346cu Enguine Numbers

[MARK HEWITT 20209]

Have in the last couple of days aquired two Cadillac 346cu Enguines ; the numbers are
             4G4548  ( stamped above water pump)
             3F5251  (     rear left of block )
My hunch these are WW2 Tank Motors. What do the experts say ?

[JIM CLC # 15000]

05-20-06
Mark, Have had a 38 La S with an ARMY tank engine.
The SN was stamped in the block, above the water-pump. I am not where I can checkthe replacement engines SN location. The difference between the SN on the ARMY tank engine you seem to have and the one that was in my La S is the SN on my engine started with an ARMY quatermasters logo prior to the number.
If you can find any OD paint on the engine that would seal it for sure that you have an ARMY TANK engine.
HTH
Good Luck, JIM
P.S. If the engines have the distrib.and it has a tachometor drive on it its for an ARMY tank.

[John Tozer #7946]

Mark,

They are both tank engines. I have 3F421. There is a Code for these engine numbers that will tell you what year they were built in but I have put it away safe somewhere. I seem to recall that the G series were 1941 but I wouldnt swear to it.

Although referred to as tank engines, (and they were used in groups of 3 in the Australian Sentinel Cruiser Tanks - you can see these if you search the Australian War Memorial Collection Database for WW2 by typing in Cruiser Tank) they were used in many other applcations including, in a marinised form, in small launches as well as, I suspect, replacements for all the 37/8/9 etc Cadillacs requisitioned during the war.

Thye were also freely available two-up on an A frame after the war still packed in grease for 50 quid each. Cheaper than a rings and bearings job so most pre war caddies in Oz dont have the original engines in them.

They did great service as pump motors in the irrigation areas back when petrol was cheap as chips and my cousins, who used them in ski boats (until they routinely ran the bearings) swear that nothing else would pull five skiers out of the water at once.

I believe I got the Code to the engine numbers from an old LaCad or Self Starter so maybe someone else remembers it too.

Regards,



John Tozer

[Don Boshara #594]

From an article by Pete Dapkus in the 10/78 Self Starter: The 4G series was used in an amphibious personnel carrier called the Alligator or Amtrak which was a vehicle utilized by the Marine Corps for amphibious landings.  There was no reference in the article to the F series.

[Rhino 21150]

Yet another 346 powered war vehicle is the T19E1. It was an armored scout car, looks awesome in the latest (July) issue of Hemmings Classic Car. Only one built with six wheels and twin 346s on a Chevrolet chassis. The T17E1 was sold to the Allies, four wheels, all Chevy.
T19: http://www.warwheels.net/T19E1ArmoredCarINDEX.html TARGET=_blank>http://www.warwheels.net/T19E1ArmoredCarINDEX.html
T17:http://www.wwiivehicles.com/usa/armored_cars/t17_armoredcars.html
I looked at the specs on the 17, my Oldsmobile is longer and wider! But only weighs half as much....

[Bill Gauch]

So would it be period correct to put (1) 37mm cannon and (2) .30 caliber machine guns on my 38 or would I need to find a few years newer car?

[Bruce Reynolds # 18992]

Gday Bill,

I think that you had better put stronger springs under your 38, and strengthen the chassis first.

Bruce,
The Tassie Devil(le),
60 CDV

[Rhino 21150]

With all the advances in modern weaponry, just put a couple of AKs and an RPG on the front seat! Although, if you have a BMG laying around you could mount that on the roof. Let the belt go through the sunroof you have been dying to install.

[Mark Hewitt]

Thank you everyone for your input .The two motors are of course in Cadillac Green which has an excellant contrast with Australian neck paint (Red ochre ) which also contrasts well with Green and Gold.

[John Tozer #7946]

Mark,

This has taken a while but a combination of the receipt of some information from the GM Heritage Centre on two cars exported to Australia in 1937 and 1938, and the post from Ralph Messina on the General Forum regarding Engine Unit Numbers has helped me put 2 and 2 together.

Here is my offering on the military engine numbers and Engine Unit Numbers:

As Ralph confirms in his post there was, in my view from 1936 at least, a difference between the Engine Number (sometimes referred to as the Motor Number on some build sheets) and the Engine Unit Number.

