C1 engine flush

[Howard M.]

I'm thinking about flushing the engine of my '60, 283 by filling the crankcase with solvent (4 qts) and circulating it through the engine with a drill motor on the oil pump shaft after removal of the distributor. There is apparently a lot of sludge somewhere since the oil pressure with a new Melling M-55 pump is showing 55 psi at idle (should be 30-35psi) and way over 60 psi at 2000 rpm.
Are there any downside risks with this method of flushing?
Thanks

[Bob B.]

Re: C1 engine flush

Howard,

I'd be pretty careful about circulating solvent through an engine that you are not going to rebuilt before you put oil in to drive it. Any solvent left can dilute your oil and then cause your oil to lose its lubricating ability and lower the life of your engine.

Did you have this problem before the new pump? If not, then there is no reason why your engine would get stopped up in between changing out oil pumps. I don't know about a Melling M-55, but the 55 makes me wonder if it is a high pressure/volume pump that would give you the increase in pressure you are seeing. I assume that your pressure is after your engine has had time to warm up because it is always higher when cold.

Bob

[Duke W.]

Re: C1 engine flush

I think you have the wrong oil pump/relief spring even though the Melling M55 is supposed to be a standard volume/standard pressure (40-45 psi hot at 2000) pump - improperly built, incorrect part number/packaging - who knows. This seems to be a common "problem" with Melling oil pumps, which is why I don't recommend them. Buy a Sealed Power or Clevite pump.

Your "engine flush" idea does not address the likely root cause of the problem, and IMO is useless and risky.

Sludge buildup occurs on engine internal surfaces that receive oil splash and poor ventilation, like the rocker boxes, and has no effect on oil pressure, which is a function of the pressure relief spring. In most cases sludge actually does little harm unless it breaks loose and clogs the pickup screen or filter, in which cases the engine may show low oil pressure.

Engines with the old draft tube crankcase ventilation typically have more rapid sludge buildup compared to PCV systems, which provide much better ventilation.

Sludged-up engines are best just left alone until it's time for a rebuild. I also recommend that old draft tube systems be converted to PCV.

Duke

[Stuart F.]

Re: C1 engine flush

I recall, back in the day say 1955 or 56, they used to have a type of off engine flushing system at some filling stations. They put your car on the rack, then connected input and drain hoses to your engine (I assume at the filler pipe and pan drain) and then performed a flush while the engine was running. I further assume the system wasn't much good as you don't see them in use today. Probably just a gimmick to get your hard earned buck.

Stu Fox

[Timothy B.]

Re: C1 engine flush

Howard, I have a Melling M55 pump installed in my 300HP car. The hot idle pressure is about 15 PSI and when the engine is reved pressure comes up to 40 +-. I think you have the wrong pump probably M55HV and the counter man did not take the time to check for the correct part # when he sold it to you.