Author Topic: How hot should oil be???  (Read 1663 times)

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Lumbee

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How hot should oil be???
« on: May 21, 2005, 07:15:23 PM »
...have a 78 750 I just finished a rebuild on.  I think it may be running a little hot.  Anybody have a range on what the oil temp should be?

Offline Gordon

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Re: How hot should oil be???
« Reply #1 on: May 21, 2005, 08:41:45 PM »
It should be somewhere between "holy #$%* that's hot" and boiling.  ;)

Offline TwoTired

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Re: How hot should oil be???
« Reply #2 on: May 22, 2005, 01:05:17 AM »
Your engine oil will be different temperatures depending on where you measure it in the circulation path.

180 F is a good temp for oil.  Some oils begin rapid breakdown beyond 230 to 250 degrees F.  Depends on the quality of the oil.

For example, my 360 cu in boxer type air cooled wet sump airplane engine has a temp sender inserted into the oil galley near the discharge point of the oil pump.  During cruise, it measures 180-185 F.  Sometimes in the summer during climbout it gets to 190 F.  But then, cylinder head temps are 450F during extended climb due to the reduced airflow over the cylinders.  Cylinder head temps are 350-375 F during cruise at 75% of full rated power output of 180HP.

I did find and excerpt in the Honda Shop manual that states an oil pump relief valve setting of 56.9 lbs at 4000 RPM and an oil temp of 176 degrees F (80 C).  So, apparently they expect those temps in the engine at that point, anyway.


Lloyd... (SOHC4 #11 Original Mail List)
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