Originally Posted By: Building3
I have a 1966 Ford 289 with about 25,000 miles. Obviously it must have sat for long periods of time. I do know that in the previous ten years before I bought it, it was only driven for short trips. 2-5 miles at a time. I have had it for a short period of time but after buying it I put in Valvoline VR1 Conventional Racing Oil 10w-30 after asking many people with old cars. I use ethanol free gasoline 90 octane. The oil analysis was fine except for the lead. Last year it was 630 and this year 403. The engine does not smoke or make any unusual noises and it does not use oil. The oil pressure gauge works fine and shows a good oil pressure. (No numbers, but right in the middle of the scale.) Why do you think the lead numbers are so high? Possibly the previous owners used leaded fuel or a lead additive in the fuel? I guess it could be the bearings but like I said, the pressure seems fine. Any thoughts would be helpful. Thank you.
My 1966 Mustang with 289 had 77k miles on it; recently sold it. Had been in the family since 1976. We got it as second owners after the first 10 years; it was a trade in at a dealer.
Good to hear that your oil pressure is solid. Ours was dropping badly; at hot idle it struggled to stay above (none!) on the dash gauge. Once the revs came up, the pressure would be near-normal. These engines are known to wear out the cam bearings fairly quickly. Although with only 25k miles on yours, it would be a bit early to think that would happen.
Most of the lead is coming from the past use of leaded fuel, as others have said. Given that you have good oil pressure, I have to think the Pb is coming from residual fuel traces and not cams.
Also, I would suggest you pop off the valve covers and look underneath. There were HEAVY deposits of gunk and sludge under mine; it was atrocious. Oils back in the day, while perhaps good at holding off wear with high levels of ZDDP, were really bad at cleaning and dispersing. I had to pull the valve cover to replace the cork gasket; finally was weeping so badly that the oil was getting onto the exhaust manifold. When I opened it up, I was shocked how full of junk the head was. Truly a reason (back in the day) for frequent oil changes. (which is where the the old habits come from ....) It was the right thing to do back then.