Hello, I was taking apart my 1928 Chevrolet car block when i noticed something a bit odd. The piston skirts are windowed, they are cast iron not aluminum. They have the factory bow tie logo on them so i assume they are oem. Does anyone have more information about these? I should also add that this block was cast August 13 1928 making it very late in the year.

. If your 1928 Chevy is model AB passenger car, it came with INVAR aluminum pistons. If you have a LO or LP one ton truck, it came with Cast iron pistons tho the rest of the block is like 28 passenger cars. Please look at page #233 of the following web site provided by GM. <https://www.gm.com/content/dam/comp...mation-kits/chevrolet/1928-Chevrolet.pdf>. .
. Lou .
. .

Thank you for the response. I just looked at the master parts catalog. The engine was a replacement in my 1927 Chevrolet Capitol LM 1 ton. The engine serial number doesn't have a T in front of the sequential number, so I assumed it was a 1928 car block. However, in the master parts catalog it shows a Piston that is a "Skeleton" cast iron piston only available on the Series K, R, V, X, AB 1/2 Ton. From this I gather that the cast iron skeleton style pistons in 1928 were only available on the AB 1/2 Ton. The piston itself is part # 348656.
http://chevy.oldcarmanualproject.com/1916_28parts/cp4cm04.htm
http://chevy.oldcarmanualproject.com/1916_28parts/index.htm

Check your serial number on the drivers side of the engine block. Truck engines started with a prefix 'T' followed by the serial number.

W_W_W posted a link to some photos of his engine. One of them shows the engine serial number, but unfortunately the front digits are VERY corroded. Here's a link his post: W_W_W's engine pics

From looking at the serial number photo, I cannot figure out if there was a beginning letter (X or T) or not.

Cheers, Dean

Just got the engine opened up. Looks good inside from sitting 80+ years outside in basically a swamp . I cleaned up the serial number completely and can confirm there is no T or X. The GM Parts catalog shows that these cast iron "skeleton" style pistons were only available on the AB 1/2 Ton for the 1928 model year. I'm wondering if since the 1/2 Ton shares the same chassis as the AB car, maybe the 1/2 Ton engines aren't marked with a T? If anyone has an AB 1/2 Ton with an original engine this would confirm it.

. I believe that "T" was only used in the serial number on trucks like LO & LP but not on light commercial like AB. If Dean's 28 Canopy has the original engine, maybe he could look. .
. Lou .

I have a '28 Canopy Express that is on a 1/2 ton chassis. Based on the history given by the grandson of the person that bought it in the 1950s it still has the original engine. Since it is 120 miles away and still assembled I can't verify either the serial number or type of pistons.

I do know that beginning in 1933 the 1/2 ton truck engine serial numbers began with a K. The 1 and 1 1/2 ton engines did have a T leading the serial numbers starting in the 4 cylinders. I don't know the exact starting date on the differentiation from passenger engines. Maybe others do?

I had the window open for an article that went into the numbers on the engines and roughly from what date to what date the different numbers applied for the different vehicles. I must have accidentally closed it thinking it was a different window I was closing.
I will have to find it again, or maybe someone knows what doc I am talking about? It was an important doc for me to find as it verified that the engine that came in my truck had a correct serial number that had it fall well within the numbers they used on the 28 LO's
For me it was one more clue along with a few others that helped me to determine (decide) if my truck was a 27 that someone had stuck a 28 motor into, or if it indeed, was a 28LO (as the wood was mostly rotted and gone, and no tags from the seat riser.
Anyway, said all that to say the engine is stamped with a 'T' at the beginning, and it had the skeleton style cast pistons in it.
I thought it made mention of this distinction in the Early Chevrolet History book written by Doug Bell also but I can't fine it right off.
It had always been my understanding that those pistons were only used in the truck engines in the 27/28 time frame
David

Are you talking about the document that Ken Kaufmann and David Hayward put together that contains their research into 1924 - 1928 engine casting numbers?

If so, it is a PDF that can be downloaded from this site: 1924 - 1928 Chevrolet engine casting date document

Cheers, Dean

That's the one Dean. Thanks! W_W_W, I think if you read through that document it may clue you into a time frame of when your engine was actually made a maybe it's application (not sure but worth a shot)
David