Next step up from the Holley 1940?

[MalcolmA]

Hi,

I was looking around trying to find an old Holley 1940 that I could rebuild, but I'm not having much luck online. Someone recommended I buy the next step up to replace my 1940, then rebuild my 1940, which sounds good to me. So the question is, what's the next step up?

 

[rbohm]

the carter YF would be a much better carb than the 1940 holley.

 

[cr_bobcat]

When you do step up, make sure you don't run into interference issues with the butterfly. The throttle blade sizes are different. You may need an adapter or a thick enough plastic/phenolic spacer.

 

[MalcolmA]

So you guys wouldn't recommend upgrading to a 2BL using an adapter?

 

[CZLN6]

Howdy Back All:

As I recall you have a relatively stock '66 with an upgraded ignition- Petronix Ignitor and coil.

FYI- the Holley 1940 is not a stock OEM piece. It is a Service replacement from FoMoCo. I would not replace or rebuild it. I would look for a stock for 1966 Autolite 1100, or better yet an Autolite 1101 from a 1969 Mustang with a 250 engine. This carb will increase CFM, from 185 stock to 210. It is a nice boost. It requires no more adaptation then flaring out the inner edge of the stock carb adaptor. Linkage, fuel line, air cleaner and vacuum line all fit like stock.

All other upgrades will require adapting for the linkage and air cleaner. Fuel and vacuum lines not so much. Those upgrade carbs would be the Carter YF from a donor car with a 250 engine or a Carter RBS from a donor with a 250 engine. These two would also require a flair out of the inlet hole of the carb to clear the larger butterfly valve.

I'd recommend that you get along with your Holley 1940 while you search for your upgrade carb, then rebuild that carb.

As for a two barrel adaptor, you will not get 100% of the potential flow of the new carb. You will get a nice increase over the one barrel. But, you will need to adapt linkage and may end up with hood clearance issues. Many have done this upgrade. Some like it and live with it. Others, eventually move to a direct mounting of the two barrel.

Keep us posted on your progress.

Adios, David

 

[MalcolmA]

Thanks David, and thanks for the book! I just got it in the mial yesterday, looking forward to getting stuck in.

My whole goal here was to learn more, by getting a version of my carb that I could have a look around in and fix up. Since they're pretty rare and expensive, I may aswell go for a rebuilt upgrade to mine (which sounds like it's the 1101) and replace my 1940 with it, then use my 1940 to look around in and rebuild.

Could you elaborate a bit on flaring out the inner edge?

I had thought about down the line having the intake machined so I coud directly mount a 2BL, so I'm not sure if it's worth me spending the money on the 1101 upgrade now.

 

[MalcolmA]

Also, is there a specific type of 1101 I'd want to get to match the choke setup for my 1940?

 

[bmbm40]

If you buy a 1101 and do the two barrel direct mount later it is not a loss. You can always sell the 1101. It is a great book and will explain a lot.

 

[CZLN6]

HOwdy Again:

The Autolite 1100,1101 are not like the Holley #1940. While the 1100 and the 1101 appear identically external the 1101 is larger inside in the venturi and in the throttle bore, hence the need to taper the in hole to allow the larger diameter butterfly valve to clear.

The Holley #1940 is a sad step sister that has little in common with the Autolites. It is a generic design that can be adapted to every Ford/Mercury that used an Autolite one barrel. It is notorious for a poor idle, sluggish acceleration and poor mileage. In a good tuners hands it is a fair replacement at best. That is not to say that the Autolites are perfect, they were poorly- especially the accelerator pump system- requiring periodic rebuilds, which leads to stripped threads, warping leaks- both vacuum and gas.

The choke system between the 1940 and 1100s is not alike. Both work fairly well when clean and in good condition. Both rely on sucking unfiltered hot air from the exhaust manifold into the carb- not one of FoMoCos better ideas.

In other words, there is no such thing as a perfect carb. Consider them raw material that requires vigilance and a masters touch regularly.

IIWIYS, I'd live with what I have, clean the dickens out of it, adjust as best possible while searching for an Autolite 1100 or 1101. Or a Carter if you don't mind adapting the cable linkage. When it's ready make the swap back to what Henry intended.

Adios, David
PS- Hope you find the Handbook useful.

 

[chad]

yep, I've had a Carter YF on my 170 since '87 w/only 1 rebuild (the new high alcohol gas caught me off guard) due to leaving it not running a few mo. & getting gumed up inside.

Keep visitin & let us know how the project goes -

 

[MalcolmA]

Thanks guys! Is there much setup involved in going from my holley 1940 with auto choke to an autolite 1101? Does anyone have any links about cleaning my existing carb?

