It's likely that I'll be coming into a low-mileage '56 Plymouth flathead six that I will go through, modify and use in a very traditional and early style hot rod project. For those unfamiliar, these engines were used in various Chrysler Corp. cars from the 1930s through 1959. Beyond that they continued to be manufactured new by Chrysler through 1972 for use in various industrial applications. This particular 230 inch version already has more HP and torque than the best flathead V8 that Ford ever produced and also a well deserved reputation as a good performer back in the early days of hot-rodding. Anyhow, I'll be building my own multi-carb intake manifold and header for this engine. And my question concerns the exhaust. Split exhaust manifolds were a popular upgrade way back when, routing cylinders 1, 2 & 3 into one pipe and 4, 5 & 6 into the other. I'm considering building a 6 into 3 into 1 header as a more advantageous configuration in regard to getting the utmost in scavenging. The firing order is 153624 by the way, very common and in fact nearly universal among inline six cylinder engines. Thoughts regarding this, cylinder pairing and other aspects would all be appreciated. I'm certainly not building this engine for all out racing. But I do wish to make it a sound performer for what it is. And one that will open some eyes, especially among those not familiar with such antiquated technology. In other words, I want to have fun with it! Thanks.

HHHHhhhhhmmmmmmmmmm.

SORRY NOTORIOUS...I AM TO YOUNG TO HELP U ON THAT ONE LOL

Wasn't it Offenhauser that built most of the split mainfolds? You mignt try a search.
I just saw one on a 6cyl ( on My Classic Car) I think.

So, I'm watching Sebring, dorking on the computer, found this: http://www.50plymouth.com/04-eng/eng.html

Good pics of the exhaust on a '50.

Since first posting this, I have indeed acquired this engine and transmission and am looking forward to delving into it. It's new home will be in my stripped down, fender-less, vintage tin 1930 Model A tudor sedan. Both the car and it's engine, in every respect, will be a throwback to the simpler days of hot rodding as it was 50 years ago.
But please don't confuse this with the current perversion of traditional hot rods known as "rat rods." A traditional hot rodder just may hurt you if you refer to their car as or ask them if it's a rat rod.
Traditional hot rodders are a growing segment who have become bored and disgusted with the billet-laden garbage wagons that pass for hot rods today. Ugly-assed wheels that would be more at home on a donk, tons of worthless, ugly shiny crap under the hood, boring and unimaginative interiors, again with too much bling and billet and with no sense of real style.
Anyhow for me, a lot of the fun will be working with this vintage power-plant.
Bogus, will you forgive me if I don't put cats on this car?

HHHhhhmmmmmmmmm.

Attach file:

---

  CATS_car.gif (4.04 KB)


  cats on car.jpg (13.02 KB)

Those kinds of cats are easy to remove, Tommy. Load, take aim and viola! Removing those cats actually helps the environment, you know how bad cat shit smells....

I like the split header design.
Here's a pic of a 30 roadster my dad and I are working on(he's 78) Hoping for about 100 hp out of the original 4 cylinder. Yup those are split headers . Sounds great

That's a beautiful little engine! I'll bet it does sound sweet. Very nice work.

Thanks. I would like to see your car with that plymouth motor in it. We're going mostly old scool as well. However we did put in one of those new rack and pinion steering units! steers nice too!

Quote:
I'd love to see more pics of that car, what you did suspension-wise and just everything about it. Why don't you start a whole new thread in this section and show it off to us? That would just be too....
Judging from the taste you've given us, it's got to be one nice car, finished or not.

If you want a 6-3-1 header you'll want to pair up 1/6 2/5 3/4

And judging by the cylinder arrangement, that makes for a very nice symmetrical looking header. Your primary and secondary lengths are going to be a factor of your hp peak rpm and your valve timing.