Exhaust Manifold for 1954 engine

delaware39 · May 21, 2016, 07:11:10 PM

Sorry to be so slow in responding. This is my busiest time of the year, plus my daughter graduates from HS in a few weeks. I have have a new manifold and everything is installed and working well. Now I'm having some issues with the clutch, but I will start a new thread about it.

jjkeenan · May 02, 2016, 08:53:40 AM

did you get manifold?? have a friend who has one intake/exhaust set .

delaware39 · February 22, 2016, 02:19:10 PM

Thanks for the info and the quick response. I'll look into the possibility of replacing the (steel, not brass) bolts with studs and brass nuts. This morning, I crawled under the beast, loosened the last bolt, and removed the manifolds. The four long connector bolts are soaking and hopefully will come out. There is evidence that some of the exhaust gaskets were leaking, too. I'll leave the exhaust pipe and muffler as is. The car is a 1939 P8, but with a '54 engine & tranny, so I'm not always sure what changed over the 15 years or where conflicts could arise.

TodFitch · February 22, 2016, 01:24:37 PM

My car has studs to hold the manifolds on to the block. I thought they were that way for all the years on up.

I'd use sealant on the threads into the block. The nuts that hold the manifolds on my car are brass and I assume that was standard for most/all years. The exception being the outer ones on the exhaust manifold where there was a special washer and an oddly slit tapered nut (both available from Vintage Power Wagons I think) designed such that there was pretty uniform clamping over a large temperature range. None of the manifold nuts are all that tight: The manifolds need to be able to expand and contract with temperature or they (especially the exhaust) will crack.

Your brass nuts should not need anti-seaze as the brass will release from the steel stud. Might damage the nut but those are available at your good local hardware store so you can put new ones on as needed.

The four bolts that hold the two manifolds together should be left loose until the manifolds are secured to the block. This allows you to get a good seal on both the intake and exhaust. Once the block stud nuts are tight then you can tighten the four manifold joining bolts and I'd use a good anti-seeze on those four bolts.

My car, and I think all of the ones from the 30s and 40s, used a steel tube between the fuel pump and the carburetor. Maybe they changed that out to rubber by the 50s but it seems a bit unlikely to me. I'd prefer steel for that.

A bunch of the early years of production of the L-6 had the exhaust system suspended from just one or two hangers (middle and back) with the front held up by the exhaust manifold connection bolts. I don't know if your '54 was that way from the factory but it would not surprise me too much if what you describe was stock.

There should be a drain plug on the water jacket some place around the distributor. It might be that the lower water jacket is silted up and pulling the plug results in nothing coming out. Lots of people have found that they needed to pull the core/welsh/freeze plugs and scoop/pry/flush out the decades of accumulated muck to get their engines to run at proper temperature and to get the drain plug area clear enough that it actually worked.

There may be a number of plugs along the bottom of the block along the oil gallery. I assume pulling those would show evidence of oil, so you will know they aren't the cooling jacket drain plug. Those plugs will line up vertically with where the oil pressure gauge and/or feed to the oil filter attach to the block. (They cover the hole needed to drill the oil passages to the bearings when manufacturing the engine.)

delaware39 · February 22, 2016, 08:05:41 AM

For better or worse I found an intake/exhaust combo for about $100. I learned a few things while starting to take apart the old one. Who would have thought that the manifold bolts go all the way into the water jacket? Or the fine folks at Mopar had to put one last bolt all the way under and behind the heat riser box? I ran out a day light before I had time to jack up the car and find that last bolt.
Perhaps someone could advise me on the few things before I put in all back together. 1: should I put some sealant on the bolts or "never seize" when I put it all back? The previous owner put everything together dry and boy is everything rusted tight. 2: the muffler & exhaust pipes are suspended by two hangers, one at the very back of the car and one behind the muffler at the point where the pipe bends to go over the rear axle. There is no support in front of the muffler except for the two bolts at the manifold. Is this correct? 3: The fuel line from the pump to carburetor is rubber. Considering how close this is to the exhaust manifold, I think I should replace it with a steel line. A good idea or a waste of time? 4: is there a a drain on the block? I tried a likely small bolt near the oil filler, but no antifreeze came out when I removed the bolt. Finally, are there any tricks I should know before everything goes back together? Thanks in advance and forgive the long post. I think I just needed to rant a bit.

