hey guys, thinking about buying a 47 plymouth coupe...going to be a hot rod. and I want to go with a flathead Mopar, 6 cyl.. which is the best to start with ?? will be rebuilt as a hot rod motor, dual carbs, headers, cam, ect.. thanks
If your gonna get to know Mopar flatheads you better make a call to a guy named George Asche. He's in the know
The 47 came with a 218, the dodge of the same era was a 230, you can make a 230 out of a 218 by swapping in the roatatig pieces from the 230. If you can find a desoto or Chrylser, they had a 251 but they are 2 inches longer so you need to change motor mount locations and move the radiator forward and maybe notch the front crossmember to accomodate the length. there are dual intakes and exhausts available, they respond well to extra compression. But long stroke so keep the rpms moderate.
'52 thru '54 Chrysler Windsors had a 265 cu in flatty...same exterior physical size as the other DeSoto & Chrysler 6's..... Ray
As you live in Canada you are in luck. Canadian Dodge and Plymouth came with a detuned version of the DeSoto/Chrysler engine. You could bore your block to 3 7/16, install the crankshaft and rods from a 265 and have a 265 cu in engine. You have to be careful when ordering parts. The Canadian D/P/C/ DeS engine is the large, 25" long engine. US Dodge and Plym came with a smaller, 23" long engine. Parts are not the same. The Chrysler built flatheads were a strong well engineered motor. Aluminum pistons, full pressure oiling system, and insert bearings like today's engines. No iron pistons, babbitt bearings or splash oiling like certain rival makes. They built basically the same motor from 1938 to 1954 (Chrysler and DeSoto cars) 1959 (Dodge and Plymouth cars) 1962 (Dodge trucks) 1968 (Dodge Power Wagon army trucks) 1972 (industrial and marine engines). Thousands were used in M***ey tractors and combines not to mention air compressors, welders, pumps, etc. Most parts are available from your local auto parts store. Edgy Edgerton makes aluminum heads, reground cams and lifters, and possibly other parts. There are other tricks that do not require buying new parts such as modifying your intake for 2 or 3 carbs, splitting the exhaust manifold for dual exhausts, milling the head for more compression, boring the cylinders, and shaving the flywheel for whippier acceleration. It is possible to get a boost of 25% to 40% in HP with a few simple mods. It is not worth while to go too crazy because the expense is not justified. It would be cheaper to put in a V8. Developed HP does not tell the whole story. People tend to underestimate the usable power of the old flatheads. They are a long stroke motor and they develop a lot of punch at low to medium RPM's. This allows them to do their work easily with minimal gear shifting. If your motor was in top shape, and developing full power, I think you will be impressed with how much power it has for a "mere" 90HP.
If you get a 55-56 Plymouth or Dodge Motor it will drop straight in and has a factory rated 117hp from its 230 inches.
Wilcap makes *****in ****** adaptors.I've got a 700r behind my dodge flatty.Really makes a difference for cruisin on the freeway these motors don't like alot of rpm but are all about torque.Keep us posted.
Look for a company called "Edge" or "Edgy." I don't recall now. He makes finned aluminum heads and 2-carb intakes for them (Chrysler and Plymouth/Dodge versions). I believe Fenton cast headers are also available new. I don't remember the name of the site, but there's a Dodge Military power wagon site that has a ton of surplus parts for these--all NOS, and all reasonably priced. 230 stroker cranks and rods, flywheels, PCV kits, bearing kits, etc. etc. Do a little searching and you'll find it. Finally, I think someone may have mentioned this already, but after they were retired from the cars and trucks in favor of the Slant 6, they lived on in airport tugs, tow motors/fork lifts, and industrial pumps, well into the '80s. You can go to just about any parts store and buy parts for them--gaskets, rings, fuel/water/oil pumps, etc. For vintage stuff, Edmunds made a cylinder head and intake for them. I found an Edmunds head a while back, and thought about building an engine under it, hence the research on my end. -Brad
id like info on modifying the intake for multiple carbs and splitting the exhaust......and info on the military site as well....
Once again, Chrysler Corporation made 2 different six cylinder motors. A small one for Plymouth and Dodge, a big one for DeSoto and Chrysler. To save money, the Canadian factory only got one engine. The big six usually found in DeSoto and Chrysler. To make motors for Plymouth and Dodge, they juggled the bore and stroke to make motors the same displacement and HP as their American counterparts. What this means is, you need parts for a Canadian Plymouth or Dodge or American DeSoto and Chrysler. Hop up parts or any parts for an American made Dodge or Plymouth will not fit. The good part is a big Chrysler or DeSoto, 237 251 or 265 motor will drop right into your car no problem. You can even bore your block to 3 7/16 and use stock Chrysler pistons. The Chrysler crankshaft and connecting rods will also fit your block. The same block was bored 3 3/8 for Plymouth and Dodge. Or 3 7/16 for DeSoto and Chrysler. By the way this block can easily be bored oversize up to 1/8". This was a normal part of a rebuild back then. They also made crankshafts of different strokes, 4 1/16, 4 1/8, 4 1/4, 4 1/2, 4 3/4. By combining different bore and stroke they made a whole series of engines from 218 to 265 cu in. A 47 Plymouth would have gotten the smallest, 218 cu in version. The highest compression head was used on 56 up cars and trucks. Chrysler and DeSoto had a full flow oil filter like modern cars. Cheaper cars had a partial flow filter or none at all. The full flow is nice to have but not a deal breaker. The Plymouth has a lot to offer. Suspension, brakes, engine etc were state of the art for the time. A mild hop up is not hard to do. Parts are available reasonable. They get decent mileage, around 20 MPG. You can have a lot of fun for not much money and have a unique car. Vintage Power Wagons is another good source of motor parts as the Power Wagons used the same motor. Last time I looked they had NOS pistons for $75 a set of 6, a good deal.
