What I think I know. Up until 1932 most V8's ran flat plane cranks, in 1932 Henry equipped the Model 18's with a cross plane crankshaft in his new V8. The 1932 and 1933 V8's used a single plane manifold with a single barrel carby. The 1934 V8 got a dual plane manifold and two barrel carb to separate the Induction to the equally spaced induction pulses of two 4 cylinders, I guess to increase power (for the low rpm range the flat head used) and make the engine smoother. Does anybody have more pre 1934 Dual Plane intake manifold info on this ? 1924 Cadillac had a cross plane crank, Manifold ??
My foggy brain remembers reading about the history of vehicle development in the early days. It seems that forging technology was crude by today's standards, which made creating a 360 degree crankshaft difficult if not impossible for the time. And castings had to be very overbuilt to survive which made the size unmanageable. Billet crankshafts were used in high end engines where cost was not a consideration. But inexpensive vehicles couldn't have a part of the engine that cost a large part of the total cost. Ford was always pushing technology and metallurgy was an area where they were probably second to none. As an example, chrome vanadium steel was used extensively in Model Ts and As. When the flathead v-8 came about it was a very innovative engine, combustion chamber notwithstanding. I believe that the crankshaft was cast steel, which allowed reductions in the overall m*** of it. And gave good strength for the part in the original design specifications. Later crankshafts were designed to be cast iron, but not gray cast iron. Instead it was cast nodular iron, which has a much better fatigue resistance due to the carbon being spheroidized. In gray cast iron the carbon looks like little tiny razor blades throughout the iron-carbon matrix, which acts like stress concentration notches. Nodular cast iron has the carbon throughout the iron-carbon matrix shaped like little tiny marbles, which cause much lower stress concentrations through the matrix. I know, no one asked for the diatribe. Sorry...
Thank you. I learned something. At my age, you’ve got to keep learning things to keep up with what you’re forgetting. Now, if I can just remember it.
Cadillac had a cross plane crank by 1924 along with Peerless but the Caddy didn't get a Dual Plane until 1939 it seems. I don't think Ardun ever did a Dual Plane manifold with their OHV conversion, that's a real pity. So far it looks like Ford was the first Dual Plane Manifold.
The main reason v8 engines run 2 plane cranks is less vibration than flat cranks. Important to p***enger car. Performance wise flat cranks rev faster less crank weight. Flat crank vibration gets worse as cu. in. increase. The same things happen to 4 cylinders You don't see to many high rpm 200 + inch 4s
Unless I can find an earlier patent it looks like I have to call Ford the inventor of the V8 Dual Plane manifold.
This thread was posted Friday, but I noticed very few responses. Now I know why. The stuff of headaches LOL. I have to admit, you guys started losing me. Sounds like it's time to learn something. Flat plane vs crossplane crank? Ok... I think. And how it relates to the firing order and the advent of the dual-plane intake manifold. Interesting. I'm listening. And it sounds like I'm gonna have to do a little research.
Same as crossover exhausts, to keep the pulses seperated by 180 degrees you need to swap side to side or run a flat plane crank. Flat plane crank was never an option for Henry because he needed the long stroke to get capacity in a short motor with low taxable horsepower.
Not overly surprised to find this. https://cite.case.law/f-supp/22/1001/ 1933 Barkeij trying to slip one in under Ford, then tried to it on GM.
Really only 1 reason for a dual plane manifold on a v8 no matter what kind of firing order you come up with you will have2 cylinders next to each other that fire one right after each other. With out a flat crank.
The Jalopy Journal
