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06-01-2020, 11:55 AM | #1 |
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Rear exit manifolds for flathead 39 Ford
Hi Fordbarn,
Does anyone know of a good exhaust manifold that’s a rear exit that will fit a 39 ford standard? My current manifold dumps in front of the steering box and I’m looking for something that will be easier to run a dual exhaust. Thanks, Chris |
06-01-2020, 12:10 PM | #2 |
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Re: Rear exit manifolds for flathead 39 Ford
Fenton cast iron headers is all I can think of. I also think one of the parts vendors (Carpenter?) used to make a repop 8BA police manifold,but I don't think they are available anymore. You could look around for one (or maybe even an original?) though.
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06-01-2020, 12:34 PM | #3 |
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Re: Rear exit manifolds for flathead 39 Ford
Thanks, let me look around for the police manifolds.
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06-01-2020, 12:44 PM | #4 |
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Re: Rear exit manifolds for flathead 39 Ford
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06-01-2020, 12:58 PM | #5 | |
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Re: Rear exit manifolds for flathead 39 Ford
Quote:
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06-01-2020, 01:05 PM | #6 | |
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Re: Rear exit manifolds for flathead 39 Ford
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Quote:
I have not used one in a 39 but think will be good candidate. maybe some know better. |
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06-01-2020, 02:15 PM | #7 |
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Re: Rear exit manifolds for flathead 39 Ford
Will isn't this interesting!
From Drake's site: "These manifolds are the single most effective way to increase horsepower through vastly improved exhaust flow, because the key is changing the stock single-exhaust to dual-exhaust." |
06-01-2020, 02:31 PM | #8 |
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Re: Rear exit manifolds for flathead 39 Ford
I have a lot to learn. Why to do you scoff at Drakes statement? Doesn't dual exhaust improve delivered horsepower?
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06-01-2020, 02:42 PM | #9 |
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Re: Rear exit manifolds for flathead 39 Ford
I have an original "police" exhaust manifold and the exhaust pipe flange is definitely bigger but as far as increasing HP by it self is questionable, exhaust gas flow better YES so maybe better throttle response and cooling
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06-01-2020, 02:54 PM | #10 | |
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Re: Rear exit manifolds for flathead 39 Ford
Quote:
Duals do sound better, though. |
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06-01-2020, 03:02 PM | #11 | |
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Re: Rear exit manifolds for flathead 39 Ford
Quote:
From what I've read, the intake tract on a flathead is the limiting factor in gaining horsepower, not the exhaust. Dual exhaust sure sounds a lot better, though! |
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06-01-2020, 03:20 PM | #12 |
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Re: Rear exit manifolds for flathead 39 Ford
Dyno tests show minimal hp gains with exhaust modifications on semi-stock engines. The Drake statement is "...the single most effective way to increase horsepower...". That is a false statement. I like headers on a flathead, I like the look, I like the sound, but it is NOT the single most effective way to increase horsepower, not even close.
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06-01-2020, 03:20 PM | #13 |
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Re: Rear exit manifolds for flathead 39 Ford
According to the old magazines
Dual exhaust 10 hp Dual carbs 10-15 hp High Compression heads 10-15 hp All is bolton ;-) |
06-01-2020, 03:21 PM | #14 |
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Re: Rear exit manifolds for flathead 39 Ford
AA Ford needs to buy JWL's book to know why he should spend his money elsewhere on his project.
R |
06-01-2020, 03:22 PM | #15 | |
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Re: Rear exit manifolds for flathead 39 Ford
Quote:
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06-01-2020, 03:23 PM | #16 |
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Re: Rear exit manifolds for flathead 39 Ford
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06-01-2020, 03:54 PM | #17 |
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Re: Rear exit manifolds for flathead 39 Ford
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06-01-2020, 04:06 PM | #18 |
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Re: Rear exit manifolds for flathead 39 Ford
That says it all. When we were kids, we'd go through the J.C. Whitney catalog and add up the horsepower gains advertised for each part. We all knew that if we had enough money, we could make a 175 HP flathead easily.
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06-01-2020, 04:32 PM | #19 |
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Re: Rear exit manifolds for flathead 39 Ford
I wonder if back in the day the muffler was a restriction so the police manifold would give you 2 mufflers on the car. Police needed to be quiet. Seems like it would be a lot of engineering, must have made a bit of difference.
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06-01-2020, 04:52 PM | #20 |
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Re: Rear exit manifolds for flathead 39 Ford
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