

Adios, David

I'm fairly set on the 1940, but I can change if need be. I am forced by my wifes rules (her car) that it needs to be as stock as possible. With that in mind, the throttle linkage needs to be as un-modified as possible, so no cable operation. I've looked a little in to those other carbs, but don't want to change to a cable setup. The shop that is building the carb did not have a 1101, and I am running out of time to get the car on the road. For the price, it seems the 1940 is the best choice at short notice.

As for the cam, that was my choice from reading the old six forum info on cams, and the info from clay smith. It was chosen for also supporting later modifications, inc. 32/36 webber, headers/2" exhaust etc. The car is going to be driven at highway(65-75mph) for about 4k miles in May. I have the 2.83 rear and taller 205/75r14 tires to get an est. 2800-3000 rpm at those speeds. AFAIK the cam choice was a compromise until future mods are done.

Wes

Wes, I guess you will have to live the 108 L/C. You will wish you would have chosen the 112 L/C with the Clay Smith
Cam. If it was the Comp Cam 260 a 110 L/C is fine. Different cams require different settings.

Howdy Back Wes and All:

I understand your limitations. Bill's concerns are that the cam you choose will likely have a rough, Lopey idle and be a little wimpy on take off. You can compensate a little by setting the idle a little higher than you might like. Also increase your initial advance setting to 16 degrees BTC. These suggestions will help with take off from a stop. Also set the low speed air screw with a vacuum gauge to get the highest vacuum reading at the lowest idle in gear [foot on the brake].

I hope that helps you get by for the immediate need.

Adios, David

UPDATE

For anyone interested, I installed the holly 1940 and it is working well so far. I will be running the engine more during the weekend, but after installation, 15 seconds cranking and fired right up with relatively smooth idle, and NO flooding. I am keeping the autolite 1100 and will mess with it later, but the carb shop guys steered me in the right direction for my engine.

For what its worth, I have to use a .4-.45" spacer for the 1940. Does anyone know where to find the factory 1101 spacer for the 240-300 engines? I am told it has the larger inner diameter. The throttle plate on the 1940 is 1.75" versus the 1.49" of the autolite/my current 1101 spacer.

Wes

Howdy Wes:

Good going on your #1940. It sounds like a big brother replacement carb with its 1.75" throttle bore.

What spacer are you using now? If it's a clearance issue due to the mismatch of the 1.75" Tbore in the Holley and 1.50" hole in the intake spacer you currently have, there is an easier solution than finding a spacer from a 240 six.

What spacer do you have? What is the casting code on the Head? If it is a '69 casting it could have either a 1.50" or 1.75" carb hole.

Adios, David

UPDATE:

For all interested, I have the car running finally! The 1940 needed a 1/2" spacer for the throttle valve to clear the factory spacer opening. after many tweaks, adjustments and lots of trial and error. I have the car set up about right.

First off, wsa111, you're right to an extent. The engine has low vacuum at idle in gear. It actually feels ok above 1000 rpm, but the 108* is ruining the idle quality and vacuum.

I'm going to try some final tweaks involving fine tuning with the vac gauge and mixture. ( which I have not yet adjusted from the initial setting from the carb shop)(thanks David, finally getting to your advice)

I ordered a vacuum canister to help. My vacuum at idle is around 8-10in/hg in park, 5-8in/hg in gear. I'm also trying to use a brake booster.

Any other suggestions are appreciated.

Wes