Here's what I have just now, pictures in this thread: http://fordsix.com/viewtopic.php?f=1&t=73958&sid=041306961f3f7e715c41180912f7bee3

 

[MalcolmA]

I have the pertronix ignitor

 

[bubba22349]

The Autolite 1100 and 1101 can be a direct swap since Ford used the Holley 1940's as replacements for the discontiued Autolite carbs. If you still have an LOD distributor you will need the right carb to match it has the SCV, some pictures of your distributor inside too would be of some help with the ID if its still an LOD with the Pertronix or the newer better 68 up point unit with the Pertronix which as a good usable distribitor. If your planing to go for a more performance build then you should also upgrade the distributor too. The best bang for your buck is a DSII or at a minimum use a 1968 up point type both of these have the better centrivical advance. You can clean much of the carb with a can of spray carb cleaner, i.e. The Exterior and throat. Good luck

Edited

 

[MalcolmA]

Thanks man, I was thinking of goign for the DSII or DUI. What would be involved for a swap to a Carter YF? They seem to be quite a lot cheaper than autolite 1101

 

[bubba22349]

First thing would be to adapt the Cater YF carbs base to the stock carb adapter so it can be bolted down to it also the throat opening is going to need to be tapered by grinding or machined big enough so that the throdle blade can clear without hitting as it opens up, picture a funnel shaped opening. You could also make another adapter to place between the carb base and stock adapter or to just replace it all together using some 1/4 or 3/8 inch Alum or plastic this may all depend on what you have now for hood clearance. There would also be some needed changes mofing, or "adjustments" by bending etc. to the stock throdle linkages so it lines up and fits to the YF, or you could also switch over to the better cable type linkage too. Also a few Other minor things such as adapting the air cleaner if you want to keep it looking somewhat stock or you can also just use an aftermarket Hot Rod type air cleaner. Then if it has an Auto Choke you would need to reshape, mod, or replace with another tube the "Hot Air Stove" to the choke housing. I.e. This is the steel tubing that's comes up from your stock exhaust manifold. Good luck

Edited

 

[CZLN6]

Howdy:

I don't have a link on carb cleaning but it's pretty simple. Buy a can of aerosol carb cleaner, make sure it has a small stray tube with it. Park the car in a spot that won't matter if some crud drips to the ground and is well ventilated. Open the hood, then remove the air cleaner. Make sure the choke is full open and spray the exterior and interior of the carb. Attach the straw tube to the cleaner can tip and carefully spray into any and all tubes and orifices inside the throat of the carb. The spray can splash back at your face so be careful. Let it set for 10 minutes or so and then start it up. be prepared for a rough idle and possible smoke from the exhaust. Normal engine operations should return in a short while depending on how much gunk is washed away.
You may need to check and/or replace your inline fuel filter in additions to carb cleaning.

Now examine your work. Wipe the exterior of any remaining gunk. If the inside is not spotless repeat for the inside of the choke. FYI- gunk is a residue of gas and dirt. It builds up over time and periodically needs to be rinsed away. The most critical part of a carb rebuild is cleaning it inside. It's also a good idea to periodically run a can of fuel system cleaner through the tank.

Have your visually verified that your choke is operating? How long does it take to fully open?

The Holley #1940 was designed to be a direct bolt on replacement for 1100s. The only adaptation is going to an1101 is to flair out the inlet hole on the adapter, assuming that you still have stock, OEM linkage. I seen to recall an upgraded point type distributor with a Petronix unit and coil. you will want to make sure the 1101 is the later 1969 for a 250 engine and not the earlier '63 & '64 versions with a SCV.

Hope that helps.

Adios, David

 

[MalcolmA]

Thanks for all the responses, I'm starting to get it. I think with my level of experience I'm best going for the 1101. I'll make a post in the wanted section and see if I can pick one up cheaper than on eBay.

When you say "flare out the inlet hole" is that a case of filing it down to match the carb? What would be the result of me not doing that? Knowing the consequence might help me get my head around it.

 

[wsa111]

You would also benefit by going the DS11 distributor route.
You will need a module to upgrade, be a GM, Chrysler,Duraspark or a MSD which with a MSD harness will plug right into the connector on the DS11.

 

[bubba22349]

You might try Rereading my above edited posts they cover the flaring or tapering of the carb opening for adapting the Carter YF carb base and why it needs to be done. You would be using this same process for the Autolite 1101 and also for that same reason. Good luck

 

[MalcolmA]

Would the DUI be overkill? It sounds like it's alot easier to install, and I don't have any experience with electrics.