Technical Arbath sump

[Adam MM]

Hi all

I building an engine for a 1965 500 and have an arbath sump there is a a cast in area that fills with oil fro the rear engine bearing ( flywheel end) but has no exit holes.

I fitted this and started the engine and have a oil leak from that area while the engine is running.

Should this area have and exit back to the oil pan and not blocked off ?

Any help would be awesome.

 

[Bambino]

?? Not sure - ?? oil temperature or pressure sensor maybe.

If you can get at it, a picture might help.

Chris

 

[RogerNZ]

There is only one oil feed down from the rear main bearing to the sump as far as I know. It's the key feed for oil under pressure back to the sump, so it's not 'blind'. Pics attached from my 4 litre Abarth sump below. Apologies if I'm on the wrong track here.
Cheers Roger

 

[Bambino]

I think you're right Roger. I was on the wrong track - not unusual sometimes.

I've attached a couple of photos as well - one from the repair manual showing the oil circulation and the other when I had the sump and head off my engine - you can clearly see the sump return.

If there is an external leak then either the return is blocked or the sump gasket is not sealing correctly.

Chris

 

[jjacob]

I think Adam was saying that the bottom of the return passage is not open, so it is blind. I looked at some other of these castings on some suppliers sites and some appear blocked or not open that much.
This return passage should be open at the bottom. I would get a die grinder and grind away enough aluminum to open the bottom of the passage. Just sloppy post casting clean up as far as I am concerned.
This can be bad for the rear bearing if the passage is blocked.

Oh, Adam, it's Abarth not Arbath!
John