Locked up Flathead 6 in 1949 Plymouth

[Cooper40]

Hello everyone!

New user here

Im probably one of the younger people on this forum (23 yrs old) but im facinated by old vehicles, especially 40s era! I recently aquired a 1949 Plymouth Special Deluxe. The engine is locked up tight! My brother and i are working on it and this is our first project car ever. Definitely new to working on engines but ive watched many "will it run" videos through the years and have a little knowledge that way. I also just started watching @keithb7 on youtube. His videos on his 38 plymouth are super helpful!

 

So far we have tried putting mystery oil in the cylinders, that didn't work. Pulled the head and it doesn't look to bad underneath to my eyes. It looks like the cylinders have been sleeved? There is a little nick in the #2 cylinder wall and a bit of suface rust in the cylinder as well but other than that, not too bad, the walls are really smooth. What do you guys think? Next step is going to be pulling the manifold off and taking the valve cover plates off and seeing if the valves are rusted. If so, how should I address unseizing them? Are the other things I have to take out in order to loosen them up?

Really looking forward to talking with the people in this forum You all seem very nice and knowledgeable! 

Edited July 5, 2023 by Cooper40

[joecoozie]

Welcome Cooper40.

First thing I would tell you is if you are going to start removing stuff take LOTS of pictures before removing anything so you know how and where stuff goes when reassembling.

Okay, as far as your siezed engine is concerned.......

How are you trying to turn the engine over? By the fan belt, the crankshaft nut, the starter????

I had a car where the water pump was locked up, not the engine. But it seemed like the engine was locked up.

 

It is a good idea to pull the manifolds/valve cover plates, not only to see what's going on, BUT to clean up in there and spray lube everything, too. Also, drop the oil pan and clean that out. If the engine has not been rebuilt you'd be surprised at the sludge you'll find in the pan....AND clean the oil sump pickup screen. Also, you can spray the connecting rods and crank journals (as best as you can) to get SOME lube up in there.

I would continue to soak the cylinders. Marvel Mystery Oil is good but I know a lot of people recommend transmission fluid and acetone - mixed 50/50. 

I use(d) Kroil penetrating oil, too.

You need to let it soak for a week or so and then try to turn it. If it won't turn keep soaking it and letting it sit. Either try turning it over by the crankshaft nut. You get a lot more leverage. Even better than that if you remove the flywheel cover plate (under the car) and use a large screwdriver or a pry bar on the flywheel teeth (be careful not to chip any teeth) that gives you even more leverage. Or, you can tap the starter. Do not hold the starter in the engaged position just tap it. This sometimes helps loosen things up. 

You can also put the car in gear and rock it back and forth to try and unlock the engine.

If you get the engine to turn watch the valves in the head to see if any are stuck. There are usually a couple that are either tight or won't go up/down.

One other comment:

Be wary of all those "Will it run" You Tube videos. From what I have seen the majority of them have some guy pull a car out of the woods (after sitting there for 50 years) and throwing a battery in it to see if it will start. REALLY BAD IDEA!!!! 

There are preparation steps (some outlined above) that need to be taken in order to avoid damaging anything - BUT it looks like you are going in the right direction

Have patience and just keep at it. 

The last engine I unsiezed took me 3 months - but I got it......

 

Here's my 49 I am working on.

Joe

[Cooper40]

We've turning it over by putting pressure on the fan which slipped and spun the water pump (so we know that isn't locked up). We also tried putting a pipe wrench on the harmonic balancer and put a pipe on the wrench and tried that but we ended up breaking the wrench (it was a cheap one off Amazon I think). I was a little wary of that because I didn't want to force anything too much.

We don't have jacks or jackstands yet because this our first project. Also, it is on grass so most likely it will end up sinking into the ground. It it was on pavement, I would've got jacks and stands and tried the flywheel. 

We ordered a chain wrench and we'll try that once it arrives. 

About the will it run videos, I'm definitely aware that some of them can be a pretty bad idea. Seeing as this is my first project and I don't want to mess anything up too bad, I'm taking it slow and reading up on things before I try tackling it. 