For example, I have a 38 La Salle engine, Engine Number 2274403. This has Engine Unit Number 2C4063. The build sheet confirms that the Engine Unit Numbers were NOT always in sequence with the Engine Numbers. The build sheet for this engine is the same build sheet for six (6) 38 La Salles exported to Australia with Engine Numbers from 2274400 to 2274405 but with Engine Unit Number 2C4059 allocated Engine Number 2274405 and 2C4069 allocated 2274400 (in fact the reverse order to the Engine Unit Numbers).

Likewise, the build sheet for eight ( 1937 75 series Cadillacs with Engine Numbers 3132081 to 3132088 have Engine Unit Numbers 3B2142 to 2149 but NONE of them in sequence with the Engine Numbers.

Finally, as  mentioned in an earlier post, I have tank engine 3F421. This number is STAMPED where the engine number is on all other flatheads I have seen - rear top of the block on the left hand side

I believe the Engine Unit Numbers started in 1936 as 3A----. In 1937, the first year of the La Salle V8, the Unit Numbers became 2B---- (for the La Salle) and 3B---- (for the Cadillacs). In 1938, the La Salle got 2C---- Unit Numbers and the Cadillac 3C----.

Following this logic, with 2D and 3D being 1939, 2E and 3E being 1940, my 3F421 engine was a Cadillac engine produced in 1941. This is consistent with a GM Holden marinised Cadillac flathead V8 manual that I have that has the test results for a 3F---- engine dated October 1941.

Following this logic, your 4G4548 ws manufactured in 1942.

But how come it is prefixed by a 4???

I am going to take a shot in the dark here and suggest that, since vitually ALL Cadillac engine production in 1942 was for the war effort, they simply classified all engines (being neither for Cadillac or La Salle cars) as the next number in line - 4.

The theory will be shot to hell if anyone ever turns up a 322 c.i. flathead unit number 2F---- (that would have been a 1941 La Salle) or ANY engine where the Engine Number belongs to one year and the Unit number to another. Someone with an original 1936 engine might be able to let me know what their Unit Number is.

ANYWAY, I would have a round or two on your 3F engine being a 1941 tank and your 4G a 1942.

Hope this is of interest.


Regards,



John Tozer

[Jeff Hansen, #4225]

John,

This is turning into an interesting discussion.  Let me see if I can add something constructive to it.

My 1942 series 7533, which left the factory Sept. 27, 1941, came with engine unit number 3G48 (information taken from the build sheet).  This would seem to go against your theory of 1942 engines starting with the 4G prefix.

However, it is possible to theorize that Cadillac used the 3G prefix prior to halting passenger car production and then switched to 4G thereafter.

Also, in referencing the 13th edition of the Cadillac Master Parts Book, published July 15, 1949, group 8.0025, crankcase fitted with pistons,  bearings, etc., a note indicates, factory will stamp engine number on block when specified on order.  One could also theorize the factory might stamp the unit number as the engine number on a factory replacement engine if the number was not specified on the order.

Hope this is helpful.

Jeff Hansen

[John Tozer #7946]

Jeff,

Actually, your information confirms my theory, though in reading my post again I didnt put it very clearly in relation to the 42s.

Your G number fits with the 1942 year and your 3 prefix fits with the theory that 2 went with La Salle cars (and matched the 2 that all La Salle engine numbers of the era start with), 3 went with Cadillac cars and 4 was reserved for all engines produced solely for military purposes, at least in 1942.

I was hoping a 1942 owner might respond as your advice adds to the investigation of my theory.

