VCCA Home Forums TECHNICAL - 1945 AND NEWER 1958-1960 60 235 Rebuild

The 235 in my 60 Impala Sport Sedan has smoked since I bought it. It runs smooth as a sewing machine and last year I drove it over 1200 miles in one week in which it used just under 4 quarts of oi. I felt wasn't all too bad , as this was all types of driving conditions. Although it has always used some oil, recently it has started using a quart every 100 -150 miles.
I've been told many opinions by friends and acquaintances like "toss the six" & put a v8 in it" , "save the six", "just do rings" , "just do valve guide seals (Umbrella seals done by previous owner) "just rebuild top end "," rebuild entire motor" (top & Bottom end) " my dads 60 6 cyl smoked & left black soot from the exhaust when it was new."
It has 86,800 miles ( believed to be original)
I've driven it 12,600 miles in the 4 1/2 years bought it
It has no oil filter ( bought one & plan to install it)
I run Shell Rotella SAE30 oil (I believe this oil has gotten thinner in the past year)
Smokes heavy at idle from breather and draft tube
Smokes heavy from exhaust if accelerating /passing
Drips oil from draft tube, quarter size drop typically after
20 mile drive (I assume it drips out while I drive)
Gets poor gas millage (I get better millage on with my 62's 327)
I'm thinking of pulling the motor this fall and I believe it needs at a minimum rings, but figure I won't know till open it up.
I'm looking for opinions & suggestions from the knowledgeable folks on this chat site.

Its the rings for sure. These 235 engines tended to use oil from new. Was common for them to develope blow-by by 50,000 miles. If it were mine I would pull the head first and check the cylinder walls s for wear. If not too excessive would install a good set of expander type rings and rod bearings. Probably pull a shim or two out of the main bearings. Replace the rear main seal with the "rubber"type.
The valve guides and/or seals are seldom the oil problem on a 235.
The oil dripping out of the breather is the result of the compression rings allowing blow-by and crank case pressure build-up.

Thanks for the reply Gene. You have great knowledge on these ol Chevys. Your article in the G&D regarding expandable rings gave me the idea I might be able to get by with rings.
I'm gonna guess that I may have waited to long, as it has had blow by for as long as I've had it. Since the motor didn't certify for HPOCF in Mankato last year, I figured I can do the motor up right. I assume because it looks as though it went through the ol OK used car spruce up with paint on the inner fenders and very old paint on the motor.
I will open her up sometime in August or September & see what I have. for the last few weeks ,I've been too busy working on getting the 62 ready to drive out to the Central Meet. Just rebuilt the steering cuplink & replaced the lower steering bearing I actually had an A Arm bushing fall out,have you ever heard of that? I'm so glad it popped out in my driveway & not while on a 400 mile trip!
Hope all is well with you, I missed going to the Middle West Meet. See ya in Flint

Brad,
Be aware that it is necessary to pull the engine to remove the pan on the 6 cylinder. An experianced mechanic would jack up the enine, drop the pan as far as possible, loosen and drop the oil pump in the pan and get the crankshaft in the perfect position and slip out the pan.....I would recommend pulling the engine. If the cylinder walls are not badly worn the rings will do fine. I would ues the Chevrolet Chrome-flex rings. Thats what we used years ago and they did a good job. Sometimes you can find a new od stock set at swap meets, ebay, etc. They were made by the Muskegon Piston Ring Co.

Thanks Gene,
My plan was to pull motor and rebuild as necessary as well as clean up engine bay, repaint & detail engine compartment, same as I did with my 62 years ago prior to joining VCCA. If cylinder walls look good, I'll be looking for the recommended rings.