A Flathead in Engine Masters?

[tubman]

Originally Posted by saltracer

spell it Flathead (capitol F)

That's the proper name for a native American tribe. I was using the generic term for 32-53 Ford V8 engines.

[Ronnieroadster]

Originally Posted by saltracer

from the HAMB, a picture of the Jimmy Stevens built flathead motor that went over 300 mph. Seems to be dry deck, or completely filled, all cylinders seemed to be sleeved. ports rerouted out the top.

Since the original exhaust ports are not used with this conversion Jimmy Stevens pumped cooling water into the original flathead exhaust ports. He also machined iron round stock into valve pockets with integral valve seats for the exhaust ports. He then cut into the sides of these new valve ports from the top of the intake deck. The engine details were written in the Bonneville Racing News. A bunch of forward thinking pretty much the best back yard hot rodding you can find when it comes to modifying a Ford flathead block for all power.

[Henry Floored]

Originally Posted by tubman

After seeing these last two examples, it would seem to me that running the exhaust out the top of the block would be a necessity for anyone wanting to make max HP from a flathead Ford. Does anyone know what they do with the conventional exhaust ports? Do they just run them as is, or are they plugged? Running them would give the exhaust a lot of places to go, but might mess up the flow characteristics.

BTW, the "spellchecker" on this site flags "flathead" as a potential misspelling whenever I post; has anyone else noticed this? Seems a little odd to me.

I don't think running the exhaust out the top is a necessity. Makes for a complicated induction system. To run exhaust out the top you're forcing it to make yet another 180 degree turn. The stock Flathead Ford exhaust ports angle down and gently away from the valve pocket area. On any side valve engine exhaust flow naturally wants to go down and away from the valve pocket area while on the other hand the intake flow travels through the port and "UP" into the combustion area. Ford had it right.

[tubman]

Notice I said "max HP". Looks to me that on a stock exhaust, it has to make a 270 degree turn. There has to be a reason for these guys to spend all of the time and effort to put it in. I don't see much "complication in the induction system either.

[Ol' Ron]

I can believe this helps a blown engine very much. Un blown somewhat.

[Henry Floored]

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Originally Posted by tubman

Notice I said "max HP". Looks to me that on a stock exhaust, it has to make a 270 degree turn. There has to be a reason for these guys to spend all of the time and effort to put it in. I don't see much "complication in the induction system either.

In a supercharged engine you are doing to the intake flow what any piston engine does naturally to the exhaust flow. It pushes it through mechanically. On a naturally aspirated Flathead we have to be sure that our intake tract is flowing enough to warrent major reconstruction on the exhaust side. The exhaust stroke happens when the piston travels upward and slams the gases out of the port. In stark contrast on a naturally aspirated engine during the intake stroke the piston draws down pulling the charge into the cylinder. This process is subject to all sorts of impediments and restrictions. Sort of like drinking water through a straw and getting a lemon seed stuck. Pretty hard to get a drink with any restriction in the line.

Now am I saying to ignore the exhaust ports? He'll no! I have never built a Flathead Ford without cleaning out rough edges and sharp turns in the exhaust passages. Even for stock rebuilds. I'm just saying that I think the intake process is the main obstacle to gaining power in a Flathead Ford. In my humble opinion I say until the intake system is improved upon enough to overcome the capability of the exhaust side you don't need radical exhaust modifications. When you supercharge you are essentially "fixing" the intake problem and then at that point the emphasis must shift to the exhaust side.

There are photos on the Internet of Flathead Ford blocks with the decks machined away and into the exhaust port passages. Except for the entrance and exit points the ports are smooth and beautifully designed. The center ports in the heat riser area is most concerning to me. In an all out engine I say that heat riser chamber should be filled to a point where it forms a back wall to those center ports with a small and smooth deflector directing the exiting gasses down and out.