Projects =Rebuilding the Plymouth Flathead=

Hey everyone. Thought I'd share some picture I've been collecting of my engine rebuild. First, a little foreword...

A few years ago, I had a '47 Plymouth (minus engine) and wanted to make it into a swell Period Custom. You know, cut coils, de-arched springs, chopped, molded, shaved, etc. And not to mention a neat little hopped up V6 under the hood!
Well, as this was my first Real project (i.e. building a car from the ground up), I came across many challenges and hurdles I had to leap over to get the hang of things. I looked and looked for an old engine. I knew I wanted the original kind of engine, just didn't know what to look for and how much I should pay for something like it. Never rebuilt an engine before and certainly didn't know what to look out for when I finally came across one. This is where the accidents come in, haha.
I ended up buying an engine from a '41 plymouth coupe. Transmission and all! Gosh, I thought I came up on a great deal for the price! I noticed there was some JB Weld on the block, by a freeze plug. Seller claimed it was to cover a gasket leak on the cylinder head and was no big deal. Wrong.
Took it home and signed up for an engine rebuilding class at a nearby community college and began my studies on engine's a and the process of rebuilding. Learned a lot! Even more when, after I tore down the motor I planned on rebuilding, I noticed a long seam-looking mark, from the front of the block, by the freeze plugs, towards the rear by the oil filter. "Crap"
Did the magnaflux test and confirmed my quote. the block was cracked. There went the cash I spent on a lousy motor. Unless I had some dough to have it stitched up. But, at that point I was too let down to continue with the project.
Luckily, a friend who was working at school mentioned he had an old motor. Said if I tore it down, saw I could use it that he'd sell it for $100 smackers. And if it was useless, then it was only my time wasted. OK! I could do that!
Long story short, I bought the motor, tore it down. No cracks! And been working on it and delving deeper into the project and learning about hot rodding history in the meantime as the project has progressed.
So, here are some pictures to share what my obsession has been, lately. More to come!

=Adrian=

 

The motor when I brought it in the shop..



Taking everything off and prepping for hot tank...



Time for a bath


Been a while since it's been this clean..

 

After a little cleaning with a wire wheel this thing doesn't look too bad.



I love the way it looks so mechanical. Maybe I can make the cracked block into an art piece. A coffee table stand perhaps

 

Another thing that came to mind when I got ahold of this motor was the rebuilding itself. If it's not cracked, great. But, what if the motor's been too abused that I can't get a decent rebuild? I could sleeve it. That means $100 smackers to sleeve a-cylinder. Hmm...

After cleaning I took all my measurements and compared them to the ones taken from an old repair manual on these little flatheads. Noticed there was some wear and figured i'd try and see if I could just bore it over to .020".





This is an older boring bar. The ones in shops today, I hear, are way smaller. But, I like the deco-looking one here

 

Hmm..maybe it'll clean up on the power hone.

 

Nice to see you rebuilding that old anchor!

Don't forget to run a tap thru all the threaded holes on the block before you start puttting it back together.

Let me know if you are missing anything as I recently scored a parts motor.

Good luck with your rebuild; it looks like you are off to a good start.

 

Well, it didn't. And it ended up cleaning a little over .040". That meant that I had to go to the next nearest size they make: .060" over. Ok, no biggie. I found out that these engines came thick! They make .080" over pistons. And, at one time they made .100" pistons! That's insane. So I definitely have another rebuild in this block, that's for sure.

Here's a shot of the first cylinder cleaned up..


All done and got my chamfer on the edge to make piston installation easier. Those seats for the valves look terrible! I'll have to replace them. Oh, and the water distribution tube was a pain in the ass to get out! Had to soak the block upright, for a week, coming by to spray it with chemicals to break it free.

 

Thanks Pal! I may need a fan and pulley but I'll see if the one i have from the '41 engine fits, then I could use it. Otherwise, I'll let you know!

 

Water Distribution=Rust

 

Now that I had the cylinder ready for pistons, I went and checked the head for warpage with a straight edge after cleaning and bead blasting. And, yes, I won again. warped about .06" and had to cut it straight on a Rotary Broach. Took out approximately .013".

