Click Here -> Please Consider Making a PayPal Contribution to the FordSix Forum!
2018 Contributors:
StarDiero75, curts56, DannyG, B RON CO, wsa111, Captainslow42, falconcritter
Econoline, THE FRENCHTOWN FLYER, 95FordFleetside, turbo6, Max_Effort, WorldChampGramp
cr_bobcat, C.S.Designs, pmuller9, gus91326, rwbrooks50, rocklord, drag-200stang, Big64my79Effie, CNC-Dude, gb500

2019 Contributors:
NJwpod, 1strodeo, mightynorseman, maxtrux, 6d7coupe, broncr, Phase3, 68Flareside240, bmbm40,
mustang6, WorldChampGramp, justintendo, BigBlue94, ags290, motorsickle1130, Rooster, ousooner919, ethanperry

Unknown->> M.Ketterer, T.Smith, J.Myers, P.McIntire - Please PM me (1966Mustang) and lemme know who you are!

Autolite 1100 Venturi Mod

Moderator: Mod Squad

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Autolite 1100 Venturi Mod

Post #1 by Creechn32 » Wed Feb 13, 2019 7:05 pm

So, I've been researching for a while. Reading through backlogs and backlogs on this forum. Great information and such a wide range of personal experience. My mind has been in overdrive. I've got an idea for modifying the removable Venturi on an SCV equipped 1100. The biggest difference between the 1100 and 1101 is the Venturi size and throttle bore. Throttle gore for the 1100 I know is 1 7/16. Venturi size on the carb I have in front of me is between 1.1-1.125, right under 1 1/8". My idea involves removing the current Venturi and using a piece of PVC pipe, some time, and some sandpaper to fashion a Venturi with at least 1.25-1.5" inner diameter. I did a little digging and ChampionCarbs sells a replacement Venturi for the 1100 but it's $89. A bit pricy I believe. Of course I could see needing a jet change also after modifying the Venturi. So far my next step is to remove, without damaging, the existing Venturi to better understand if I might be able to modify it, if the walls are thick enough or replace it with something else. This is an idea I have as a step around not being able to upgrade distributors for less than $400.00 as my 170 engine has the 1/4" oil drive and a DSii conversion isn't possible for less expense. What is everyone else's thoughts on this. I even thought if possible I could find someone to turn me a Venturi on a lathe out of aluminum. Wondering if anyone sees any flaws in what I'm thinking, what might or might not work, and possible solutions???
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

CZLN6
VIP Member
Posts: 3322
Joined: Fri Nov 15, 2002 11:07 am
Location: Idaho Falls, Id
Contact:

Re: Autolite 1100 Venturi Mod

Post #2 by CZLN6 » Wed Feb 13, 2019 7:25 pm

Howdy Creechin:

I like the way you think. I can tell you that I have tried to remove the plastic venturi insert from a '65 200 1100 carb. No success. I destroyed the insert in removing it. I couldn't figure how the insert was installed and secured. If it was glued in I found no evidence. So, I wish you luck and hope that you will your success and/or?????

I tried heat. No luck. Keep us posted.

Adios, David
co-author of the Falcon Performance Handbook
http://www.falcon6handbook.com/

User avatar
wsa111
FSP Moderator
Posts: 3245
Joined: Sat Jan 24, 2004 5:28 pm
Location: South Carolina
Contact:

Re: Autolite 1100 Venturi Mod

Post #3 by wsa111 » Wed Feb 13, 2019 8:43 pm

David, Jon at Pony Carbs used to install a 223 six venturi insert in the 1100 that i still own.
I believe the main jet is a .069".
The venturi insert is held in by having the main body staked in several areas.
The venturi vacuum tube also is inserted through the plastic insert.
Maybe the present owner of Pony Carbs can help you. Bill
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, DSII dist. MSD-6al & MSD-Blaster 8252 Coil. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
2003 Ford Lightning daily driver. Recurving Distributors. billythedistributorman@live.com
Image

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #4 by Creechn32 » Wed Feb 13, 2019 9:40 pm

I noticed the three indentations and the vacuum port. Removing the vacuum tube might take a bit of ingenuity but a file or dremel should take care of the pressure points formed to keep the Venturi in place.

Image Image Image Image Image
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

User avatar
wsa111
FSP Moderator
Posts: 3245
Joined: Sat Jan 24, 2004 5:28 pm
Location: South Carolina
Contact:

Re: Autolite 1100 Venturi Mod

Post #5 by wsa111 » Wed Feb 13, 2019 10:39 pm

If you want to delete the SCV this is the time to convert it to ported vacuum. With ported you delete the venturi vacuum tube & plug the exit with a 6-32 brass set screw.
There is a link on this forum in the tech section on the other 2 blocked ports.
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, DSII dist. MSD-6al & MSD-Blaster 8252 Coil. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
2003 Ford Lightning daily driver. Recurving Distributors. billythedistributorman@live.com
Image

Georgia200
Registered User
Posts: 139
Joined: Sun Oct 21, 2018 3:38 pm

Re: Autolite 1100 Venturi Mod

Post #6 by Georgia200 » Wed Feb 13, 2019 11:28 pm

Another option may be to swap the guts from a 68 distributor into your 170 distributor body.

I think thats how the Y-block guys get away from the LOM. Im not sure if it would work on a Falcon Six, but its worth looking into.

I think for this to work they both have to be Motorcraft distributors. If your 170 distributor is an Autolite, then it will not work.

That would get you away from the LOM, then you can modify your carb or buy a later non SCV carb.

