Needing some help.... I have a '41 Plymouth Deluxe with original flathead 6 & 3 speed. Don't know much about one this old, so I'm looking for advice. Started off running great, was driving when started hearing a knocking that increased or decreased with speed. Went completely quiet and I was dead in the water. Had towed home and now I can't even get it to turn over. When you engage the plunger to start, you either hear nothing or a slight whirring sound. Would greatly appreciate any insights or suggestions. Feeling lost with this one. THANKS
Can you put a wrench on the nut on the front end of the crank? See if the engine will turn over that way . Be sure the key is off . Knocking sounds in the engine is not a good thing . May have spun a bearing and locked it up.
Yeah those original drivetrains were kind of junk from what 36dodgeram tells me. Do what the above poster said and pull the plugs to see if you hydra locked as well. How many miles are on it?
Whirring sound indicates the starter is not engaging. Try taking the starter off and spraying the Bendix with WD40 and get it moving easily. The knocking is bad. Could mean the engine is toast. If you can fix the starter and fire it up, and it knocks, check oil pressure gauge then shut it down immediately. If there is no oil pressure (or no oil) goodbye engine. It is due for rebuild or replacement. If you like the flathead (I do) they are not hard to rebuild, and all the parts are available cheap. Vintage Power Wagons have all the parts including NOS pistons for $75 a set.
These engines were only good for 20k-30k miles without some kind of major work being done to them. You should be able to find a replacement engine for this fairly easy because they were taken out still running all over the country for CHEAP. like a hundred bucks or something.
There are quite a few engines around the country, they were used in Plymouth and Dodge cars and Dodge trucks from 1938 to 1959. The larger Chrysler/DeSoto engine was used in cars up to 1954 and in Dodge trucks to 1962. Normal engine life, given proper upkeep was 80,000 to 100,000 miles between rebuilds. An engine could be rebored and rebuilt 3 or 4 times before its useful life was over.
That statement baffles me. I have never heard of one of those engines only lasting 20-30k unless horribly treated. Where did you ever get that sort of information? It's just silly to say that.
Yeah, I would have to agree with 31Dodger and question your source of info as well. These engines were workhorses. They were used in industrial applications long after they weren't going into cars anymore. That's the main reason that you can go get parts for them from any Napa. What I'd really like to know is where it is you think you can pick em up for $100. I'd be interested in several if that were the case. As for the OP's question I second the notion that it's starter related.
In my experience these were tough little engines. I actually had a freeze plug pop out one time and unbeknownst to me, I had lost all the coolant. I seized that engine up tight. I let it cool off, replaced the freeze plug and filled it with coolant. It fired right up - no knocks, no oil consuption, or other issues. I ran that engine for a lot of miles. At the time, My dad recalled having a similar experience over 60 years ago.
Mucho wrongo information about those drivetrains being junk. They were some of the most bullet proof engines on the market.
I am assuming the OP has high miles on this car. Back in the 40's and 50's oil technology wasn't like it is today, also filtration was equally bad. The head often had to be removed several times in the 100,000 mile(ish) life of the engine for head work at the very least, if not for other issues like rods knocking. They overcompensated in the design for the lack of technology by building them beefier than what you see today in engines. Since they were a more robust design it took them longer to heat up, etc. and since the technology wasn't exactly perfect at the time of this cooling wasn't quite there either and they had their share of problems with this as well. In turn, if you saw that the engine temp was on the high side, it was actually even worse than what the gauge read. I am not saying that they were garbage when they came out, yes they were good. Who knows how many times the OP engine has been rebuilt in its 70 years, but it is probably safe to say that it is junk if the rod is knocking (probably not its first time). Let's not forget all of the oil additives that were put into the oil to keep it from leaking from every gasket (even used throughout the 60's). This crap gummed up everything, including blocking some oiling abilities to the crank and other components. You are assuming that by "major work" I mean full rebuild with new everything... I am talking about "regular maintenance" for what they had to do back then. People just don't want to screw with them anymore, that is why they are cheap, especially around here. You are also assuming that the 40/41 industrial equipment (forklifts and the like) didn't have rods knocking or other issues. Give me a break.
Before WW2 most engines needed a ring and valve job at 20,000 to 30,000 miles. During the war many advances were made like chrome piston rings, better alloys for pistons and engine blocks, better filters and better oil. After the war engines that looked identical to their mid 30s ancestors, commonly went 80,000 to 100,000 miles if looked after. Look at this report by the original owner of a 1951 DeSoto 8 passenger Suburban. It did 184,000 miles on the original engine with one rebuild at 80,000. If the flathead six can make it in that whale, towing a trailer through Death Valley and to the top of the Rocky Mountains it can make it anywhere. http://www.allpar.com/cars/desoto/suburban-1951.html
This was a couple years ago, I tried selling a set of engines and trannies for several months, finally someone took them for $150 for each engine/tranny set. This is about the going rate for something like that around here, it hasn't changed that much. Its cheaper to build a 350 chevy with twice as much HP than it is to rebuild one of these now.
While no big fan of the Mopar flat sixes, they were tough-as-hell motors. My dad bought a '50 Plymouth from my godparents for a work car, and my godmother had drove it for eight years with virtually no maintenance (and her parents had bought it new). Gas, and add oil when low, that was it. Got it cheap ($25?), but it needed a clutch and we thought brakes. The clutch was shot (from not being adjusted), but the brakes just needed a little love with a brake spoon. Did a tune-up and oil change, the car ran great for several years until I broke both rear main leafs in the springs speed-shifting it. One leaf wore through the fuel line, the car caught fire and the back half got burned. Car had 160K+ miles on it when my dad sold it (original motor, never rebuilt) to a guy who dropped the motor into a old Dodge truck... that truck was around for another ten years, with the same motor...
