Go Back   The Ford Barn > The Archives > Model-A

Sponsored Links (Register now to hide all advertisements)

 
 
Thread Tools Display Modes
Old 01-01-1970, 12:00 AM   #1
Guest
 
Posts: n/a
Default Downdraft Carb?




Which is the better carb, Stromberg 97 or 81, for the mildly hot Model "A" engine? Pros and cons? Thanks in advance.

Billy





<table><tr><td><font face="arial">


 
Old 01-01-1970, 12:00 AM   #2
Guest
 
Posts: n/a
Default Re: Downdraft Carb?







The 81 is preferred due to the smaller size, idles and runs perfect, the 97 needs some tweeking, adjustable jets, ect. to get to run nice, since its a larger carb, but will work fine once tuned.



<table><tr><td><font face="arial">


 
Sponsored Links (Register now to hide all advertisements)
Old 01-01-1970, 12:00 AM   #3
Guest
 
Posts: n/a
Default My thoughts...







<font size=4> IMO, the 97 and the 81 are both a little outdated by the technological advances we have brought our engines to these days. I know that Ed Johnson is using two 97s on his blue speedsters but is having issues with them. I run 94s in both single and dual carb applications and find them MUCH superior to the 97 or the 81 in all respects. I have the ability to tune all of the stumbles, hesitations, and etc. out PLUS, most of the leaks!!



The old thoughts were that the 81 ran better because the 97 was too big. The problem is that the engines most people were bolting them on had "deeper problems" inside engine (worn or sloppy camshafts, poor ignition, weak compression (under 6:1)) so naturally the 81 was a better band-aide. Do the math on the size engines that the 81 and the 97 originally came on. Doesn't it seem unlikely that a smaller carburetor would give better performance on a Model A engine that has had the compression increased and the camshaft changed for better mid-range?



My opinion is go to the 94 which has a much superior pump circuit, a power circuit (with tunable power valves), a nice idle circuit, and an affordable price to the availability.



Here is the new carb & manifold going on my wife's speedster. Gonna be street driven to...











<table><tr><td><font face="arial">
<ul>[*]MY WEBSITE[/list]

 
Old 01-01-1970, 12:00 AM   #4
Guest
 
Posts: n/a
Default Re: My thoughts...







The 97 was designed for a 221 inch motor, cant see why it wouldnt handle a 200 inch engine.Henry Ford didnt like out side suppliers.The Dodge bros supplied parts for the early fords and owned a lot of ford stock.Henry got rid of all stock holders as he did not care for their attempts to control the company.Stromberg supplied carbs to many early auto companies.I find it hard to believe that they didnt build a good carb.Ive used both makes over the years and found both worked well if I used clean fuel and good gaskets.Ive run dual Strombergs on a 59a,tried adjustable main jets and found they complicated performance.Introducing a lot of variables makes it harder to get things working right.The troubles of the 12 volters is a perfect example of this.



<table><tr><td><font face="arial">


 
Old 01-01-1970, 12:00 AM   #5
Guest
 
Posts: n/a
Default Re: My thoughts...







I'm envious of what you have there. I'm also building a speedster , starting out stock(to get it running)then I'll put on adders(carb, exhaust,maybe head). What would be your suggestion?



<table><tr><td><font face="arial">


 
Old 01-01-1970, 12:00 AM   #6
Guest
 
Posts: n/a
Default Re: Downdraft Carb?







The 81 is preferred due to the smaller size, idles and runs perfect, the 97 needs some tweeking, adjustable jets, ect. to get to run nice, since its a larger carb, but will work fine once tuned.



<table><tr><td><font face="arial">


 
Old 01-01-1970, 12:00 AM   #7
Guest
 
Posts: n/a
Default My thoughts...







<font size=4> IMO, the 97 and the 81 are both a little outdated by the technological advances we have brought our engines to these days. I know that Ed Johnson is using two 97s on his blue speedsters but is having issues with them. I run 94s in both single and dual carb applications and find them MUCH superior to the 97 or the 81 in all respects. I have the ability to tune all of the stumbles, hesitations, and etc. out PLUS, most of the leaks!!



The old thoughts were that the 81 ran better because the 97 was too big. The problem is that the engines most people were bolting them on had "deeper problems" inside engine (worn or sloppy camshafts, poor ignition, weak compression (under 6:1)) so naturally the 81 was a better band-aide. Do the math on the size engines that the 81 and the 97 originally came on. Doesn't it seem unlikely that a smaller carburetor would give better performance on a Model A engine that has had the compression increased and the camshaft changed for better mid-range?



