If you read any of my pieces on Engines, you’ll know that I enjoy learning all I can about the various makers’ details on their features. I thought that I might start a series that took a year by year approach to what the US automaker build and used in the cars they produced.
So here is the engine line up for the 1971 Chevys.
Of course Chevy had the V8’s in 1971, not yet strangled by smog control, as well as 6 cylinders and 4 cylinders.
All of the 6’s were inline (often referred to as straight 6 – for the pistons all being in a straight line configuration) these were 250 cubic inch displacements – (very similar to the Ford 250, with the exception of the Blue upping the compression to 9.1:1 vs Chevy’s 8.5:1). These were cast iron with hp running about 145 with hydraulic lifter, and normally topped with a Rochester one barrel carb. Any car that had a 6 in it had this engine and it was an option with most any Chevy model.
1971 Chev Inline Six (this one is in a Chevy Nova)
Next up is the 4 cylinder used exclusively in the Vega (remember those?). They were inline 4’s with Over head Cams, aluminum block (not iron) and managed to displace 140 cubic inches. The compression ratio was less than they 6 at 8.0:1 with hydraulic lifters and a one barrel carb.
Vega Four Cylinder
There were 3 basic V8 that year the 350, 400 and the 307.
The 350 cid was cast iron with overhead valves and compression ratio of 8.5:1 with an hp of 245 hp when it was topped with a 2 barrel Rochester carb. These were widely used in the Biscayne, Bel Air, Impala, and Monte Carlo.
The 400 was cast iron as well with matching stats. However due to the larger bore (4.125 vs the 4.00 for the 350) and longer stroke (3.75 inches compare to the 350’s 3.48) it was able to push the hp’s up to 255 (umm..seems like a lot of work for 5 hps) when it was topped with the same 2 barrel carb.
The 307 rounds this out with its cast iron block and over head valves, it to had the compression ratio of 8.5:1 but with a smaller bore and shorter stroke (3.875 and 3.5 inch)it bu down roughly 200 hp. The 307 was used in Chevelle, Malibu, Nova and the Camaro.
Thanks for reading.
Tim
