Technical 218 Plymouth acceptable compression?

Anyone know where to get a new isolator screw and the isolator parts?This is an autolite or presto lite IAT 4003 distributor. I dropped one of the nuts and couldn’t find it. I found a wing nut that fits, made a new wire as best I could ( with the wrong kind of terminals ) and put it together. My circuit tester tells me it’s shorted so something is not right. I did find some NOS ignition parts in the trunk.

the isolator screw for an international Cub looks very close but for $20 I’m not sure if it really is or not. I think they were prestolite distributors and + ground 6v but I’m not a tractor guy.

also I noticed that the road draft tube misted the entire bottom of the car and side of the car with oil mist, so those 2 dead cylinders almost certainly are blowing compression directly into the crankcase. I either need to try a leak down or pull the head.

i think I’m kind of in recovery mode and looking for a good 230 to put in it but regardless also trying to get this engine running so I can move it to where it needs to be.

 

A side of the road or not your own garage fix could be to put a glob of RTV on, then the screw (not touching the sides) and let it harden. It should get you running, but wouldn't expect it to be more than a temp repair. An engine that hasn't been run long enough to get up to operating temp for years with a couple fouled plugs can easily overload the rings. Don't count it out until it's been run for a while and the valves adjusted, fully tuned, and then check compression again.

 

On my Dodge pickup it's 105 PSI for the Flathead 6 mine is a 230 but as far as I know it's the identical head.
More important than the PSI number as long as it's above about 50 psi it will run They really need to be about 10% within each other so if five of them are 100 and one of them is 80 it will cause the engine to run bad let's say you had some '90s and one 100 You usually won't be able to notice anything...
If you notice you have lower compression in one cylinder which is probably a high likelihood with the age of the engine pour some oil down that cylinder, If the compression comes back you have bad rings or stuck rings I should say If you don't have any significant improvement it's more than likely a valve issue.
Flathead mopar's are notorious when they've sat for years to get a stuck valve honestly pretty much all flat heads are notorious for that issue It doesn't matter if it's a continental engine a Studebaker engine or even a Model A engine they all like to stick valves open.


Edit I apologize I just realized your post was well over a month ago and was answered more than once I guess I got overly excited.

 

The only thing I didn’t do was lube the cylinders to see what they would recover to.

I know the day I looked at it, it started great but ran a little rough at first. It started to run better as it got warmer. I don’t know if he put doctor juice in the cylinders to make it run decent that day, but a little marvel down the hatch while running might do it and have put it in before I got there. Jokes on me because I had it delivered by him.. when he dropped it off I knew it had a dead miss but wasn’t worried at that time.

 

After thinking about this. I think my next course of action is a wet compression test, and then if it fails the heads gotta come off

 

Sorry to make you do all this work...but at least now you know what it will take.

 

It’s less work, and cheaper than swapping it for another. But I told my wife, if I have to pull it for another, I’ll go all out with a rebuilt engine, dual carbs and split manifolds

 

And what did she say Matt?

 

She actually agreed…. With the full rebuild part lol

 

Just got my 230 on a stand. I didn’t have any stands available anymore so I bought an EBay special 1,000 pound stand. Didn’t fit the engine so I had to get resourceful to make it work. I bought 5# of bolts from TSC and still didn’t have all the right length bolts. Off to get the car tomorrow

 

I’ve also got to address the carburetor. It works but it’s leaking like a sieve. It seems to meter the fuel decently okay. Not quite sure if I want to stay with the Carter B&B or go to a Holley 1904 or something 2bbl. I could probably re gasket the carb on it but my luck with carburetors isn’t great

 

It isn't a great carburetor!

Jon

 

The Carter B&B you mean? I knew its not great

 

I got to my moms; pumped the gas 3 times, held the pedal half way down and it fired on the first rotation. I ordered an old Heathkit CM 1073 ignition analyzer as I don’t know where my dwell meter is but I’d guess that it’s probably pretty close. The dead cylinder seems to be coming back online. I might get lucky just warming it up running it with marvle mystery oil in the engine oil and gas

 

Got the car home yesterday. It starts every time now very quickly but the heads gotta come off. And the carb is puking fuel out the side of it. The cylinders act like they want to run but falls flat under load

anyone know what carb might directly bolt on? I know the 1904 Holley should but the linkage I’m not sure of. I’ll probably drop something on so that it can be driven while I send away the B&B

 

I had good luck with using a Carter WA-1, # 413s in my '48 plymouth. The base is is a "universal" dual patern, so it is a direct bolt on. Lots of adjustments for tuning.

 

@Matt Dudley , I'd suggest PM'ing @carbking and discussing your options. He will have price and availability plus the knowledge to guide you.
With an engine that ran good, then didn't, then kind of did, I'd try to keep it running for a while and see if it wakes up and clears out more. Older stuff doesn't like lots of cold starts and not getting up to temp.
especially with a bad carb. Give the valve guides and rings a chance to warm up and reseat. Toss some seafoam or techron in and let it clear out. Then repeat the compression test.
Pulling the head is simpler and easier than an OHV.
If the engine has to be pulled after diving in, it's not much effort gone to waste.

