LaSalle Engine Numbers

[Tom Beaver CLC 22002]

Can anyone indicate the location on the block where the engine numbers are stamped.  I have attacked the block out of my 38 LaSalle with wire brush and scraper at all places I thought likely with no result.

[JIM CLC # 15000]

03-19-05
Tom, Im working from memory right now, but I think if you will clean the area to the Rear of the drivers side cylinder head, on the block,  you will find it, if not there, try any flat spot on the block. It may be on the block above the water-pump.
Good Luck, Jim

[John Tozer #7946]

Tom,

My 38 La Salle motor has the engine number on your drivers side rear of the block immediately behind where the casting rises up around the back cylinder on this side. It runs parallel to the fire wall. When you find it, let me know if it has a star stamped into the block at each end of the engine number please.

Regards,


JOHN TOZER

[Tom Beaver CLC 22002]

John,
I found it where you and Jim said to look, on the left rear side of the block right near the parting line with the bell housing.   The number is 2244881.  It definitely has a star after the number and maybe before its hard to tell.  The confusing thing is that the membership directory indicates that this engine number is a 1937.  However it was supposed to have come from the car I have which is a 38-5027.  Now I have a second engine which was supposed to be for spare parts.   The number on it is 2277821 (with stars on each side of the number)  which I guess is a 1938, however the heads on it have 10mm spark plugs which I thought were used on engines after 1938.  Im not sure what I have.

Anyway what is the significance of the stars?

Thank you for your reply.

Tom Beaver

[Doug Houston]

It appears that the engine in question is an assemblage of parts from a few other sources. I just went through researching the changes made on that engine series from 36 to 48 for an article I have written.

Near the engine number as youve found. you will see an alpha-numeric number stamped. This is the engine unit number, which is the true serial number of the engine. it went on the engine as it was built, and before it was assigned to a chassis on the line. The letter in the engine unit number tells the year of the engine.

Letter "A" means 1936, "B" was 37 and so on. If your engine is a 38, the letter will be "C". The engine unit number is rarely of  use for servicing, although in 1956, there were some changes made to the engines, and the parts book gives the break points by engine unit number, so the unit number has some significance.

The spark plugs on Cadillac were 14 MM through 1938, and went to 10 MM in 39 through 48. Someone may have put later heads (1941, maybe?) for higher compression. Compression ratio was raised in 41 to 7.25:1 Some heads had numbers like: 346  725  stamped in the center rib of the head. this wasnt a part number, but it told that the head was for a 346 Cu. in. engine, with 7.25:1 compression ratio. Another trick that Cadillac did was to use LaSalle heads on the 75 series cars prior to 41 to get increased compression ratios, and a bit of a boost in horsepower.

Now, the stars. Theyre mostly for making changes difficult or impossible, if possible.  If the stars are gone, presumably, the engine number has been changed. I seem to remember that when you ordered a service engine, the factory stamped the old number on the new engine for you.  

[John Tozer #7946]

Hi Doug,

In your research did you happen to turn up anything that suggested that the engine numbers assigned to military or tank engines followed the same or a similar alpha numeric system for their engine numbers?

As you probably know, the military engines (at least all the numerous ones that I have seen here in Australia where they were sent in their thousands) have a number like 3F421 or 3G8641.

I have read somewhere that this was just a continuation of the same numbering system - e.g., F was 1941, G was 1942 etc. following on from the "A was 1936" - that you refer to.

I have in my collection of manuals a power curve drawing prepared by GM Holden off engine number 3F4057 that was used in a marine engine developed in the early days of the war to power light general purpose launches. The drawing is dated 30 October 1941.

I am also very interested in your comment about service engines having the same number as your original engine. This might explain something that Matt Larson turned up for me when researching the 1937 75 series cars that came to Australia. He found a build sheet refering to six engines that replaced six that were dropped by the shipper on the dock while loading on a steamer. They had numerically the next six engine numbers to another group of eight engine numbers that came out here. Matts comment is "It is very unusual for serialized engines that were to have been installed in production cars to be shipped as replacement units."

This comment would seem to support your view that service engines always had the same numbers as those they replaced.... as long as they came from the factory!

Your information on these engines is very interesting by the way. Are you proposing to publish it some time in the future?

Regards,



JOHN TOZER

[Doug Houston]

Since I have had very (mighty) little involvement with the tank engines, it appears that your data tracks with engine unit numbers as they were used. That convention followed even to the V16 engines. I hasve a couple of blocks here that have the numbers on them, and the unit numbers do follow the serial numbers on the blocks. The serial numbers are 527XXXX and the unit numbers have a "C" in them. That means:1938. On serial numbers on service engines, Ive always understood that it was a felony to alter an engine number, other than by the manufacturer. that all seems to add up.

 In fact,thinking of it, the first car that I owned was a 46 Plymouth. It had been my Mothers car, and was given to me  in 1952. Back in 1948, there had been problems with the engine, and Father had connections with Chrysler Engineering. They had me take the car over to the engineering garage for examination. This was in Highland Park, a city surrounded by Detroit, and the community where I was a Junior college student. When I picked up the car a couple of days later,  the engine had been replaced, and the serial number on it was carried over from the original engine. Here it was: the FACTORY supplied the new engine!

Publication of the article will be in the Michigan Region of CCCA  "TORQUE", in a couple of months. Ill give the manuscript to the editor this evening. As Ive written it, it covers 6 pages, and has 10 illustrations. The reference material was from the annual service manuals, and parts books. Fortunately, I have all of the shop manuals from 1936, into the seventies. Theyre handy. I think that individual copies of the magazine will be available. Theres usually a surplus thats printed.

[John Tozer #7946]

Doug,

It all fits into the overall pattern. Thanks for that and put me down for a copy of your article if you would please.

Regards,


JOHN TOZER