Customs Bigger newer motor or stock motor in my 49 plymouth???

Hey guys been fixing and driving the ol plymouth for the last 7 years. Been slowly fixing it up and making her better. Still running the stock 6 flattie with HEI and duals. Runs and drives perfect.

Im getting the itch to drop in a V8 or something with more power. My be able to get my hands on a 383 big block mopar. Would be nice to have the power but also really like the nostalgia of running the stock. What to do? What to do?

 

In a perfect world, you'd find a bigger flathead six out of a Chrysler with all of the proper vintage speed equipment.

 

Yea I do have another stock flattie 6 in my parts car that isn't stuck. Thought about pulling it out and rebuilding with some cool vintage speed parts. Prob wont be a tire fryer, but cool nostalgia piece.

I don't know huge V8 would be fun too. Would have to be mopar.

 

An A Poly or LA would fit nicely!

 

Yeah, but. Tubman said "Bigger" That's the key. I think the large Chrysler 6 was 256 cid? Beats 218 any day. Still not a 383 but satisfying in it's way.

 

We built a number of them in high school in the early 60s, they run pretty good. Might be tricky finding one these days but its a bolt in if my memory is correct, maybe a little exhaust work is all.

 

Personal painful memory is that at least with certain '48 Plymouth's, if you drop in a '52 De Soto the extra length will locate the front motor mounts right on top of the brake line. And squash the crap out of it. You might want to look at that before you lower the engine.

 

How about having the spare head milled while you're deciding?
A little money and short down time=more fun while you build your second motor with all the right parts.

Also, this is from carbking on the HAMB:
"The Carter W-1 574s (1946~1948) Chevrolet is a great upgrade; and can almost be considered factory, as Plymouth used them during the "Ball & Ball" strike in 1947. There is even a factory intake for the carburetor.

Good for about 5 HP and at least 2 MPG (most report 4~5 MPG) increase over the Ball & Ball."

 

I'd run the piss out of the six and if and when it breaks then upgrade to V8.. Very cool car by the way.......

 

Tough call, 10 years ago I would have said yank the flattie and go big block, but if you think it runs and drives great with the six, maybe just freshen that up and tweak it a bit or the bigger Chrysler six as stated above . . .

would be so much fun to blow a honda into the weeds with a fine looking custom though!

 

Another vote for keeping the flathead 6. You're looking at the engine that Johnny Mantz drove to victory in a '50 Plymouth in the first Southern 500 at Darlington SC in 1950.

 

nice ride no matter what you do. i'd have an 8 in it, though.

 

A 383 with dual fours or tri-power is my vote...great looking ride anyway you end up!!!

 

383 for sure. A car looking this good needs a good sound too.

 

Its not gonna break I have a '53 DeSoto with the original 251 six(long block), Shaved .050 off the head and split the stock exhaust manifold with 2" pipes with Porter steel packs going straight out the back. I love it! Problem is its backed be the "clunk-a-matic" transmission, to winning at the drags is out of the question. I've had the car up to 80mph and it seemed to have alot left. The reason I left the flathead in there is because almost every other car out there has an 8 in it. No one expects to see an inline six flathead when you open the hood anymore. 9 times out of 10 people expect to see a small block chevy.

George Asche told me than you can shave .090 off these engines and still run pump gas. He also told me that if you put the multi carb setup with split exhaust you can get around 25mpg. He also makes an adapter to run a 5spd trans behind these L-heads

Besides customs ain't meant for speed. Stick with the six

 

If you thought the 6 was enough, you wouldn't be asking for opinions. Find yourself the v8 that you want (if you got the cash) and drop it in. You'll be happier sooner than later.

Hope to see your car someday...

 

I am sure Plym_46 will chime in on this thread soon. He is an avid flathead lover. He has a great setup in his car. If memory serves that is a 218 also, but he did all the right stuff.
(edit: the 218 was replaced by a 230)

 

Got the same thoughts as tankwilson, though mine's the older 201 ci, but decided to keep the six. Question: should I do the shaving-dual carb-dual exhaust job on my 201 "short block" or should I go for a bigger (maybe still short) newer one and do the "old scool" tweaki'n up?

hillbilly4008, how to get in touch with George Asche? 5 spd trans sounds awesome.

 

Gary "73RR" @ QEC makes tranny adaptors for the flat 6.

 

Zero, are you familiar with the p15d24 forum?(www.p15-d24.com) That is where I got Asche's contact info, unfortunately I no longer have it. The guys on that site will be more than willing to get that for you.

Here is a thread I found that you may find interesting. http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=24666&highlight=asche

Note: the threads on this site read the opposite that they do here. The first thread page you see is actually the last page.

 

flat 6::my vote.
but like it was said above it's your car..a nice looking car!

 

I will probably pull the 6 out of my spare car and rebuild her using some cool vintage speed parts. I really like the nosalgia of the old flattie. I only have the need to burn off the tires once in a while.

Thanks
matt

 

you can change that you know

 

I'd take that spare and go through it, doing stuff to increase the HP and keep the longevity. Get the 5 speed adapter and a nice stick trans. Should be able to swap in a long weekend or maybe a week if the clutch and driveshaft give you issues.
They have the torque, they just don't RPM, so the extra gears should make things a lot better. Besides, it's easy to spend your money!

 

Yea for sure!!!! I have a t-5 i could use. The rear end that in her now is a much higher gear than stock almost too high. What would be a good rearend gear for a t-5 with a rebuilt slightly higher HP motor?

Thanks
matt

 

It depends on the tire height. There are a bunch of online calculators so you can play with different rear gears and find the RPM to vehicle speed. Figure out what a good cruise RPM is, and what top RPM is, then plug the numbers in and find a happy place. Remember to use the 5th ratio for hiway cruising.

http://vexer.com/automotive-tools/speed-rpm-calculator

http://www.corral.net/tech/gearcalc.html

T5 ratios
http://www.moderndriveline.com/Technical_Bits/transmission_spec.htm

 

how bout a biiiiig flattie 413 out of a 2 ton truck.. not too much hp but tourque for days

 

how much????

 

There are posts on the P15-D24 forum from Don Coatney who put a DeSoto
25 inch flathead, with a T5 trans and later model Mopar rear end into his
47 Plymouth. He had to notch right in front of the motor a bit. He gives
a pretty complete blow by blow account over time. I suspect you might
have to do similarly on your car.

If putting a V8 into your car, you may have to place it a couple of inches
to the passenger side to miss your stock steering box, if you still have it.
Not sure of that - but might be the case.

 

Search will show a lot of threads on dropping a V8, espicially an LA into the 46-48-54 Plyms.