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A Technical Question to Ponder


jon haney

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What would happen if you removed the oil cooler from a 99 Bird, and just blocked the ports on the engine cases?  No by-pass, just blocked, and no other modifications.

Aside from higher oil temps, what else would or should happen in the engine?

 

 

 

 

 

 

 

 

 

 

Yes, it appears I have tried this, accidentally.  I'll fill in the details of this, um, um, accident, once I hear some responses. 

🙄

Edited by jon haney
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48 minutes ago, Furbird said:

Logic would say certain destruction.  Oil would build against the restriction until something failed.

At worst, I would think the extra oil would just run over the relief valve, robbing HP and further heating the oil.  Since the Bird only has a single rotor oil pump, I'm assuming there is an internal orifice that limits the amount of oil that can go to the cooler, and the rest goes to the engine.  If all oil goes through the cooler before it goes to the engine, this thread would be 8 years old by now, and would likely had to rebuild an engine.

 

Basically, I'm replacing the trans on the Drag-Bird to a stock unit, and re-installing the balancer shafts.  As I'm cleaning the lower case half, I pop out the seals (or so I thought) for the oil cooler lines.  Then I remember there were already o-rings on the tubes.  What I pulled out was a couple of top-hat style rubber plugs like you might use to keep out dirt and debris, while you do other stuff.  Both plugs are completely intact, and the cooler line connections never leaked.  Being a race bike, I never ran it long enough to over heat the oil.  Crank bearings (factory original) look fantastic.  IDK

 

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7 minutes ago, jon haney said:

At worst, I would think the extra oil would just run over the relief valve, robbing HP and further heating the oil.  Since the Bird only has a single rotor oil pump, I'm assuming there is an internal orifice that limits the amount of oil that can go to the cooler, and the rest goes to the engine.  If all oil goes through the cooler before it goes to the engine, this thread would be 8 years old by now, and would likely had to rebuild an engine.

 

Basically, I'm replacing the trans on the Drag-Bird to a stock unit, and re-installing the balancer shafts.  As I'm cleaning the lower case half, I pop out the seals (or so I thought) for the oil cooler lines.  Then I remember there were already o-rings on the tubes.  What I pulled out was a couple of top-hat style rubber plugs like you might use to keep out dirt and debris, while you do other stuff.  Both plugs are completely intact, and the cooler line connections never leaked.  Being a race bike, I never ran it long enough to over heat the oil.  Crank bearings (factory original) look fantastic.  IDK

 

 

Sounds to me like you discovered an inside trick to win more races!
You should get rid of the oil cooler completely for a reduction in weight and then put her back together and run a few more passes to set some new personal best times ! More trophy's - more wins with your new secret formula!

 

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1 hour ago, jon haney said:

At worst, I would think the extra oil would just run over the relief valve, robbing HP and further heating the oil.  Since the Bird only has a single rotor oil pump, I'm assuming there is an internal orifice that limits the amount of oil that can go to the cooler, and the rest goes to the engine.  If all oil goes through the cooler before it goes to the engine, this thread would be 8 years old by now, and would likely had to rebuild an engine.

 

Basically, I'm replacing the trans on the Drag-Bird to a stock unit, and re-installing the balancer shafts.  As I'm cleaning the lower case half, I pop out the seals (or so I thought) for the oil cooler lines.  Then I remember there were already o-rings on the tubes.  What I pulled out was a couple of top-hat style rubber plugs like you might use to keep out dirt and debris, while you do other stuff.  Both plugs are completely intact, and the cooler line connections never leaked.  Being a race bike, I never ran it long enough to over heat the oil.  Crank bearings (factory original) look fantastic.  IDK

 


I guess it depends on how the system is designed.  I have been told that on a GM engine, if you plug the oil cooler lines (which are NOTORIOUS for leaking,) bye-bye engine.  You can loop the two lines together, or remove the entire adapter and put the non-oil cooler plate on it (which is what I did) but plugging the lines equals destruction.  Who knows.

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Just took a closer look, and there are two rotors.  The first one appears to go directly to the cooler with no relief valve.  After the cooler, the oil goes into the outlet side of the second pump and I guess is combined with the second pump's output.  If the cooler line gets plugged, where does that oil go?  The pump appears to be undamaged.  WTF.  Even if there is an internal by-pass for the pump, does that mean I've been pumping half volume to the engine all these years?  Maybe it by-passes to the other pump?

There has to be an explanation.  I'm not that lucky.  Stan, where are you?

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The pump feeding the cooler does have a pressure relief so whatever it's set at is all you were "forcing" against the plug.  The oil exiting the cooler is fed to the inlet of the main pump so you weren't starving the engine.  I know this because I'm a CRB1100XX super expert.

 

 

or because I had no fucking clue and needed to know so I opened the manual to page 4.0 and looked at the "lubrication system diagram".  Check it out then rest peacefully, no damage was done and no luck points were spent.  Actually, if you were only drag racing you probably did the motor a favor by killing the cooler.🤗

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23 minutes ago, superhawk996 said:

In case you don't have one.

IMG_0187.thumb.jpeg.c5b8e43211ef2c6a1a52c20101b8109b.jpeg

Thank you, Oscar.  I just have a Haynes manual.  Was thinking of looking through the online version for that diagram.  Gotta really look close to find the by-pass on the cooler half of the pump.

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