MG42
Active member
hello all what is the best oil to use in these old motors. a buddy of mine told me to use royal purple. thanks Ed
the only part that 72 left out was that all OTHER comments derived from what their father or older person said because that is what "they" were told!with a roller motor you don't have the same issues as a flat tappet, but you might want to use a high zinc oil anyway.
they removed zinc from most oils because of emissions regulation, so there are fewer and fewer blended conventional and synthetic oils on the market with high zinc levels.
there are so many oil topics on various websites that it will make your head spin. there are also oil test websites that give breakdowns of most oils on the market and testing.
as an example
from testing:
Royal Purple 10W30 Break-In Oil conventional = 62,931 psi
zinc = 1170 ppm
phos = 1039 ppm
ZDDP = 1100 ppm
10W30 Royal Purple HPS (High Performance Street) synthetic = 66,211 psi
zinc = 1774 ppm
phos = 1347 ppm
ZDDP = 1500 ppm
you can find a list here
http://speedtalk.com/forum/viewtopic.php?f=1&t=35836
now you can also add ZDDP to most motor oils it comes in a small bottle and you follow the directions and mix it in when you do an oil change.
everyone has a brand they love, and there are brands that have gotten a bad rap because people feel they caused an engine to fail.
Some people like conventional and some only synthetic.
another issue is changing regulations on emissions, many lists on the internet are out of date and formulas kept changing. Rotella is a good example it used to be that mobile oil was good all around then one day they changed the formula people found out and switched to the diesel version, but then the diesel version changed a couple of years later. all very confusing.
Conventional, has wax in it and it tends to clog up, which can be a good thing if you have a leaky motor, or one where the tolerances are a little open.
synthetic, is more controlled and clean usually goes longer but an old engine may start leaking because the synthetic cleans out the internals and usually breaks a chunk of conventional oil away from where it clogged a leak and some people hate it because a leak free engine suddenly starts weeping oil from all the seals.
the truth is there is no direct answer for the best oil, even bad ones can be good, better then they were originally made 40 years ago.
some people will send off there oil change samples to be tested for bushing wear and adjust what oil they use based on the reports.
i've used royal purple engine-break in oil, but i've been wanting to change over to something more conventional.
LOL! Used to get a LOT of kids at the Auto Hobby Shop that would do various things along similar lines, usually for the same reason (their Dad always did it). Things like:the only part that 72 left out was that all OTHER comments derived from what their father or older person said because that is what "they" were told!
as the story goes a newly wed wife cooks a ham she cuts off both ends prior to cooking. Her newly wed husband ask "why"...that is the way my mother did it. So upon a family gathering he ask the mom the same question. "well that is how my mother did it" . later on at yet another family gathering he ask the wife's grandmother. "so tell me why you always cut the end off the ham prior to cooking it" she responds "because my pan was TOO SHORT"
As Dan mentioned, very true for factory set-ups or flat-tappet cams and valve-train. Roller cam systems however, not so much.Fact is if it doesn't have zinc...it may not be good for our cars.
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