Hot Rods 51 Plymouth Questions & Build Plan

Hey guys, posted up recently and introduced myself.
I've got a 51 Plymouth Concord, 2 door fastback.
It's got a 217(?)ci flathead six & three on the tree.
Engine/trans is bone stock.
Car is very clean, new interior, runs amazingly well and is in DD condition.

I'm trying to make my plan on what I want to do, and in what order to do it.
I've also got a couple questions.
I'm gonna try and contain everything in this thread.
If you guys can help out and answer any of my questions, it'll be much appreciated.

Questions:
*Clutch:
The 3 speed shifts well, and each gear feels fine. I've noticed that the clutch seems to be slipping. Accelerating in any gear, I can feel it slip slightly before speeding up.
I'm not real familiar with car trans (rebuilt many motorcycle trans & clutches however, so I definitely know the basics). Is there any sort of adjustment to the clutch to get rid of this slip, or should I be looking into replacing all the plates & bearings?

*Gas gauge:
Was told by previous owner the gas guage worked fine. When I picked up the car, gauge was flipping around erratically from E to F, but the car only had a couple gallons in it.
I filled it up completely full, and the gauge stuck at dead E.
After driving ~80 miles, the gauge has now began the erratic E to F flipping.
Is this more likely the sending unit in the tank, or the gauge itself?
Any tips or ideas tracking this one down?

*Tires/Rims:
The car had somewhat recent tires on it, but was running tubeless 1" whitewalls on stock rims, WITH tubes in them.
Going to be replacing the tires soon, what tires should I be looking at with a larger whitewall. I'd also like to get some new rims, chrome dog dish style I think...any suggestions?

*Suspension:
I'd like to lower this thing a little bit, as well as freshen up the suspension.
Its absolutely drivable, but front end especially is pretty sloppy.
What are my options for dropping the front & rear(blocks rear, lowering springs front?)? Should I looking into a full front end rebuild kit? What about the rear? New leafs and blocks? Definitely need shocks all around as well...any recommendations there?

*Engine:
I'd really like to wake up this little flathead, I love these things!
Looks like dual carbs, new intake, split 2x3 exhaust manifolds, and straight pipes. I think I'd like to run lake pipes on this, but what are your thoughts on this? What about mufflers? What diameter pipe should I be looking at?
Running dual carbs, should I be looking at 2x 1bbl 's?
I've been drooling over the parts at Langdon's Stovebolt...is that the best place to go for this stuff?
I'd really like to get this thing sounding pretty mean, and power it up a little bit. I'm not looking to win any races, but want to make a pretty lively DD.

*6V -> 12V conversion:
What are your thoughts on this?
Everythings working just fine with the stock 6v system, and it's got a new battery.
I'd like to step it up to 12v sometime soon to get a stereo in here, but its not at the top of the list by any means.

*Paint/Body:
I've got quite a bit of mechanical experience, but have never done any bodywork/welding. I'm going to learn on this thing!
It has a few minor rust spots, and I'm gonna hone my (nonexistent) welding skills removing and patching them.
As far as body, what do you think for modifying it? I'm thinking dump those turn signals to begin with, repair the rust for now.
I'll definitely be painting it, as I'm not a fan of the yellow.
Any comments or ideas on color, and graphics?
I'm a fan of pinstriping & scallops, but I'm not quite sure of the rules on this era car! What is historically accurate for a hot rod of this age?
Or should I just say screw it and do whatever the hell I think looks cool?
(haha will probably go this route!)

Well thats about it. I appreciate any and all help, opinions and suggestions.
I've had alot of different cars, but this is the first one quite this old, and will be my biggest dedicated project. It's gonna be a learning experience for me...and I'll keep you guys posted the whole trip.

Took some new pictures today...here she is:
(link to gallery)
http://picasaweb.google.com/egrist/1951PlymouthConcord1956PontiacStarchief

 

Neat little car.

I had a 50 Plymouth three passenger coupe, all stock, for a number of years.

Kept an eye on a similar fastback in Exeter, California for a couple of years and when I finally found the owners at home they wouldn't sell.

Anyway, your front end may not be bad at all.

I put new shocks on mine and the front shocks were a Monroe stock type replacement shock.
It still wallowed around.

The trick is - from what other Plymouth owners tell me - get the tube shock kit or make your own copy and install gas shocks from frame to lower arm.

As is, the front shocks are mounted between upper and lower A-arms and don't travel much at all.