 

I’ve got B12 chem tool in with some 94 octane ethanol free right now. I was going to put some PB blaster in the 3 trouble holes after checking the valves for burning with my borescope. I should be able to see stuck valves as well. I agree pulling the head is trivial at best. My only worry is the temp probe but there is a Welch plug that can be removed to work it out


Do you think I should change the oil and take it for a couple mile cruise? The carb works pretty good for being a leaker. No black smoke, no smoke really. Smells slightly strong but that could be me. It doesn’t crack, pop or hesitate with throttle. But I know the ball and ball isn’t the best that ever was.

 

Current carb is a fire hazard and not doing the engine any favors. Repair/replace first.

After that, let it run for at least a half hour, driving even better IF you can be assured it won't overheat or leave you stranded. Driving will get to work time and heat into the drivetrain and chassis, which are also probably cranky from sitting.

So long as the oil looks like it's in decent shape, I'd prefer to get everything up to temp at least once and then drain rather than a cold drain and putting the fresh oil thru the wake up. Also, if the engine doesn't respond and you end up yanking it, fresh oil is wasted.

 

If it will sit and run at idle for 10-15 minutes w/o overheating then a short cruise would be in order.
This would give everything a chance to, hopefully, free up so you can get better comp numbers.
Stuck rings will drive the average guy crazy. Next is an oil change.

 

Perhaps I could throw a couple gaskets in the carb. I’m no rebuilder but the one gasket it leaks from, I could probably just split clean and re gasket without messing with too much. Then I’ll actually put it on the road. It’ll sit and idle as long as you want it to

 

Completely understand workin' with what you've got, but if the plan is to keep it flathead check into a good carb. It will work with the current engine or the replacement, if needed.

 

I’m keeping it flathead. I was just thinking about taking it down to the turnaround and back a few times sometime this week, since Napa should be able to get a carb kit sooner than I could get a carb.

goal is a Memorial Day parade and I know even running like it is, it’ll make that parade.

 

If my memory is correct Carbking said that for a time, Plymouth used Rochester carbs when they couldn't get Carters and these were a much better carburetor. I think they were the same one used on Chevrolets .

 

I read something about the Carter W1 547 which was used by Plymouth for a short time due to a strike. I think, if my GM knowledge is correct, the W1 was co developed with Rochester and that would make sense why Mopar stuck with the ball and ball as they likely had to pay patents to use the W1.

but I don’t know if that 547 carb is specifically the only version that will work.

 

Stromberg made BXOV2 carburetors for Mopar applications as well. 3-46 is one of the numbers for them.

 

We used to play a game called "gossip" when we were kids; whisper something to the one next to you, and let it go around the circle. Really interesting what comes back at the end of the circle.

Carter introduced the W-1 in 1932, 17 years before Rochester sold their first carburetor. Rochester did not help Carter develop the W-1 (actually, there was a W-2 before there was a W-1).

The "so-called Carter BBR-1" is NOT a Carter carburetor, rather a Chrysler design that Carter built for Chrysler.''

Carter and Plymouth had an agreement for a short time in 1947 for Carter when the Carter plant producing the BBR-1 went on strike. The carburetor Carter sold to Plymouth at this time was the W-1 574s, normal application 1946~1948 Chevrolet 216.

The Chrysler design is horribly inefficient, needing to be a "size 3" (mounting spacing 2 15/16 center to center) for the 218. The much more efficient W-1 is a "size 2" (2 11/16 center to center).

The 1938 Plymouth intake manifold was for a size 2 carb, so Plymouth produced a run of 1938 intakes, with a different casting number).

Today, a Carter WA-1 tag number 413s would be the cat's meow!

Jon

 

https://www.thecarburetorshop.com/Carter_574_Plymouth.pdf

 

@carbking do you have the info sheet for the carb @Matt Dudley is trying to get working?
If the one you posted is a rather rare carb that also needs a rare intake, it's proof of your words but not much help. I know you are not in the business to give stuff away, but you have been very helpful in the past. Will a gasket replacement fix a leak on these or do they often have a warp issue that would require more than the typical clean and kit?

 

The 1951 Plymouth Chrysler carb should have the number "D6H2" stamped on the vertical strengthening vane. There are dozens of different possibilities if the original has been replaced. Once I know what carburetor he has, I am reasonably sure I have the sheet.

I cannot post here as my internet supplier has messed up my access to adding files to my website, but I can email it.

These carbs are EXTREMLY prone to warpage. To stop it from leaking (at least for a few year), the castings will need to be straightened using pressure and heat. A gasket is NOT going to stop the leakage.

In the FWIW category, even when we were still rebuilding carbs, we would NOT rebuild these! Can I make it not leak? Yes, until it warps again, and it will; but I could rebuild 10 quadrajets or 10 Carter AFB's in the same time it took to rebuild the BBR-1. How much can you charge to rebuild a single barrel carb??? Better simply to not offer the service, than be thought of as a bandit.

We ALWAYS suggested replacing the BBR-1 unless the vehicle was an absolutely numbers-matching show vehicle, that was driven only from the trailer to the show field!

The 574s is NOT rare, as Chevrolet used it from 1946 through 1948. I do not know the scarcity of the 1938 Plymouth intake.

The 413s I mentioned above WILL bolt to the 1951 intake.

Jon