Technical Reverse Flow Flathead V8

When I was young my family made many camping trips to the desert to ride dirt bikes and dune buggies and to just get away from home for a weekend. El Mirage dry lake was a favorite spot for a number of years, and many of our camping trips coincided with the SCTA events. This would've been from late 60's to late 70's. On those occasions my brothers, and friends and I would ride over to the pit area and walk through the pits looking at cars and talking to the drivers. I have great memories of those days, a great part of growing up in So Cal.

On one of those times, as we were walking through the pits we saw a car with a flathead Ford V8 with the exhaust exiting out the top of the block instead of the sides. WTF??? So we stopped and talked the crew about it, and they told us that it was an old trick to get a little more horsepower out of the engine, run it backwards. Now we were just kids, not driving yet, what I knew about cars and engines was what I learned from magazines and from helping my dad work on the family cars (no flathead Fords), which was very little. Of all the sites and sounds and experiences, that one has really stuck with me, for some reason I was amazed with it.

Over the years I never saw another example like that or heard or read anything about it again. So I got to doubting myself. Did I really see what I thought I saw? Maybe the guys were just pulling our legs, and then laughing their ***es off as we walked away. Yeah, that's probably it I started to think. Maybe it was a Cadillac flathead where the exhaust does exit out the top. So I did a google search on running a flathead Ford backwards, and no ****, there it is! They call it reverse flow. So yeah, this was a thing, I didn't imagine it.

Here's an article from Gray Baskerville talking about it:
http://www.flatfire.com/flatfire2.htm

 

Racers would add an extra exhaust port out of the top of the head for more flow and less heat in the motor
Eric Hannson does that with his flatheads
Sorry I don't know the exact area they drill the motor or head?

 

The extra port opened on a Ford flatheads sometimes is just the original crossover port opened up, with a bit of intake manifold flange cut to suit. The port itself can be opened some, there are adjacent bolts to mount a pipe, and a lot of the casting in water jacket can be seen to help in planning the opening, Whether this does anything other than sharpening the staccato I have no idea.

 

This guy did it on a sbc. Why?
Because he wanted to!
I think it looks great !

Anyone with first hand experience with a reverse flow flatty?

 

A guy named Rick Scnell from minnesota runs a flathead dragster with a sutup like you described. U-tube " worlds fastest flathead dragster" to see the car run. I think it runs in the 7's.

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That does look cool. Those look like CV carbs off a motorcycle.

 

I wonder on a street flathead what heating the intake mixture by it running through the block does?

 

It definitely helps. Here is a pic of a HIGHLY successful engine of it's day.

 

Really cool? You guys obviously have a way different idea of cool than I do.

To me that just looks ridiculous

 

To each their own!

 

One of the guys that own the machine shop I use raced sprints for years and started with flathead. I was talking one day about the reverse intake and exhaust setup and if it works. He said a few guys tried it back in the day but then they would try anything. If it works better it never took off.

 

This is a fairly common way to run a compe***ion flathead Ford. Filled water jackets in block. Ron Mains deal cost a fortune. Jimmy Stevens did something similar. But not quite the same. They have the only two 300 mph flatheads ever, Running the intake charge through the exhaust p***ages would seem to be a really poor way to make power to me.

 

Another view of the one posted by Rich

 

I've seen pictures of numerous blown nailheads that are set up to run in reverse. Some of the pics in here are quite interesting

 

Like to see one. Don't think I ever have. Can you post?

 

I use to work with the owner builder of this '63 Stevens. He said it didn't run any better or worse than before he built the engine as reverse flow.

 

to do the reverse flow is a special grind cam ????

 

How do you make it go backwards? Crank standard rotation for the ****** and rear end?........2 sprockets engaging like gear drive instead of a timing chain to reverse the cam? reverse grind on cam?
Thats the only way I can come up with it....does the oil pump care which way it rotates ?

 

I was on a boat similar to this


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Reverse flow doesn't mean reverse rotation. They are talking about switching the cam shaft so that the old intake valve and port becomes the exhaust and the old exhaust becomes the intake. Distributor and oil pump still rotate as normal. If you did have a reverse rotation engine it would have a distributor and oil pump that also were made to run backwards or a cam that runs backwards from the crank

 

I'm quite sure the one I originally saw several decades ago at El Mirage had the intake running into the exhaust ports and the exhaust out the intake ports.

 

Not saying you didn't, but using the very restrictive flathead exhaust ports as intake ports would be about the worst thing you could do to build power. It would do a great job of limiting the power though. About the only thing worse is the siamesed intake ports on a Lincoln Flathead V12.

 

Thank you RichFox. PMed you.

 

The mega dollar flathead **** Landy built for Ron Main did use the original intake ports as exhaust. New intake ports were built up and welded into the top of the engine, The original exhaust ports were no longer used for anything. This would have been in the eightys at least. If you saw one with the intake into the original exhaust ports, they are down low on opposite sides of the block

 

Is there an engine in that picture?

 

The picture that Petel posted with the exhaust coming out of the heat riser in the intake caught my interest. I noticed that it also used the stock port while the front and rear cylinders had new ports closer to the exhaust valves. Would give the two center cylinders a lot better flow. I wonder if it would help with heating problems to do that on a flathead since the two center cylinders share an exhaust port. Could follow the head back and tie into the exhaust behind the engine.

 

The Montana Dodge Boys run a reverse flow Dodge Bros. flathead four in their Bonneville roadster. Something I had thought about but went with an OHV conversion instead. Tha Dodge Boys engine is a well thought out project with a real reason for the reverse flow. Not just a desire for the freak effect. Google them.

 

We all know what a Flathead Ford looks like. The one in this picture. Now if you switch intake and exhaust. The carburetors would need to go down on the sides of the block where the exhaust is now. And the blower would go away for headers. And more carbs on the other side. About at frame height. Is that what you saw? Throttle linkage must have been a bear.