"Just testing the waters"      I think thats a interesting comment....  

When I was using my 67 Chevelle to drive to work back in the 1990s it ran so smoothly and so quietly I could run up and bump someone on the back of the legs. Mine is the big 250 and it had no trouble keeping up with traffic. It was easy and effortless to drive.

True story, I saw what was eventually 427carl's 66 Strato Chief on Highway 427 (seriously!) while I was driving home from work in 1996 with my 6-cylinder Chevelle. I wanted to catch up to see if it was a U.S. Catalina or a Canadian Strato Chief so I got on the throttle. I guess he thought I wanted to race him so he got on the throttle as well. I stopped trying to catch up once I hit 90 mph. They are smooth and torquey, but high speed running was never a design goal. With a 1-barrel carb, siamesed intake ports and a 6-into1 exhaust manifold it is clear that simplicity, not scavenging, was the goal. That and fuel economy, since sixes were sold to cheapskates back then.

Canadian Poncho wrote:

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Cameron, I don't think we've seen photos of your Chevelle. Would you post some?

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I will start a new thread rather than hijack this one.

since 1983 wrote:

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but high speed running was never a design goal.......

my chev is not a pleasure to drive faster than 65 i seem to hear the engine rev ......is it the dif ratio that could be to high ?? it s a 3 speed std

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A full-size 1965 Chevrolet sedan with a six & 3-speed manual (standard using the old vernacular) would have come standard with a 3.08:1 rear ratio. A convertible came with 3.36 while wagons came with 3.55. A 3.08 axle ratio would hardly be called busy at highway speeds. My theory is that the six was tuned for down low torque and it ran smoothly. Once you try to lean on them in stock form they are not as comfortable and the quiet smoothness is replaced by apparent strain, although they arent straining. They are gasping for breath more likely due to the restrictive factory manifolds (intake & exhaust). Compare the exhaust note of your Bel Air under strain, to say an inline six in a Jag XKE or an Austin-Healy 100-6 or 3000. The Chevy six was designed & tuned for simplicity, smoothness & economy. A cam change and better carburetion & exhausting would make the strain sound more like a nice smooth hum.

Dad had a 66 Biscayne with a 250 3-speed, followed by a 1970 version of the same. I learned how to drive on the 70. I also remember belting along the highway in California back in 1972 in that car. In the days before the 55-mph limit, California had a speed limit of 80 mph and dad was keeping up with traffic. The engine seemed to be out of its element, in fact it was so unaccustomed to running at that speed that after the highway run the entire exhaust system dropped to the pavement. The nuts at the manifold flange backed off and the hangers seemed to do the same. I should also mention that there were 5 passengers plus an 800 pound tent trailer plus all our gear for a 3 week vacation on board. He should have bought at least a 350 V8 for that kind of work. Still it was a good car that went a lot of miles without incident. It went to California, Newfoundland, Florida, Vancouver Island, plus it had been on logging roads and many hunting trips.