Thank you for the advice, I'll keep you posted.

[greg g]

Before you screw up the crank pulley, put it in third gear an rock it back and forth with a couple folks pushing from each end.   I have been using a 50 50 mix of atf and acetone as a penatrant with good results.  Soak it, rock it.  Pull the spark plugs while rocking, you should be able to feel when it revolves freely.  There is also the tow at 20 mph it and dump the clutch in second gear but that is pretty harsh.

But still better than bunging up the crank pulley.   

Edited July 5, 2023 by greg g

[Los_Control]

Good looking car, to be honest from what the cylinders look like ..... My next move would be to remove the oil pan, start checking the bearings.

Assuming it is not a locked up water pump or starter causing the problem.

 

It is common for these engines to get stuck valves from sitting. Usually the oil gets gummy from sitting, the valve opens & stays open.

penetrating oil on the stems a rubber mallet to tap them down ... rinse & repeat til the move freely on their own.

Rings tend to stick to the pistons from sitting, causing low compression.

 

IMHO the engine does not look terrible & was probably a good running engine, til it didn't run. There is some muck on the cylinder walls .... How long did it sit since last run?

I just do not see any evidence of water getting into the engine to be a major rust issue to lock it up. Valves or pistons.

 

These engines while incredibly reliable, they were made into the 1970's with very minor changes done to them .... They do not stand up to high revolutions stock.

Max RPM I believe is 3500 .... If someone did not care about the car, wanted to Hot Rod it around ... It would be easy to spin a rod bearing & lock it up like you describe.

 

I think you can pull the pan without removing the engine, just remove one rod cap at a time for inspection ... put it back in place do not mix them up.

Check to see if it frees up with the cap off.

Is nice to know the condition of them anyways .... probably some sludge in the pan that needs cleaned out. .... You know you want to anyways 

While I would suspect a rod bearing, it could just as easily be a main bearing also.

 

Grandpa back in the 1960's had a 51 plymouth & he was drinking .... He Hot Rodded it & locked it up.

 

[squirebill]

Years back I sent my '49 B1B to the body shop to have the 4 cab corners repaired.  When they returned the truck (months later) they used a flat bed tow truck because the engine was "seized". They had soaked the cylinders with ATF, Marvel lube,

etc with no luck.  I removed the drive shaft and transmission.  Engine spun OK.  Turns out trans was seized not the engine.  

[Cooper40]

@Los_ControlThanks for the feedback.

Yeah to me it doesn't look too bad in the cylinders. I don't know when the last time the engine was run but it had old AC plugs from the 60s! They were pretty badly rusted and on one of them, the threads were rusted. Here are some pictures. 

Is it possible for a starter to be the problem like you said? I don't have any way of jacking the car up to get to the starter. Could I try and get it out from the top?

[Dave72dt]

I don't want to be the bearer of bad news but cyl 2 looks for all the world like it has a crack in it.  I think you're questioning it also since your first pic is of that cylinder.  start checking for sharp edges

 

Your # 2 plug also shows signs of moisture

Edited July 5, 2023 by Dave72dt
added info

[Cooper40]

@squirebillthe guys who delivered the car rolled it off of their trailer so probably not the transmission? Unless I'm missing something...

[Cooper40]

@Dave72dtI don't think there is a crack. You might of just been seeing the reflection of my flash? Here are some pics of the same cylinder without the flash. Also, the previous owner took the plugs out and just piled them in the battery tray so I don't know the order. 

Edited July 5, 2023 by Cooper40

[Dave72dt]

If I'm wrong, that's good news for you.

[squirebill]

To clarify:  rear wheels of B1B truck were not  rolling/moving.  They were sitting on wheel roller dollies to get winched onto the flat bed.  When delivered the bed was tilted and the roller dollies rolled until they were on the ground then the tow truck was driven from under the B1B.  Transmission was seized and needed a rebuild.  Gears were rusted together.  