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #7 by Creechn32 » Thu Feb 14, 2019 6:25 am

wsa111 wrote:If you want to delete the SCV this is the time to convert it to ported vacuum. With ported you delete the venturi vacuum tube & plug the exit with a 6-32 brass set screw.
There is a link on this forum in the tech section on the other 2 blocked ports.



Part of my motivation for doing this is searching for a modification that will work along side of the LOM distributor. There's a lot of ideas I have for my current engine but they are all curtailed by difficulty in swapping the distributor. I've also wondered if I could swap a later vacuum diaphragm on the LOM distributor that would function off ported vacuum. Really, other than the lack of mechanical advance, the biggest downfall to the LOM is it runs off Venturi vacuum and the SCV. If the diaphragm was able to be swapped to a later ported style that was adjustable would that not also help to solve this issue? All this thinking revolves around me wanting to be able to add a 2 barrel carburetor. Whether by adapter plate or modified head, the issue becomes none of them will function with the LOM and Venturi vacuum. At the same time not wanting to spend $400 on an HEI to fit in its place. There is also an Aussie electronic distributor alternative, for less money, to the LOM but information about it has been difficult for me to find. My mind has really been thinking about a synchronous dual carb setup on a log manifold. All my thinking has led me to searching for 1101's equipped with an SCV but they seem to be like unicorns currently, or super expensive. So, in my quest for an alternative carburetor for improved airflow, that works with the LOM, I have arrived at this point. The 1100 has a removable Venturi, why don't we just open it up? Airflow should be able to increase at least to the size of the throttle bore. Once again, someone correct me if my thinking is off. I'm not 100% when it comes to the science of airflow and airflow characteristics when it comes to porting heads, intake runners , and the like. I've done a ton of reading online for a few years now. I understand air does funny things sometimes. All my rambling aside, if the Venturi is able to be opened up, I see no reason why an 1100 couldn't flow just as much air as an 1101. For those without an SCV equipped carb it should be even easier, if it's successful.....
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

User avatar
bubba22349
Global Moderator
Posts: 9048
Joined: Sun Jan 03, 2010 4:46 pm
Location: Flagstaff, Az. 86005 near the old Route 66

Re: Autolite 1100 Venturi Mod

Post #8 by bubba22349 » Thu Feb 14, 2019 12:17 pm

Creechn32 wrote:
wsa111 wrote:If you want to delete the SCV this is the time to convert it to ported vacuum. With ported you delete the venturi vacuum tube & plug the exit with a 6-32 brass set screw.
There is a link on this forum in the tech section on the other 2 blocked ports.



Part of my motivation for doing this is searching for a modification that will work along side of the LOM distributor. There's a lot of ideas I have for my current engine but they are all curtailed by difficulty in swapping the distributor. I've also wondered if I could swap a later vacuum diaphragm on the LOM distributor that would function off ported vacuum. Really, other than the lack of mechanical advance, the biggest downfall to the LOM is it runs off Venturi vacuum and the SCV. If the diaphragm was able to be swapped to a later ported style that was adjustable would that not also help to solve this issue? All this thinking revolves around me wanting to be able to add a 2 barrel carburetor. Whether by adapter plate or modified head, the issue becomes none of them will function with the LOM and Venturi vacuum. At the same time not wanting to spend $400 on an HEI to fit in its place. There is also an Aussie electronic distributor alternative, for less money, to the LOM but information about it has been difficult for me to find. My mind has really been thinking about a synchronous dual carb setup on a log manifold. All my thinking has led me to searching for 1101's equipped with an SCV but they seem to be like unicorns currently, or super expensive. So, in my quest for an alternative carburetor for improved airflow, that works with the LOM, I have arrived at this point. The 1100 has a removable Venturi, why don't we just open it up? Airflow should be able to increase at least to the size of the throttle bore. Once again, someone correct me if my thinking is off. I'm not 100% when it comes to the science of airflow and airflow characteristics when it comes to porting heads, intake runners , and the like. I've done a ton of reading online r a few years now. I understand air does funny things sometimes. All my rambling aside, if the Venturi is able to be opened up, I see no reason why an 1100 couldn't flow just as much air as an 1101. For those without an SCV equipped carb it should be even easier, if it's successful.....


Sorry but the later model vacuum canisters won't fit the LOD and even if they did it wouldn't change its operation to be of any benefit. Next wether you use a venturi vacuum or a ported vacuum source under power the engines vacuum is going to drop and with that the vacuum controled advance of the LOD this is just the opposite of what is needed for good performance. It's also why the later models 1967 Calif. and all 1968 Ford Six engines up all used a distributor with both mechanical advance for better power / performance and a vacuum advance system for best economy. Even with a Pertronix installed (a good mod that helps quite a bit) or the use of the electric MoPar control box another good mod that I have also used the operation of the LOD advance system isn't good for a performance work. So in my opinion a LOD should only be used for a totally stock restoration, since there are much better units available for a performance build up, you need to ditch the LOD because they don't have the better mechanical advance. This was a first step mod even back when these engines were stil relatively new, back then there were dual point distributor's with mechanical advance only (by Mallory) to solve this problem today there are even better choices. Below is a group of posts that discuss most of the options for the early engines that used the 1/4 inch drive LOD. To me if you have the block apart for rebuilding then the best way is to machine the block to fit the late model DuraSpark II. If the engine isn't apart there are a number of other ways to do this swap and they should come out cheaper than a DUI. Good luck :thumbup: :nod: Edited

1/4 inch Distribitor swaps
viewtopic.php?f=1&t=77360&p=595417&hilit=1%2F4+inch+Distribitor+swap#p595407
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #9 by Creechn32 » Thu Feb 14, 2019 12:20 pm

