Guest Merchant Xpress Posted November 19, 2008 Share Posted November 19, 2008 Hello all, my 29 Dodge Bros pickup has a Plymouth Silver Dome 4 cylinder engine that I know nothing about. Is this a splasher engine or is it pressure fed? I know it has oil pressure that was running great but I lost the oil pressure one day. I need to drop the pan to check the pickup screen if there is one. There should also be a check valve that may be stuck. Does anyone have a manual for this engine? I know this engine was Chryslers choice for the Merchant Express truck when they bought the DB name plate but I don't know how many years it was used. I think they went to six cylinders pretty quickly. Thanks in advance for any help you can offer my way.Harry Link to comment Share on other sites More sharing options...
keiser31 Posted November 19, 2008 Share Posted November 19, 2008 Try the Walter P. Chrysler Museum. They have a website and a library. Link to comment Share on other sites More sharing options...
Steve Braverman Posted November 20, 2008 Share Posted November 20, 2008 The Plymouth four is pressure lubricated. I believe that they are all pretty much the same internally from 1928-1932. Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted November 20, 2008 Share Posted November 20, 2008 Thanks guys, I know there is one of my trucks in the Chrysler museum. I talked with the man who sold it too them a few years ago. He thought his was the last on the road when he sold it and was surprised to find out I had one. Now that I'm working on it I'm finding out how rare they are. No information and no parts, I had to have the front motor mount made. This weekend I'm going to drop the oil pan to see if the screen is plugged up. Steve, how far have you gotten into your engine on your 32? Harry Link to comment Share on other sites More sharing options...
Steve Braverman Posted November 21, 2008 Share Posted November 21, 2008 I've never really had it apart. It only has 39k miles on it. I have had the head off many times, because a valve will hang up if it sits too long. I do have a spare engine with the pan off. I also have an owners manual somewhere. Maybe I could scan parts of it for you. Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted November 21, 2008 Share Posted November 21, 2008 Steve, that would be great if you can. You can e-mail them to me at AACAhjhill@gte.net take off the AACA, it is just there to stop spammers.Harry Link to comment Share on other sites More sharing options...
Steve Braverman Posted November 21, 2008 Share Posted November 21, 2008 It may take me a few days. Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted November 22, 2008 Share Posted November 22, 2008 Steve, at your convenience of course. I'm just so happy to find someone with a manual. I have been worried about getting too far into it without a reference source. Tomorrow I will drop the pan and check the oil pickup screen. I also want to check the pressure plug to see if it is stuck but I'm not sure where it is so I will wait until you get a chance to scan your manual.Harry Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted November 23, 2008 Share Posted November 23, 2008 I'm having a hard time navigating the Chrysler museum site looking for the library. Sometimes I wonder if the website designers ever try to get around in them. Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted November 23, 2008 Share Posted November 23, 2008 I dropped the oil pan today, there was a layer of sludge in the bottom but not what I would expect after 80 years of use. I cleaned it and painted the pan. The screen looked clean and I don't think there was enough sludge to plug it up so I still don't know why I lost oil pressure. The vacuum oil pump looks good, maybe the springs that push the arms out are getting weak. The internals looked good from underneath the truck. I had to use gasket maker for the pan gasket, who would guess the NAPA store wouldn't have a pan gasket for a 29 DB truck.Harry Link to comment Share on other sites More sharing options...
Steve Braverman Posted November 23, 2008 Share Posted November 23, 2008 Harry,If my memory is still working, I believe there is an oil pressure relief valve on the side of the engine. Did you check that? Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted November 23, 2008 Share Posted November 23, 2008 Steve, I haven't checked it yet but I will today when I get back from business I have to do first thing. As I told Keiser31, I just thought that was some kind of crankcase vent. Have you ever had the pressure relief off? I think there should be a plunger and spring in it if I remember correctly.Harry Link to comment Share on other sites More sharing options...