[Los_Control]

Just now, Cooper40 said:

They were pretty badly rusted and on one of them, the threads were rusted. Here are some pictures. 

I hate to say it, those plugs kinda look normal for a flathead 6. If you look at the head, they have a bowl shaped area where the plugs are inserted .... The bowl fills with water and you get surface rust on the exterior of the plugs. When the threads are rusty means the little washer on the plug is leaking & needs replaced.

This can allow moisture into the cylinder.

I have a truck with the butterfly hood that opens from either side .... water leaks through the hinges & gets into the plug area .... If you drive it regularly not really a issue as the motor warms up & dries off the plugs.

Looks like you have a one piece hood that opens from the front & would keep the engine dry, but after many years they will still collect moisture there & rust.

Some of them get rusted so bad they break off when trying to remove them ..... I would not be worried about the plugs. Just replace them.

 

Just for a example, here is a 51 Ford engine been sitting for decades in a barn with the head off. There is more rust in the cylinders then yours.

The engine was locked up tight.

It cleaned up nicely for disassembly .... still locked up.

 

 

So I removed every bearing cap 1 at a time & it was the very last main bearing at the rear of the block that had some mouse piss on it that caused it to lock up.

I was using a 3' pipe for a cheater bar to turn it over ... would not budge til I removed that last bearing. Funny thing is, I could probably reuse the bearing if I was desperate ... crank is fine.

 

Point of the long story, this was a farmers truck he used it hard. While the 1951 engine has been parked since the 60's-70's. It has low miles on it, original pistons with no cylinder wear. It has been rebuilt & the crank is turned .010 - .010 because he spun a bearing in it. .... then the fuel pump quit, I imagine he was busy & just bought a new truck.

Just not uncommon to lose a bearing on a flathead  ... I was 18 years old when I spun a bearing on my 51 Ford truck.

 

Now I'm going to suggest I would not worry about the engine too much at this point.

This will be a project that will take some time to get it on the road.

I would say your first steps should be to get it jacked up & safely supported on blocks. You have lots of work & cleaning inspection under it for brakes, drive line, fuel system.

Is the frame all rusty?  Is the transmission locked up? ..... You can fix or replace the engine, you need to get under it to further check it out.

Just take your time & do not get in a hurry.

 

[soth122003]

Hey Cooper, welcome to the forum. Nice car. The engine looks to be in decent shape, but will definitely need the cylinders honed at a minimum or bored to take out the rust if it is to deep for the hone. Since you say this is your first project, i have a couple of questions.

1. Do you have a service manual? If not get one. It has a lot of good info in it.

2. Do you plan to keep it on the grassy area or move it to a concrete area? If you are going to stay in the grass, get 2 sheets of 3/4 inch 4x8 foot plywood sheets and park the car on that. This will allow you to use jacks and stands with out sinking in the ground and it should keep the car level. Plus when you drop things (and you will) it makes it easier to find them.

3. If you stay outside while working on this, get a 10x10 foot tarp to cover the car during rain. That center piece running in the middle of the hood is not waterproof. (hence the rusted plugs. ask me how I know)

4. Depending on how deep your pockets are, while trying to unseize the engine, work on the other things you know will need to be done. The carb, the distributor, the fuel system and the brakes are the first things that come to mind and in that order. The carb is an easy thing with kits about $50-60. The fuel pump. Has it been upgraded to ethanol resistant or will you run ethanol free gas in the car? The distributor will most likely need cleaning at the least and points rotor and cap at worst. When ordering or buying parts for the carb or the distributor, order by model number of the part you are fixing and not for the 49 Plymouth. Carbs and distros on these cars are very inter-changeable from like 1937 to 1953. Is the carb a B&B or a Stromburg? The model no. will be on the top of the carb on the slanted part. Is the distro a IGT, IGS, IGW, IAT etc.. it will have a plate riveted to side of the distro with the numbers you need.

