what's happened here please

DjNeil

Member
sripped down a flattie that started banging in my friends 51 Merc and here's what I saw when i pulled the inlet
What caused this sludging up round the valves
Thanks




 
From what I have heard that sludge is fairly normal on an old flathead that has not been apart in years and has the stock crankcase ventilation.
 
That's one of the clean ones. Sometimes you can't see the valve springs. It'll never get rusty.
 
Short trips without thoroughly warming up the engine will cause massive sludge build up. The moisture never gets evaporated out and the oil soaps collect due to low operating temps. An engine that is warmed up and run a good bit after will always look cleaner inside but the oil filtration system on the stock motors leaves a lot to be desired. Few look very clean inside.
 
I think Jim is right. When I pulled the original engine out of my'51 (which I, at least, have been running detergent oil in for the last 38 years) and took it apart, it was much better than that.
 
Exactly what Scott said. I doubt it had anything to do with your cracked valve. They all look like that when you open them up.









T
 
I don't know exactly what is meant by "banging" in the engine but I don't think the problem has been found, just judging from what the pictures reveal.
 
This is probably why Ford added thermostats in '33 and re-engineered the ventilation system in '35. And why many WWII flatheads got PCV systems!
Water is essential for good sludgemaking...remember that the engine not only gets water from condensation from the air, but is also making gallons of water as the main combustion byproduct and some of that gets by the rings. Thermostats are needed because the engine is likely way too cold when running under light loads to cook off the water. The '35 up type ventilation systems depend on movement, and are probably pretty much ineffective at light loads. I suspect that PCV might be more beneficial than full flow filtration as a modification...
Also, sometimes when you take apart a flathead you find serious corrosion on the various sheet metal baffles in there...parts that spent their whole lives soaking in oil!
I think this is likely from the various combustion byproducts in blow-by dissolving in thw water, joining the sludge, and making badness.
 
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