I read through that post not long ago. Question would be has anyone done it or just in theory? Reading through it again I wonder what the cost comparison between a DSii conversion, machining of the distributor end, and an oil pump plus shaft is to just an HEI distributor with 1/4 drive....
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

User avatar
bubba22349
Global Moderator
Posts: 9048
Joined: Sun Jan 03, 2010 4:46 pm
Location: Flagstaff, Az. 86005 near the old Route 66

Re: Autolite 1100 Venturi Mod

Post #10 by bubba22349 » Thu Feb 14, 2019 12:42 pm

Yes this has been done by a few site members it's not a theory it's basic machine shop practices. I don't know how hard it is to find a competent machineist in your area though, but I was doing this type machine shop work back in high school in the mid 1960's. A new Melling M 65 oil pump that also comes with a new 5/16 inch oil pump drive shaft is about $75.00 this is usually a normal replacement item anyway during a rebuild, a rebuilt DSII can range from $50.00 to $90.00, I used to sorce a complete DSII system (distributor, plug wires, coil, wire harness, ICM) from the local pick a part cheap $25.00 to $35.00. You could get a calabrated DSII for about $230.00 but you should contact Bill wsa11 (in above posts) to verify this cost. Also not a theory is the fact that the Australian Ford small sixes for many years used a hybrid distributor that was a combo of the early 1/4 inch drive distributor OD shaft size with a 5/16 inch hex broched drive socket plus the M 65 type oil pump with the 5/16 inch oil pump drive shaft. Good luck :thumbup: :nod: Edited
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

User avatar
bubba22349
Global Moderator
Posts: 9048
Joined: Sun Jan 03, 2010 4:46 pm
Location: Flagstaff, Az. 86005 near the old Route 66

Re: Autolite 1100 Venturi Mod

Post #11 by bubba22349 » Thu Feb 14, 2019 1:10 pm

There is another couple of meathods too using the Ford EDIS waste spark system. Check out the posts by the "sameguy" where he adapted the EDIS from start to finish. Last is if you were lucky enough locate one of the old Mallory dual point distributors that were made for the early 1/4 inch oil pump drive engines (144, 170, pre 1965 200) though they are probably a rare item in this day and age. Good luck. :thumbup: :nod: Edited

Ford EDIS
viewtopic.php?f=98&t=67718&hilit=Ford+Edis#p518607
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

User avatar
wsa111
FSP Moderator
Posts: 3245
Joined: Sat Jan 24, 2004 5:28 pm
Location: South Carolina
Contact:

Re: Autolite 1100 Venturi Mod

Post #12 by wsa111 » Thu Feb 14, 2019 4:59 pm

Get your machine shop to ream the distributor shaft bore to .517"-.518" so you can go with a DS1 or a DS11 distributor & convert your carb to a non SCV state as i previously mentioned.
The only difference between the DS1 & The DS11 is the size of the cap, both use the same housing.
Bubba mentioned the old Mallory unit which will fit your block without being modded, or go with the DUI which offers the 1/4" oil pump hex drive.
I can recurve your loadamatic using my Sun Distributor Tester which has a vacuum pump to help in a recurve. Don't expect a miracle though.
Then install the Pertronix conversion with a newer coil which will help.
Any way you go unless you want to live with the loadamatic get your wallet out.
I would go with a later 200 engine & that will save $$$ in the long run. Good luck. Bill
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, DSII dist. MSD-6al & MSD-Blaster 8252 Coil. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
2003 Ford Lightning daily driver. Recurving Distributors. billythedistributorman@live.com
Image

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #13 by Creechn32 » Thu Feb 14, 2019 7:39 pm

wsa111 wrote:Get your machine shop to ream the distributor shaft bore to .517"-.518" so you can go with a DS1 or a DS11 distributor & convert your carb to a non SCV state as i previously mentioned.
The only difference between the DS1 & The DS11 is the size of the cap, both use the same housing.
Bubba mentioned the old Mallory unit which will fit your block without being modded, or go with the DUI which offers the 1/4" oil pump hex drive.
I can recurve your loadamatic using my Sun Distributor Tester which has a vacuum pump to help in a recurve. Don't expect a miracle though.
Then install the Pertronix conversion with a newer coil which will help.
Any way you go unless you want to live with the loadamatic get your wallet out.
I would go with a later 200 engine & that will save $$$ in the long run. Good luck. Bill


My thoughts are to eventually go to a 200 but for now I was wanting to do what I can before I start sinking my real money into the suspension parts this car really needs....

I am more interested at the moment of squeezing what I can out of the current setup. There is a 200 C4 combo not far from me for $325 on Facebook. I am also looking towards the future with this carburetor. I have already upgraded to a hotter coil in this car. An Accel superstock coil replaced the stock coil when I replaced everything else ignition wise. Now I'm wanting to experiment carbwise.
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

Georgia200
Registered User
Posts: 139
Joined: Sun Oct 21, 2018 3:38 pm

Re: Autolite 1100 Venturi Mod

Post #14 by Georgia200 » Thu Feb 14, 2019 10:28 pm

With a 1.5 carb hole and 170 ci, you are really just throwing money away looking for performance.

I would snag the 200/C4 and build that at your leisure and keep the 170 on the road.

I find that when someone takes a running car off the road, there is a good chance it never goes back on the road.

I bought my 67 in Oct and kept it running. Ive been working on the 5 lug swap for 5 months now and Im still a weekend or two from being ready to make the swap happen.

