Oil coolers

[biglady112]

I thought a little about my "stagnant" comment. Basically I was getting at oil changes. In my case, the cooler holds an entire quart. I basically wanted all the oil to drain back when the motor shuts off. Not have a crappy old quart of oil still trapped in the cooler every oil change.

Sorry, I just shot my response from my hip earlier.

 

[turbowop]

Would it not drain back if the inlet were on the bottom and the outlet on top?

 

[mooserage]

I guess I dont see why it wouldn't drain back as long as the cooler was above the drain (oil pan plug in this case). Gravity will want to move the oil past any air and through the system to the area of least resistance, no?
-shamus

 

[cheekychimp]

This is pretty interesting actually. I cannot see how the oil system as a whole can ever be air tight, particularly with a stock sump. The fact that oil drains back into the sump pretty much makes it impossible for the lines/cooler not to be filled with air when the system drains. The question here is how is that air eradicated once the system restarts? In this respect I actually think Mark's suggestion of having the outlet at the top has merit.

For pressure to really work in terms of helping to fill the oil cooler, I would think inlet flow would need to be higher than outlet (even if only marginally so) other wise any obstruction in the cooler is going to 'divert' the oil straight out of the outlet (path of least resistance). Seeing as all the coolers I have seen have equal sized inlets and outlets, I can see how air trapped in the cooler 'could' prevent the entire capacity being used.

That said, I was thinking of this from the point of view of water passing through a system. Does oil respond differently to water? Will it absorb the air and carry it out as it flows rather than just allowing it to 'float' and collect at the top of a container as water would?

 

[biglady112]

I am referring to if the inlet/outlet are on the top. I thought I read somewhere here someone talking about that. I also feel the same way about the inlet/outlets going side ways. Just don't see ALL of the oil getting out on a oil change.

Oh, and until recently, I have not used a turbo oil filter housing in years. So I have not seen the brass thing on a filter housing in over five years.

 

[turbowop]

You'll never get all the oil out of the system during an oil change anyway. A ton of it stays in the pickup tube and throughout the motor. As long as you change what drains out of the pan, it'll be fine.

 

[AWDnot2]

Quoting BarnesMobile:
The big brass looking cap thing on the bottom of your oil filter housing is oil 'thermostat' or whatever you call it.



Jon, yep. That's a vernatherm or oil temp control valve. It's normally open which lets some oil bypass the cooler. Once the oil gets up to temp, the plunger extends and it closes off the passage and routes the oil into the oil cooler. If the oil drops below the min temp or pressure becomes too great (clogged cooler) it will open back up or "crack" and bypass the cooler. Helps the engine warm up quicker and allows the oil to stay warm if driving in severely cold climates.

 

[misterfixit]

Isn't that how the factory oil cooler mounts?

One other thing is the autos came with the cooler mounted in the wheel arch (where the abs pump would otherwise be with a fan on.

If the oil does get air in it surface tension will caus it to foam. That is why the oil suction tube is always in the bottom of the sump. What it will do is have a glop of air in it until it is purged out by the pressure. As it will all be the same pressure it will flow through and out (bled system) its how we don't have aircraft hydraulics full of air, and trust me they are some convolouted routings.

Rich

Quoting iceman69510:
Quoting turbowop:
This thread is really messing with my thinking on how oil coolers should be mounted. I don't understand how it would be correct to have the inlet and outlet both on the bottom. Any oil flowing through the cooler would only flow through the bottom passages. With the inlet on the bottom and outlet on top, the oil would be forced through the entire core, or if both the inlet and outlet were on top, same deal. This doesn't make any sense to me.



I think it may depend somewhat on the internal design of the cooler, but you have to remember Mark that pressure is equal everywhere. 70 psi of oil coming in to the cooler is going to be 70 psi everywhere in the cooler, not just dribbling in at the bottom. Think of air pressure in a balloon.

I am struggling with the talk about the air in the system and how that may effect oil flow, and if it gets out in normal running, does it come back again next time?

 

[boostedinaz]

It won't really matter either way. The system isn't sealed like a cooling system so what ever air gets "trapped" in the cooler will be purged once the oil pressure pushes it out. In a cooling system once the cap is on the system is sealed so whatever air was in it is now trapped taking up space. In the oiling system you have breathers, PCV systems, etc that will allow the air to escape.

As far as port location that won't matter either. I have a feeling the people that think the oil will only fill up a portion aren't thinking about the pressure in the system. At 70 to 100+ PSI that our oiling system can build I guarantee either oil cooler is full the brim with oil. If you were thinking the air was "trapped" refer to my above comments.

 

[cheekychimp]

Quoting misterfixit:
Isn't that how the factory oil cooler mounts?



Yes .. exactly! It was the first thing I looked at after seeing this thread.

One other thing is the autos came with the cooler mounted in the wheel arch (where the abs pump would otherwise be with a fan on).



Now that is good to know. So some new lines and I could have a factory configuration installed oil cooler if/when I delete the ABS. Would seem to make more sense having a fan on in Hong Kong too with all the stop and go traffic and would leave the stock location free for something like a diff or transmission cooler.

 

[CP]

FWIW, B&M makes a nice oil cooler with a fan and 175* thermal switch. 1/2" NPT ports. Part number 70298.