A newbie question cause I'm new

[UncleDonnie]

Subject: 1951 Plymouth P-23 engine. I'm in search of an engine to rebuild while still driving my car this summer. Question: Are there any differences from a standard shift (mine) and the fluid drive crank flange etc? Question: What year spread and brands (Chrysler, DeSoto, Dodge, Plymouth) should I look for in a donor vehicle? Thanks in advance, Don

Edited March 18, 2015 by UncleDonnie

[Plymouthy Adams]

do you wish later to have the car judged and if so you will want to retain the P23 stamping on the engine boss..as 51 and 52 shared P23 stamping..you will want to ensure you engine number will therefore fit within the 51 build sequence also....the P23 is 218 and the Dodge of the era, with fluid drive predominate is the 230 and will have the 8 bolt holes...either will work on the Plymouth..only the 8 hole will work on the fluid drive Dodge..moving to some

Chryslers of the era you will want to be watch for the length of the block as the 251 and later 265 are a bit longer..quick compare..23 to 25 inches.  Desoto is also an option but do your homework here also..

[Don Coatney]

Crankshaft flange depth may be different on an 8 hole crankshaft. Your starter gear to flywheel ring gear alignment may be different. Measure carefully.

[Plymouthy Adams]

is it not the flywheel itself that is machined differently for the offset mounting on the Dodge..?  Many have made the 218 to 230 upgrade and I think they used but just the rods and crankshaft...I have never first hand did the 230 component swap (stroking) of the 218 in the Plymouth

[Don Coatney]

In my case using a Desoto 8 bolt crankshaft and a P-15 flywheel and bell housing I ran into the problem.

[Plymouthy Adams]

now the next question, is this due to the Desoto being a longer block engine..mixing and matching 23 inch items to the larger 25 inch block...

[Don Coatney]

now the next question, is this due to the Desoto being a longer block engine..mixing and matching 23 inch items to the larger 25 inch block...

Possibly?

[greg g]

My suggestion would be to try to find a 230 engine. If you are not interested in maintaining

Plymouth Owners Club judging criteria, this would be a worthwhile upgrade to your cars driveability. So late 54 Plymouth and later would be the easiest swap. I have a 56 engine in my 46 coupe. Stock HP was 125 compared to 97, and basically parts is parts when looking at the rebuild stuff, so why not go for the more cubes in the bargain? You can look for non automotive sources also. Massey Furguson used 230 to power combines, Clark tractor used them for airplane tugs and other ground support equipment, lots of forklifts, welders air compressors and other construction stuff had industrial engines from Chry corp. Also Dodge trucks can be as donors but will recuire the use of your current bell housing as rear motor mounts were different. Many options available to you but you need to define your needs as per driver or show car.

[David Strieb]

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[48ply1stcar]

I switched engines from a 218 to a 230 that had been an automatic.  Both 23 inch engines, but the crank was 3/8th inch longer on the 230.  Maybe the crankshafts would have been the same length had they both come from cars with manual transmissions.