348 Engine Patent


Well Known Member
Supporting Member 9
Just a little something I came across in my research that an engineer might find interesting. The rest of us can use it as a sleep inducing aid. It does dispel the ever ongoing myth that it was designed as a truck engine. It explains in great detail how the design was intended to be very flexible to allow various and expanding bore, stroke, and compressions for all possible production applications.
Unfortunately its a PDF file and too big to upload. If anyone is interested in trying to read this or just needs to take a nap, you can google it . The scale drawings are the best part.

Last edited:


Well Known Member
My first '58 Impala had a 348 and was told it was a truck engine. I didn't care because I bought the Impala days after returning back from overseas then drove it back to Ft Benning, GA to my next duty station.. It served me well having driven it to Ft Sam Huston, Tx for addition training, back to Ft Benning and finally back to Ca after being discharged from the army. Since then I've owed three '58 Impala and currently finishing up with my fourth. Wished that I never sold the other three but that's another story.


Well Known Member
Supporting Member 8
I have shared before, if it was designed to be a truck engine why did Chevrolet only put less than 5% in trucks.
Spend all the money for a new design engine for such a small production number.

Ed Cole did get Zora to make changes to improve the HP.


Well Known Member
The perception that the W was designed as a truck engine dates back to at least 1963 probably longer.The Chevrolet Performance Handbook by Ocee Rich published as part of the Hot Rod magazine technical library in that year,has an article titled "Engineering the W 348-409 powerplant" that references the perception that the engine was designed as a "truck engine",while they made effort to dispel that myth by explaining the goals of Chevrolet to design an engine that wasn't much larger externally but capable of much larger displacement to power future cars that were continuously getting larger and heavier and for use in truck lines,they were obviously unsuccessful in stopping that perception.


Well Known Member
It is interesting to note that both Ford and Mopars performance big blocks of that era went on to be prolific truck motors,the 390 and 413 were way more common in medium duty trucks and motorhomes than the W's ever were,but it makes sense that the marine and industrial divisions would use the components of the manufacturers highest capacity engines since it stands to reason they would also be the toughest.