The Ford Barn

1930artdeco · 01-14-2014, 10:05 AM

Mr. Chauvin got me to thinking, would just polishing the upper carb, manifold and block ports smooth things out any? I know with more efficiency comes more power or would I just be wasting my time without porting. Just thinking outloud...

Mike

H. L. Chauvin · 01-14-2014, 10:38 AM

Again FWIW, in today's unending varied science of internal combustion engines & unending discussions of same:

1. After performing smoothing out my new Model A intake manifold stated in above paragraph (2.) of above reply no. (10), rather than boring out my new Model A intake manifold with the recommended approximately 1.25" for use with a B carburetor, I experimented using a Dremel tool to open only the bottom end of the intake manifold to approximately 1,25" where it meets the larger Model B carburetor flange & larger Model B carburetor gasket.

2. When looking at this end of the intake manifold opening, near the carburetor, it resembles looking at a Model A or Model B carburetor venturi with an opening that resembles the flare at the end of a trumpet, thus allowing a rapid opening of unobstructed flow from the larger diameter B carburetor into the A manifold.

3. As far as how this particular intake manifold airflow shape & setup works, i.e., to have the fuel/air mix going through that which somewhat resembles a double venturi, one above the carburetor & one inside & below, I honestly have no idea what would be the result if tested to verify results on a dynamometer. I just did it my way.

4. In my opinion, designing internal combustion features are similar to today's empirical design used to make today's gunpowder for rifles & artillery weapons; i. e., make a different batch of gunpowder, shape the shell's internal chamber, then ignite it -- afterwards, "wow" -- check the shell's internal chamber psi and the muzzle velocity with delicate calibrated instruments to observe the results by trial & error -- thus being somewhat similar to internal combustion engine trial & error designs, while using a dynamometer for documenting the varying end results.

5. Today's internal combustion engine design has not yet reached perfection -- like in the 1930's, there will always be room for performance improvement -- just good to share what works & what does not.

Terry,NJ · 01-14-2014, 12:25 PM

Idealy, the manifold would have gentler curves (Larger Radii where the bends are) this would cut down on turbulence of the mixture. Also, the manifold is basically a "T" with the center part (Throat) feeding the two cross arms. I think that 1.250 and Brent's 1.300 are even too small. I was think of welding up a manifold with a 1.500 throat. Next time I run across a broken manifold, I think I will do this. But clearly, The A manifold is a constriction.
Terry

01-14-2014, 10:05 AM	#21
1930artdeco Senior Member Join Date: May 2010 Location: Lynden, Wa Posts: 3,550	Re: Boring A intake for B carb.... Mr. Chauvin got me to thinking, would just polishing the upper carb, manifold and block ports smooth things out any? I know with more efficiency comes more power or would I just be wasting my time without porting. Just thinking outloud... Mike __________________ 1930 TownSedan (Briggs) 1957 Country Sedan

01-14-2014, 10:38 AM	#22
H. L. Chauvin Senior Member Join Date: May 2010 Posts: 4,179	Re: Boring A intake for B carb.... Again FWIW, in today's unending varied science of internal combustion engines & unending discussions of same: 1. After performing smoothing out my new Model A intake manifold stated in above paragraph (2.) of above reply no. (10), rather than boring out my new Model A intake manifold with the recommended approximately 1.25" for use with a B carburetor, I experimented using a Dremel tool to open only the bottom end of the intake manifold to approximately 1,25" where it meets the larger Model B carburetor flange & larger Model B carburetor gasket. 2. When looking at this end of the intake manifold opening, near the carburetor, it resembles looking at a Model A or Model B carburetor venturi with an opening that resembles the flare at the end of a trumpet, thus allowing a rapid opening of unobstructed flow from the larger diameter B carburetor into the A manifold. 3. As far as how this particular intake manifold airflow shape & setup works, i.e., to have the fuel/air mix going through that which somewhat resembles a double venturi, one above the carburetor & one inside & below, I honestly have no idea what would be the result if tested to verify results on a dynamometer. I just did it my way. 4. In my opinion, designing internal combustion features are similar to today's empirical design used to make today's gunpowder for rifles & artillery weapons; i. e., make a different batch of gunpowder, shape the shell's internal chamber, then ignite it -- afterwards, "wow" -- check the shell's internal chamber psi and the muzzle velocity with delicate calibrated instruments to observe the results by trial & error -- thus being somewhat similar to internal combustion engine trial & error designs, while using a dynamometer for documenting the varying end results. 5. Today's internal combustion engine design has not yet reached perfection -- like in the 1930's, there will always be room for performance improvement -- just good to share what works & what does not.

01-14-2014, 12:25 PM	#23
Terry,NJ Senior Member Join Date: Nov 2013 Location: Northern Bucks Co. Pa Posts: 632	Re: Boring A intake for B carb.... Idealy, the manifold would have gentler curves (Larger Radii where the bends are) this would cut down on turbulence of the mixture. Also, the manifold is basically a "T" with the center part (Throat) feeding the two cross arms. I think that 1.250 and Brent's 1.300 are even too small. I was think of welding up a manifold with a 1.500 throat. Next time I run across a broken manifold, I think I will do this. But clearly, The A manifold is a constriction. Terry