My opinion is go to the 94 which has a much superior pump circuit, a power circuit (with tunable power valves), a nice idle circuit, and an affordable price to the availability.



Here is the new carb & manifold going on my wife's speedster. Gonna be street driven to...











<table><tr><td><font face="arial">
<ul>[*]MY WEBSITE[/list]

 
Old 01-01-1970, 12:00 AM   #8
Guest
 
Posts: n/a
Default Re: My thoughts...







The 97 was designed for a 221 inch motor, cant see why it wouldnt handle a 200 inch engine.Henry Ford didnt like out side suppliers.The Dodge bros supplied parts for the early fords and owned a lot of ford stock.Henry got rid of all stock holders as he did not care for their attempts to control the company.Stromberg supplied carbs to many early auto companies.I find it hard to believe that they didnt build a good carb.Ive used both makes over the years and found both worked well if I used clean fuel and good gaskets.Ive run dual Strombergs on a 59a,tried adjustable main jets and found they complicated performance.Introducing a lot of variables makes it harder to get things working right.The troubles of the 12 volters is a perfect example of this.



<table><tr><td><font face="arial">


 
Old 01-01-1970, 12:00 AM   #9
Guest
 
Posts: n/a
Default Re: My thoughts...







I'm envious of what you have there. I'm also building a speedster , starting out stock(to get it running)then I'll put on adders(carb, exhaust,maybe head). What would be your suggestion?



<table><tr><td><font face="arial">


 
Old 01-01-1970, 12:00 AM   #10
Guest
 
Posts: n/a
Default Re: Downdraft Carb?







The 81 is preferred due to the smaller size, idles and runs perfect, the 97 needs some tweeking, adjustable jets, ect. to get to run nice, since its a larger carb, but will work fine once tuned.



<table><tr><td><font face="arial">


 
Old 01-01-1970, 12:00 AM   #11
Guest
 
Posts: n/a
Default My thoughts...







<font size=4> IMO, the 97 and the 81 are both a little outdated by the technological advances we have brought our engines to these days. I know that Ed Johnson is using two 97s on his blue speedsters but is having issues with them. I run 94s in both single and dual carb applications and find them MUCH superior to the 97 or the 81 in all respects. I have the ability to tune all of the stumbles, hesitations, and etc. out PLUS, most of the leaks!!



The old thoughts were that the 81 ran better because the 97 was too big. The problem is that the engines most people were bolting them on had "deeper problems" inside engine (worn or sloppy camshafts, poor ignition, weak compression (under 6:1)) so naturally the 81 was a better band-aide. Do the math on the size engines that the 81 and the 97 originally came on. Doesn't it seem unlikely that a smaller carburetor would give better performance on a Model A engine that has had the compression increased and the camshaft changed for better mid-range?



My opinion is go to the 94 which has a much superior pump circuit, a power circuit (with tunable power valves), a nice idle circuit, and an affordable price to the availability.



Here is the new carb & manifold going on my wife's speedster. Gonna be street driven to...











<table><tr><td><font face="arial">
<ul>[*]MY WEBSITE[/list]

 
Old 01-01-1970, 12:00 AM   #12
Guest
 
Posts: n/a
Default Re: My thoughts...







The 97 was designed for a 221 inch motor, cant see why it wouldnt handle a 200 inch engine.Henry Ford didnt like out side suppliers.The Dodge bros supplied parts for the early fords and owned a lot of ford stock.Henry got rid of all stock holders as he did not care for their attempts to control the company.Stromberg supplied carbs to many early auto companies.I find it hard to believe that they didnt build a good carb.Ive used both makes over the years and found both worked well if I used clean fuel and good gaskets.Ive run dual Strombergs on a 59a,tried adjustable main jets and found they complicated performance.Introducing a lot of variables makes it harder to get things working right.The troubles of the 12 volters is a perfect example of this.



<table><tr><td><font face="arial">


 
Old 01-01-1970, 12:00 AM   #13
Guest
 
Posts: n/a
Default Re: My thoughts...







I'm envious of what you have there. I'm also building a speedster , starting out stock(to get it running)then I'll put on adders(carb, exhaust,maybe head). What would be your suggestion?



<table><tr><td><font face="arial">


 
 

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 09:32 PM.