 

Seems like I might be throwing a lot at you, but at least you can re-visit the thread and see what comes next. Also there are a lot of very knowledgeable and funny old people with ideas and wisdom on this forum Just ask and they will toot their own horns pretty loudly. All kidding aside, we have made the same mistakes you will make, we just did it eons ago but still remember how dumb we felt when we finally figured something out. We may kid you some, but any one who is into old cars is more than welcome here. So please don't hesitate to ask questions.

 

Joe Lee

[Jerry Roberts]

4 hours ago, Cooper40 said:

Next step is going to be pulling the manifold off and taking the valve cover plates off and seeing if the valves are rusted. If so, how should I address un

You don't need to pull the manifolds off to inspect the valves . 

[Ivan_B]

Plenty of good advice here. I have another one: what do you plan to do with this car? Are you planning to fix it up, for fun, and maybe drive it someday? Or are you actually interested in driving an old car? If you are into this for the process - then go ahead, but keep in mind that most of those "will-it-run?" videos are nonsense. You can make a car run, it is not hard; but it will not last long and is certainly not safe to operate on public roads unless properly repaired to OEM specs. Those video guys are not in car-restoration business, they just make fascinating videos... So, take their advice only if you want to make a video, that's it. ?

 

Now, if you are actually interested in driving an old car, here is what you need to do: get rid of this car immediately, and get another one, which runs and drives, and which you can reasonably maintain with the space/tools/skills you have. Since you are new to old cars, find a more knowledgeable buddy and look around. Do not set your mind to any particular year/make, just look for the best condition car you can find for your budget. Trust me on this, I've had those never-ever-done projects. Any car in good condition, which you can readily and constantly enjoy, and improve over time, will be much better than having a pile of immobilized metal in your garage, for years... And remember, it is never too late to quit. Do not fall into the gambler's fallacy, life is short.

 

My first antique project was a 58 Cadillac 62. I was around 20, at that time, very much mechanically inclined with garage, tools, and experience. But I never worked with cars older than 20-30 years before. The car was a parts donor, at best, but I did not realize that until much later. Floors/rockers/frame - rusted through, no brakes. I was able to get the engine running, and that's it. Had to sell it for unrelated reasons, and I am now very glad that I did.

Edited July 5, 2023 by Ivan_B

[Sniper]

If your valves are stuck, pretty sure they will be, brake fluid on the valve stems works really well.

 

 

Edited July 5, 2023 by Sniper
can't spell

[Booger]

6 hours ago, joecoozie said:

Welcome Cooper40.

First thing I would tell you is if you are going to start removing stuff take LOTS of pictures before removing anything so you know how and where stuff goes when reassembling.

Okay, as far as your siezed engine is concerned.......

How are you trying to turn the engine over? By the fan belt, the crankshaft nut, the starter????

I had a car where the water pump was locked up, not the engine. But it seemed like the engine was locked up.

 

It is a good idea to pull the manifolds/valve cover plates, not only to see what's going on, BUT to clean up in there and spray lube everything, too. Also, drop the oil pan and clean that out. If the engine has not been rebuilt you'd be surprised at the sludge you'll find in the pan....AND clean the oil sump pickup screen. Also, you can spray the connecting rods and crank journals (as best as you can) to get SOME lube up in there.

I would continue to soak the cylinders. Marvel Mystery Oil is good but I know a lot of people recommend transmission fluid and acetone - mixed 50/50. 

I use(d) Kroil penetrating oil, too.

You need to let it soak for a week or so and then try to turn it. If it won't turn keep soaking it and letting it sit. Either try turning it over by the crankshaft nut. You get a lot more leverage. Even better than that if you remove the flywheel cover plate (under the car) and use a large screwdriver or a pry bar on the flywheel teeth (be careful not to chip any teeth) that gives you even more leverage. Or, you can tap the starter. Do not hold the starter in the engaged position just tap it. This sometimes helps loosen things up. 

You can also put the car in gear and rock it back and forth to try and unlock the engine.

