The worse exhaust manifold design in the history of the internal combustion engine!

[MARTINSR]

Originally Posted by NeilBlanchard

Hmmm,



...except it's a six cylinder!

And if you thought it was only the exhaust manifold that was funky -- checkout the intake manifold!

I said earlier that the intake was in the head, I'm sorry, the carb bolts to the head but the "intake manifold" is in the block and you can see it in my photos. It is the large "valley" just to the side of the valves.

Brian

[MARTINSR]

Here is a stock Ford Flathead, and yes the stock manifolds were horrible. Were they "good enough", yeah, for a grocery getter it did the job.


But for a mild hop-up, it got something a little more like the modern header.


Most common for a race car was "zoomies".


Here is a modern hot rodded flathead.



This is an interesting example of a Flathead Ford, and pretty common. For the very high performance motor the exhaust is ran out the top of the motor! You can see the un-used old exhaust ports on the side. Another thing they used to do was to run the motor in reverse so that the exhaust was the intake and vs-vs.


I have looked it over pretty well and building a header flange from a piece of tubing is going to work fine, and the flanges on the block are plenty strong. I only plan on making short header, no equal length or anything like that.

Brian

[jamesqf]

Originally Posted by MARTINSR

Nope not a bit. It was in my parts car, darn thing purred like a kitten!

But did the horn go beep beep beep?

[MARTINSR]

No, but I have heard people sing that song MANY times since I got the car. It actually has a couple of BIG horns someone put in. I think to counter the song myth.

Brian

[kurtis1971]

wow i never seen one like that before

[gone-ot]

...regarding the "flathead" exhausts (I had a '53 Victoria), you failed to mention or show that the two left and right exhaust ports were connected by a cross-over piple that went over the front of the engine, above the water pump, and connected the right- and left hand exhaust manifolds together so the exhaust from BOTH sides went by one side before it went back through the single exhaust header pipe and then to the muffler.

[Zerohour]

Coming from someone who interned in an iron foundry, you'd be surprised at how complex a designed cast in iron really becomes. Where I worked we used core machines (the part that goes into hollow space of a casting) that were used by Ford supplier plants. The molds just to make the cores cost into the XX,XXX thousands, that that doesn't include design time by engineers. That is just the machine to make the empty space. The mold forms used in the machines slso runs into XX,XXX thousands. Then you need to purchase the machines to make the molds, plus the furnaces...and the sand systems...ungodly amount of capital in a modern casting. Thats why back then they did it with what they could and utilized craftsmen to make the parts. Hence why you exhaust manifold was built on the cheap and was probably cut, hand bent, and assembled on the motor by three different people and transported by another two. And those five workers were still cheaper than machines!

[evilskillit]

Looks like a flute. It may or may not be worse than mine, allow me to explain.



On the left is my factory exhaust manifold. It looks like a demonic squid or something, all sorts of tubes intertwined together and then straight into a catalytic converter. This is a great idea in theory as the cat warms up very quickly giving the car great early emissions. However in practice the first cat is too close to engine, it can and will over heat and break down. Especially if anything is causing the car to not run right, or it runs hot. When this happens the broken down gravel/dust parts of the cat swirl around and back into the cylinders through the exhaust valves. This scores the snot out of the cylinder walls, valves, etc etc, causing oil consumption, loss of horsepower, poor fuel economy, poor emissions and eventually catastrophic engine failure.

Great design right? Hence why so many people with the qr25de replace the upper exhaust manifold with a performance header. Not because we're racers, but because we don't want our engines to explode.

[cosmic_kid]

I love how the V-8 is described as a 'grocery-getter' lol!

[slowmover]

Had a friend when we were in high school with a Rambler American. Reliable, but the steering was beyond slow. We all had man steer cars, but his was dangerous. I'd certainly look to convert to r&p if possible (Mustang II rack).



Good stuff about tuning here (temp control).

OLDSmobility.com - The 1967 Oldsmobile Cutlass and 442 Resource - 'Turnpike Cruiser' - Car Life April 1967

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