Steve Braverman Posted November 23, 2008 Share Posted November 23, 2008 I've never had it off, but it's definitely a pressure valve, not a vent. It's probably your problem. Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted November 23, 2008 Share Posted November 23, 2008 I am cross posting this off the Dodge Bros trucks site so forgive me if you read this twice. I'm looking for all the help I can get.I have the relief valve out, it clicked when I first turned the cover nut so it may have been stuck, lots of carbonized oil on it so I'm giving it a good cleaning. There appeared to be a leather or some kind of fiber disk in the seal unit that has deteriorated into little chunks. I don't think it's rubber. I'm not sure of it's function unless it is to seal the bottom of the plunger at the relief holes to the engine side, not at the spring side. If I can get this clean enough I may find some parts numbers on the valve, not that the will be a lot of help, who knows though the local parts store may have one on the shelf. I wonder if the disk restricted how much oil got past the plunger at the relief holes?Harry Link to comment Share on other sites More sharing options...
Steve Braverman Posted November 26, 2008 Share Posted November 26, 2008 I found a stack of Plymouth Owners manuals today. Is yours an early engine with the generator in front of the block and thermo-siphon cooling, or a later engine with a water pump and the generator on the side? Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted November 26, 2008 Share Posted November 26, 2008 Generator on top at front of engine, water pump on drivers side of engine, it is a U model engine, circa 1929.Harry Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted December 1, 2008 Share Posted December 1, 2008 One of my biggest problems is I can't stay focused on one thing at a time. So yesterday I slipped home from work and pulled a brake line off and sent it to my parts guys to see if we can get others. I have to wait until monday to find out so today I decided to pull the carb. Sure glad I did that, it was full of white crystal like powder. All the jets were plugged with the junk, not sure what it is but I'm thinking some residue from the new fuels or something leaching from the pot metal. I pulled it all apart and gunked it, the loose stuff all came out but the metal still has a coating of it. I am glad the float is still complete without any holes. I'm not sure what the float level should be but I'll start at 1/2 inch and work from there. No varnish in the bowl though and that surprised me. Still waiting for my motor mount to come home.Harry Link to comment Share on other sites More sharing options...
R W Burgess Posted December 12, 2008 Share Posted December 12, 2008 I've moved this to the restoration forum as Harry requested.Wayne Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted December 16, 2008 Share Posted December 16, 2008 I'm getting ready to put the carb back together and I'm wondering if anyone knows what the float setting should be. This is a tillotson updraft carb.Harry Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted December 18, 2008 Share Posted December 18, 2008 The carb is back together and I have my new motor mount and it rained all day on my day off today so nothing got done as far as installation. I want to say a special thanks to Steve Braverman for scanning his 30 Plymouth Silverdome manual and e-mailing it too me. It is really going to be helpful as I work on this engine.Harry Link to comment Share on other sites More sharing options...
Steve Braverman Posted December 18, 2008 Share Posted December 18, 2008 Glad to be of help. I was wondering, did this truck come with this engine, or was it swapped at some point? Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted December 18, 2008 Share Posted December 18, 2008 Steve, this is the factory engine for this truck. In late 1928 Chrysler bought the Dodge Bros and in 1929 they produced this truck called the Merchants Express, they also built a screenside truck on the same frame and running gear. Chrysler wanted to do something than what the Dodge Bros were already producing in bigger trucks so they put in the Plymouth Silverdome engine and as far as I can tell only built the truck for this one year before they went to the six cylinder engine and the all metal cab. From what I have read the Merchant Express was mostly built to order as far as the bed went as the purchaser could order any bed from the factory depending on the buyers needs. Mine has wrought iron braces going to half inch pipe over the bed rails, which are flat and about 6 inches wide. It looks like something a plumber might use. Anyway, to answer your question, the engine is stock. Harry Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted January 2, 2009 Share Posted January 2, 2009 Well, I sort of made some progress today. It was my first day off in a few weeks where it wasn't raining and I didn't have company so I got some work done on the truck. I put the Carb on and decided to see if it was working correctly, so I added some gas to the vacuum tank and hooked up the fuel line and tried to start the engine. It fired up pretty quickly and ran but once again no oil pressure. In the process of running though it pumped a lot of oil out the exhaust. I'm guessing my valve guides are shot or my rings are gone. Not sure which. I'll pull the valve cover off next and see if I can see a problem there. This must be my oil pressure problem. It could be my oil pressure gauge isn't working as it was definately pumping out into the cylinders. Am I missing something here or does it sound to the rest of you like I am on the right track?Harry Link to comment Share on other sites More sharing options...
