Found this in my shed yesterday....
Competition Series AFB, 400 CFM
I'm 65 and I've never seen a real one until now. It was in a box of carbs my friend gave me.
Looking at the size of the venturis and butterflies makes me think that the primary CFM is less than 200 cfm which will work on the mileage 273
I've gathered all the parts for.
My friend was a NHRA racer for years. He campaigned a 63 Plymouth wagon with a factory 383/343 hp.
I think the 383 hp rating at the time was 330 single four barrel. The 383/343 hp had two 4 barrels, each 400 CFM AFB.
The point here....my friend is like many other racers of the era who cheated until they got caught.
When I saw the size of the rear boosters on my carb today, I knew they were from a 750 CFM carb.
I could be wrong but the brass fuel feed tube on the underside of the primary boosters, compared to others, looks large to me for a 400 CFM.
I do know that he seriously cut the heads on that car, so much he had to seriously elongate the intake mounting bolt holes. He put washers just big enough to cover the elongation, then sprayed a little paint on it.
This is the same guy I was telling you about that spent a day with a propane torch and scraper, getting the undercoat off the car. Total weight of scraped off undercoat, 25 lbs the equivalent of .25 or a 1/4 of a second.
Back in the day another trick was of course to reduce compression chamber volume to raise compression ratio.
If you car was contested, and you were accused of cheating, there was a teardown of your engine by NHRA officials , at your expense. My friend got a plug from "somewhere" (he worked for and did some racing for Chrysler)
Your plug was the plug the officials used to measure the combustion chamber volume of your heads. The spark plugs were designed to look stock and hold an extra 5cc of fluid. 5cc X 8 combustion chambers is 40cc. So the cc volume would be correct as measured by the officials, but the true situation would be an increase in compression.
Competition Series AFB, 400 CFM
I'm 65 and I've never seen a real one until now. It was in a box of carbs my friend gave me.
Looking at the size of the venturis and butterflies makes me think that the primary CFM is less than 200 cfm which will work on the mileage 273
I've gathered all the parts for.
My friend was a NHRA racer for years. He campaigned a 63 Plymouth wagon with a factory 383/343 hp.
I think the 383 hp rating at the time was 330 single four barrel. The 383/343 hp had two 4 barrels, each 400 CFM AFB.
The point here....my friend is like many other racers of the era who cheated until they got caught.
When I saw the size of the rear boosters on my carb today, I knew they were from a 750 CFM carb.
I could be wrong but the brass fuel feed tube on the underside of the primary boosters, compared to others, looks large to me for a 400 CFM.
I do know that he seriously cut the heads on that car, so much he had to seriously elongate the intake mounting bolt holes. He put washers just big enough to cover the elongation, then sprayed a little paint on it.
This is the same guy I was telling you about that spent a day with a propane torch and scraper, getting the undercoat off the car. Total weight of scraped off undercoat, 25 lbs the equivalent of .25 or a 1/4 of a second.
Back in the day another trick was of course to reduce compression chamber volume to raise compression ratio.
If you car was contested, and you were accused of cheating, there was a teardown of your engine by NHRA officials , at your expense. My friend got a plug from "somewhere" (he worked for and did some racing for Chrysler)
Your plug was the plug the officials used to measure the combustion chamber volume of your heads. The spark plugs were designed to look stock and hold an extra 5cc of fluid. 5cc X 8 combustion chambers is 40cc. So the cc volume would be correct as measured by the officials, but the true situation would be an increase in compression.