RonJ Posted December 23, 2022 Report Share Posted December 23, 2022 Hours of internet research has not provided a definitive answer. I am interested in learning what engine size is in my car. I was told it is original but some points made in another topic lead me to question that. It is a Canadian car with Dodge emblems. The ID plate says Model D25C. The engine number indicates it could be from a 1940 Plymouth (but says 23”) based on documents and the Allpar website, Flathead Six and other groups and forums. I will remove the plug on #6 as suggested to determine the stroke but the diameter of the bore will be still be a question. Can the actual engine be determined from the casting numbers below? Stamped P10C6262 Above the starter 666029 On the head -K158 1139403 On the block A307 On the manifold 1116291 Quote Link to comment Share on other sites More sharing options...
rallyace Posted December 23, 2022 Report Share Posted December 23, 2022 A P10 motor would be 201 cubic inches. They had standard overbores and I think the max was 0.060" which would not add much to the displacement. Quote Link to comment Share on other sites More sharing options...
Los_Control Posted December 23, 2022 Report Share Posted December 23, 2022 (edited) 56 minutes ago, RonJ said: Text removed .... Sorry was meant for another thread Edited December 23, 2022 by Los_Control Quote Link to comment Share on other sites More sharing options...
RonJ Posted December 23, 2022 Author Report Share Posted December 23, 2022 Thanks. And here I was thinking I had the powerhouse 230 cu in. At least this one runs quite smoothly. Quote Link to comment Share on other sites More sharing options...
andyd Posted December 27, 2022 Report Share Posted December 27, 2022 The problem you might have is that while the engine might be stamped "P10" if its a Canadian built car then rather than the 23" engine with a 201 cube engine it maybe a 25" engine as Canadian built cars were supposedly all 25" engined cars and therefore be a 218.8, 228 or 250......measure the head length and check the stroke via that plug over # 6..........andyd Quote Link to comment Share on other sites More sharing options...
RonJ Posted December 27, 2022 Author Report Share Posted December 27, 2022 This morning proved that someone has been down this road before. The engine for sure is 25”, however the plug above #6 is either stripped or is an odd size. A 3/16” Allen wrench just spins and a 7/32” does not go in the opening on the assumption it was an Allen head. I’ve listed the casting and serial number in the flat head forum to see if anyone may know more or have a Canadian cross reference. Quote Link to comment Share on other sites More sharing options...
Sniper Posted December 28, 2022 Report Share Posted December 28, 2022 It might be metric. The bleeder fittings on my rear brakes use an 8mm wrench but have SAE threads, go figure. I found this out when I went to replace one because the hex was rounded off and my SAE wrenches wouldn't work. Quote Link to comment Share on other sites More sharing options...
RonJ Posted December 28, 2022 Author Report Share Posted December 28, 2022 That’s interesting. I’ll try it, but likely I’ll have to trim an “Easy Out” to the right diameter and insertion depth but may not go through the trouble at this stage. I have been given some detailed information on the Flathead Six Facebook page. The summary is that it is likely a 218.06 cu in. from a 1940 Plymouth. Quote Link to comment Share on other sites More sharing options...
RonJ Posted January 2, 2023 Author Report Share Posted January 2, 2023 Just for reference for those that may find this thread in the future. It is not the spark plug that is being referred to. The plug is above #6 cylinder is located as shown by the pencil. Unsure of what the original purpose was. Quote Link to comment Share on other sites More sharing options...
RobertKB Posted January 2, 2023 Report Share Posted January 2, 2023 I own a D25 which is the Canadian 1946-48 Dodge. If the engine is original to the car it is a 218. The engine serial number should also start with D25. Quote Link to comment Share on other sites More sharing options...
keithb7 Posted January 2, 2023 Report Share Posted January 2, 2023 A Canadian 25" long 218 ci engine This is 3 ⅜" bore x 4 1/16" stroke. Be aware that this is a very different engine than the USA 23" 218 engine. The USA 218 is 3 1/4' bore x 4 ⅜ stroke. Quote Link to comment Share on other sites More sharing options...
Sniper Posted January 2, 2023 Report Share Posted January 2, 2023 1 hour ago, RonJ said: Just for reference for those that may find this thread in the future. It is not the spark plug that is being referred to. The plug is above #6 cylinder is located as shown by the pencil. Unsure of what the original purpose was. the original purpose was to set the timing. Quote Link to comment Share on other sites More sharing options...
RonJ Posted January 3, 2023 Author Report Share Posted January 3, 2023 Makes sense. Never would have thought about using #6 instead of #1. Now I really need to work at getting that plug loosened, just in case. Quote Link to comment Share on other sites More sharing options...
keithb7 Posted January 3, 2023 Report Share Posted January 3, 2023 If you look at #1 you’ll see the thermostat and related parts are in the way of where a timing pin hole would sit. 1 and 6 are in the same position of crank throws. So they put the timing pin above 6, where it could sit easily. Quote Link to comment Share on other sites More sharing options...
RonJ Posted January 3, 2023 Author Report Share Posted January 3, 2023 Very informative. I’m learning every day. Quote Link to comment Share on other sites More sharing options...
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