Oil Filter Info. Needed

[chuckwp]

Dumb Question. On the early oil filter systems, how does the oil flow out of the housing into the hose that goes to the front of the engine? The hose attaches to center tube of the housing on the bottom but, the tube is where the bolt that holds the lid on threads into. So, how does the oil go out? I have spent lots of time searching and not found the answer. Does it drain around the tube at the bottom? The housing was about 1/4 full of oil when I took the top off so, that would seem to indicate that it is not draining. I suppose the hose could be clogged up but, I want to know how it works.

[marko39]

Oil returns thru two holes on side of center tube.

[big job]

Read the oil restriction orifice post topic . It will show you two .063 holes in the tube
a little under where the tube treads are. That is where the oil drains out. There is also
a .063 restriction inlet fitting. Maybe your holes are plugged up I changed a filter
this week and the little holes are visible. on 8BA Napa #1006 filter........

[JSeery]

Where the drain tube or hose connects to the block depends on the year and make of the by-pass filter. An earlier model has the return to a banjo fitting on the timing cover. (51merc here on the Barn has posted a lot of oil filter photos).

[Floyd]

No such thing as a dumb question. Now you know more than you did yesterday.

[alanwoodieman]

Sponsored Links (Register now to hide all advertisements)

questions are only dumb when asked for the second time. otherwise ask away! we as a group will try to help answer all questions to do with flathead fords. I just took a filter off a car and the po had changed the return lines and accidentally blocked off the return. did not filter much oil!

[flatjack9]

Originally Posted by big job

Read the oil restriction orifice post topic . It will show you two .063 holes in the tube
a little under where the tube treads are. That is where the oil drains out. There is also
a .063 restriction inlet fitting. Maybe your holes are plugged up I changed a filter
this week and the little holes are visible. on 8BA Napa #1006 filter........

I don't think the restrictor fitting was used until the introduction of the 8BA.

[JSeery]

They all have a restrictor on the inlet side to the filter canister. They are sometimes located at the bellhousing outlet.

[chuckwp]

Now I am less dumb, and know what to check. Thanks for the assistance!

[chuckwp]

Originally Posted by marko39

Oil returns thru two holes on side of center tube.

Originally Posted by big job

Read the oil restriction orifice post topic . It will show you two .063 holes in the tube
a little under where the tube treads are. That is where the oil drains out. There is also
a .063 restriction inlet fitting. Maybe your holes are plugged up I changed a filter
this week and the little holes are visible. on 8BA Napa #1006 filter........

I seem to have only one hole on one side of the tube. I do not believe it is just plugged as I cleaned the tube shiny and cannot see a hole on the opposite side. So, now I am not sure what is going on. Is it possible for it to only have one hole? The engine is a '38-does that make a difference?

[51 MERC-CT]

Originally Posted by chuckwp

I seem to have only one hole on one side of the tube. I do not believe it is just plugged as I cleaned the tube shiny and cannot see a hole on the opposite side. So, now I am not sure what is going on. Is it possible for it to only have one hole? The engine is a '38-does that make a difference?

What size is the one hole?
If the one hole is at least .080 dia. it should be OK.

[chuckwp]

Originally Posted by 51 MERC-CT

What size is the one hole?
If the one hole is at least .080 dia. it should be OK.

A 5/64" -.078 drill bit will no go nor, will a 1/16"-.0625 drill bit.
I suspect the hole to be .060 but, do not have a way to gauge it.
So, suggestions?

[51 MERC-CT]

Originally Posted by chuckwp

A 5/64" -.078 drill bit will no go nor, will a 1/16"-.0625 drill bit.
I suspect the hole to be .060 but, do not have a way to gauge it.
So, suggestions?

Have you determined if there is a 1/16" restictor hole in the inlet fitting?
If so then the hole in the tube should be twice the volume (5/64").
If there is no restrictor hole anywhere on the inlet side, then the hole in the return tube appears to be acting as the restricion hole. (probably early design )

[chuckwp]

I will check for inlet fitting restriction.

[chuckwp]

Originally Posted by 51 MERC-CT

Have you determined if there is a 1/16" restictor hole in the inlet fitting?
If so then the hole in the tube should be twice the volume (5/64").
If there is no restrictor hole anywhere on the inlet side, then the hole in the return tube appears to be acting as the restricion hole. (probably early design )

There is no restriction on the inlet side in the fitting on the block nor, is there a restriction in either end of supply hose.
This has me leery of using the filter now. I do not know the history of this engine. I suppose I could see how much oil pressure it has once I get it to running condition and go from there.

[51 MERC-CT]

Originally Posted by chuckwp

There is no restriction on the inlet side in the fitting on the block nor, is there a restriction in either end of supply hose.
This has me leery of using the filter now. I do not know the history of this engine. I suppose I could see how much oil pressure it has once I get it to running condition and go from there.

Then this is apparently the way the early filters were designed, the one hole in the return tube is the restrictor and should be good to go.
The later filter design was an apparent effort to reduce the buildup of pressure within the canister.

[chuckwp]

Originally Posted by 51 MERC-CT

Then this is apparently the way the early filters were designed, the one hole in the return tube is the restrictor and should be good to go.
The later filter design was an apparent effort to reduce the buildup of pressure within the canister.

I dunno, if they redesigned it because of a problem, it will still have the problem, right. Thanks for all the information. We will figure something out.

[51 MERC-CT]

Originally Posted by chuckwp

I dunno, if they redesigned it because of a problem, it will still have the problem, right. Thanks for all the information. We will figure something out.

The only problem would have been a buildup of pressure in the canister that presented a gasket sealing problem on the cover.
Those systems worked as intended for a number of years.

[tubman]

I have never had a leak on a stock 8BA oil filter, and I've had a few, some for over 30 years.

There must be a problem with yours.

[JSeery]

It was my understanding that the by-pass filters always used the inlet side restrictor. The early models used a separate fitting that screwed into the T fitting located at the bellhousing outlet. Later it was moved up near the canister. If there was a version without this inlet restrictor that would be interesting to know.

I know from past post that a lot of people have a difficult time locating the holes in the canister drain tube.