Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 10-06-2019, 06:19 PM   #1
UncleBill
Junior Member
 
Join Date: Jul 2019
Posts: 5
Question Multiple Carbs

Proud owner of a 1941 2dr sedan. Equipped with an original flathead with offenhauser heads and 3 deuce manifold. Question is, when adjusting multiple carbs do you adjust idle mixture screws on all three carbs or just the center one? Been turning wrenches for years just never encountered multiple carbs before.
UncleBill is offline   Reply With Quote
Old 10-06-2019, 07:00 PM   #2
scicala
Senior Member
 
scicala's Avatar
 
Join Date: Jun 2010
Location: Detroit suburb, MI
Posts: 3,697
Default Re: Multiple Carbs

Welcome to Ford Barn. If your tri power is set up with progressive linkage, you do all of the idle adjusting on the center carb as far as speed and fuel mixture. The front and rear carbs need to have the speed screws backed off all the way so the throttle plates are seated. Then turn in speed screws a hair...., just enough to keep the plates from sticking in the bores, but not enough to pass any more air (or very very little air). Front and rear also need the idle mixture screws lightly seated to prevent fuel flow.
If running direct linkage where all three carbs open up together, then you need to balance all three carbs to the same idle air flow and adjust the mixture screws on all three carbs.




Sal
scicala is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 10-06-2019, 09:39 PM   #3
UncleBill
Junior Member
 
Join Date: Jul 2019
Posts: 5
Default Re: Multiple Carbs

Thank you very much. Very useful info.
UncleBill is offline   Reply With Quote
Old 10-07-2019, 05:56 PM   #4
Ol' Ron
Senior Member
 
Ol' Ron's Avatar
 
Join Date: May 2010
Location: Chester Vt
Posts: 8,842
Default Re: Multiple Carbs

If this is a completely stock engine. You might consider blocking off the center carb and running it as a Dual set up
Ol' Ron is online now   Reply With Quote
Old 10-07-2019, 06:55 PM   #5
drolston
Senior Member
 
drolston's Avatar
 
Join Date: Jun 2014
Location: Williamsburg, VA
Posts: 1,623
Default Re: Multiple Carbs

Or, run progressive linkage adjusted so that the secondaries do not start to open until half throttle on the center/primary. With opening that late the secondaries will probably not reach full open at full pedal. That will run fine, and even with the secondaries not reaching full open, you will have plenty of carburetor CFM for a stock engine.
drolston is offline   Reply With Quote
Old 10-07-2019, 07:03 PM   #6
Init1
Senior Member
 
Init1's Avatar
 
Join Date: May 2010
Location: Oregon City, Oregon
Posts: 208
Default Re: Multiple Carbs

Sponsored Links (Register now to hide all advertisements)
What O'l Ron said. A stock flathead will have trouble swallowing that much gas and run rich.
Really not worth the trouble unless you like changing fouled plugs alot.
Init1 is offline   Reply With Quote
Old 10-07-2019, 08:47 PM   #7
UncleBill
Junior Member
 
Join Date: Jul 2019
Posts: 5
Default Re: Multiple Carbs

Purchased this vehicle this past summer. Came equipped with aluminum heads, (high compression?), three stromberg carburators, headers. Unknown whether cam is stock. It doesn't have adjustable lifters. The individual I bought it from received it from the estate of the man who put it together. Recently repaired a distributor problem now I am going to tackle the carbs.
UncleBill is offline   Reply With Quote
Old 10-08-2019, 06:54 AM   #8
Ol' Ron
Senior Member
 
Ol' Ron's Avatar
 
Join Date: May 2010
Location: Chester Vt
Posts: 8,842
Default Re: Multiple Carbs

A good book to purchase is JWL's "Flathead fact". The first 100 pages discuss the modifications you can make to a "stock" engine. Along with dyno results for all the mods. This will save you time and money, along with a better running engine.
Ol' Ron is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 10:50 AM.