 

First off, you need to check out the P15-D24 website http://www.merc583.addr.com/mopar/framesets/referenceframeset.html there is a lot of experience with the flathead Mopars there.

*Gas gauge: Look at you ground, these things need to have a very good/clean ground.

*Suspension: Both Fatmans and Ply-Do sell dropped spindels. You will have to go to disc brakes if you use the dropped spindles as the drum backing plates will interfere. Even if you modify the backing plates your turning radius will be greatly reduced.

Olddaddy on here http://www.rustyhope.com sells disc brake kits as does Scarebird http://www.scarebird.com and a few others.

You will also want to consider shock relocation for the front. Olddaddy and Fatmans have kits for these as well. There is also a good thread on here showing how to make you own if you do a search.

Fatmans and Ply-Do also have rack and pinion kits available using a Cavilere rack. People who have used them say they work good, but that with a little planning and fab you can save some cash and make your own.

*Engine: Mine with all the Langdon's goodies attached is going in right now. Should be done by the start of next week and I will let you know how it runs.

One thing you didn't address is the transmission. You might want to consider looking for a Borg Warner R10 overdrive if you want to keep the column shift. If the column shift is not important to you then you can adapt a T5. Don Coatney
<DD>http://www.jalopyjournal.com/forum/member.php?u=829 </DD> has done one in his 48 Plymouth and is a good source of advice. There are also a couple of kits available approaching this from different angles, one from Langdon's and another from Paul Curtis pjplymouth@netscape.net

The extra gearing will help a lot with driveability and highway cruising.

Good luck and keep us posted.

 

The guy who owned Ply-Do died. Business probably isn't open. Rumors the family might try to reopen. Mr. Street Rod has disc & shock relocation kits for the 46-8, maybe for your also. Any part house should have the rear shocks.

 

I wouldn't touch that body! It's beeeyoooteeefulll! Spend your time and money making it more driveable. Front end rebuild, hop up the Six, and the O/D trans is all good. When you blow the flat six, a slant six will fit easy. The 833 overdrive 4-speed might fit the flathead, too.

 

I don't know if the transmission is slipping as the trannys were a sort of semi-automatic. You could stop at a stop sign in third gear leaving it in gear and just stepping on the brake, then accelerate away without using the clutch and shifting. Take my word for it it was very forgiving to a kid learning to drive.

 

Beautiful Car! but the turn signals look like warts on a pretty girl.... The flat-6 will run forever if cared for but the slipping clutch is just like any other slipping clutch and should be replaced before it causes real damage. There are many options available if you choose to replace the old trans, I can hook you up with an adapter for Mopar 4-spd or Torqueflight. Send a note if you need more info.

Gary

 

go here they can answer a lot of your questions and tell you where to get parts.

http://www430.pair.com/p15d24/mopar_forum/

 

Plymouth did ot offer a semi automatic or fluid drive transmission till 53 (but they used the same three speed trans) there is a turnbuckle type deal on the clutch rod it might need a bit of adjustment. The transmission is basically bulletproof. For a rear end upgrade, MOPAR B bodies are nearly a bolt in as are early Jeep Cherokee. ratios are 3.55 to 3.23 area, yours is likely a 3.99 or 3.89.

That body style was the least produced and there seems to be few left. Tha one looks really solid.

Easiest cheapest wake up for these engines is more compression. Stock is about 6.7 to 1. You can go upto .070 off and still run regular. Take about .020 off the block and the rest from the head. No relieving is necessary. although rounding the ramp in the cumbustion chamber will help the flow a bit. You might also consider a 2bbl with an adapter. Plymouth offered a similar setup in 56, and the gain was about 8 HP.

Engine swaps were prevelent in these cars. There is a boss on the block above the generator just below the head, there is a stamped number there. Post that number.

It should be P 20 something. If so it will be a 218 cu in, about 102 HP. Lotsa torque down low. Don;t like lotsa revs as stroke is 4 3/8".

 

Years ago, like 45 or so, a kid in Tampa had one of those and he put a big old Chrysler 6 cylinder in it and it ran like a bat out of hell. Would nearly keep up with a 55 Chevy. If I remember right I think the things only weigh something like 2,800#s. Cool ride actually.

