Alfa Romeo Forums banner
1 - 13 of 13 Posts

·
Registered
Joined
·
1,690 Posts
Discussion Starter · #1 ·
Hi All.

Before I go and create a lot of work for myself I wanted to test with those out there what they have done with their oil reservoirs after 50 yrs of service.

Background;
My engine has just had a complete overhaul completed. It blew a head gasket shortly after purchase. Further inspection revealed tired crank bearings, out of spec valve guides, a failing water pump bearing (failed really) and so on. So a very extensive rebuild ensued. This is now complete. All supporting ancillaries have been replaced or overhauled as we have gone along.
Which brings me to the dry sump oil reservoir. Upon inspection it has quite some oil sludge at the bottom, a partially blocked wire mesh filter (car had good oil pressure..surprisingly) and the internal horizontal mesh filter has a one inch hole in it with no sign of the remnants in tank that we can see....

Ordinarily I would flush it thoroughly and move on but with the horizontal mesh partially missing it does bother me.
1...its not doing its job...I guess to catch things someone inadvertently might drop in the tank...a nut...a leaf...who knows.
2...the tank has a baffle below and the tank is quite convoluted...so ensuring it is clean is tricky. Ok it has a filter at the bottom...but it would be nice to have a new motor AND a clean oil circuit.

My current thinking is I need to grind the welded tank flange, split it, repair the horizontal mesh and tig back together.

Many must have had to ponder this question. What have folk done or reccomend? I've not turned up anything on the internet or in my
Automotive tire Automotive lighting Bumper Fender Rolling

Essential companion book, manuals etc.

PS the 22 mm hex head lower filter fitting required a hex hex 3/4 inch socket and rattle gun to remove...no luck with bolt head. Should anyone need to borrow it...well...it would be nice if it got used twice!
Hood Cloud Gas Automotive tire Cylinder
 

·
Registered
Joined
·
1,111 Posts
During the light "rise" carried out on a customer's car, I proceeded to send the tank to a specialist for treatment: completely etched, pressed and finally painted with special protection. el doubt I put a cap with new wire mesh although a little expensive.

Sergio
 

Attachments

·
Registered
Joined
·
1,690 Posts
Discussion Starter · #3 ·
Thankyou for the excellent photos Segio. I didn't quite follow what was done internally to yours. I think I've decided to thoroughly chemically flush. The mesh will have to stay as it is, I'm not convinced it serves a purpose...although I know all to well that manufacturers do not add expense to their vehicles without good reason. All I can think is the mesh catches debris during oil filling making it a little easier to retrieve. Actauly the upper wire mesh is installed in 2 sections with a gap of about 10mm between the two sections, so it really does seem superfluous. Thoughts?
 

·
Registered
Joined
·
1,111 Posts
The cylindrical filter I would install working without doubt. Do you think it is superfluous? I do not know how much time and money you spent on the remake of the engine, but if I were you I would not skimp on a "doubt" that could cost me a great displeasure. Look at what condition it was in when you disassembled it.
But you see of course...
My 2 cents.
 

·
Registered
Joined
·
219 Posts
The horizontal wire mesh is very important. Dry sump engines require scavenge pumps to evacuate the oil pan and return the oil to the tank. These pumps need to have at least twice the capacity of the pressure pump, so they can keep the oil sump empty. If the scavenge pumps cannot keep up with the pressure pump, the engine will slowly fill to the very brim with oil. Since the scavenge pumps can pump more oil than the pressure pump puts out, they are always sucking a mixture of oil and air from the oil sump. This mixture is returned to the oil tank and the last thing you want is your motor lubricated with a mixture of oil and air. As a result, the oil tank is designed so the oil/air mixture falls through a series of screens on its way to the bottom of the tank. These screens serve to remove the air from the oil(deaerate), thus assuring only oil is used to lubricate the engine.
 

·
Registered
Joined
·
1,690 Posts
Discussion Starter · #8 ·
Great advice, thankyou all.
To be clear, I certainly do see the need for the filter I the bottom of the tank, a new one was purchased. It is the horizontal mesh I was enquiring about the purpose of. The explanation above about oil and air makes sense, should have thought of that.

Someone asked where did the missing bits of wire mesh go? Very good question. I have owned the car for 2 of its 48 years of ownership...From the oil circuit diagram I can only infer it has ended up in the filter at the bottom of the tank, or going through the oil pump and on to the oil filter on the engine.

Disassemble 'oil temp regulator'...do you mean oil cooler temp bypass? If so, every part on this engine has been thoroughly cleaned.

Went with thorough flush and new filter. Still considering the mesh hole (about 20mm).
 

Attachments

·
Registered
Joined
·
9 Posts
"Disassemble 'oil temp regulator'...do you mean oil cooler temp bypass?"

Yes, per the diagram.

If the "missing" tank screen parts went through to the oiling pressure pump there will be visible damage to both of the gears and, very possibly the housing. And if the debris made their way to the engine sump, you'll see similar damage to the scavenge pump components and the housing.
 

·
Registered
Joined
·
1,690 Posts
Discussion Starter · #12 ·
I see that you have a RHD car, not trying to tell you how to suck eggs but don't try to install the engine with the distributor fitted.
I appreciate the advice but it came too late :). The engine was installed with distributor fitted...very carefully, always with clearance to bodywork. Having done it, I agree, there would be less risk of damage if it were installed afterward, as it is tight. The use of threaded spreader beam made for precise adjustment. Engine was installed with gearbox attached and headers. Two man job. Without issue thankfully.
 

Attachments

1 - 13 of 13 Posts
Top