Chevrolet developed the W series, named after the rocker covers that resembled a W, mostly because they needed new engines since the demands in the market pointed att bigger vehicles and more powerful performance. So the exisiting engine alternatives really didnt match the demands of a new and booming market. Chevrolet introduced the small block V8 (265 ci) in ’55 but it couldn’t obviuosly do the job alone.
The Chevrolet 348 was first introduced in October of ’57 as a new Truck engine, but as cars became bigger due to the general trend it was decided that the 348 would be used for cars also.
It presented some new thoughts in engine construction which basically delivered good tourqe all over the range. It developed its - as it’s called - maximum brake mean effective pressure - at relatively low speed giving the driver a powerful and comfortable ride - even if it was in a big car or truck. You now that krusin’ feelin’. Gliiiidin'.
The first engines came in two alternatives, a 250 hp and a 280 hp. Late in ’58 a 315 hp 348 was introduced. The higher hp engines were given high lift cams, solid lifters and a 3-2 barrel carb set up.Evetually the heads were improved and they were fitted with dual point distributors
And in the great american tradition of koool and over-the-top names and brands the different alternatives were given such names as: Turbo-Thrust escalating in the Supert-Turbo-Thrust and with a final climax in the... yeahhh you guessed it! the Special-Super-Turbo-Thrust! Dang I’m blown away - just gotta have one of them!!!!
Chevrolet continously developed higher hp 348 engines through the years ending up with a 350 hp 348, Chevy took a full step and introduced the famed 409 engine in ’61.
The 348 was produced until ’64. But after ’61 it only served in trucks.
And finally a spec sheet I found googleing around...
- Cubic Inch=348
- Firing order=1-8-4-3-6-5-7-2
- Engine Weight=640/650lbs
- Forged Crank=has round flywheel bolt flange
- Connecting rod length=6.135 inches
- Crankshaft mains=2.4977
- Push rod length=exhaust 9.140, intake 8.772
- Push rod diameter=5/16" (all)
- Fuel pump push rod length=5.75 inches
- Dipstick on Drivers side
- Ignition timing=4 degrees B.T.D.C.
- Spark plugs=AC44 (standard), AC45 (hotter), AC43 (colder)
- Spark plug gap=.035"
- Rocker arm ration=1.75:1
- Internally balanced
- All 348's were assembled at the Tonowanda plant.