 

Keep the flatty 6 until she gets too tired...I have had 4 of the old mopars with that engine and it's hard to kill them...currently I have a 54 dodge panel with offy intake with twin carbs, split exhaust hooked to lake pipes that can be blocked off for a little quietude with single exhaust through a flowmaster...12 volt converted (I didn't do that but we've done it to the previous three)...don't touch the body...that thing is cool

coming soon: rodtees.com

 

Thanks so much for all the answer guys, it's much appreciated!!
I will not be touching the body (first off anyways), as I totally agree, I will focus on driveability issues first (is that a word? I hope so...)

One quick question on the engine, I've noticed after getting it up to temp driving to work, when I park it I get some white smoke drifting out of the oil filler cap.
From reading some other threads, this tends to point to bad rings correct?
It's not too much, and the engine seems to run very well, so I'd rather not look into rebuilding yet.

I'd rather collect all the hop up parts for it, run it for awhile til it gives up, then rebuild it.

What do you guys think of lake pipes on this girl?

 

If you lower it and run the lakes it will look sweet...my .02...I am just up here in Ramona if ya ever want to check out how my engine is plumbed...drive it with the lake pipes to hear the difference (kinda loud)

coming soon: rodtees.com

 

Hey oddrod,
Awesome man, Ramona's not far at all!
I'm actually might be heading up to Ramona this afternoon right after work to stop by my buddies place.
I'll PM you.

 

could be just condensation or if the smoke is thicker white smoke out the oil breather is indicative of ring blow by. Remember you have no PCV just the road draft tube which relies on low pressure behind the slant cut of the pipe to draw fumes out of the crank case. No movement no draw.

A compression test will give you an indication of ring condition. Stock was about 110 to 120. If you are anywhere above 90 and within 10 &#37; across all 6 you are in prety good shape.

 

It is definitely white smoke out of the oil breather, but it is very little, and only noticeable when the engine is shut off, and hot after just being ran.

I will do a compression test this weekend and see where I'm at.

Any idea on the exhaust pipe diameter?
Would it be more beneficial to split the stock one piece exhaust manifold into 2 and out to side pipes?

Or wait and get the split 3 cylinder headers from Langdons?

I'm impatient and just cant wait to get started. I have to change something this weekend! hahaha

 

Sweet fastback. Here's my '50





Photoshops of other 49-50 Fastbacks;

Dropped 3"


Dropped & '50 Dodge grille

 

Contrary to popular belief, these cars make killer customs.

Johnnyscat's chopped '50 is one of the best



They were also fodder for customizers back in the day as well.

http://www.jalopyjournal.com/forum/showthread.php?t=284213&highlight=mopar

As far as dropping the car, mine is dropped 3" via cut coils and blocks. I believe George Cerny's historic 50 station wagon (mid-50's built) was dropped via reworked lower control arms & coils.

Hop up parts are tough to find, but do a search and keep an eye out on epay for edmunds intakes...they pop up a couple times per month.

As for your car, I'd say drop it, put some Caddy Sombreros on it, shave those bumpers, french the headlights and put a bullnose on the hood and you've got yourself one heck of a mild custom.

 

Oh yeah, nice ride!!

 

congrats on the score! sounds like everyone has you in the right direction - Im also in san diego county, let me know if you need anything

 

Awesome thanks so much for the help getting me started in the right direction you guys...it's much appreciated!
I can't wait to get started on this thing!
Murfman - thanks for your excellent response!

 

For the difference in flow (negligble) the split stock exhaust is just as effective and a lot more cost effective (unless you re going for eye candy) as the Langdon fenton repops. There are a couple folks doing it and a couple ways to do it. rusty hope will split you intake and exhaust and George Asche also does the deal. You can also look up Moose on this board and see if he is still making steel tube headers.

George Asche is in Pa and he will usually have a couple ready for exchange, sending yours to him is usually part of the deal. you can call him at 814 354 2621. Be prepared to talk for a while....George also remenufactures Carter carbs for use on the manifolds. Ad makes decent linkage. I have his carbs on a fentin intake and made my own linkage out of hardware pieces and go cart heim joints.

He splits maifolds by either justadding another dump. and also rmoves and blocks the heat riser so 1-3 and 4-6 are seperate.

I am running 2 inch ID pipe all the way back on a single exhaust with a Dynomax turbo flow shorty muffler. Everybody tells me it souds great. I just got back from an 1100 mile round trip to Detroit for the Plymouth owners club show there. So they can be good road cars. Charlie at Rusty Hope also sells disc brake conversions. You can also use the Chrysler /6 dizzy and the mopar electronic ignition by changing the drive tang on the /6 dizzy and doing a bit of modification to where it fits into the block. You can probably get the whole system out of a pick and pull for less the 50 bucks.

