Has anybody cleaned the "Lubricating System" of an old flathead?

[bobrich47]

Hello, I am in the process of getting my '47 60S back to life, after it has been restinging patiently about 25 years. I removed the core plugs and flushed the block with a garden hose connected to compressed air. I am amazed at the amount of rust that came out ( the photo is of a jar with some of the rust that I was able to collect. Most was fine dust that washed away in the driveway. ). I highly recommend it.    Now I am wondering if any of you have done a similar thing to the oil passages as suggested in the '42 shop manual. See in the photo Cadillac recommended using Kerosene and compressed air.  I have removed the oil pan and cleaned it out. From what I can tell so far is that there is not much sludge . The engine has not run in many years, but I have repeatedly spun the crank & sprayed Mystery oil or some other lube down the pug holes through the years. It spins freely and ran well before. I had to stop driving it because the wiring was shot & would start a fire.  I have a new harness, but have yet to install it.  So have any of you flushed the oil passages?  Thanks, BOB

[Poncholover]

That procedure sounds like a very exciting mess to me!

[The Tassie Devil(le)]

G'day Bob,

What the Shop Manual is referring to is the cleaning out of the engine whilst the engine is out of the car, fully stripped down, and prior to being reassembled.

This sort of work just cannot be done whilst the engine is in the car.

Bruce.

[James Landi]

Bob,

For "cleaning oil passages," in my judgement, spinning the engine with very light (i.e. low viscosity) oil might be helpful and, in doing so,  not risk scoring vital bearing surfaces. Without disassembly, aggressive action will risk distrubing encrusted particles that could do damage.   I would keep the rings well lubricated on the top end should you decide to  do this.  It's impressive that you found very little sludge deposits, because most "pre pcv" engines would sludge up with incredibly large, ugly sludge,   So I'd caution you about making the comparison between what you found in the water jackets and what might be in the oil passages.  Respectfully,  James 

[fishnjim]

I don't think this is recommended for on the car with motor assembled as someone stated.   The procedure refers to "before you install new bearings", so it's disassembled at that point.
I'm of the camp that the NO oil filter cars are "handle with care" when resurrecting.   The old lead high ash gas, non-detergent oil, and low compression gave lots of combustion products that sludged out and were not obviously filtered.   So mostly they ended in the pan and most all of the manuals call for "annual" pan cleaning for that reason.  Plugs fowled a lot too.   That procedure continued into the partial filter era as well.   If a channel is plugged I doubt it'll be opened when oil starts flowing so if you start it, some of it may not be getting lubed, so refrain from the "rev it up" kneejerk until it's at operating temperature and not making any noises.  If only partially open, modern detergent oil will eventally clean the channels but the sludge will remain in the motor and can go places you don't want it.   So change the oil at least 2-3 times in the first miles.   You can inspect the oil color and feel it between your fingers for "grit".   I also like a magnetic plug to replace the factory one to catch iron particles.   
I don't see a lot of "harm" if you put kerosene in the pan cold not running and drive the oil pump to flush the channels, but there's nothing to say some sludge won't go somewhere else.   Then carefully drain the kerosene and clean/flush the pan again.   
I used kerosene to clean the pan on my "P" even though everyone said not to.   I just filled pan full to gasket and let it sit cold overnight, and drained and flushed til I got clear kerosene.   Motor sat for at least 5 years that they knew of and I started it no problem once the wiring etc. was fixed.

[bobrich47]

Thanks for the advice,  Fishnjim, are you saying that it might be ok to switch to non detergent oil? Thanks,Bob.

[fishnjim]

Although I don't recommend these type products*, "liqui moly" (probably others) has an engine sludge cleaner for this.   You add to your oil before a change and run it for so many minutes before you drain the oil.   [Probably just a higher dose of detergent, emollients, etc.]   But I don't know if it specifies for use in a filtered system or not.   I don't like the idea of loosening sludge and letting it circulate unfettered as it'll just relocate and plug something else.   i"d talk to manufacturers before I used anything.

FYI:Back in the day, the oils coming out of PA had a high level of parafins(waxes) and these would stay behind and accumulate in the motor.   Easily seen if the valve covers are heavily "coated".   This was corrected some time in the '60-70s via "dewaxing" at the refinery.   So a lot depends on how the motor was operated and what fluids it saw in it's life, what condition it'll be in.

re: oil   Check with the manual first for recommended oil.
If you get it "clean - no sludge left, I don't see a proper modern grade detergent oil for high mileage being harmful.
if not clean, go with the non-detergent as probably specified originally.   Just be prepared to deal with the future cleanings, but should be less since today's gas and oil is "cleaner".   
It's impossible to judge from here the type and amount of contaminate in your motor.  Long term. if going to drive much, I'd be investigating a full oil filter add on.   Some came equipped with the ports for filters and were "optional" and not put on, some didn't have ports, if not option.   We tried for the '58 since partial filter, but wasn't an easy conversion without bigger ports.
* - certainly would not use on an "uncleaned/sludged" motor.   Once majority of sludge is gone, maybe OK.   But I do not endorse products.   Just for awareness.   Doing what the kerosene in the manual did more or less.

[bobrich47]

Thanks for your help Jim!

[LaSalle5019]

Definitely use an ashless dispersant (aka detergent) oil. It'll keep new combustion particles in suspension and prevent sludge formation. Any talk of detergent oils removing old sludge deposits and causing issues is mis-information. Manually cleaning sludge out of your oil pan caused by the use of non-detergent oils is always good but there is no reason not to switch to detergent oils, unless you want to stay with "authentic" maintenance procedures of periodically cleaning sludge out of your engine.

[Ron Parker]

If the engine has noisy lifters when started it may have clogged lifter tubes. The flathead has small copper tubes under the valley cover that carry oil to the lifters. These are the smallest passage ways in the engine. They can be cleaned by pulling the intake and valley cover and the remove these copper tubes. I spent a few hours with pipe cleaners and solvent cleaning mine.

[bobrich47]

Ok guys, thanks for the advice.