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #15 by Creechn32 » Thu Feb 14, 2019 11:07 pm

Georgia200 wrote:With a 1.5 carb hole and 170 ci, you are really just throwing money away looking for performance.

I would snag the 200/C4 and build that at your leisure and keep the 170 on the road.

I find that when someone takes a running car off the road, there is a good chance it never goes back on the road.

I bought my 67 in Oct and kept it running. Ive been working on the 5 lug swap for 5 months now and Im still a weekend or two from being ready to make the swap happen.


Car is currently on the road. I've been enjoying driving it. This carburetor is one I bought off a guy not far from me. An experiment really. Something to mess with. What's the worst that could happen, it not work out? I will try to keep the original Venturi intact that way if my way doesn't work I can return the carburetor to original form. But the 1101 is worth about 5hp from what I've read and it only has a 1.29 Venturi, if my memory serves me correctly, and 1.5 would be better than that. Besides, if it works out I can use it on a 200 at a later date.
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

User avatar
chad
Registered User
Posts: 4737
Joined: Sat Oct 24, 2009 9:51 am
Location: Lawrence Swamp, S. Amherst, MA

Autolite 1100 - '68+

Post #16 by chad » Fri Feb 15, 2019 9:20 am

don't 4get to 'source over into' the '65 models for the bigger dizzy hole in the block (many don't recommend the DUI) so U can go w/the DSII (post '67 for oe equiped non SCV/LOM - but those R easy to swap out).
:thumbup:
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", tool boxes, etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

peeeot
Registered User
Posts: 123
Joined: Thu Feb 07, 2008 5:07 pm

Re: Autolite 1100 Venturi Mod

Post #17 by peeeot » Sat Feb 16, 2019 1:24 am

Creechn32,

In order for a carburetor to work, there has to be a certain pressure difference between the inside bore of the carburetor where the fuel discharge nozzle is and atmospheric pressure outside of the carburetor. This pressure difference is what pushes the fuel into the airstream.

A Venturi is a narrowing in the carburetor bore that increases air velocity and reduces pressure relative to the conditions present at the wider parts of the bore. By enlarging the Venturi of a carb, you reduce the velocity through the Venturi and thus decrease the pressure differential it generates.

Every aspect of the main fuel circuit of the carb is calibrated based on the Venturi size and the expected air flow through the carb at different engine speeds and loads. So, if you enlarge the Venturi, the carb will probably flow more air, but it will require more calibration than a jet change alone to function properly. If the Venturi is opened up to the same size as the throttle bore, you lose the Venturi effect entirely, and fuel will not discharge or atomize very well. The engine may still run but throttle response and fuel economy may be poor.

Additionally, any changes to the Venturi will alter the vacuum signal used to operate your LOM advance, which will require distributor recalibration to recover the “liveliness” of the advance curve.

Is your carburetor marked 1.20 on the side? This was the largest 1100 venturi Autolite used. 170s came with 1.10 Venturi size stock.

You can make a noticeable difference in how lively the car feels just by improving your loadomatic distributor calibration. You can change the springs and the preload on the springs, the total advance range, and the initial advance. Manipulating these for a shorter, tighter curve with more initial advance than stock will make the engine feel more eager.

It’s worth experimenting with your main jet too. If the carb is calibrated too lean for e10 gasoline, there is noticeable improvement to be had by getting the mixture right.

I hope this helps.

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #18 by Creechn32 » Sat Feb 16, 2019 11:04 am

peeeot wrote:Creechn32,

In order for a carburetor to work, there has to be a certain pressure difference between the inside bore of the carburetor where the fuel discharge nozzle is and atmospheric pressure outside of the carburetor. This pressure difference is what pushes the fuel into the airstream.

A Venturi is a narrowing in the carburetor bore that increases air velocity and reduces pressure relative to the conditions present at the wider parts of the bore. By enlarging the Venturi of a carb, you reduce the velocity through the Venturi and thus decrease the pressure differential it generates.

Every aspect of the main fuel circuit of the carb is calibrated based on the Venturi size and the expected air flow through the carb at different engine speeds and loads. So, if you enlarge the Venturi, the carb will probably flow more air, but it will require more calibration than a jet change alone to function properly. If the Venturi is opened up to the same size as the throttle bore, you lose the Venturi effect entirely, and fuel will not discharge or atomize very well. The engine may still run but throttle response and fuel economy may be poor.

Additionally, any changes to the Venturi will alter the vacuum signal used to operate your LOM advance, which will require distributor recalibration to recover the “liveliness” of the advance curve.

Is your carburetor marked 1.20 on the side? This was the largest 1100 venturi Autolite used. 170s came with 1.10 Venturi size stock.

You can make a noticeable difference in how lively the car feels just by improving your loadomatic distributor calibration. You can change the springs and the preload on the springs, the total advance range, and the initial advance. Manipulating these for a shorter, tighter curve with more initial advance than stock will make the engine feel more eager.

It’s worth experimenting with your main jet too. If the carb is calibrated too lean for e10 gasoline, there is noticeable improvement to be had by getting the mixture right.

I hope this helps.


