Mercury 3.0 Crankcase pipe (bearing oil feed lines)

**MaDneSS** · 06-18-2020, 03:14 PM

Looking at a later 3.0 Crank case and it doesn't have the little loop pipe from #6 down to the bottom bearing, however the early 300 promax manual shows it there.

Do I add the line to the later Crank case or leave it off?

**Chaz** · 06-18-2020, 09:52 PM

Madness ,
The "pan vac" hose .. LOL , yea man , put one on it . Otherwise that whole cavity fills with gas and oil. Don't forget the check valve ..

They did some weird things with bleed lines over the years …

**Capt.Insane-o** · 06-18-2020, 10:44 PM

Yeah I have BIG TOMs motors and the reman powerhead that was on it was missing those...and . not to mention the .007 to .012 cylinder bores. The 3 liter bleed systems are something else

**Dave Strong** · 06-19-2020, 10:49 AM

Originally Posted by Chaz

Madness ,
The "pan vac" hose .. LOL , yea man , put one on it . Otherwise that whole cavity fills with gas and oil. Don't forget the check valve ..

They did some weird things with bleed lines over the years …

Why they show a check valve at both ends, a 3.0L thing?

Dave

**Chaz** · 06-19-2020, 03:26 PM

The blocks are all drilled and tapped 1/16" NPT . The fittings are all 1/16" male x 1/8" hose barb. Some are T's some are hollow some are checked one direction and some the other way .. I put the "exit check" at the bottom and a hollow at the top .
Keeps the hose full , but now that I think about it , if the check was at the top , it would be like putting your finger over a straw , wouldn't drain until ya lifted your finger ..

Now I'm so "corn~fruzed" …

**Dave Strong** · 06-19-2020, 03:29 PM

Originally Posted by Chaz

The blocks are all drilled and tapped 1/16" NPT . The fittings are all 1/16" male x 1/8" hose barb. Some are T's some are hollow some are checked one direction and some the other way .. I put the "exit check" at the bottom and a hollow at the top .
Keeps the hose full , but now that I think about it , if the check was at the top , it would be like putting your finger over a straw , wouldn't drain until ya lifted your finger ..

Now I'm so "corn~fruzed" …

Thats what I was thinking, know thats how the small motors work.

Dave

**MaDneSS** · 06-30-2020, 02:30 PM

Probably should have been clearer, I mean the little loop, not the long one that pumps oil upto the top bearing.

Just circled it in the pic for clarity, For some reason this later engine I have it wasnt fitted?

**Chaz** · 07-02-2020, 05:28 PM

Originally Posted by MaDneSS

Probably should have been clearer, I mean the little loop, not the long one that pumps oil upto the top bearing.

Just circled it in the pic for clarity, For some reason this later engine I have it wasnt fitted?

I knew which one you meant. That's why I called it ( or call it ) the "pan~vac" hose, because it clear's the excess gas / oil out of the lowest cavity . Or "oil pump drive gear cavity" would be more accurate .. But then , they haven't used a mechanical type oil pump in 20 years .. Wait .. never mind they don't even make Merc's any more .. only quatro~valvola" LS's on a stick ..

Yea man , at the end of the run .. I think they did a lot of .. Hey Wilbert .. go get us some of them blem front halfs and see ifin they gonna fit these here left over blocks ..

All kidding aside , I don't see any diff in running one way or the other if the gear is off the crank . Other than when you take the lower seal carrier off .. a bigger mess pours out the bottom when you don't have the line installed .

Capt.Insane-o

Yeah I have BIG TOMs motors and the reman powerhead that was on it was missing those...and . not to mention the .007 to .012 cylinder bores.

Factory Reman Powerheads ... sounds official , looks like .. third round picks at the parts bin ..