My advice was to make sure the engine was not locked up and to pull plugs so you don't have to fight the engine. smart aleck. This whole thing was spurned from my comment on 20-30k miles for major work that someone didn't like or agree with. Of course everyone that has had an argument with that statement has had flatheads from the early 50's, which is like comparing apples and oranges. Rusty has confirmed what I had to say. The OP 40/41 engine didn't have half of what made these flatheads great in the 50's. Like I said, the technology was not there. I suggested that he maybe better off looking into another drivetrain if it is trashed because he is going to be out a boat load of money for something that isn't worth the cash unless the engine and tranny are original. If he wants to keep them, I am not his mother, he can do what he wants with HIS car. It was merely a suggestion. Thanks for riding my ass, I appreciate it
I got this information from MoToR, the garage trade magazine from 1937. It said that most cars required an overhaul at 20,000 to 30,000 miles, and garage operators should be aware of this, and be ready to sell this service to their customers. An overhaul would consist of replacing piston rings, grinding in the valves and tightening the bearings if they were babbit. On the typical flathead this could be done in a few hours. Even then, engine design and construction was advancing rapidly. The WW2 came along and made reliable, long lived engines crucial. The desert campaign in North Africa was particularly brutal on equipment. This is where chrome piston rings and better filters were first used. I was surprised by the short life of the mid 30s engines. The same old engines, outwardly identical, were good for much higher mileages in the forties and fifties cars I grew up with. As I said, by then 80,000 miles was typical and 100,000+ was not unknown, although it was unusual enough to brag about. If an engine wore out at 50,000 or 60,000 miles it indicated hard use, neglected maintenance or maybe defective parts. This goes for American engines only. The first import cars from England and Europe, late 40s - up to the sixties, had short lived engines, 20,000 30,000 maybe 50,000 tops unless you were talking about a very expensive car in the Rolls, Bentley, Jaguar class.
Gee....my all original 1931 Dodge flathead six has never needed anything except the occasional plugs/points.....with 90,000 miles on it. Must be a fluke.
The 41 engine can be rebuilt with modern parts and give good reliable service. I know one guy who had a 41 Plymouth engine rebuilt just a few years ago. Before the rebuild he contemplated a rear axle or transmission swap for better performance. The rebuilt engine took away all desire for any changes. Once it was running right and developing full power for the first time in many years, he found it very satisfying to drive and not at all slow, considering. By that I mean he had plenty of power to get where he was going without holding up traffic. Although not enough to do any racing or long interstate hiway trips.
I, for one was not trying to ride anyone's ass. I was just curious as to where that info came from. My other '31 Dodge coupe had 80,000 on it without the head ever being removed, too, so I guess from that and from what I know about the early '30s Chrysler products, I was mystified by your statement. As far as finding flathead sixes cheap, it all depends on the location. Usually the ones located near the guy who needs one will be expensive. Usually, the ones out in the sticks where they are hard to retrieve or nobody wants locally are cheap.
You are literally like an encyclopedia for this stuff. Thanks for posting. I will have to try to find that magazine, I wish these ads and stuff were up on the web so we could review it easier. So the OP knock started, stopped, and now the engine just stopped running. We still haven't heard from him on whether or not the engine is locked or not or if his starter is engaging or not.
That comment was not meant for you, you were at least respectful and curious. I am surprised on your mileage, that is great. Do the parts from 50's flatheads work in the 40/41's? If not I know that, like everything else with the 40/41's, are extremely expensive.
I don't know why you think parts are so expensive. From Andy Bernbaum's site Complete engine gasket set, $85. Valves, $12.50 each. Rod bearings, $100 set, main bearings, $125 a set. All for a 41 engine, parts for 42 and up are even cheaper. http://www.oldmoparts.com/parts-engine.aspx Vintage Power Wagons has NOS pistons for $75 a set. http://www.vintagepowerwagons.com/pdf/parts/01engine.pdf Most parts are available from your local NAPA or other good parts store.
Ha ha ha thanks. If you get a chance to pick up some of those old MoToR magazines they are lots of fun. The articles are great, the ads are even more fun. They also published things like tune up specs, new car specs including prices that are very interesting to an old car guy. If you see a box of them at a flea market they usually go for peanuts like $5 or $10 for a box full. Nobody seems to want them because they are a garage magazine not an enthusiast magazine. Did a quick search and found this, about their annual auto show issue. http://www.sirensofchrome.com/sirens/?p=547 They sold for $1.25 compared to a quarter for the regular magazine. Wish I had some.
When I was in high school, I bought one of those little two door 49 (?) wagons sitting on the street for $30.00. I jumped the battery, and drove it to the gas station I worked at. The water pump leaked, but it had a grease fitting. I lubed it, and drove that wagon for another thousand or so miles. Great little flatty.
Thanks for all the advice. Sorry haven't updated, haven't had a chance to tear into it yet.(work gets in the way) As for the previous owner, I am not sure what all has been done to the engine. We purchased from his widow, and she knows nothing about the car other than the cosmetics that were done to it. So we are kinda working blind on our engine background and knowledge. If this one is dead, we want to change it out to something with power. (Just didn't expect it to be this soon.)
Ah, the power of the internet. I'd like to know what type "...head work..." would be needed on a flathead six several times in the first hundred thousand miles of use? It's a hunk of cast iron for cry'n out loud. I've had two old Chryslers with the 241 engines, neither needed any head work, aside from a quick re-surface when rebuilt at around 90K miles and 50 years of age. One of them injested a screw down the carb throat that did unkind things to a piston, and the other one shelled the top ring and headland of two pistons, which made some interesting noises, but they both still ran. Didn't hurt either head at all. Some truely useless advice in this thread...
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