So, this is not the original carburetor to my engine and is not the carburetor currently running on my engine. I say that so you know I'm not going to ruin something vital to the current state of my engine. This is a carburetor, that has the 1.1 Venturi, that I picked up for less than $50. You sound a little more up to speed on Venturi and air speed effect in a carburetor so I'll run my thinking by you. I've read quite a bit on these engines, carburetor, heads, and intakes. My question at this point would be: Will air speed through this engine decrease that much by increasing a single inlet from 1.1 to 1.25-1.5? I would think this single inlet would still carry more air speed than a 2v carburetor. I understand that I will have to fiddle with vacuum signal to distributor and carb jetting at the same time. My current initial advance settings and timing issues are completely covered in a previous post I had (1963 170 hesitation issues). This whole carburetor Venturi mod is an experiment of mine. I am going to try and save the stock Venturi. This is vital to me being able to return the carburetor to usable state if my experiment doesn't work. I say all this to let everyone understand that this isn't a modification to my car as much as it is an experiment to see if it's possible. Don't worry about my car and its current state as I have a working 1100 that will remain untouched to keep my vehicle in a state of being street worthy if this Venturi mod doesn't work. What I was hoping from this post were ideas of how to make this mod work, definitive proof it won't work, or workable ideas to make it work. I'm not going to back myself into a corner of my vehicle being inoperable with this experiment. I say all that just so we are all on the same page. If this works it could be a very easy inexpensive modification to the more abundant Autolite 1100 and a stock head. Also, just because I have yet to upgrade the ignition to a DSii or HEI doesn't mean this modification, if successful couldn't work along side an ignition upgrade. Ignition and engine upgrade are not the subject of this post however. But I do appreciate all the invaluable knowledge, experience, and wisdom when it comes to those subjects though. I hope everyone is enjoying their Saturday.....
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #19 by Creechn32 » Sat Feb 16, 2019 4:19 pm

Update: took some fiddling to get the Venturi out without damaging. After Venturi is out you can see the brass vacuum port pressed into where the Venturi vacuum was. Applied a small bit of heat from a propane torch around the area and pressed the brass piece out with a pair of channel locks. 1-1/2" PVC didn't work too well. Going to try 1-1/4" PVC next.

Image Image Image Image Image Image
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

CZLN6
VIP Member
Posts: 3322
Joined: Fri Nov 15, 2002 11:07 am
Location: Idaho Falls, Id
Contact:

Re: Autolite 1100 Venturi Mod

Post #20 by CZLN6 » Sat Feb 16, 2019 5:42 pm

Howdy Back Creech:

Good going. I love your adventurous spirit. Good progress. I've reread this post and I am aware that your 170 is running and that you don't want to disturb that. Good plan.

I got thinking back on the early day of The Handbook and recalled a couple of items that may help your quest to get a little more out of the 170 before moving on to a 200 and came up with a couple of item that may help you. Back in the day finding Autolite carbs was easy. Finding info was scarce. We experimented with a '63 comet and a '73 Maverick over the years. Both were 170 autos.

The Autolite 170 1100 is rated at 156 cfm. A 200 Autolite 1100 is rated at 186 cfm. Throttle bores and mounting bolt holes are the same. So simply bolting on a 200 Autolite 1100 offers a noticeable increase in power.

We came accross a rare tidbit in a publication were Ak Miller was playing with a stock '65 Mustang with a LoM. He inserted a screwdriver blade into one of the springs that retain the advance in the LoM distributor. He gave the blade a twist and opened the spring slightly, allowing the advance to come in more quickly. How much- I don't know, but the change seemed to make a difference on the pep of the 170s we were playing with.

Also the throttle linkage on the relatively new Comet was way out of wack. Full throttle on the gas pedal was no where near full throttle on the carb. We adjusted the linkage to get full throttle on the carb. It made a difference.

We also played with smaller tire sizes on the rear tires for better gearing on the Maverick. FYI the Maverick was a three speed auto.

I know. This is not along the lines you are pursuing but your adventure engaged my brain so I thought I'd share.

Another idea on your LoM delima is to install a Petronix Ignitor kit. You keep the LoM function and it is an easy bolt-on. Aka- Bill could help you to recurve the advance on your LoM. BTW- What distributor is on the 200 you are considering?

Anyway, good memories for me. I hope they are useful to you.

Adios, David
co-author of the Falcon Performance Handbook
http://www.falcon6handbook.com/

User avatar
bubba22349
Global Moderator
Posts: 9048
Joined: Sun Jan 03, 2010 4:46 pm
Location: Flagstaff, Az. 86005 near the old Route 66

Re: Autolite 1100 Venturi Mod

Post #21 by bubba22349 » Sat Feb 16, 2019 7:26 pm

:hmmm: one thing you might want to test before you invest lots of your time is how the PVC material reacts around gasoline. Don’t know the answer to that question. Good luck on your experiment. :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

Georgia200
Registered User
Posts: 139
Joined: Sun Oct 21, 2018 3:38 pm

Re: Autolite 1100 Venturi Mod

Post #22 by Georgia200 » Sat Feb 16, 2019 9:10 pm

Couldnt you build the venturi body thickness up with a high temp putty, then bore it to the desired size?

JB Weld and Permatex both make a fuel tank repair putty that might work.

You would retain the needed bell shape on the top and bottom.

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #23 by Creechn32 » Sat Feb 16, 2019 9:46 pm

I'm liking these ideas. I did try playing with the eccentrics in my distributor but was unable to get them to budge. I also swapped around springs but that was at a point I didn't have the engine tuned properly. Perhaps I could try again. I'm not sure the distributor that is in the engine that's for sale in my area. I'm unable to tell from pictures and I have yet to see it in person. I did some reading over whether PVC was fuel resistant before I thought I'd go that route. I found info that said it was resistant to oils, detergents, and chemicals. That's when I realized we use it to flush anything and everything down the drains in this world. I think we even use certain kinds of acid to clear out plumbing drains. This had me convinced it would stand up to what I might throw at it. Only way to really tell will be over time though.