Another good site to look at is P15D24, they cover Plymouth Dodge and Dodge trucks of the forties and early fifties. To make a 2 carb or 3 carb intake, go to the muffler shop for 2 flanges and 2 short pieces of pipe. Cut 2 holes in the intake with a hole saw and weld on the pipes and flanges. For 2 carbs, put a block off plate over the middle hole. Easy way to get dual exhaust, split the exhaust manifold. A neat way to do this is to make a square plate that bolts on the bottom of the manifold using the stock bolts. Weld on a short pipe and flange. Bore a hole up into the exhaust manifold with a hole saw. Bolt on your adapter plate. The other way is to weld a pipe onto the exhaust manifold. By cutting a piece off a junkyard exhaust manifold. Other things you can do without buying new parts, have the head milled .060 to .080 for higher compression. Shave the flywheel for snappier acceleration. Have the cam reground for more lift. Of course the Edgy head is the ultimate aluminum head but they cost nearly $700.
Olddaddy (www.rustyhope.com) can hook you up with a split manifold and disc brakes. George Asche is a must-call guy. 814-354-2621 If you want to run a TF I can help. If you want a cheap 5-speed then consider the Ford Ranger unit. http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=19456 I would suggest going to the 251-265 Chrysler. .
Vintage Power wagon has a site on the web for their catalog, George Asche does the dual carb from stock cast iron intake manifolds and also splits the exhaust. Charlie aka "Rusty Hope" here on the forum also does the manifolds and has a disc brake bracket and instructions to install disc brakes on the stock spindles with part numbers for all of the parts you will need. To reach George Asche you will have to go to www.P15-D24 home page and he and charlie are listed in the vendor section. Terrell Machine in DeLeon,Tx is also listed there and has all of the engine parts and can also rebuild the vacuum advance unit for you
I rode in George Asche's 265 flat motor and it kicks ***. I also have a very nice Edmunds aluminum head for a 265 you can buy.
Nothing cackles better than a mopar flatty.Fenton repop headers are worth the money and not that expensive,muffler shop down the street built me some tube headers they came out really *****in.Intakes pop up occasionally on this and other sites and they also repop those.The smaller shorter engine is easier to find aftermarket speed parts for than the longer chrysler at least that's what I've found.Sometime cams become available if you watch for them you'll probably have to have yours reground as stated in another post.You can also put the bigger chrysler valves in it but the intake valve has to be cut a little as the engine is shorter so not quite enough room but doable.Pertronix ignition or I've seen a converted HEI also available.Plydo and Andy Bernbaum are also good places for hard to find parts.
damn, I miss my ol flatty... <iframe src="http://www.youtube.com/embed/NkW17CYcTA8" allowfullscreen="" frameborder="0" height="360" width="480"></iframe>
WOW, what a ton of info, thanks a lot.. this sounds like a lot of fun comming up. One more thing, I live 10 miles from the US border, and buy a lot of old cars from Washington state. so should I just go south a buy a parts car.??? I also shop ebay when needed.. I would like the easiest way to go... sounds like the US motors and parts are easiest to get.??? thanks again, Lloyd
You aren't listening. I just finished telling you more than once, and others have also told you, that a Canadian made Plymouth is different from a US Plymouth, at least the engine and engine compartment are completely different. Some US parts will fit but others won't. Your engine is basically the same as any CANADIAN MADE Plymouth, Dodge, DeSoto or Chrysler and any AMERICAN MADE DeSoto and Chrysler. So obviously you would be better off with a CANADIAN MADE parts car.Hope this is clear. Motors are easy to get as such things go, because they were used in so many different cars, trucks, farm implements, boats, and industrial machines for a LONG period of time. Also they are not all picked over like Ford flatheads. I'm not saying every junk yard is full of them, although they were in the seventies. I am saying they are around if you look for them. I have six of them laying around. None cost me over $75. All were found within 30 miles of my house. All within the last 3 years. I could have had twice that many if I really wanted them. Like being willing to go 60 miles and paying $200. Also have some spare parts, including a brand new set of genuine Chrysler pistons, bought off Ebay for $10 apiece. Try that with NOS Ford flathead parts.
If it still isn't clear... Canadian made Plymouth and Dodge came with the big block of flathead sixes. Just like if you bought a Chev and it came with a big block V8. Wouldn't that be nice? Well when you buy a Canadian made 47 Plymouth that is what you get. Small block engines may be easier to get in the US but practically non existent in Canada. So why not be happy with what you have?
Heres how I split my exhaust. 251 Desoto The pictures pretty much tell the story. The second dump tube was cut from a Chevy V6 manifold. I MIG welded it on, and put a block off plate inside the heat exchange area.
hey Rusty, I do NOT have a motor yet... that is why I was asking, is it better for me to get a US car. that way parts are esier to get.. also there are not many Mopars, that old, in my general area, but lots in Washington....
contact member Moose he builds intakes and headers for Mopar Flat 6's go to his member page and click on his website link.
It is NOT better to get a US car. Parts are NOT easier to get. Even in the US, Chrysler and DeSoto parts are not that rare and in Canada, they all used the same motor anyway. Lots of American Plymouth and Dodge owners envy your car because the bigger Chrysler six fits so easy.
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