Regards and thanks,


John Tozer

[JIM CLC # 15000]

09-0-06
John T. When I got my 38  Cadillac-La Salle it had an ARMY tank engine in it.  Because of the condition of the engine, I replaced it with an engine from a 47 60S or a 47 62. On the ARMY engine the S/N stamped above the water-pump had an ARMY Quartermasters insignal (world globe with flames) and four (4) numerails (sic),which I dont remember.
HTH
Good Luck,JIM

[Ralph Messina CLC 4937]

John,

I’m not certain what to say about this discussion as I’m not familiar with pre-’49 engines. My comments on the other forum about Engine Unit Numbers (EUN) were based on my experience in manufacturing. Every industry /company has lot control systems that enable them to track the subassemblies that make up the finished product. In each case the system may be for internal purposes only, and lost to antiquity when a new system is instituted and those with the corporate memory retire or move on.
In the case of automobiles, traceability was not mandated by the government until we started recalls and lawsuits in the mid 70s. In the 40s and 50s, the life expectancy of a car from the manufacturer’s viewpoint may have been 5-7 years, during which they expected to support service for their product. As such, they were free to change their traceability systems at will. Over time with regulations, faster technology changes and greater corporate wide components, manufacturers have had to keep better records for longer periods. I suspect in the chaos surrounding the massive and rapid conversion to war production almost anything could and did happen as long as to parts left the shop on time.

I think the best way to get an answer to our questions about EUN and Engine Number (VIN) would be comments from someone who worked in GM manufacturing. Maybe one of our readers knows a GM employee from the 50’s and could get their comments.

I’d like to add to Jeff’s comment about replacement engines. In the 50s and 60s the factory would supply a replacement engine with a vehicle’s original Engine Number (VIN); however the EUN would be different than the original’s. It would be the then current EUN corresponding to when the new engine was built.

Regards,
Ralph

[John Tozer #7946]

Jeff,

Latest update after a message from Tony Simione who is restoring a 36 coupe - his Engine Number is 60144-- (last two digits illegible) and his Engine Unit Number is 6A49-- (last two digits illegible). This so far confirms the theory that the Engine Unit Number started as an A  classification with the first producion of this flathead in 1936 and ran alphabetically through to 1942 at least (G classification) in strict alphabetical order.

The only part of the theory that has had to be modified is that, while the prefix 2 as in 2D---- in the Unit Number always seems to have been used to identify the 322 c i La Salle engines, the 346 c i Cadillac engines could be prefixed 3 or they could pick up the first digit (6 in Tonys case) from the Series number).

By the way, Tony has confirmed that the Frame number stamped into his vehicle chassis also starts 6A44-- matching he thinks (as it should) the Engine Number stamped into the block in front of the fan support but, interestingly, with the A from the Engine Unit number inserted.

Regards,



John Tozer

[Warren Rauch]

 You would think Cadillac would list these numbers somewhere. The 1949-56 which are in the same series are listed in the front of the early 50s parts books. Ive found some of these,not all.
 1936 series 50 is 2A,series70,75 is 3A,series60 is6A
 1937 series 50 is 2B,series 70,75 is 3B,series 60 is 6B,series65 is7B
 1938 50 is 2C,70,75 is 3C, 60S is 6C, 65 is 7C, 60 is 8C
1939 50is 2D, 75 is 3D, 60S is 6D ,61 is 8D
 1940 50 is 2E,75 is 3E,52 is 4E,60S is 6E,72 is 7E, 62 is 8E
 1941 No luck finding
 1942 67,75 w/std trans is 2G,67,75 w/auto is 3G,60S,61,62,63 w/std is 8G, 60S,61,62,63 w/auto is 9G
 1946 75 ( std?) is 2H, 60s,61,62 (std?) is 8H
 1947 75 (std?) is 2J, 60s,61,62 (std?) is 8J
 1948 No luck
 1949 75,86 w/std is 2L,60s,61,62 w/std is 8L, 60s,61,62 w/auto is 9L
 1950 75,86 w/std is 2M,86 w/auto is 7M,61 w/std is 8m, 60s,61,62,75 w/auto is 9m
 1951 86 w/std is 2N, 86 w/ auto is 7N, 60s,61,62,75 w/auto is 9N
 1952 start w/ R
 1953 start w/ S or SK
 1954 start w/ T or TK
 1955 start w/ V or VK
 1956 start w/ X or XK

 The K on these last few is for air cond. cars.The late 40s look like you could add K for 1948  and 3 and 9 for auto trans for 1946,1947 &1948, like the 1942s.The 1941s , are anyones guess. Warren