Bender · December 24, 2015, 06:52:24 AM

Quote from: delaware39 on December 23, 2015, 11:57:34 PM
I had a friend who runs a very respected machine shop (Alderman Machine). He felt that a weld wouldn't hold up. That's why I'm pursuing a replacement. Pictures will be forthcoming, probably after Christmas.

Why would a weld not hold up if it was made using cast iron welding rods,,the crack had been sand blasted and ground out, and holes drilled at each end if done by a welder who has experience welding cast iron and understands it's special requirements? It's been done ever since cast iron was new and high tech.

delaware39 · December 23, 2015, 11:57:34 PM

I had a friend who runs a very respected machine shop (Alderman Machine). He felt that a weld wouldn't hold up. That's why I'm pursuing a replacement. Pictures will be forthcoming, probably after Christmas.

RC Drown · December 23, 2015, 07:45:12 PM

), the exhaust manifold just cracked. Any help in locating a new one would be greatly appreciated. The engine number is P25-291780, 23" block, with intake manifold number 1811805. I could

Depending how badly the manifold is cracked it could be welded by someone who is experienced in cast. Might be cheaper than a new one. Also on the P15-D24 website there is a member who goes by the name Moose, who can do you a nice looking manifold

How about some photos when you get a chance?

Good luck with the '39

Bender · December 19, 2015, 06:24:27 PM

Quote from: Bender on December 18, 2015, 08:59:50 PM
I am GUESSING that pretty much any flat 6 Plymouth or Dodge exhaust manifold would work. I have a 33 Dodge engine and a 47 Dodge truck engine sitting on my shop floor,and if you send me a PM to remind me,I will look at and measure them tomorrow to verify they are the same.

BTW,since your manifold is cracked,this would be the perfect time to put split exhaust on it. Offy still makes the 2x1 intake manifolds for this engine,too. Right at $250 retail for a brand new aluminum 2 carb intake/

A "PM" is a private mail box that this web site hosts,so members can "talk" to one another without cluttering up the public threads. Every "hobby" web site I have ever been on has one,including this site.

Go to your proflie page (there is a link at the top of every page that says "profile",and put a check mark inside the box that says "allow PM's" . Look for another box that allows you to receive email notifications from this web site that you have a PM and they will send you a email with a link you can cllck on that will take you to your PM page.

delaware39 · December 19, 2015, 05:45:33 PM

Sounds like an interesting idea. I don't really want to have two carbs, but a split exhaust might be nice. Any chance you have a website for where I could get one? If I can find a plain manifold cheap enough, I will most likely go the stock route. You mentioned that I should send you a "PM." What is a "PM?" Just curious. Thanks for helping.

Bender · December 18, 2015, 08:59:50 PM

I am GUESSING that pretty much any flat 6 Plymouth or Dodge exhaust manifold would work. I have a 33 Dodge engine and a 47 Dodge truck engine sitting on my shop floor,and if you send me a PM to remind me,I will look at and measure them tomorrow to verify they are the same.

BTW,since your manifold is cracked,this would be the perfect time to put split exhaust on it. Offy still makes the 2x1 intake manifolds for this engine,too. Right at $250 retail for a brand new aluminum 2 carb intake/

delaware39 · December 18, 2015, 07:44:35 PM

After years of waiting, I now own a 39 P8 4-door sedan. It's a bit of a a hybrid, however, with a 1954 engine/transmission, a12 volt electrical system, and 15 inch radials. Among the many surprises (none of them pleasant), the exhaust manifold just cracked. Any help in locating a new one would be greatly appreciated. The engine number is P25-291780, 23" block, with intake manifold number 1811805. I could find no markings on the very rusty exhaust manifold. I have an old master parts list book and repair manual for '36-'42, but I don't know much about a 54. Never thought I would need to. I sent a message to Bernbaum & Dawson, but both seem to need a part number. Thanks in advance for your help.