Hey, Cecil

Ronnie Russell

Well Known Member
Supporting Member 2
#1
Cecil, Was the release date for 348s in trucks the same as cars? Just curious if there was a lag time for the trucks or if the release date was the same. Could or did people go to a Chevy dealer in Sept. 1957 and view both?
 

Tom Kochtanek

Well Known Member
Supporting Member 9
#2
That would be interesting to know, and I look forward to learning more. We do know that the 348 castings were made for the trucks well after they stopped making them for the passenger cars. In fact, I seem to remember 348 castings being made after 1965?
Best,
TomK
 

oldskydog

Well Known Member
Supporting Member 9
#3
As far as I know, they came out with the new model year for both, although the 348 was only available in 90 and 100 series trucks until mid year when the 2 barrel version 348 was offered on 70 and 80 series .
There are some interesting facts though about the truck engines. They all came with heavy duty bearings, induction hardened crank, and the heads came with replaceable exhaust seats, stellite faced and sodium filled ex valves with hardened tips, and aluminum coated intakes. The waterpump had a larger impeller.
The early 58 truck heads were basically the same as car heads with no combustion chambers, had ex valve rotators and 8:1 CR with notches only.
In late 58-59 new heads with spark plug cooling came out. The valves were 1/8th smaller diameter and recessed .050 into the head, and the sodium filled valves were eliminated. The pistons were a new design and with the double notch in the cylinders dropped the compression to 7.75:1.
Not sure about W castings after 65 as I've never seen or heard of any for sure, but how would you know with just Julian dates? I would imagine they would have to provide service support for at least a few years after 65 to honor the warranty and the bean counters wouldn't want to stockpile castings and parts any more than was necessary.

More on truck engines here:

http://chevy.oldcarmanualproject.com/chevyresto/58index.htm

http://chevy.oldcarmanualproject.com/manuals/1958npi/index.html

http://chevy.oldcarmanualproject.com/manuals/1959npi/index.html

http://chevy.oldcarmanualproject.com/chevyresto/59index.htm
 

Ronnie Russell

Well Known Member
Supporting Member 2
#5
Cecil, all the information you supplied was interesting, as usual. The only reason I brought it up was the age old reasoning that the 348 was initially designed for trucks, then the brass decided that they would use it in cars too. That's why I ask if there was lag time for the trucks in Sept '58. If the cars came first with 348 then it would be hard to see it as truck first, pass car later. Really doesn't mean anything, just curious.
 

oldskydog

Well Known Member
Supporting Member 9
#7
I don't have any documentation on that. Tonawanda Engine records for 65 and later should show it if they were still being cast.
I've heard anecdotal stories that they were still available through parts department through sometime in early 70's but have no documentation there, either, and even if they were, they may have been slow moving inventory of new old stock instead of continued production. Perhaps a check of truck parts catalogs for those years would verify that they were still available beyond the date of my newest Truck Parts Catalog which is May. 1966 and partial engines, fitted blocks and heads were still listed.

As far as the question of whether the W was orignally designed for truck only and added to the car line as an afterthought, I think the article written by Don Francisco for Hot Rodding Magazine pretty much covers it in this excerpt:

"This may not seem to make much sense, but it was the immediate success of Chevy's 265-inch V8 when it was introduced in 1955 that prompted development of the 348. Demands for the 265 by many thousands of motorists to whom it brought their first taste of enjoyable driving presented Chevrolet with the problem of producing the engines fast enough to meet the orders. The only answer to the problem was additional engine production facilities. As such facilities are expensive, it was decided after a long look at the problem to design them for an engine that would be suitable for both passenger and trucks being produced then and in the forseeable future. This would make them good for many years. When it was determined that the 265-inch engine did not have the displacement potential it was estimated would soon be necessay, and that cylinder head production for it to meet different compression ratio demands had become too involved, the route was clear: design a new engine.

A set of design requirements was drawn up for the new engine. It woud have to be adaptable to a broad range of displacement with a minimum number of changes to its parts. It would have to be adaptable to a broad range of compression ratios to enable full advantage to be taken of future fuels. It would have to have exterior dimensions suitable for present and future passenger car installations. It would have to have mounting provisions for both passenger car and truck accessories. It would have to be easily modified for future demands with existing machine tools."

I think it is unrealistic and illogical to believe that the W was designed for trucks and at the last minute they decided to put it into the passenger car line. GM, as did every other manufacturer, could not afford to do things on a whim. Everthing was planned and engineered years in advance. They knew that cars were getting bigger and heavier and they would need a powerplant with the torque and horsepower to propell them down the road with a reasonable power to weight ratio to do so without overloading the smaller engines. Yes, they still installed 6 cyl and small block engines in the big cars for years after, but most of the 348's went into the heavier Impalas and Bel Airs with lots of accessories.

In short, the engine was purposely designed to meet multiple market needs in the most cost effective way. No way was it designed specifically for trucks.

That's my story and I'm sticking to it.:deal
 

Ronnie Russell

Well Known Member
Supporting Member 2
#8
Cecil, That's exactly what I was looking for. I had read that years ago but would never have figured out how to find it. Thanks a million !!
 

Tom Kochtanek

Well Known Member
Supporting Member 9
#9
That sounds intriguing that the success of the early V8 stimulated the development of the "W". Are there sources that note the initial dates of planning that went into the early 348? Had to be around the time of that first 265 (1955?). I wonder if developments in other parts of GM had any influence (Pontiac, Olds, Buick, Cadillac)? After all this was the beginning of what was to be called the Muscle Car Era.

Best, TomK
 

models916

Well Known Member
Supporting Member 7
#10
Pretty sure in By the Numbers there is a list that shows a Z11 partial engine assembled at an engine plant in 1972. Bet there were lots of 348 409 blocks and parts laying around for years. On the other hand, I'm pretty sure I had a Posi unit from one of these cars with a 1968 date on it. I would bet the 348 was designed to go into everything from the start.
 
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