VCCA Home Forums TECHNICAL - 1945 AND NEWER 1958-1960 1958 Chevy 6

I am doing a little experiment/research. I am curious how long the 1958 Chevrolet six cylinder would last, mileage wise. Also, what kind of gas mileage did they get city to highway comparison? Gene I hope you see this.
Thx
Jim Greene

Will reply Friday morning.

The following are my observations from life in the dealeship from 1950-1977.

First being in the northern part of the country may present some diferences compared to cars operate in a warmer climate.
By 1958 the 235 was improved and was a fairly durable engine for 1958 standards. Probably was comparable to a 283. The "bottom end" seldom had problems. Valve grinding was not too common compared to a 216 or early 235. Chevrolet finnaly made a better quality exhaust valve. We did have a few that had lifter problems. After driving at high speed for a length of time a lifter could loose oil and clatter. This was improved for 1959 by going to a lower lift cam and weaker valve springs, Also it increased low speed torque and gas mileage. If oil was not changed often enough in the winter the oil passage in the block and head would plug up and rockers would starve for oil. Timing gears seldom gave a problem. The average 235 could go 100,000 mils without arebuild if oil was changed every 2000 miles. Oils were not as good as todaays oil even inspite of having a detergent. As a note most cars were considered to be worn out by 100,000 miles back then and by 10 years old the car was considered a junker. Some 235s did use a little more oil from new but never wore out the cylinder walls. City short trip driven cars did not last as long as long distance high speed driven cars.

Gas mileage on the open road would be in the 18 MPG gallon range and 20 with overdrive. Ciy could be any where from 15 or 16. Oil milage a QT. in 1000 miles.

I clearly remember the oil feed problem to the rockers, and eventually the lifters and cam on the 235 in our '58 wagon. Dad had bought the car used and it was obvious that the oil had not been changed frequently. There was lots of sludge due to the relatively low detergent oils of those times. It was hard to keep it from plugging the oil feeds.

There are lots of debates about whether to modify the head bolt to allow more oil or where to put a restriction or whether a bypass oil filter helps or hurts oil pressure and flow or.... It can get pretty confusing!

Plus that was a marginal engine performance-wise for a full size station wagon with a PowerGlide. It was acceptable in the flatter terrain of eastern North Carolina. It really struggled with a family of 6 for the annual vacation to West Virginia.

The dealership where I was employed had a (new) 1958 6 Cyl. wagon with Power Glide for a courtesy car. It was very sluggish, the brakes were horibble and a 6 Cyl. did not have a front sway bar so it rocked like a boat.
In a sedan the 6 with PG felt adquate.

Oil to the rocker arms - The oil pumped up thru a passage in the block then zig zaged into a head passage The block to head part was the thickness of the head gasket and would fill with sludge.

Gene: Thanks for confirming my childhood memories!