Steve Braverman Posted January 2, 2009 Share Posted January 2, 2009 I would hook up a gauge that you know works before you go nuts tearing the engine apart. My Plymouth usually has about 30psi at idle. Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted January 2, 2009 Share Posted January 2, 2009 Steve, I believe it must have some oil pressure or the oil wouldn't have been coming out the exhaust. There sure was a lot of it. Of course this could all be from when I poured oil in the cylinders to keep the rings from seizing. I just remembered doing that but I don't remember putting very much oil down the hole. I need to get another oil pressure gauge to check things out.Harry Link to comment Share on other sites More sharing options...
ply33 Posted January 2, 2009 Share Posted January 2, 2009 If I recall correctly, on the 1928-29 (and perhaps early 1930) Plymouth four cylinder engines used the oil pump to provide vacuum to the fuel pump. (This is different from most cars that used manifold vacuum to run the pump.) I have heard that a problem with the fuel pump can result in loss of oil pressure.Not sure if they used the same setup when if/when the engine was installed in a truck. Link to comment Share on other sites More sharing options...
F&J Posted January 2, 2009 Share Posted January 2, 2009 A couple of comments;I had a 29 Ply U and a 32 Ply PB years ago.I am sure the U engine was thermo-syphon cooling without a water pump. I recall the hoses were very large diameter for that reason. I have no clue if a U engine was changed to a water pump when used by Dodge truck division, however.The Ply U fuel pump was a firewall mounted vacuum tank that ran on manifold vacuum.On the oil-in-exhaust; I think the oil came from your soaking of the cylinders. If the rings/pistons were so worn to cause that oiling, it would be very, very low on compression and real hard to start. I always disconnect the oil gauge line to see if oil will squirt out, before I ever start a "barn find". Babbit bearings will run quite a while with zero oiling, but when they finally get hot enough from zero oil, the babbit will drop out instantly from one rod. "been there, done that" Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted January 3, 2009 Share Posted January 3, 2009 The U engine uses an oil pump called a vacu-motive oil pump that pulls vacuum to fill the fuel canister. It is designed so if you lose oil pressure there is no vacuum so the engine stops before you burn it up. Good plan until you don't have oil pressure. So I pulled the oil line at the block and no flow, then I pulled the cap off the oil pump and still no flow so the pump isn't pumping oil. In the pump are two finger like vanes that are spring loaded. The springs appear to be good but I am going to see if I can find some heavier springs that will also work. I have a manual for the U engine that Steve Braverman copied for me, I am going to go through it and see if there is an internal oil pump I'm not seeing.By the way my engine does have a water pump mounted on the drivers side of the engine, the mount of it is cast into the block. When I had the pan dropped I couldn't feel any slop in the connecting rods or crank so I don't think I've damaged the bears but I haven't let it run long without oil pressure. I do start it when I am checking for oil flow or pressure but I don't let it run long. The oil in the exhaust has quit so it must have been in the cylinders from me.Harry Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted January 3, 2009 Share Posted January 3, 2009 Okay, no internal pump. Thats the good news, the bad news is I think the oil pick up tube may be cracked or I am losing vacuum somewhere or there would be oil flowing. So tomorrow I'll pull the tube off the oil pump and see if there is an obvious problem. Maybe I'll get lucky and see something I can easily fix. Maybe where it comes out of the block. For some unknown reason the pump isn't picking up the oil. I will also check the gasket on the pump in case it is losing vacuum there. Wouldn't that be too easy of a fix.Harry Link to comment Share on other sites More sharing options...