If you get the engine to turn watch the valves in the head to see if any are stuck. There are usually a couple that are either tight or won't go up/down.

One other comment:

Be wary of all those "Will it run" You Tube videos. From what I have seen the majority of them have some guy pull a car out of the woods (after sitting there for 50 years) and throwing a battery in it to see if it will start. REALLY BAD IDEA!!!! 

There are preparation steps (some outlined above) that need to be taken in order to avoid damaging anything - BUT it looks like you are going in the right direction

Have patience and just keep at it. 

The last engine I unsiezed took me 3 months - but I got it......

 

Here's my 49 I am working on.

Joe

Be still, my heart

Edited July 5, 2023 by Booger

[Ivan_B]

What's the point of getting the engine unstuck, in this case? If it got stuck from age/sitting, it will likely need to be rebuilt, anyway. There is visible rust inside. Trying to get it moving will likely only cause mode damage, if anything. Or am I wrong? ?

Edited July 5, 2023 by Ivan_B

[keithb7]

Carbon steel piston rings sitting nicely in bare cylinders rust. Humidity in the air and time is all that is needed. Depending where the car has been sitting, and for how long, will determine how rusted the rings are. If you could get it jacked up and work under it, I’d pull the oil pan and have a look. The bottom sides of the cylinder walls may tell a story.  As seen here. This one would not budge. I got it to move but there was nothing left to pull from the engine. A 2x4 and a big hammer from the bottom side is what finally got the pistons out the top. 
 

[Cooper40]

@soth122003

Thank you for all of that info!

1. Yes I got the service manual for it. It is super cool and I love how detailed it is.

2. Yes I plan on keeping on grass for now. Ok so you think only 2 pieces of 4x8 plywood would be enough to fit all of the jack stands under? Also, what jack stands would you recommend that are good quality and (possibly) not crazy expensive?

3. Yes, we have it covered. We're using this weird bug tent thing that can go over the front of the car and that works for keeping out the water. The day after we got it, it rained and all of the water leaked through the middle seam in the hood and collected around the spark plugs (just as I expected). We covered it after that.

4. The carb is a Ball & Ball Carter carburetor. It seems like the original one. Haven't checked distributor or fuel pump. 

Thank you again! I will for sure reach out when not if I have more questions haha!

 

[Sniper]

I get the feeling that jack stands will end up punching a hole thru the plywood.  Unless you have a set with a flat base

[Ivan_B]

2 hours ago, Cooper40 said:

@soth122003

Yes I plan on keeping on grass for now. . .

Also, what jack stands would you recommend that are good quality and (possibly) not crazy expensive?

 

 

?

For the jack-stands and most of everything else you need - Craigslist.

[Dave72dt]

Build your own jackstands from 2 x 4's cribbed up, nailed or screwed together, 18" long, 16 pieces per corner.   

[Bryan G]

Overall, I'd say your cylinders look better than the worst of mine did. I honed them the best I could, installed new rings, and buttoned it up. I've put somewhere around 8-9k miles on that engine now. I pulled the plugs last week and they all look great, even the one with the most miserable looking walls.

 

Mine was stuck tight. A month or more of soaking and lots of beating on the pistons, using a long piece of pipe as a breaker bar on the crank bolt to the point I bent my ancient Craftsman wrench...nothing. With the pan pulled, a lined up my floor jack with one of the crank throws, cushioned it with a scrap piece of 2x4, and started jacking. After a few pumps, with the whole car starting to rise, there was a pop and the engine was finally free. In my case, old gasoline had simply turned to glue and cemented the piston rings in place, along with every one of the exhaust valves. It was a great learning experience, and I don't regret a minute of it. Hard to buy an education like that! Tip: buy good tools, even if old ones. Lots of swap meets, antique tractor shows, etc., this time a year. I was at one a couple weeks ago and I guy must have had a half-dozen flathead-style valve-spring compressor tools on his $5 table. For things like piston ring compressors, hones, etc., better to buy something like a Lisle brand vs Harbor Freight. You'll get that money back, and then some.