What oil for 230 flat 6

[Guest 52dodge]

Hello,was wondeing what oil i should be running in my 52 dodge meadowbrook with the 230 flat 6,shes got 108,000 miles on her ,a valve job at 50k so i was told,but runs like a watch.

[Steve9]

I am running 30 wt non-detergent in my 56 Dodge 230. Mine is freshly rebuilt and I was advised to use non-detergent oil so the oil will carry any impurities and deposit them on the bottom of the oil pan. This is because the oil filter only cleans a small percent of the oil. Modern engines send all the oil through the filter and detergent oil carries all impurities in suspension to the filter for elimination. Using detergent oil in the old motors will run these impurities in suspension through the oil pump and into all the bearings!

[Steve9]

I am running 30 wt non-detergent in my 56 Dodge 230. Mine is freshly rebuilt and I was advised to use non-detergent oil so the oil will carry any impurities and deposit them on the bottom of the oil pan. This is because the oil filter only cleans a small percent of the oil. Modern engines send all the oil through the filter and detergent oil carries all impurities in suspension to the filter for elimination. Using detergent oil in the old motors will run these impurities in suspension through the oil pump and into all the bearings! Yikes!

[Rusty_OToole]

First of all it's a flathead six, not a flat six, unless someone has transplanted a Subaru, Porsche or Corvair engine in there.

Multigrade detergent oil was introduced about the time your car was built. Chances are it has never used anything else. 10W30 was the default choice for oil changes in all garages and dealerships through the fifties, sixties and seventies.

I have a Chrysler owner's manual from 1952. They recommend NOT to use 30 wt except in very hot weather. They say modern engines (modern in 1952) do not need heavy oil and lighter oil will work better.

You should use 10W30. Given the miles on your engine, if the oil pressure is on the low side you could use Rotella 15W40.

[c49er]

I would run a straight 30W in your flat six if you like. I do and have in all my MoPar flat sixes and straight eights. My first car I learned to drive in- a 1951 plymouth we rebuilt the engine in 1968 and have always run 30W penzoil 30 detergent. It still has a tight good running motor today!

I just don't over rev the engines and I don't like mixing brands of oil-can cause sludge.

Bob

[Rusty_OToole]

By the way, if you have the bypass oil filter it does filter all the oil, just not all at once. All the oil in the crankcase passes through the filter every 15 or 20 minutes. This filter does a very thorough job, getting the oil cleaner than the full flow filter.

Chrysler did NOT recommend 30wt oil except for temps over 70. 10W30 will do the same job and can be used year round.

[c49er]

Chrysler generally recommended 30W as shown in this 1950 Chrysler owners manual and did not show 10/30W at all. My 1952 Dodge truck manual also shows 30W to be used. I agree that 10/30 can be used. The oil today is way different than back in the early 50's.

If the OP is interested he should read what "Bob the Oil Guy" says about oil. I say use what works for you and change it on a regular schedule.

Bob

Edited February 12, 2013 by c49er (see edit history)

[Guest 52dodge]

thanks guys,mine does have a bypass oil filter,the previous owner told me to run straight 30 ,i just wasnt sure if this pratice was still the best for the motor,seems like everwhere i read everyone has mixed opinions

[Steve9]

By the way, if you have the bypass oil filter it does filter all the oil, just not all at once. All the oil in the crankcase passes through the filter every 15 or 20 minutes. This filter does a very thorough job, getting the oil cleaner than the full flow filter.

Chrysler did NOT recommend 30wt oil except for temps over 70. 10W30 will do the same job and can be used year round.

Rusty, I have followed your posts and trust your advice, but isn't it reasonable to assume dirt in suspension will get sucked into the oil pump. This is how an old mechanic explained it to me. Life would be easier running modern multi-grade oil but I'm still not sure?

[Rusty_OToole]

Of course dirt gets sucked into the oil pump, exactly the way it does on your modern car. Then it gets pumped through the oil filter, and thence to your bearings and other parts (in your modern car).

The difference is the partial flow filter gets only part of the oil at one time. Eventually, it gets all the oil and filters out all the dirt. With the proper filter, which is much finer than today's full flow filters, the oil stays clean looking between changes or until the filter gets clogged.

The full flow is supposed to be better and I don't doubt it is. But the partial flow is better than nothing, certainly better than leaving the dirt in the oil and changing it every 1000 miles, which was the practice before oil filters became available.

Go ahead and do whatever you want. It's your motor. Chrysler did recommend lighter oil when better oil became available, they recommended multigrade detergent oil when it became available. But the flatheads are tough old engines. For all you drive it, it probably won't make much difference especially if you only drive it in hot weather.

PS I notice you picked a manual from 1950, the year before the first multigrade oils were put on the market. Naturally at that time they did not recommend something that did not exist. See if you can find a book from 5 to 10 years later, still within the flathead era, and see what it says.

Edited February 12, 2013 by Rusty_OToole (see edit history)

[c49er]

Here is the specified oil requirement from the factory owners manual for the 1952 Dodge D41 and D42 cars same as the OP has. Once again SAE 30 is required as per the factory owners manual.

I'm not trying to play year games here Rusty.I pulled a 50 Chrysler owners because it was handy. I could pull a 52 Chrysler or 53 Dodge truck owners too for oil requirement. But they say the same thing. I will have to charge a fee to photgraph more of these manuals!

Bob

[c49er]

Here is the oil requirement out of the 1953 Chrysler factory Owners manual- SAE 30 is recommended above 30 degrees. The 1952 chrysler is the same Rusty. Just sayin....!

I also looked at my 1957 Mobil oil chart and it doesn't show multi weights at all. I do believe later 50's is when the multi grades started.