Merle Coggins Posted June 2, 2011 Report Posted June 2, 2011 (edited) Last night when I was messing with my charging issue I got to looking at the markings on my engine block and head. I know this has been talked about here a few times in the past, but I just wanted to clarify it for myself. According to the casting marks my block was cast on Dec 5th of 1950 at around 2:00 PM. Is that right? That would cooespond with the "Dec 1950" stamped on the back of my head lights. This confirms to me that my truck was most likely built in December of 1950, or possibly Jan of '51. I don't see any date on the head, but it has the D/N thing. And it would appear that I have an elusive "P" head. Does that mean anything? Edited June 2, 2011 by Merle Coggins Quote
Young Ed Posted June 2, 2011 Report Posted June 2, 2011 I think that would mean your truck has possibly had a car head swapped onto it. I'm also surprised to see the casting date so closed to the suspected build date. I have heard Chrysler liked to let the blocks sit and season for a while. Quote
JBNeal Posted June 2, 2011 Report Posted June 2, 2011 ...I don't see any date on the head, but it has the D/N thing. look again, the casting date is partially in the lower right corner of the pic...the '48 had a '53 Plymouth engine in it, painted dark green, with an OKC engine rebuild tag on the block under the starter. From what I've read, engine swaps were common back in the day as it was feasible to pull a worn engine and replace with a refurbished unit. Quote
ggdad1951 Posted June 2, 2011 Report Posted June 2, 2011 (edited) yah, I doubt the blocks were made right as the truck was. Most of them were probably cast way in advance of the build. To get one close would be hugly odd IMO. It seems you also have head bolts that have been replaced. On my block (ed has seen this) there one side says "D" and the other "N"....someone forgot to turn the indicator in the tool! Edited June 2, 2011 by ggdad1951 Quote
Don Coatney Posted June 2, 2011 Report Posted June 2, 2011 On my block (ed has seen this) there one side says "D" and the other "N"....someone forgot to turn the indicator in the tool! Bet your block was cast on a Friday and that guy no longer works there:D Quote
Merle Coggins Posted June 2, 2011 Author Report Posted June 2, 2011 Yes, replacement head bolts used when I rebuilt the engine. I suppose it's possible that my truck wasn't built in 1950. It is titled as a 1951, but I call it a '50 as it's a B-2 model. I suppose it's also possible that it have a replacement Plymouth head. When did Plymouth switch to internal bypass? I'll have to have a closer look at the head for a date. I did see those other numbers showing in the picture but I didn't notice them as I looked at the head. They appear to have been ground down a bit. The block has the correct numbers for my truck so I don't suspect it has had a replacement engine. Also, the truck only had around 47,000 miles on the clock when I got it. Maybe I'll have to spring for info from the Chrysler Historic people to find out for sure. What all with their report show? Has anyone got one lately? Merle Quote
Young Ed Posted June 2, 2011 Report Posted June 2, 2011 Merle I believe Plymouth switched for 1951. Quote
maverick Posted June 3, 2011 Report Posted June 3, 2011 the heads on my 51 and 53 both have this "p" on them and they are both original heads. one even had the original factory gasket under it. the d & n are for day (first) and night (second) shifts. in 52 or 53 they added a third shift indicated by a 3 after the n. the clock indicates on what hour of the shift the block was cast, but i am not sure where the first hour is located. I would imagine that your block was cast in the second hour of first shift on that date. Quote
Don Coatney Posted June 3, 2011 Report Posted June 3, 2011 the heads on my 51 and 53 both have this "p" on them and they are both original heads. Intertesting! The "P" head may be a Dodge Truck only item. Others believed the P was a Plymouth item and some have paid huge sums of money to find this head to install on there Plymouth. Quote
Dodgeb4ya Posted June 3, 2011 Report Posted June 3, 2011 (edited) Maybe "P" means powerful performance head? Edited June 3, 2011 by Dodgeb4ya Quote
Fernando Mendes Posted June 3, 2011 Report Posted June 3, 2011 To facilitate with Jeep block markings. Quote
greg g Posted June 3, 2011 Report Posted June 3, 2011 P might be for Peter who was a forman in the casting shop. He was exceedingly proud of his work and marked all casting made on his shift with the P. Quote
HanksB3B Posted June 3, 2011 Report Posted June 3, 2011 and those individuals that have a "Plymouth" head on a Dodge truck (due to usual assembly line screw-ups and last minute shortages) are in denial. Hank Quote
Young Ed Posted June 3, 2011 Report Posted June 3, 2011 The engine in my 46 dodge truck which is out of a 52 plymouth car. The picture of my 48 engine doesn't show the letter area very well but I believe its blank. So I'm going to guess that the P heads came out after the 46-48 series. Quote
Don Coatney Posted June 3, 2011 Report Posted June 3, 2011 P might be for Peter who was a forman in the casting shop. He was exceedingly proud of his work and marked all casting made on his shift with the P. So is born the Peter principal. Quote
Fernando Mendes Posted June 3, 2011 Report Posted June 3, 2011 http://ww2jeeps.com/htm/heads.htm Quote
greg g Posted June 3, 2011 Report Posted June 3, 2011 no P one either my p15 head and my p28 heads. Quote
HanksB3B Posted June 4, 2011 Report Posted June 4, 2011 The engine in my 46 dodge truck which is out of a 52 plymouth car. The picture of my 48 engine doesn't show the letter area very well but I believe its blank. So I'm going to guess that the P heads came out after the 46-48 series. between just below spark plug #5 Hank Quote
John-T-53 Posted June 4, 2011 Report Posted June 4, 2011 I have a P head! But it's not original to the truck. The head is dated 7-18-55 and the block is 3-10-53. To support the ggdad's earlier comment, my bellhousing has a 1948 date casting on it. 1 Quote
norrism1 Posted June 4, 2011 Report Posted June 4, 2011 Could the "P" mean the plant location. Plymouth MI. maybe? Quote
ggdad1951 Posted June 4, 2011 Report Posted June 4, 2011 (edited) or possibly rev level but talking to my buddy today plant location is a good guess as well Edited June 4, 2011 by ggdad1951 Quote
Jocko_51_B3B Posted November 29, 2015 Report Posted November 29, 2015 (edited) I'm bringing a flathead six back to life. This head came from a 50 Dodge 1/2 ton. Anyone have a clue about what PT means? And what about the number under PT? There is another mark on it too. I think it says NH or something as well as a clock pointing to the fourth dot starting from the one o'clock position. Here's another number on the block. I read that the A means "morning shift". There are a few numbers and markings on the crank too! I have no clue what they mean either... Unless I have it wrong this means the block was cast during the "first hour on the day shift" Edited November 30, 2015 by glenn777 Quote
JBNeal Posted November 29, 2015 Report Posted November 29, 2015 I do not see a casting date on the head, so I am not sure what is going on there. My interpretation is that flathead block was cast November 20, 1950, first hour day shift. The crankshaft p/n appears to be 952068; according to my B-series truck parts manual, the crankshaft for the truck engines was 952066...maybe your crankshaft was from a car engine? The stamped serial number on the block could give a clue as to what is going on with the engine with some deciphering 1 Quote
Dodgeb4ya Posted November 29, 2015 Report Posted November 29, 2015 Engine casting #'s can be a number or two off from the parts books. The Mopar car and truck parts books show part # 952066 for a 218 with the 3.3.75" stroke crankshaft. two #'s off. Both my Federal Mogul bearing books show a part # 952068 as the 218 crankshaft casting # which is correct. Quote
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