 

rotary broach..




Cleaned up very well

 

Let me congratulate you, by golly, you are taking a course and learning with the hands on method.
Keep it up, sure looks good, and I can , I think, tell you are enjoying the experience.

TraderJack

 

Thanks TraderJack, I am enjoying it! More pictures later today. Had some problems uploading last night.

 

Can you get a new water distribution tube? That's good. You may be able to gring the valve seats to clean up, it helps if you get slightly larger valves to movr the seat out to cleaner metal. Maybe DeSoto? How are the guides?

 

nice work, Adrian. pics of the car?

 

Nice to see that you stayed with the Flat 6. What is planned for the rest of the car?

.

 

RichFox, I did! I got mine through Andy Bernbaum. They've raised their prices since earlier this year, though. Not insanely but for there being few mopar suppliers out there I wont complain. Look out for more pictures on my seats install

Thanks! I'm going with a traditional Period custom. Nothing Overkill, just subtle-with a chop! I'll try and post some ideas later on.

 

Meanwhile, aside from trying to save the dough for parts, I did a little metal work on the oil pan. Maybe overkill but it kept bugging me that it had some dents and dimples, here and there. After bead blasting I coated it with a rust encapsulator and started slapping away with a file.





Almost there


And, here pretty much done..

 

These had to be cleaned and prepped also..

 

wow that ole flatty 6 is lookin' good...glad you stayed with it...I have 5 old mopars with the flathead 6 and they all have come back to life and been very reliable...my daily hauler (54 dodge panel) is running the 6 with twin carters on an offy intake with split exhaust and gets me where I need to go and starts every time on the first try...post up some pix of your car when ya get the chance...meanwhile keep up the good work

 

Thanks Pal, you're right! When these little flatty's are tuned right they just go! Mine starts every time, bearly one rotation on the crank and it fires up.
Here's my Plymouth currently. Little rusty and haven't finished the skirts but it'll do for the meantime..

 

Well, back to cleaning parts...

 

This is fun!
I sent my 218 to have it rebuilt years ago, but didn't get to see the process or the machinery used to do it.
Please keep posting!

 

One thing you don't want to do is to reinstall that road draft tube.

One of the things that killed these engines was the grit that got sucked into the engines from the ambient air. Combine with poor lubricants, poor oil filtering, and poor aluminum poston alloys and you have three strikes against you right off the bat.

Install a PCV system so that only filtered air is drawn into the crankcase, and get yourself a tiny bit of extra top-cylinder lubrication in the process.

Vintage Power Wagon has the adapter that replaces the road draft tube. It gives you a place to thread in a 1/8 nipple. Or, simply modify your original road draft tube. Run a line from the road draft outlet on the block to your PCV valve and then into the intake manifold. Intake air can come from a line that you plumb from the base of your air cleaner, or incorporate a small air filter into your oil fill tube.

This one small modification will keep your rebuilt engine running well longer, adn it also helps promote a cleaner under hood experience.

 

I sprayed everything with High Heat paint to insure adhesion..It took me a couple times, changing color variations and finding the color I had in my head for the block, but when I did I found out that it was just a basic enamel. My solution was this: I sprayed the base coat with a High Temp primer, then the color and then a high temp clear. This way the color's sandwiched between high temp paints to protect it from heat and peeling from oils and such (if for some strange reason).

 

do ya need a split manifold??pm me.i gots some for mopars.

 

That makes sense. I will have to look into that, plym49. Thanks for the insight.

 

Went through similar process 5 years back ( 10K miles) 30 off the head 10 off the block 30 over, dual carters on a fenton, stock cam. Started with a 230 out of a 56 Plymouth. Had and old school builder do the machine work. ( he used to work with Don Gartletts whe he was running flathead fords. Runs great lots of power, good hill climber. Only problem is high RPM's at highway speed. 3280 = 62 with 4.11 rear.

Keeping the flattie is a choice that lots don;t make but I am very happy with mine.

Driven from CNY to charlotte, detroit, Vermont and VA.

 

The paint is called Buckskin. I wanted something simple yet that one could say would be a color someone would see back then.