VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Use of non detergent oil in rebuilt 235 6 cyl eng

Is it advisable to put non detergent oil in my newly rebuilt 235 c 6 cyl engine?

I used detergent oil in our 54/235 for several years and never had a problem. I also use 10W30 Penzoil Detergent oil in our 31/194 engine. I drive our cars about 2,000 miles per year and change the oil at the end of the season and am ready to go the next year. This is just my experience with no problems. I'm no expert.

I have been running 30 weight detergent oil in winter and 40 weight detergent oil in the summer months when it get pretty hot out here .. I'm having the engine rebuilt (bearings rods, rings, etc.) wondered if it was good idea to switch to non detergent oil going forward?

Alan, I would certainly not consider using non-detergent oil in your 235 engine. Even where you live I would use a good brand of detergent 10-30 W oil, year round specially after doing an overhaul. You didn't say whether your engine was hydraulic lifters or mechanical lifters. I would never use non-detergent engine oil in any of my Chevrolets from 1928 roaring four thru a 2011 in an engine in good condition.

I would not advise using non-etergent oil in any new or rebuilt engine. First you would want the detergent to keep the insides of the engine clean. Detergent oils also contain various other additives that prevent wear and scuffing, additives that reduce friction, swell seals and prevent corrsion. For the first 2000 miles I would also recommend adding an additve that will increase the ZINC content of the oil.
As far back as 1958 Chevroler w warned "Practice of operating new engines with straight mineral oil (non-detergent) to promote early seating of rings should be discontinued as this type of oil does not give camsafttand lifters proper protection."

Alan,
I would use detergent. I'd go to Wal-mart (or similar vendor) and look at the letters in the circle on the back of the cans. If the letters on the store brand matched the other brands offered, then I'd buy the store brand. I don't believe you gain anything of importance by spending more money for the popular high-priced oil if the letters in the circle are the same.

Just my take on the subject. Gene has been consistent in his opinion over time. I just don't like throwing money away on oil that offers nothing better than a cheaper brand (does). (l think I already said that.) As can be gleaned from the above, I have no loyalty to any certain brand of oil.

Chipper? Please share your scientific opinion. (Note: Failure to do so may be understood as sharing my views. Will too!)

Has this topic been discussed ad nausea? Maybe so. Anyway, it's a popular topic and it doesn't hurt to bring it up up now and then.
Charlie

BTW: Does anyone run a synthetic blend or straight synthetic? Why?

Recently the Petroleum Instiute of Oil Quality tested 10 or 12 brands of "store" brands of oil. Only one did not contain the correct additives required for the SM grade of oil. The container can not have the SL rating shown unless the oil qualifies. The sorce for the oil got a warning and thus changed the oil so it would meet the SL rating.
I prefer to use brand names and stock up on oil when there is a good rebate....usually paying about $1.00 a quart or so.
I have used full synthetic in my cars and thats what is in my 1957right now.....This was synthetic oil I bought a couple of years back for around a $1.00 a Qt.
I do use Synthetic in my modern cars.

Gene,
I understand.

The trouble for me with rebates is that it requires me to fill out the form, tape the receipt and stuff to a card and then mail it off to the manufacture. Then when the check comes in, my wife gets it. She'll then spend it on something foolish, like food. Go figure.
Charlie

I agree with all that detergent oil is the way to go. Some folks swear by the synthetic oils too, but at 8 bucks a quart it is expensive.

Also, consider using a zinc additive to your oil like ZDDP because flat tappets need the extra lube for rebuilt engines.
Today's new oils have lower zinc levels because they want to preserve the catalytic converters in modern vehicles. Old car motor oil listed in the G&D is made with the higher zinc levels too.