1926 EW350 Crankshaft/Bigend Lubrication

[SteveTea]

Hi All, I looking to start rebuilding the engine on my EW and have had the crankshaft components refurbished but I'm worried about the oilways in the central component of the crank.  I've cleared the main drillings through the part but I'm not sure about the oilways to the bigends.  These were blocked with hard carbon deposits which I have cleared as far as I can but I'm concerned that they are not fully clear.  I've put two of the plugs back in the crank and blocked the oil inlet then mounted the crank upright in a vice and filled it with WD40.

I was expecting a small flow of WD40 out of the oilways but there is nothing.  However, if I use a small compressed air nozzle pointed into one of the bigend oilways the level of WD40 in the main oilway drilling rises which implies there is some path through the bigend oilway.  I’m not expecting a free flow through the bigend oilway as this would lead to over oiling at one end of the crank and the other end being starved.

So, how can I tell if the oilways are clear enough?

And finally, one of the oilways is still blocked does anyone have any ideas for clearing this?  Would a soak in something like caustic soda to dissolve the carbon be an effective solution?

[EW-Ron]

Hot caustic is whats been used to hot tub iron auto engines for donkeys years.
Whether or not it will dissolve/loosen hard carbon deposits in oilways is another matter.
I've seen carbon/sludge deposits in sumps set so hard they partly had to be chiseled out.

But you might be lucky, you can only try it.
Caustic generally won't hurt iron/steel components.
It could harm roller bearings though if left long enough that rust may set in ?

I'm not entirely familiar with all the oilways in my EW even - but they had to be machined,
so with enough disassembly you should be able to access them all enough to clear them ?

[SteveTea]

Thanks for that Ron.  The crank has, I believe, been disassembled as far as could be reasonable done.  I think the crank pin you see in my photo has been shrunk fit into the body of the crank with the oilway that you can see being machined into the pin prior to the pin being installed.  So, the upshot is I can dismantle it no further but I do want to ensure there is enough flow through the oilways but I don't know how to do this!
If any of you guy who know your Douggies feel what I've said is wrong please feel free to correct me

Best regards, Steve

[cardan]

I've not done it with a Douglas, but from other engines I've worked on I'd expect a squirt from an oilcan into one end of the big-end oil way to result in a squirt of oil from the other end. Your oil way sounds like the definition of "blocked". I use pipe cleaners, maybe try a small bowden cable inner in the drill? The gunk in there should be just deposited "sludge" rather than baked-in carbon - it's usually cleared with a good poke and squirts of WD40 and oil. Obviously if the crank is built-up, make sure the oil holes are aligned on assembly!

Leon

[carl denton]

hi their is plugs in the end of the oil gallery drilling if you look on the forum you will fined the article . they are very hard to fined but they are there i hare removed them you will be shocked how much sludge is in them .

yours carl

[SteveTea]

Hi Carl, Yes, I did find the plugs and was suprised how much crud was in the oilways.  I could clear out the main drillings that the plugs screw into as theyare straight and could be cleared with screwdrivers and pipe cleaners.  I don't know how the poor engine was running as these drillings were completly blocked with something like black toothpaste!
My main problem is the smaller passageways that exit at the bigend bearing.

[carl denton]

hi steve

the only thing i can suggest is if you slightly radius the hole in the big end to improve the flow . the oil must get over hot and burn all my cranks were the same when i pulled them apart .

yours carl

[oily bloke]

Hi, When I rebuilt my EW crank I removed the grub screws which cap the drilling's in the centre web.
I cannot remember the size of the oil passages but i cleaned them out with drills and solvent in a hand chuck.
The oil is pumped into the web and distributed to either end by centrifugal force. The oil flow should be resistance free when using a small oil can
through the mainshaft drilling.
Hope that helps.
Andy

[Alan]

Have you tried a few drops of Kroil into the blocked part....don’t know if it would work on a carbon deposit, but worth a try.
The best penetrating  fluid I have found and works very quickly.

[SteveTea]

Oily Bloke and Alan, thanks for your info/suggestions.
I've cleaned out the main drillings but its good to know the oil flow should be resistance free.  I have clearly been over thinking this with the idea that the flow would be restricted to regulate the flow against the centrifugal force.
I've not tried Kroil (actually I've not heard of it!) but have found it on Amazon as "Kano Aerokroil Penetrating Oil" more expensive than my usual PlusGas but I'll give it a go.