Oil Drain Through Cover Plate?

[rcsails]

I seem to remember reading somewhere that oil drainage from the reversing gear was more complete than from the dipstick tube due to engine installation angle. I may also have read about the following idea, although I can't find it now:

Is there any reason why I can't install a pipe plug or some other easily removable fitting into the cover plate at the correct location to facilitate regular oil removal? Any ideas about specific location on the plate? Is there such a fitting already produced, maybe something like a nipple with a fitted cap so I wouldn't even have to deal with removal of a threaded fitting each time?

[Dennis L.]

I drain my oil from the transmission, as I was advised that this was the best place to extract the most oil. Its easy to do for my installation, but, you have a gasket to deal with at each change. I ordered a few spare gaskets from Moyer and I can templet to make my own for the future. However, your idea is a good one. In my opinion, there is no reason why that wouldn't work. I would go with a gasketed, screw on fitting, so that I could insert my pump hose to the bottom of the transmission case. That fitting would be on the side that favors where I would be working. We are talking about the cover plate right? I would not consider drilling into the transmission casting to insert a fitting, although it may be possible. I'd be curious to here what Don might think on this subject.

[Don Moyer]

Dennis,

Universal provided a 3/4" pipe-threaded hole in the upper ledge of the oil pan, between the carburetor and fuel pump, to extract the oil during changes. Because of the triangulation of the base of the oil pan, this location is generally the low point of the oil pan. In the case of early model engines, the factory actually installed a small hand pump in this pipe-threaded hole to extract oil, but discontinued the practice in late model engines.

We designed an oil change kit some years ago to install in this same opening, which you may want to consider instead of modifying your rear cover. It's listed in the online catalog on our web site as Product number KTAS_05_90.

Regarding oil capacity, on a level bench, it will take approximately 5 - 1/2 quarts to fill an Atomic 4 after an overhaul. Tilted at an angle approximating a normal installation on a sail boat, an engine will only take from 4 to 4 - 1/2 quarts to bring the level to the full mark.

When changing oil, it's common to only be able to remove 3 quarts (or slightly less), due to the fact that a quart or more is trapped within the pressurized oil channels and the reversing gear.

Bottom line: On a late model engine, always maintain the oil level to the full mark, and on an early model engine maintain the oil level to the uppermost mark on the dip stick.

Don

[C3058]

I have a pretty substantial leak at the 3/4" plug in the pan. This seems odd, since I read that the fill level is below this plug and the change kit can be installed without draining. It has a square head plug, which I don't know if i have a socket that will fit it and of course it is hard to reach with an adjustable wrench, so i have to figure out how to remove the old one, re-tap the pan and install a new hex headed plug. I assume since it is leaking, i should fully drain the oil prior to removal. Any advice?

[roadnsky]

I have a pretty substantial leak at the 3/4" plug in the pan. This seems odd, since I read that the fill level is below this plug and the change kit can be installed without draining. It has a square head plug, which I don't know if i have a socket that will fit it and of course it is hard to reach with an adjustable wrench, so i have to figure out how to remove the old one, re-tap the pan and install a new hex headed plug. I assume since it is leaking, i should fully drain the oil prior to removal. Any advice?

No need to drain the oil before removing that plug.
As stated, it's above the oil level in your engine UNLESS you're drastically overfilled... :eek:

You CAN get a socket or ratchet on there and if you remove the carb it's even easier.
I can't recall the size, but it's a standard SAE wrench.

As Hanley said in your other post, it's more likely that the leak is coming from a gasket.
First place to look is the Valve Cover.
Second, the Mechanical Fuel pump cover.

Finally, here's a document from Don about searching out sources of Oil leaks.

[tony201]

Are you talking about that lower drain below the starter?

[C3058]

So, the oil was accumulating on the oil drain plug (under the carb), and after removing the carb and electric fuel pump, it looked like it was coming from one of the bolts that holds the valve cover in place. I removed the cover, destroying the gasket. I made a new one from a sheet of cork and reinstalled. After replacing the carb and fuel pump, started the motor, only to see the oil accumulate on the plug again. More careful search showed the oil coming from the oil pressure sender & switch tree at the front of the motor. As soon as i tried to tighten it, the 1/8" pipe immediately broke off. I used an easy-out to get the stub out of the block and replaced the nipple, put it all back together and all is well.

The really weird thing is that the exact same thing happened on the opposite side of the motor to the pipe extension that is threaded into the low point drain for the fresh water cooling passages. Now i will start a separate thread about that, but my motor runs really rough when in gear, and i wonder of the heavy vibration actually caused these two pipes to crack, draining oil & antifreeze into my bilge.

Thanks for the support, at least the fluids are all on the inside now!

[roadnsky]

Sounds like you actually avoided a possible A4 meltdown! :eek:
Don mentions (in the A4 Manual) the potential for that same 1/8" fitting breaking while the engine is running and draining the A4 of oil so fast you have major damage.

[sastanley]

C3058,
My block drain tube broke off long ago. The threads were no good either, so I had to tap new threads and upsize my drain to 1/4".