F&J Posted January 3, 2009 Share Posted January 3, 2009 I forgot where/what type the oil pump is. On real oldies that won't pick up the oil, I have used a funnel and rubber hose to back feed through the oil gauge line. With luck, the oil ends up in the pump to help it go. Talking about gear pumps, though.Sounds like you will figure it out just fine. Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted January 3, 2009 Share Posted January 3, 2009 I was thinking about setting up a feed system also but first I will check the gaskets and pick up line. I think it has to be something simple. I don't see any obvious leaks but a suction leak may not show. There is a cap on each end of the oil pump, the vacuum line for the fuel goes to one side. I think the other side could be used to set up a oil reservoir to feed the pump to get it picking up again. Once it is picking up it should keep going as long as the pick up line isn't cracked.Harry Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted January 3, 2009 Share Posted January 3, 2009 Okay, one step forward, one step back. Not making much headway but I am making some. I fixed the gasket on the oil pump and set up a feeder to get oil into it. I tried to start the truck to check if I got oil pressure but it wouldn't start. That's the bad news, the good news is when the engine was turning over the oil pressure started coming up so priming the pump helped. I think it lost prime when I put the vacuum line onto the vacuum tank from the oil vac pump. My engine has a Tillotson carb but I'm not sure this is the stock carb. It looks like a Carter in the manual. Someone told me the Plymouth used a Carter BB-1 card. The Tillotson is leaking so it needs new gaskets and fiber washers. Now to find a source or a Carter.Harry Link to comment Share on other sites More sharing options...
John Gelfer Posted January 4, 2009 Share Posted January 4, 2009 Try Jon Hardgrove @ The Carburetor Shop in Eldon MO. I'm sure he has a Carter BB1 for you.http://www.thecarburetorshop.com/ Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted January 4, 2009 Share Posted January 4, 2009 Thank you John, I sent off an e-mail this evening to Jon and will try to call him on Monday.Harry Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted January 5, 2009 Share Posted January 5, 2009 I now have oil pressure. I need to back off the spring on the pressure valve now. At a fast idle I had 60 lbs pressure. The pressure is easy to regulate so that isn't a big issue, much better thing to deal with than no pressure. The carb still has a leak and so far I haven't found a rebuild kit for a tillotson updraft and I'm looking for a Carter. Now that I know the engine will run with oil pressure I will move the truck indoors (the garage) and start rebuilding the cab, which is still pretty solid for the most part. The top is in real bad shape but the rest of the cab is pretty good. The inside is real basic, speedo, amp meter and oil pressure gauge. Time to put my wood working skills to use.Harry Link to comment Share on other sites More sharing options...
keiser31 Posted January 5, 2009 Share Posted January 5, 2009 Excellent to hear that you now have oil pressure. It is unnerving not knowing whether or not the engine is being oiled well enough. I used to drive a 1930 Plymouth and a 1931 Plymouth that a friend of mine owned and for the most part, both ran at about 60 lbs while driving and about 15 at idle. They were both 4 cylinder cars and one was restored and the other was not. They both ran the same engine wise. Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted January 5, 2009 Share Posted January 5, 2009 keiser, thank you. I know how to adjust the oil pressure and I cranked it up while I was trying to find the problem so right now my biggest issue is the carb. If I could find a kit I would rebuild the Tillotson, heck, I have two of them. Both sat dry to long and everything is dried out. When the truck was running, so long ago, it ran fine on the present carb. I'm sure now I lost oil pressure when I was setting up the vacuum tank system. My vacuum tank must have a leak that let the pump break suction so I lost oil pressure. This carb can't stand up to an electric pump so I need to fix the vacuum tank. Right now it won't hold back gravity as it leaks and lets all the fuel drain from the vacuum tank. It may just be me but leaking gas in the engine compartment doesn't instill a lot of confidence. I may have to add an onboard fire system.Harry Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted January 5, 2009 Share Posted January 5, 2009 Dave, yes, the engine is correct. 1929 was the first year that Chrysler owned the DB truck line and they wanted to make a light truck for around town businesses. They made this half ton truck with the Plymouth 4 cylinder engine, all their other trucks had a six. This truck was also the first year they had four wheel hydraulic brakes on their truck though the cars had them two years previously.I just replaced the front brake lines, had them make locally.Harry Link to comment Share on other sites More sharing options...
keiser31 Posted January 5, 2009 Share Posted January 5, 2009 Try to have a fire extinguisher handy when dealing with gas leaks. Link to comment Share on other sites More sharing options...
Guest Merchant Xpress Posted January 6, 2009 Share Posted January 6, 2009 <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: keiser31</div><div class="ubbcode-body">Try to have a fire extinguisher handy when dealing with gas leaks. </div></div>Yeah, I'm pretty sure I can't go fast enough to blow the flames out. Maybe I should just fix the leak.Harry Link to comment Share on other sites More sharing options...
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