I like the idea of building the Venturi body up and using it but that might just be a last resort. Only because it's my save all for the experiment not working out. I found 1-1/4" PVC fit snugly into the throttle bore where the Venturi was located. It will need some shaping and tapering as I'm not planning on leaving it as a straight shaft. I will probably have to taper the lower side removing about 1/4" inside diameter so it will match the 1-7/16 throttle bore. I searched around to see if someone had a large tapered grinding stone I could put on the end of a drill for shaping the inside of the PVC but I was only able to find them large enough online. I will probably use a half round file to shape the inside of the pipe. The top side will be rounded over to help the airflow smoothly into the Venturi. After that I plan on cutting the grass plug I removed so it will flush up with the inside of the throttle bore. Then I will drill a very small hole with a #53 drill bit I picked up for the Venturi vacuum. If this size hole does not provide adequate vacuum I can enlarge it one step at a time. I'm pretty sure the jet said .59 so I will probably try to open that up as well.
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

jimlj66
Registered User
Posts: 123
Joined: Tue Dec 29, 2009 9:54 am
Location: Evanston Wy

Re: Autolite 1100 Venturi Mod

Post #24 by jimlj66 » Sat Feb 16, 2019 10:02 pm

With the venturi out, can you take a hole saw and run through it to open it up? May be easier than trying to build a new one. You could take sand paper and wrap around a piece of pipe or dowel and smooth the bore out after running a hole saw through it.

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #25 by Creechn32 » Sat Feb 16, 2019 10:16 pm

So, as previously stated the 1.1 Venturi 1100 was rated at 156 cfm and the 1.2 Venturi carb was rated at 186 cfm. If the Venturi is opened up by a small amount of .05 this should be good for another 15 cfm resulting in or around 200 cfm. If I could uniformly open the Venturi up to 1.375(1-3/8) this should flow between 210-215 cfm. At that point we are getting close to the flow rate of an Autolite 2100 with 1.01 Venturi. Any ideas on how to convert to annular discharge??? Lol....
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #26 by Creechn32 » Sat Feb 16, 2019 10:25 pm

jimlj66 wrote:With the venturi out, can you take a hole saw and run through it to open it up? May be easier than trying to build a new one. You could take sand paper and wrap around a piece of pipe or dowel and smooth the bore out after running a hole saw through it.


The stock Venturi is made of a thin plastic. Before removing this was one of my ideas, just open the stock version up but it just doesn't have the material in place to be able to do it. I did have the idea of opening the throttle bore up just a little. At that point I would need a throttle plate to match though. If this little experiment works out though a person, for very little money could open their stock 1100 up for a performance boost. Could even be done on a multi carb setup. With all my thought process lately I've wondered what two of these carbs ran synchronously and not progressively could do on one of our engines.....
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

peeeot
Registered User
Posts: 123
Joined: Thu Feb 07, 2008 5:07 pm

Re: Autolite 1100 Venturi Mod

Post #27 by peeeot » Sat Feb 16, 2019 10:32 pm

Creechn32,

The concern with enlarging the Venturi too close to your throttle bore size of 1.4375” is not that you would lose velocity specifically, but that you would weaken the vacuum signal to the main fuel circuit, resulting in poor throttle response and fuel economy. The new insert you are making from PVC needs to imitate the profile of the stock insert you removed, with the narrowest part at the same height as the stock insert so that the booster Venturi cast into the air horn will still be able to amplify the vacuum signal.

All that being said, there is no harm in experimenting, so good luck and have fun!

User avatar
bubba22349
Global Moderator
Posts: 9048
Joined: Sun Jan 03, 2010 4:46 pm
Location: Flagstaff, Az. 86005 near the old Route 66

Re: Autolite 1100 Venturi Mod

Post #28 by bubba22349 » Sat Feb 16, 2019 10:38 pm

Creechn32 wrote:
jimlj66 wrote:With the venturi out, can you take a hole saw and run through it to open it up? May be easier than trying to build a new one. You could take sand paper and wrap around a piece of pipe or dowel and smooth the bore out after running a hole saw through it.


The stock Venturi is made of a thin plastic. Before removing this was one of my ideas, just open the stock version up but it just doesn't have the material in place to be able to do it. I did have the idea of opening the throttle bore up just a little. At that point I would need a throttle plate to match though. If this little experiment works out though a person, for very little money could open their stock 1100 up for a performance boost. Could even be done on a multi carb setup. With all my thought process lately I've wondered what two of these carbs ran synchronously and not progressively could do on one of our engines.....


The answer to your question is that two Autolites, 1904 Holley's, or severial others with solid linkage are about the perfect combo on a mild six build up. This was a faveriote of the Ford 223 Six Hot Rodder's in the 1950's and 60's, the carb's were moved from center of engines intake so that each carb was centered over a set of intake ports. Performance was very good and many claim to have even better economy than the stock single 1V.

On the Venturi experiment, remember that a Venturi works on the same principal as an air planes wing so shape needs to follow that. Good luck :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #29 by Creechn32 » Sat Feb 16, 2019 10:50 pm

peeeot wrote:Creechn32,

The concern with enlarging the Venturi too close to your throttle bore size of 1.4375” is not that you would lose velocity specifically, but that you would weaken the vacuum signal to the main fuel circuit, resulting in poor throttle response and fuel economy. The new insert you are making from PVC needs to imitate the profile of the stock insert you removed, with the narrowest part at the same height as the stock insert so that the booster Venturi cast into the air horn will still be able to amplify the vacuum signal.

All that being said, there is no harm in experimenting, so good luck and have fun!


