Kilgore47 Posted August 8, 2022 Report Posted August 8, 2022 I finally got brave enough to pull the oil pan on the 47 P15 today. It was actually easy. Except for the really grubby part. Stuff falling in my face. Probably going to toss that T shirt in the garbage. When I adjusted the valves there wasn't any sludge in there. So I didn't expect to find very much if any in the pan. I found a little more than a quarter inch of sludge in the bottom of the pan. The pick up screen was clean. The surprise part is that under the black sludge there was a gray sludge. This gray matter is dense and around the outside and in the corners. It has metal in it. I was able to pick up the metal with a magnet. The other surprise part is that I also found small wire brush parts in the gray sludge. The wire brush parts were probably left over from the rebuild in the mid 70's. The other very fine metal flake looking stuff may be from the break in 45 years ago. Metal in the pan is never a good thing. But the gray sludge appears to have been held in place all these years by the black sludge. I checked the rods and there is a little front to back movement but no up and down movement that I could feel. The PO told me they put a rebuilt engine in the car in 1974 when they pulled it out of a field. They also told me that it didn't have many miles on it. I guess it is what it is. I'm going to clean everything I can get to and put it back together with a magnet glued to the drain plug. Drain the oil in a couple of hundred miles and see in any more metal has collected on the magnet. I'm also going with a detergent oil when I put it back together. Not telling what viscosity I'll be using. That would get too many comments? More news latter 3 Quote
Young Ed Posted August 8, 2022 Report Posted August 8, 2022 Typically I would say that's lead from the gas that settles into the pan as that grey sludge. Since yours was rebuilt I guess it depends on when it was done and what fuel they used afterwards. Quote
keithb7 Posted August 8, 2022 Report Posted August 8, 2022 10W30 20W30 15W40 20W40 20W50 Don’t run synthetic Add zinc! Use oil designed for diesel engine! Use Hot rod oil with zinc already added! Add lead to fuel! Run synthetic oil! 0W50 Add Marvel Mystery Oil to crankcase! Add marvel mystery oil to fuel tank! Run SAE30! There yes indeed, there is your single firm, solid answer. If anything if might prevent 25 more posts in this thread. Maybe. Maybe not. Lol. ? 3 3 Quote
Kilgore47 Posted August 8, 2022 Author Report Posted August 8, 2022 Lead. Never would have thought of that. It was a thin layer at the bottom of the pan. I was wondering why more of it didn't stick to the magnet. I'm sure the PO used leaded fuel as long as it was available. That's what everyone did back then. And keithb7. Your guess is correct. That's exactly the oil I'm going to use. How did you know 1 Quote
greg g Posted August 8, 2022 Report Posted August 8, 2022 Half can of STP provides all the zinc needed. That lead pudding is also in the valve galleries. Some times enough to stop up proper draining of the area which combined with out of spec valve guides can cause clouds of oil smoke upon acceleration after cornering sharply and briskly. The sludge in the pan was part of the design kind of on the same particular entrapment as the oil bath air cleaner. After shutdown, stuff in the oil settled into the pan staying there till drained at change time. Quote
kencombs Posted August 8, 2022 Report Posted August 8, 2022 I don't worry about adding zinc as there was none in the oils available when these cars were new for the most part. It only became common after high performance OHV engines came on the scene. The increase invalve train weight, higher rpm and spring pressure drove the need to reduce wear at the cam/lifter interface. The gray is primarily aluminum from piston wear, fine cast iron particles from the cylinders, and lead alloys from bearing wear. Larger Iron/steel particles come primarily from timing components, chain and gears.. I've never seen any research confirming lead from combustion contributing to sludge. It's interesting to me to see the difference that was apparent back in the 60s whe full flow filters became common. Back then I was deeply into at least a couple of engines a week. Engines just didn't have the heavy gray deposits if equipped with full flow filters like the yblock fords, poly head mopars and small block chevys. Blowby create black sludge from oil carbons , but not the gray stuff. 2 Quote
keithb7 Posted August 8, 2022 Report Posted August 8, 2022 47 minutes ago, kencombs said: Blowby creates black sludge from oil carbons , but not the gray stuff Somebody get this man a beer! Very accurate assessment. 1 Quote
Sam Buchanan Posted August 9, 2022 Report Posted August 9, 2022 (edited) 1 hour ago, kencombs said: I've never seen any research confirming lead from combustion contributing to sludge. I don't need research to know lead can cause gray sludge in an engine, I've seen it in aircraft engines. It can get so bad there is an airworthiness directive for cleaning the stuff out of hollow crankshaft galleries. These engines use non-detergent oil. Edited August 9, 2022 by Sam Buchanan Quote
Kilgore47 Posted August 9, 2022 Author Report Posted August 9, 2022 So it sounds like what I found is normal and nothing to worry about. Kinda scared me when I first saw it. Found the same gray stuff at the bottom of the by pass oil filter. Quote
Loren Posted August 9, 2022 Report Posted August 9, 2022 Ethyl Lead ( the heavy grey muck ) will be seen much less in the future. My Dad used to ask me to collect some of it from time to time when I found it in the bottom of an old oil pan. He mixed it with grease to make Center Lube. He said you used to go to the paint store to buy it in tiny 1/4 pint cans but the feds stopped that. The company that made “Dutch Boy” paints was once known as The National Lead and Varnish Company and they offered it for that exact purpose. My Dad was a machinist who specialized in cylindrical grinding between dead centers. When you had centers that squeaked a little dab of white lead would stop it. When you think about the thousands of gallons of leaded gasoline that have to be burned in an engine to generate that much lead in the crankcase, it boggles the mind! The best lead came from engines made after 1965. The positive crankcase ventilation system sucked the water blow by out of the engine leaving a hard layer of grey lead and no sludge. There are wall charts in some automotive machine shops which show the various conditions you will find bearings in and what caused it. Dirt and metal particles that have done damage are mostly found imbedded in the soft metal of the bearings. The stuff you find in the oil pan can be harmless. I’ve learned not to get too excited by oil pan debris. It’s what the bearings have absorbed that really matters. 1 Quote
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