intake boring

1930artdeco

1930artdeco

Well-known member
OK, I am going to install a brand new exh manifold to seal up the leak I have. I am going to send the manifolds in to be planed flat obviously. BUT, should I have the intake bore out so that I can use a Model B someday? I currently use a Marvel carb but who knows I may want to a Model B for kicks in the future.

So, here is the question-will boring out the up portion and 'runners' affect me using the Marvel in any way? Negatively that is.

Thanks,

Mike
 
Hi Mike years ago, when I was still working, I had the shop foreman bore out three intake manifolds. Got all three 3 back but one had a big hole in the side when the boring bar when thru the wall!
Tell the shop not to set up 90 degrees to the flange. The flange is at slight angle to the bore. Have to use the boring bar or drill to set the manifold correctly.
I used one of those on my T/S when I got it back on the road in 2010, all the time using a Marvel carb has worked out great, maybe that's why I can get to 20mpg!
 
Dropping a name here , David Renner stated you only need to hand grind the miss match 3/8 to 1/2 in up from the flange to smooth out the transition . Using the model B carb gasket and use a burr in a hand grinder , this is 98% of the gain , he also said DON’T bore all the way up ! If you go back to your model A carb will not hurt a thing .
 
The right angle turns at the top of the vertical section probably restrict flow more than anything else. The momentum of the air crowds the top of the manifold after the turn and has the effect of making the passage smaller. Bore it out if you want. That will make a slight difference. I used a honing tool to bore mine. It follows the existing vertical passage and makes the inside nicely smooth.
 
From Renner's Corner http://rennerscorner.com:

591083
 

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Herb, you DO NOT get 20 MPG driving at 75 MPH;). Thanks all, I just want to make sure boring it out will not interfere with the throat being two different sizes. If nothing else it should help with efficiency and maybe just maybe give me one more HP!:)
 
There is a young guy on you-tube that installed a single venturi side draft garden tractor carb on a Ford V8. He just wanted to see if it would work. It not only ran well enough but he drove it some and it worked way better than I ever thought it would.
 
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rotorwrench said:
There is a young guy on you-tube that installed a single venturi side draft garden tractor carb on a Ford V8. He just wanted to see if it would work. It not only ran well enough but he drove it some and it worked way better than I ever thought it would.
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This is interesting. The new Marvel Schebler replacement (tractor) carburetors are inexpensive. I wonder if they would work on an A ?
 
duke36 said:
This is interesting. The new Marvel Schebler replacement (tractor) carburetors are inexpensive. I wonder if they would work on an A ?
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Bruce of MN said:
Is that this carb?

https://www.amazon.com/312954-Tractor-Carburetor-Made-Models/dp/B01AKDH0R2/ref=asc_df_B01AKDH0R2?tag=bingshoppinga-20&linkCode=df0&hvadid=80883033959983&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=90681&hvtargid=pla-4584482511860407&psc=1&hvocijid=13271626009539045796-B01AKDH0R2-&hvexpln=0
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Alexa (Amazon AI) sez this carburetor is not designed for my Model A. I should look on Snyder's Antique Auto for a compatible carburetor for my Model A.
 
It would be fair to say it wasn't designed for Model A's, but I see a Ford 641 tractor is 2.2 liters and 46 hp. An A is 3.3 liters and similar hp. If the outlet flange matches the A manifold, it might be good and an experimenter might try it.
 
Bruce of MN said:
It would be fair to say it wasn't designed for Model A's, but I see a Ford 641 tractor is 2.2 liters and 46 hp. An A is 3.3 liters and similar hp. If the outlet flange matches the A manifold, it might be good and an experimenter might try it.
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I guess my point was that Amazon referred me to Snyder's.
 
There are companies that do extrusion honing. They force a thick paste with abrasive particles through a manifold. That may be the right thing to do to round out the transition from the vertical to the horizontal runs at the T section on top. And at the same time open up the passages a tad.
 
nkaminar said:
There are companies that do extrusion honing. They force a thick paste with abrasive particles through a manifold. That may be the right thing to do to round out the transition from the vertical to the horizontal runs at the T section on top. And at the same time open up the passages a tad.
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Now we are talking big bucks and not worth it with a stock manifold.
 
It would take some experimentation but you could fill the inside of the manifold with acid Slowly acid eat away some of the metal to open the passages.
 
I run a Model "A" Zenith 2 Carburetor on a Model "B" motor in my Victoria, and cruising at 50 MPH it gets 23MPG. The 6:1 cylinder head is partially responsible for the great gas mileage and the motor has excellent power.
 
Y'all must be talking highway miles because I sure can't get that kind of mileage driving around town, which is what I do mostly.
 
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