What are the latest recommendations for oil? I have my 29 15L apart again after about 2000 miles on a complete rebuild. Wrist pin noise alerted me to problems. Knurling worn off the piston skirts, oil in the bottom of the oil pan looked like metallic paint. My model 63 has a bypass filter that filters very little oil. So is detergent or nondetergent called for? I'd think you'd want the particles laying in the bottom of the pan instead of flowing through the bearings.I know I need an oil with zinc also. Boring the engine and don't want to go through this again. Not even positive my oil was the cause. Stock pistons were used on first rebuild. Could it be the cylinders were honed with too coarse of stone and ate the 80 year old aluminum(?) pistons? Any info would be appreciated. THANKS!!

Dave

Dave You can send in a sample of your used oil to find out what's in it, but sounds like you already know. I was always told to use a non-detergent oil on a freshly re built engine, then go to a detergent oil. I use Valvoline 50wt racing oil, because it has the zinc additive. You will get many different opinions on this I'm sure. Ross

Where Are You From? Orygun

Do You own a car built by Durant? 1930 6-14 standard coupe

Dave,

I suspect that the source of the problem is much more than just oil. Somebody else will chime in here and offer an idea.
I use Valvoline racing oil 30wt, because it has the highest amount of zinc on the market. But I have used non detergent oil in other engines of the era and received good service.

Where Are You From? Fremont, CA

Do You own a car built by Durant? 1929 Model 60 Deluxe Roadster

Thanks for the info. I was using Shell 40wt detergent oil. I agree it may be more than the oil. On the 15L the rods never touch the oil in the pan so I believe the only oil the cylinders and wrist pins get is the oil leaving the rods. There isn't a pee hole in the rods like the 22A. I figured any modern oil was better than what they had in 29!

Dave

Dave, with the filter installed did oil pressure stay above 30 PSI?

Where Are You From? Cerritos CA

Do You own a car built by Durant? 1929 D 63 4 dr

The filter filtered so little oil I bypassed it thinking I was better off with more oil pressure.There was just a pin hole in the fitting to allow oil it the filter. Maybe that's part of my problem. I had probably 45-50psi at 45 mph, and 10 psi idling hot. Oil pressure was never a problem.

Dave

Some questions? Did you really, really clean the cylinders? Use white towels.

Did you have the proper clearance between the pistons and cylinders? Aluminum needs more room to expand when it gets hot.

I don't think the kind of oil used had anything to do with it. Where oil and its additives seem to be most important is in the camshaft and follower area.

It makes sense to me to use non-detergent for a fresh engine so that loose dirt particles sink out of the oil. Once drained, then use good diesel grade tractor oil.

Do You own a car built by Durant? yes

Dave;
Opinions on oil are as plentiful as bees in a honeycomb. Some time ago I wrote a maker of a synthetic oil about the use in both the Durant and my other car. Their experts advised that you should break the engine in with regular oil, then there would be no harm in switching to synthetic. As a matter of fact the technical department guy I spoke with had a Model A and used their oil in there and never had any problems. The amount of miles put on one of our Durant products doesn't even effect if it's detergent or not. Change the oil once a year and in their opinion you will be fine. Also in a recent article in the Pre War Auto Notes a technical adviser from the Skinned knuckles magazine advises that you change your oil often even if the car sits for periods of time because the oil will become acidic and still take on contaminates. But this article did not indicate how "often" often was. There has also been a recent article on the hype about getting zinc in the oil. I read an article from a motor expert that says unless you have a late 60's early 70's muscle car with a high compression high performance engine that you run at high RPM's you don't really need the zinc in there.

Where Are You From? Oviedo (near Orlando) Florida

Do You own a car built by Durant? 1928 Durant Model 65 4 dr