I was actually thinking of just this earlier. I'm glad you reminded me. I was thinking it would do me well to have the exact height overall, and taper the interior to the same point, height, as in the original. I guess we will see if air speed will remain fast enough for proper operation. This has been mentioned once already so now I'm curious.
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

Georgia200
Registered User
Posts: 139
Joined: Sun Oct 21, 2018 3:38 pm

Re: Autolite 1100 Venturi Mod

Post #30 by Georgia200 » Sat Feb 16, 2019 11:31 pm

What schedule pipe are you using?

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #31 by Creechn32 » Sat Feb 16, 2019 11:58 pm

Georgia200 wrote:What schedule pipe are you using?


Schedule 40
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #32 by Creechn32 » Sun Feb 17, 2019 10:16 am

Working on some shaping and filing of the interior and exterior of the PVC. Im using a half round file. Had to taper the exterior just a little bit to get the PVC to slide down far enough to seat, basically the last 1/4" seemed to taper in just a small amount and wouldn't allow the PVC to seat all the way. From there I made a line on the interior at the same height of the narrowest part of the original Venturi for a tapering point. I filled the rest of the interior in, up to that point to know when I have reached the final point and not go further from that direction.

Image Image Image Image Image
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #33 by Creechn32 » Sun Feb 17, 2019 12:04 pm

More profiling, sanding and shaping of the PVC. You can notice the beveling and shaping of the upper side of the Venturi. Did some research last night over Venturi and understand how the bottleneck in the Venturi increases air speed and in turn creates a drop in pressure. This is what creates the vacuum/suction of gas through the carburetor. I've tried to duplicate the point at which the bottleneck occurs, where the Venturi gets smaller. Hopefully we are still small enough to have enough air speed for the carburetor to still function correctly. You can also see the increase of inner diameter over the original Venturi. We still have a bottleneck compared to the carb inlet. Hopefully this change in diameter helps with the air speed. I believe I am done shaping on this piece of PVC for now. The next step for this carburetor will be a kit as it sat for a number of years before it came into my possession.

Image Image Image Image Image Image Image Image Image Image Image
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

User avatar
bubba22349
Global Moderator
Posts: 9048
Joined: Sun Jan 03, 2010 4:46 pm
Location: Flagstaff, Az. 86005 near the old Route 66

Re: Autolite 1100 Venturi Mod

Post #34 by bubba22349 » Sun Feb 17, 2019 12:54 pm

:beer: nice work! :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

Georgia200
Registered User
Posts: 139
Joined: Sun Oct 21, 2018 3:38 pm

Re: Autolite 1100 Venturi Mod

Post #35 by Georgia200 » Sun Feb 17, 2019 2:16 pm

If you are to big on the bore you can buy a piece of 1.5in thin wall and cut through one wall on a table saw down the length until you remove enough material to compress it and force it inside the 1.25in tube.

I have done this before with good results. The thin wall in the freezer and a heat gun on the sch40 helps for a snug fit. If you cut just right the seam will be nice and tight.

That will give you a smaller inside diameter, the same outside diameter and give you more material to shape the bell.

User avatar
wsa111
FSP Moderator
Posts: 3245
Joined: Sat Jan 24, 2004 5:28 pm
Location: South Carolina
Contact:

Re: Autolite 1100 Venturi Mod

Post #36 by wsa111 » Sun Feb 17, 2019 8:57 pm

Very nice piece of craftsmanship.
You really need to upgrade to a later distributor to take advantage of the extra CFM air flow.
Your 1/4" oil drive is the ???? Either bite the bullet on a DUI or ream the block to .517-.518" so you can use the 5/16" oil drive with an oil pump to match & a distributor @ half the cost.
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, DSII dist. MSD-6al & MSD-Blaster 8252 Coil. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
2003 Ford Lightning daily driver. Recurving Distributors. billythedistributorman@live.com
Image

User avatar
Econoline
Registered User
Posts: 1293
Joined: Tue Nov 12, 2013 8:37 pm
Location: Anacortes, WA

Re: Autolite 1100 Venturi Mod

Post #37 by Econoline » Sun Feb 17, 2019 9:56 pm

This is a job for a 3d printer. With that venturi core you could model it and then alter the venturi size and shape all you want and print something that fits and just needs minimal work to smooth and make fit. Notches, holes and all
It ain't gonna fix itself

frozenrabbit
Registered User
Posts: 174
Joined: Fri Feb 12, 2016 1:01 pm

Re: Autolite 1100 Venturi Mod

Post #38 by frozenrabbit » Sun Feb 17, 2019 11:05 pm

Is that enough venturi to function as a venturi?

At some point, the ratio size of the venturi to the main bore will fail to create enough vacuum differential to function.

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #39 by Creechn32 » Mon Feb 18, 2019 6:40 am

wsa111 wrote:Very nice piece of craftsmanship.
You really need to upgrade to a later distributor to take advantage of the extra CFM air flow.
Your 1/4" oil drive is the ???? Either bite the bullet on a DUI or ream the block to .517-.518" so you can use the 5/16" oil drive with an oil pump to match & a distributor @ half the cost.


