1100 carb venturi(s) Q

[james singleton]

I recently bought a Autolite 1100 carb (PN#C3OF-9510-A), which according to the Manual I have, was used on a 1963 170cid engine w/ standard transmission. I have some notes from a different website that says that in 1963 the 1100/1101 1 barrel carb had 3 different teflon type insert/venturi sizes. They were a 1.0" insert/venturi for the 144ci engine, a 1.10" insert/venturi for the 170ci, and a 1.20" insert/venturi for the 200ci engine. By the way I have a 66' - 200ci engine w/ manual transmission.
I have a couple of questions concerning the carb above that apparently was designed for use on a 170ci engine. #1. Will it make that much difference using a carb that has a venturi sized for a 170ci engine on a 200ci engine??? How significant would the difference be in performance using the smaller venturi carb insert (designed for the 170) on a 200ci engine??? #2 Could the teflon/plastic insert somehow be enlarged (say by wet sandpaper for instance) in opening the insert to the spec opening of 1.20" used on the 200ci engine??? I hope I made sense with my questions. Thanks for any input! Jim

 

[simon]

Actually, the smaller venturi will keep velocity up, thus providing better throttle response and low-end torque.
On the downside, the max CFM at WOT is more restricted than on the other carbs with bigger venturis.

Since the stock carbs for six cylinder applications all came with chronically aenemic air flow rates, this means even less performance as the rpms go up.

The plastic (actually polyamide) venturi insert can be removed by grinding on the little pressed-in tabs, and replaced by a new venturi turned from aluminum. BTDT

 

[page62]

^^^^^
Perfect response!

So...it all depends on how you drive your car. The narrow venturi can actually function well for a daily driver. But if higher-RPM performance is what you seek, it may be necessary to change that venturi and probably re-jet the carb...

 

[CZLN6]

Howdy James:

To clarify, There were no 200 sixes until the '64 model year when they first appeared in Fairlanes.

The 1101, in '63 were the stock OEM carb of full size Ford cars with the 223 six cylinder engines. It has a 1.29" venturi insert and is rated to flow 210.

Yes, a carb from a 170 will work nicely on a 200 in all but one area. That is performance. Acceleration and top end will be down. The 170 1100 is rated to flow 150 cfm as compared to 185 cfm 1100s from 1965 to 1967.

Adios, David

 

[ludwig]

Where could you find a 1101? Off the shelf somewhere or salvage?

 

[james singleton]

Thanks guys for your info! Since the majority of my driving is around town I like the idea of.... "better throttle response and low-end torque"... that Simon mentions. But David (CZLN6) I am confused by your response when you say that this carb (with the smaller venturi).... "will work nicely on a 200 in all but one area. That is performance. Acceleration and top end will be down"......! Is this a contradiction from what Simon is saying about "better throttle response and low-end torque"..????, or am I missing something here??? Does this carb perform better on the low end (acceleration), but not on the high end (higher RPM's)????? Also, do you know what effect this smaller venturi might have on gas milage???? Thanks again guys! Jim

 

[james singleton]

David / CZLN6, I forgot to mention something in my earlier post. You mentioned the following:... "JUST TO CLARIFY, THERE WERE NO 200 SIXES UNTIL THE 64' MODEL YEAR WHEN THEY FIRST APPEARED IN FAIRLANES"... You may be right about that, but in the old motor manual that I have (that belonged to my Dad), which is the thick Motor's Auto Repair Manual 1965 (copyright 1965), it lists a 1963 singe barrel carb (Part No. C3YF-9510-H) for a 6 - 200 Auto Tr. ! I know that the last letter normally indicates which type of vehicle this is for; but I don't know what the letter "H" stands for in this case??? Maybe it was a "Checker" or some other type vehicle???? I will see if I can find out what the letter "H" stands for. Thanks again, Jim

 

[CZLN6]

Howdy Back James:

The letter "H", and the rest of the code indicates that it likely came on a 1963 Comet with a 200.

Your Dad's book is correct. My mistake. 1963 was the 1st year for the 200 to appear in Fairlanes, Comets & Meteors.

As far as a 1.1" venturi carb getting better mileage then a 1.2", I doubt it. It takes a specific amount of fuel (and air) to do a specific amount of work. Given equal loads, the smaller venturi carb will have to use more pedal to accomplish it. A slight variable may exist if your driving requires alot of idleing, which is never good for fuel mileage.

You would also notice a significant difference in traffic acceleration between the two carbs.

Ludwig- The 1101s have two sources in the recycle yard. With SCV- 1964 & 1965 full size Ford cars with a 223 six. And, without SCV- 1969 Mustang & Cougar with a 250 engine.

You may be lucky enough to find one through a parts house, but they frequently try to pass off a Service part Holley #1940 in its place. They are nowhere near the same carb. The 1101s look very much like the 1100s. Measure the throttle bore to be sure. A 1101 Tbore measures 1 11/16".

Adios, David

 

[page62]

Have you bolted it to the engine and tried it? The rest is all armchair blather...

 

[james singleton]

Page62, Yes I did bolt it to the engine back a few weeks ago and this supposedly rebuilt carb (1100), that I bought off of Ebay, runs a bit rough. I did not run it out on the street, only in the driveway, because it was running a bit too rough. I just got some carb rebuild spec's for the 1100 and want to check things out a bit before I re-install the carb. If I get the carb running well enough, I will compare the performance of this carb and the one that is on there presently; which is a Holley/Motorcraft 1940 carb. Jim

 

[page62]

Your problem is likely the main jet. I was lucky to have a couple of carbs lying around. It's taken 3 carbs so far to make the one I have run right. One is an ebay carb, the second came with my engine and provided the main jet, and the third I got from a fellow forum member -- the top of that carb is now bolted to the bottom of the ebay carb. It idles pretty good and has no rough spots...