M8 Oil Cooler/Circuit

[nomadmax]

I have someone trying to convince me that all the oil in a M8 engine doesn't go through the oil cooler.  I've looked at the oil circuit and I get that there's a diversion for part of the oil to go to the heads and part to go to the engine.  My theory is that eventually ALL the oil that's recirculated to the pan will go through the oil cooler as there is no mechanism to keep the oil that had previously taken separate paths separate.  This fellow maintains that without something in the pan to mix the oil, part of the total volume never makes it through the oil cooler.

This is clearly the deep end of the intellectual pool over here and I merely hang on to the sides and watch others swim.  Who's right?

[rigidthumper]

Simply put, there is only 1 oil pump.

[SixShooter14]

... This fellow maintains that without something in the pan to mix the oil...

Well this M8 is supposed to be real smooth running.

Seems to me if there's 1 pump, 1 pan/tank/bag/etc then the oil is going to get mixed. Heck, a rough road or speed bump will do it.

[Admiral Akbar]

There is a good discussion over here..

http://www.hdforums.com/forum/milwaukee-eight-m8/1140770-m8-advanced-oil-cooler-system.html

[hattitude]

This is clearly the deep end of the intellectual pool over here and I merely hang on to the sides and watch others swim.  Who's right?

Wow.... His comments are bothering you so much you have to debate it on two forums....      

[nomadmax]

There is a good discussion over here..

http://www.hdforums.com/forum/milwaukee-eight-m8/1140770-m8-advanced-oil-cooler-system.html

Yeah, I'm part of that thread and I wanted to get a few more opinions from folks I think would know.  The crux of the conversation has me very curious though. (the not all the oil goes thru the oil cooler at one time or another)

[nomadmax]

Wow.... His comments are bothering you so much you have to debate it on two forums....      
[/quote]


No not really.  I guess I'm just a slow learner and can't grasp how it could be any other way.  I'm not really cut out for arguing on the net; it doesn't really accomplish anything.  I didn't mention who it was or even where it was.  All I want out of it is the knowledge (one way or the other) from a source I think I can trust; that's all.

Now if I would have been looking for the best Get Back Whip or Ape Hangers to put on my bike I would have stayed over there;) 

[rbabos]

Any oil from a common pump, even if the head and cooler are in a separate circuit have a common starting point and end point for the oil. That would be the sump or pan. The vrod for example takes engine oil, meters it though a certain size jet as to not drop main line pressure to feed the center of the trans. Now I haven't dug into the M8 but it would only make sense the oil flow is metered jet in that circuit as well to control main line pressures within normal .
Ron

[SixShooter14]

Any oil from a common pump, even if the head and cooler are in a separate circuit have a common starting point and end point for the oil. That would be the sump or pan. The vrod for example takes engine oil, meters it though a certain size jet as to not drop main line pressure to feed the center of the trans. Now I haven't dug into the M8 but it would only make sense the oil flow is metered jet in that circuit as well to control main line pressures within normal .
Ron

If so, then the pump is essentially a mixer??? As in its always pumping more flow than the jet can pass to maintain proper pressure.

[guydoc77]

The pan or tank would be where most of the mixing would occur. A lot of heat transfer from the hotter returning oil to the cooler returning oil also as temp equilibrium is occurring in the oil mixture. But yeah, mixing would occur at the pump too. But also in the passageway from the pan to the pump and in any other common passageway or oil line.

On another note, upon reading the thread in the link,  it is interesting to note that personality disorders do remain remarkably stable. Unlike what is feared for oil temps in the M8.

[Bike31]

I've followed the thread's evolution for fun. Ultimately the oil temp in the pan and bike engine temp (heads/whatever) will be interesting to discover (per the plans to do that). Would like to see how it compares to current TC's A and B models before I pick up a pitchfork and torch.

[nomadmax]

I'd like to thank you folks for your responses. I have what I needed to know. I won't be headed back to the other thread; no need in it for me. Honestly, I've learned more when I was wrong than I ever did when I was right;) However, being simple minded I sometimes suspect I'm wrong when the answer seems simple.

[Don D]

Steve Coles findings are significant. If the average oil temperature is 335 deg f even the best of oils will breakdown fast.
Breakdown. .
Oxidation that increases acid number.
Drives a strong case for a full synthetic.
Also I can't believe they don't send the hot oil to be cooled out of the heads straight to cooler then back to tank.

[rbabos]

Any oil from a common pump, even if the head and cooler are in a separate circuit have a common starting point and end point for the oil. That would be the sump or pan. The vrod for example takes engine oil, meters it though a certain size jet as to not drop main line pressure to feed the center of the trans. Now I haven't dug into the M8 but it would only make sense the oil flow is metered jet in that circuit as well to control main line pressures within normal .
Ron

If so, then the pump is essentially a mixer??? As in its always pumping more flow than the jet can pass to maintain proper pressure.

Or, look at it as a basic leak that won't effect this larger oil cooled heads (pump) for normal pressures. I suspect normal engine oiling and with some of this oil run into the heads via a reducer of some form.
What you said is also correct. M8s have two different pumps. The big one for the oil cooled heads extra demand is the way I take it.
Ron

[les]

Reading the service manual, the oil comes out of the cam chest (from pump) to the oil cooler.  After going through the heads, it ends up going directly into the oil pan.  It's not possible for this oil to segregate itself from any other engine oil.


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[hattitude]

Wow.... His comments are bothering you so much you have to debate it on two forums....      

No not really.  I guess I'm just a slow learner and can't grasp how it could be any other way.  I'm not really cut out for arguing on the net; it doesn't really accomplish anything.  I didn't mention who it was or even where it was.  All I want out of it is the knowledge (one way or the other) from a source I think I can trust; that's all.

Now if I would have been looking for the best Get Back Whip or Ape Hangers to put on my bike I would have stayed over there;)
[/quote]

I absolutely agree with you about this site.

While there are certain very knowledgeable people on that forum (took awhile to figure out who they were), this is the site I go to for reliable technical information......

It has been interesting reading, following both threads.....

[glens]

The definitive solution to this riddle is that while there is no way to guarantee that any given molecule of oil in service will ever pass through either the cooler or the filter, it's fairly likely that it will at least occasionally do so.

[joelp34252]

I guess you could also say there is a chance  that some of the molecules of oil could be lazy and never ever leave the oil pan.

Joel 2001 FLHT

[rbabos]

I guess you could also say there is a chance  that some of the molecules of oil could be lazy and never ever leave the oil pan.

Joel 2001 FLHT

Naw, their friends will come along and take them for a ride.
Ron