Hiya there, so if my engine looks like this... what should I do? The engine is a runner in decent shape, but there's just a lot of crap in the valley. Should I just wipe it out with a rag or what?
That's what happens when you don't use detergent oil. You probably have a layer in the oil pan also. Probably best to leave as is until time to rebuild. When trying to clean it you might drop small pieces into the oil pan which is worse than leaving it alone.
I would carefully try to clean out as much as possible if mine looked like that. Run some Marvel mystery oil through it for a long time. Not only non detergent oil causes sludge but also the fact that the breather system on these engines leave alot to be desired. Normally they get clogged and prevent the important venting of gasses and condensation. The best thing you could ever do for any flatty is installed (easy and cheap to do) a PCV system. It forces breathing throughout the crankcase and you wouldn't believe how much cleaner your oil will stay. Check out the tech section on installation.
Be aware, much of that sludge is due to lead in the gas/oil, it is toxic! It can be absorbed thru the skin, too. Personally I would take the engine out, vat it repeatedly til clean, and start over with a PCV as suggested above. Any attempt to just loosen it is bound to cause problems in the oil system, pickup screen, etc.
I would be interested to know if anyone has actually ruined a flathead by cleaning the sludge out of it. I frequently hear admonitions against it, but I've never heard any first hand experience. If the engine is out of the vehicle, I would be inclined to clean everything that doesn't actually involve the oil distribution system. Better yet, being the kind of nut case I am, I would tear it down, making sure all the pistons and lifters got back in the same holes they came out of, and give the block, pan, and maybe the crank a good scrubbing, then put it all back together. Actually, I would probably take a good runner and spend a bunch of money on a hot rod rebuild whether it needed it or not. But that's just me.
Warm yer motor up. dump a can of Rislone consentrate in yer oil. run for 30 minutes, then flush with clean oil. Run for a week and flush again. Most of that will come out the drain plug.
I don't recall ever actually ruining an engine by cleaning it up, or know anyone that has. I have seen an engine or two that were pretty sludged up that were also on their last leg. Mayhaps someone tried cleaning one of those up and when it blew or they discovered it was a mosquito fogger they blamed it on cleaning the engine up. If it were my engine today I would probably pull it down and overhaul it, but in years past I have cleaned old eingines up like that one and run 'em until I could afford to rebuild or a better mill came along, or both. What I would suggest is that you take your wet/dry vac and suck the big pieces up from the lifter galley, of the mill is not in a car anyway you might pull the pan and make sure it is cleaned out and get a look at the pickup, clean the screen on it also. Then when I fired it off I would give it a mix of oil and kerosene, or buy some of that engine boil stuff in a can (its just kerosene) and run it for about 20 minutes to half an hour (or follow the instructions on the can). Then drain the oil and fill it with good oil and drive it. What happened on a lot of those old motors ( or engines if you prefer) is that they used a high parafin oil like pensoil or quaker state, and what you actually have is a parafine buildup along with carbon and othe impurities. Anyway its a common malidy in a lot of older mills.
The accumulation is normal, from years of use, even if it was run with modern oil, it happens with all motors over time, not just flatheads. Leave it be, it won't hurt. The places you can't see it affect the operation of the motor more, like in the ring grooves. Over time, with frequent oil changes, you can probably help the situation, if it already don't blow a lot of smoke. Loosening it up by running with marvel oil could be catastrophic, chunks could clog the oil pump screen. If you do try to clean it out, use a vacuum cleaner to pick up the chunks after you scrape loose with a spoon. Since some will get away, down in the bottom end, clean out the pan and the pump inlet screen too.
The "you'll ruin it by going to a HD oil" is a myth. If it is out of the vehicle then put it on an engine stand. Pull the pan and oil screen and clean thoroughly. Flip it upside down so that the top is now down and clean the valley sludge out with kerosene, and a bunch of brushes. Wear old clothes and use a big washtub or similar to catch the crud. Let it drip for a day after youre thru. If you got a few extra bucks put in a new oil pump, cheap insurance. Put it back in the vehicle, fill with a good grade 20W50 and drive the pants off it.
If going the "miracle clean" solution, try SeaFoam in the oil. I first heard about it on the Saturn forums (Saturns had a problem with the oil rings sticking "in"). It is a little more agressive than MMO, particularly good on varnish deposits.
Ya gotta leave that old sludge in there! think of what that motor will be worth in a few more decades, probably the only flatty left in the world with the original sludge! besides, the sludge doesn't hurt anything....
I'm really torn on this discusion. I have a flathead sitting here that a "Quick and Dirty" clean up was done on. (not by me, the engine was sold to me as "Re-Built" ) Sludge was cleaned out of the lifter galley, (with a scraper, then washed) the pan removed and cleaned, oil pump pickup screen cleaned, new oil pump installed, new rings (on existing pistons) and bearings replaced. Engine re-installed and run. After about 6 hours of running, it siezed. On investigation, it was found that particals of sludge found their way under the bearings. (they WERE new) Checking the oil galleys in the crank showed most of them were pluged solid; even though they had been cleaned before re-assembling the engine. (according to the guy I bought it from) If the engine above was mine; I would tear it ALL the way down, and do it RIGHT! BTW - I DID get my money back! He has never come back to collect the pieces.
yup, just goes to show, you can't generalize! If the sludge had been left alone, it probably would not have hurt anything. But if you're gonna clean it out, then go ahead and tear it down, vat it, clean all the passages, and do a complete job of it.
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