VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 Engine date

Can someone date the engine, T2627002 ?
Thanks in advance.

Need the casting numbers off the block just below the pad where you got the numbers off of. I can tell you right now you have a truck engine. That is what the T stands for.

Thanks. I'll get the data on next trip to it.
I am guessing a 1926 as it has an internal gear oil pump. The 27 had a vane pump and the 25 had an external pump.
However that is what I know about automobile engines.
What would be typical differences between a truck and auto engine. Must be something to make the use the T desigination on the engine number needed by the factory.

Not really sure what differences are but suspect thinks like piston fit and ring fit may be some. I know later engines like Oldsmobile 455s and 350s had several specs used for engines bepending on use. Like irrigation engines had certain valves used and marine engines had other items used. The high performance W-31 350 engine had special fit pistons that were acually loose in the bores right from the factory. They broke down the clearance tolerances, into letters which covered a small part of the size tolerance. In the W-31 they used A size pistons in D size bores. Pistons were stamped on top and blocks were stamped next to the bores.I have seen that on many GM V-8s. They used those size codes to help the engine assemblers fit the pistons faster on the line as 1 engine could have several bores that were different letters. The 20s Chevy truck engines may not have used stamping like that but may have just been measured by hand which would take more time.

Casting number is On the water jacket there are these numbers, 346709.

Still interested on what makes a truck engine a truck engine.

Thanks for all of the input thus far.

This might help you a bit. As far as I know the only difference is the 'T' in front of the engine serial number.

http://clubs.hemmings.com/clubsites/chevytalk/GMhistory/1924-28.pdf

346709 is the casting number for a 1926 block.

Roger

My guesstimate is that it dates to around September 1926. The T prefix indicates that it was a Utility Express Series X engine, and its number that it's a 1927 Selling Season unit.

Glad to see that members are still referring to my website!

Down here in Aus all our 20's engines had an R prefix for cars and a TR prefix for trucks.
The truck engine in 1928 for both models LO and LP still had cast iron pistons, I guess they being stronger than aluminium ones, and I believe a slightly lower compression ratio. Other than that they are exactly the same as the car.
Chris

In 1928 in the AB Light Delivery chassis there was also the rare X- and XR[rhd]- prefixed engines. These had the truck compression pistons in the car engine. This meant 32bhp from the 4.3:1 cast iron pistons versus the 4.5:1 and ally pistons. Ideal for hard work that would not overheat the engine, and thus for export. New Zealand had some though no evidence yet that Ausralia did.