I guess the first step,will be to,see if this even works. There is always the possibility I install the carburetor and it won't even function properly. I'm hoping for the best but ya never know. Ignition upgrade has been on my mind since I've started tinkering with this engine. I've had to prioritize a few things for the car though and for me I had to do it before I got started or else I'd just go in circles. The car is in dire need of new suspension parts. In the rear and in the front. My goal with the engine was to just get it running properly before I really get into it. After that I have a transmission leaking like crazy on me. Once drivetrain was sorted I wanted better than stock suspension parts. I want to make the car fun to drive. In the meantime anything I was going to do to the engine was going to be transferable onto a 200. That's where my current resistance to an ignition upgrade, at least a $200-$300 dollar upgrade, comes in. If I upgrade this engine To a DSii or HEI it won't be transferable to a 200 down the road, or won't be ideal. In that respect, if I could improve airflow in and out of the engine while having a "good enough" ignition for the moment, the improvements I make can get used on a future engine. I did upgrade to a hotter coil. Do you know if an Accel super stock coil #8140 can be used with a Pertronix Ignitor?
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

User avatar
wsa111
FSP Moderator
Posts: 3245
Joined: Sat Jan 24, 2004 5:28 pm
Location: South Carolina
Contact:

Re: Autolite 1100 Venturi Mod

Post #40 by wsa111 » Mon Feb 18, 2019 12:15 pm

The Accel coil will work fine. You will need a relay for a full 12V power for the coil.
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, DSII dist. MSD-6al & MSD-Blaster 8252 Coil. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
2003 Ford Lightning daily driver. Recurving Distributors. billythedistributorman@live.com
Image

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #41 by Creechn32 » Sun Feb 24, 2019 5:59 pm

Ordered a kit, a couple diaphragm springs, and an assortment of main jets from Mikes Carburetor Parts. Hopefully will arrive this coming week. Does anyone have a recommendation for a carburetor dip that they use? Kerosene? Mineral spirits? Normally I just hit all the passages with carburetor cleaner but I think this carb will do good to soak a couple days since its sat and had some buildup of corrosion in a few passages.
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

User avatar
wsa111
FSP Moderator
Posts: 3245
Joined: Sat Jan 24, 2004 5:28 pm
Location: South Carolina
Contact:

Re: Autolite 1100 Venturi Mod

Post #42 by wsa111 » Sun Feb 24, 2019 7:39 pm

Advance has a 1 gallon of carb cleaner, where you lower the parts into the basket & leave them sit. Its best to agitate them for a more through cleaning.
Do not put your new venturi into the canister to be on the safe side.
Then wash with water.
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, DSII dist. MSD-6al & MSD-Blaster 8252 Coil. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
2003 Ford Lightning daily driver. Recurving Distributors. billythedistributorman@live.com
Image

User avatar
Econoline
Registered User
Posts: 1293
Joined: Tue Nov 12, 2013 8:37 pm
Location: Anacortes, WA

Re: Autolite 1100 Venturi Mod

Post #43 by Econoline » Sun Feb 24, 2019 9:49 pm

Bill beat me to it. Berrymans carb dip in the gallon is hard to beat outside of using an ultrasonic cleaner. The only downside is $20-25 a gallon. It works very well.
It ain't gonna fix itself

63falconATX
Registered User
Posts: 71
Joined: Fri May 22, 2015 4:16 pm
Location: Just outside of Coupland, Texas
Contact:

Re: Autolite 1100 Venturi Mod

Post #44 by 63falconATX » Mon Feb 25, 2019 12:47 pm

DIY block fix, 30 min with a sharp adjustable hand reamer and a bore gauge. Less than $100 at MaMaster. Done! Use whatever carb and dizzy you want.

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #45 by Creechn32 » Sat Mar 09, 2019 8:02 am

A little update: first try with the Venturi mod did not go well. I got the carb really clean and rebuilt. Installed on car and it idled wonderfully. When accelerated slowly in park the engine would struggle. Slam on the gas and the accelerator pump would get the engine going nicely. I tried re-jetting from .062 to .066 with very minor improvement. I originally was shooting for a Venturi size of 1.25 instead of the stock 1.10. My end result was around 1.375" or 1-3/8. I believe this had an affect on the air speed as we previously discussed. I re-installed the factory Venturi to make sure everything was good with the carburetor and left it jetted at .066, it ran quite well and functioned ain't should. I am going to try my hand at one more Venturi around 1.2-1.25. On a side note this carburetor has done away with the last bit of stumble/ hesitation off the line I've been having. I put a kit in the old carb but went a couple steps further with this one replacing both the Accel pump spring and the dashpot spring and cleaning out the power valve cavity on top of the carburetor. I have gotten quite good at disassembling the carburetor while on the car in order to re-jet.....
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

User avatar
wsa111
FSP Moderator
Posts: 3245
Joined: Sat Jan 24, 2004 5:28 pm
Location: South Carolina
Contact:

Re: Autolite 1100 Venturi Mod

Post #46 by wsa111 » Sat Mar 09, 2019 12:23 pm

You should have tried a .069" jet. The larger venturi flow more air & the signal is weaker. Maybe jets into the low .70",s would work.
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, DSII dist. MSD-6al & MSD-Blaster 8252 Coil. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
2003 Ford Lightning daily driver. Recurving Distributors. billythedistributorman@live.com
Image

Creechn32
Registered User
Posts: 63
Joined: Sun Dec 09, 2018 6:53 pm

Re: Autolite 1100 Venturi Mod

Post #47 by Creechn32 » Sat Mar 09, 2019 1:45 pm

wsa111 wrote:You should have tried a .069" jet. The larger venturi flow more air & the signal is weaker. Maybe jets into the low .70",s would work.


I didn't order any that size when I ordered the kit. I could probably drill one of the jets out instead of ordering more. I did think about even larger jets but at $5.25 each they start to add up. They jump from .069-.074-.078 on Mikes Carbs site. I still might try this out, I haven't scrapped the first Venturi I made yet.
1963 Ford Falcon 4 door: 170/2sp automatic, all original except paint, in need of front and rear bumpers and brackets, soon to upgrade suspension
Newton, NC

Who is online

Users browsing this forum: No registered users and 22 guests