3 1bbl's

[Anonymous]

Does anyone have pics and details on doing 3 1bbl's on a log head? I have seen some pics somewhere but can't remember where. My thoughts were to use three 1100's.

Some of the details I am interested in are:

Are 1100's the right carbs to use?

How do you set them up?

Jetting on a stock 200?

Are there "weld-on" or bolt-on 1bbl carb adapters that I affix to the log (after machining the log) for the end two carbs?

I think the basic set up is to run idle/low rpm through the center and start opening the two end carbs at higher rpms (can you simply shut down the idle mixture screws on the end carbs to disable the idle circuit?)

Feel free to set me straight where ever it is necessary. I have an extra head to play with and this sounds interesting.

Thanks.

 

[CobraSix]

Mr wilson, see if that helps:

http://www.kastang.net/offenhauserreview.html

That is with Autolite 1100s. on the 65, the offy will have some cleareance issues, so you have to small air cleaners (or cut down the one like I had). Some people use the webers, but I love the 1100s. Only thing you have to do to make them fit is remove the automatic chokes from the front carb (and I ended doing to the rear for symmetry). They'll work fine.

This is how i installed it:

http://www.kastang.net/offenhausermod.html

As far as tuning, that's another story. You'll need a unisync gauge which allows you to sync multiple carbs. It also takes some drive and tune sessions where you drive it and see if you like where the outer carbs are kicking in.

Slade

 

[Anonymous]

Thanks for the info and the pics. Looks very cool. Where did you get your parts (if it was in the article I missed it)?

As far as tuning, I realize that will be a trial and error process, but can you give me some place to start? What size jets are you using? What did you do for idle mixture?

 

[Guest]

Not sure how much you know about the system, but it is a progressive system. The center carb is the only one with a choke and is the only one you need to worry about the idle circuit with. The outer two carbs remain completley closed (in theory anyway) during idle up to roughly 1/3 throttle, then the outer 2 begin to open. By WOT, all 3 carbs are wide open together.

Al

 

[CobraSix]

I stuck with the standard Autolite 1100 sizing for jets. you can't change them as far as I know.

For idle, I completely closed the outer carbs idle fuel/air mix screw and then set teh idle speed from the center carb.

I got my carbs from various places. The outers were bought from mustangs unlimited, the center was a rebuilt pony carb I bought used.

It look slike the place I got my intake isn't around anymore. but www.vintagespeed.com has them.

Slade

 

[Anonymous]

Thanks again.

I did see some pics of carb mounting plates welded right to the log. I don't know if the plates can be purchased or if they have to be fabbed. It positioned carbs ninety degrees from the position the Offy intake does, but it afforded more vertical clearance for air cleaner. I remember that the carb plates were installed on the log angled slightly so that the carbs sat level.

Has anyone else seen this or did I imagine it?

 

[CobraSix]

You're not crazy, there are pictures of them out there. Not sure where I saw them, but they are around.

Slade

 

[Anonymous]

You're not crazy, there are pictures of them out there. Not sure where I saw them, but they are around.

Slade

Thank you, I was beginning to wonder.

 

[Anonymous]

Some issues I have had with them are if the car sits for a long time garinteed at least one will have a stuck float. Be prepaired for it. I usally used a smaller carb in the middle than the outer ones. With hotter cams one must modify the power circut and make it adjustable to keep it from activating at low vacum idle and cruse speeds.

 

[Anonymous]

......With hotter cams one must modify the power circut and make it adjustable to keep it from activating at low vacum idle and cruse speeds........
turbo2256

What do these mods entail? My intent is to play with this on my stock motor to see if I can make it work and if I'm capable. After my cabuerator confidence level is a little higher I'll build the motor and then these changes will be necessary.

Wilson

 

[Anonymous]

Actually its been so long (20 some years) and I have modified so many carbs since (had the same issues with the 5200 holleys) I dont rember exactly how I did the 1100. Simply power valves are either held closed or open with vaccum against a spring. This is the first thing you need to determan. Then either weaking or strenghining the spring changes the opening point. A vaccum tester helps with this (for bench work) and a undampened vaccum gage to monitor engine vaccum at idle and cruse speeds. A Holly tuning book will explain most of it and the different systems better than I can here. Changing the opening point can be done with springs, shims or making the rod running through the spring adjustable. In my tri power setup I just modified the center carb since the others didnt open at cruse and idle so there blocking or diabling an going to larger fixed main jets is a simple solution. With out changes to this circut with a hot cam idle is hard to maintain and cruse economy is poor.
Ever have a car with a Holley carb with a blown power valve.

Someday I shoud desclose how I got 45 MPG from a 200 6cyl hiway 35 to 40 city.

 

[Anonymous]

Thanks alot turbo2256, I get the drift now. Hopefully I'll get to that point before I get discouraged. I do have access to a pretty good carb man locally here as well.

 

[Anonymous]

I have the 3 one barrells as well. Feel free to ask me any questions.

Bill

 

[Anonymous]

plate,s ? flanges ? i did alreay cut them , had a year ago the same idee , did cut some plates for the log head , 2 plates in differends hight for a vertical air cleaner instal with the right log inside and 2 outer tread log,s for bolting on the carbs 3 x 1100 autolite !

almost the same idee like this setup ! [ dont remember who,s is it ? ]

 

[Anonymous]

That looks like the same setup that I saw and can't find again (it's not the same specific one, but very close). Now I just need more specifics on carb sizing and tuning. This is where my lack of carb experience shows-Are there different throat/venturi sizes of 1100's? If so, how do you tell? Are the jets interchangeable? I know there is a difference between automatic and manual carbs, does it matter for the secondaries if they are one or the other?

 

[XFlow_Fairlane]

well it lokos like I might be welding up a head fo rtripower this winter I go tthree 1100's for it and need one more carb base (using three stock bases) going to weld with a regular buzz box and some Ni rod. going to mig the plates on the stubs later on and then bring it down to school and set i tup on a mill to take a cleanup pass on the flanges.

nick

 

[CobraSix]

As far as I know...all 1100s had the same venturis. But I'm not an expert on this either.

Slade

 

[Anonymous]

I would have to go dig up some info but I think my center carb is a 170 CFM and the two outer carbs are 210 CFM. Anyway I still have the setup with Offy manifold with like one hour of rumnnig time on it. Its for the older round log. I would sell the whole car and /or engine for that matter.

 

[Anonymous]

Autolite 1100/1101 1 Barrel:

This was introduced in 1963 and was used on all 144/170 and 200 cubic inch engines. Ford made different venturi sizes for each engine. All carburetor bores are 1 and 7/16 inch. A teflon type insert is placed in the bore to adjust the true venturi size. The 144 used a 1.0 inch, the 170 a 1.10 inch and the 200 a 1.20 inch venturi.

Notes on the autolite series

*All of these were manual choke until the 65 model year.

http://www.tffn.net/1960.html

I found this surfing around. Does it sound right?

 

[CobraSix]

yeah, that rings a bell. i got mine for a 200.