 

Couple more questions:

Can I find an original shop manual for this anywhere?

Also, she started up an exhaust leak on the way to work this morning.
After getting home I was investigating the leak. Turns out it's coming from the center of the block, where the intake manifold sets on top of the exhaust manifold, directly below the carb. I can feel it coming out right by the heat valve (?) thing with the spring (rusted and nonfunctional by the way).

It looks to me like the intake manifold and exhaust manifold meet and are connected directly below the carb, which I'm assuming that spring operated heat thing works.

Any ideas here? Most likely a gasket wore out or what?

Looks like I might be moving up the plans to do intake/carb/exhaust...if I'm gonna pull it all apart, might as well do it right.

Any tips/comments?

Also I registered at P15-D24, but they still haven't activated my account. Any idea how long that'll take?

 

The webmaster at p15 d 24 is pretty much a one man show. It might take a day or so. He activates each individually as a result of a bunch of spammer attacks. Hope you don't wait to long. I believe you can read and search withour logging in.

Yes there is a gasket between the intake and exhaust manifolds. Usually the heat riser fails in the open position that is providing heat to the intake, as the spring functions to close it as it is a bimetal deal and heeds heat. so if you can turn the stem counter clockwise, and secure it there, it will close the riser directing the exhaust through the exhaust only. There are 13 fasteners holding the manifolds in place, they should be removed together. Chances are high the bolts will break as you try take the manifolds apart. And sometimes the manifold assembly can be a bear to remove even with all the bolts free. It could also be leaking around the swivle so moving it may staunch the leak a bit if you can move it and keep it in a different position.

 

Ok no problem on P15/D24, just figured I'd ask. I've been reading up over there as well.

Well the heat riser is worthless I think. The spring is completely loose, and I can spin it and the cover around easily. I'm not sure what happened or why it just started leaking there. Is that a common spot? Is it something with the heat riser that is allowing the leak?

I emailed Langon Stovebolt...I'd really like to swap over to the Dual Webers, new intake, and the split tubular exhaust manifolds. Then I'm thinking no mufflers, and straight pipes to lakes on the sides.

As far as the exhaust leak...do I risk any damage running it with a leak at that spot? Can I burn a valve from that leak?

 

Congrates on the nice ride. as there are lots of us earley ply owners here I think it fair to say theres lots of support.I own a 52 with 49 rear fenders and bumpers, My old flat 217/218 depends on who you talk with, was bad so in went a 318 LA class 8. and an 904 lock up converter. I have a friend with a complete overdrive for ? would pass the number if your enterested. while I am not affred to cut a roof at a drop of the hammer and dolly, that is a real nice serviver so think hard. but if you do were with ya. mounting the front shocks to the frame will make alot of diffrence, I love the rack kit, and disk brakes, mine are for rustyhope( Charlie Akers) but the northwest company is as I understand a good company, have fun

 

The pivot the flap rides on just wears and then a bit of exhaust frinds the easiest route to freedom. Wouldn't worry about the valves.. Like I metiuoned if you can turn it all the way counter clockwise and secure it this will close the route to the intake and the flow will be directly out the pipe and may reduce the leak a bit.

Several folks are having trouble with the langdon set up running rich. inquiries back t ohim have been of little help. They are nice I candy but may be more trouble than they are worth. You can also source a new Offy manifold from Summit racing. They don't show it int he catalog but if you call they have a number for it. They also sell the linkage I believe. Two stock carbs work well.

 

Dammit, I've been wanting one of these cars and this thread ain't helpin'! I've had a '47 sedan and a '56 Plaza but now I want one just about like yours, anything '49-'54 would do. Sweet car, man and kudos on your interest in keeping and building that wonderful little flatty. I'm getting ready to drop one into my Model A.

 

Hey thanks bodacious. Let this be your inspiration to pick up an old Plymouth!
The more I drive this thing the more I love it. Its just an awesome old cruiser.
I'm still working on my overall plan, but I intend to drive the hell out of it.

I talked to Tom Langdon today on the phone, I emailed him and he called me back!
Great guy, very knowledgeable, and I'll be going with his intake/exhaust manifolds and carbs very soon!

 

Sorry I missed ya on Friday night...sounds like you are hitting all the right sources...really dig that car...bring it up some Sunday from 4-8 up here in Ramona at the Albertson's shopping center...we have a little cruise in that's gaining some momentum