Carrier block numbers
 

Brought a New Zealand carrier which came with this spare Carrier C81A engine. So tempted to leave it but after a day of transport then a day of wire wheel, water blaster and socket set , here is the before and after. Prefect in every way but seized. Currently don't have the tools to un-seize it. Can someone please decode the block stamp. Looks like 1MTWS! or 1MTW51

Attachment 139947 Attachment 139948

Attachment 139949

Carrier Engine?
 

I would have thought an 81A engine is 3&1/16th in the bore , so not a Carrier engine, These can be bored out to 3&3/16th to make a "100hp" engine, cheers Andrew.

I wasn't too sure if carrier engine. The family did have three carriers but may have had a supply of wartime engines from GT Gillies in Oamaru. Does the stamping indicate the bore size?

Using chat GPT:

Breaking Down "1MTWS1"
1M – Indicates a Mercury or Ford truck engine, commonly used in Canadian-built vehicles.
T – Typically stands for Truck application.
WS – Possibly refers to a casting location or production variation.
1 – Could indicate a revision or casting batch number.
Possible Identification:
Likely a Canadian-built Mercury flathead V8, possibly the 255 cu in (4.2L) version used in post-war trucks.
Related to the 8RT or 8CM engines, used in 1948–1953 Mercury trucks or heavy-duty Ford trucks.
If it has 24 studs on the cylinder heads, it’s a later flathead (1948–1953).
How to Confirm?
Check the stroke:
255 cu in Mercury engine → 4.00-inch stroke
239 cu in Ford engine → 3.75-inch stroke
Look for additional casting marks on the intake deck or bellhousing area.

Update
 

Quick update. I've learned a lot about flathead V8's over the last couple of weeks. Andrew is correct it is not a carrier engine but a model 81B engine. Which is 1938 221 cu.in.

I have a second engine I am working on for my carrier. It is not seized like the 81B. It is a model 99A, 1939 239cu.in. Out of a 1948 Fordson Thames truck.

I'm planning on getting this one going and I did get one bang out of it today on a engine stand. Get the carrier inside a workshop which has an overhead gantry crane. Take out carrier engine for a check and possible rebuild. Get the truck engine in so I can move the carrier around.

I did that about 11 years ago. I removed the original engine for rebuild, and in the meantime modified an 1948 8BA Ford engine to fit into the carrier (as opposed to modifying the carrier to fit the engine) to get ready foe an event. I loved the extra horsepower along with the great oil pressure. That engine is still in the carrier and the carrier engine (aolong with another working carrier engine I since picked up) remain on the sidelines.