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  #1  
Old 08-02-2018, 02:24 PM
RicoB RicoB is offline
 
Join Date: Mar 2017
Location: Glendale, CA
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Exclamation #2 running hot and high oil temp

its's an 9A with a O-320 E3D / MT C/S electric prop, Just trying to get any tips on solution for hotter number 2, it's usually 15-20 degrees hotter than 1,3,4. others are around 385 and #2 is above 405, on a climb i see up to 425. I have already removed the front dam completely. also my oil temp is running about 210-215, my oil pressure is at 60psi at running temps, if i raise the oil pressure the oil temp goes up, if i lower the oil pressure down to 45 it runs around 185-190. Looking for ideas on how to attack this problem.. thanks
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  #2  
Old 08-02-2018, 02:43 PM
BobTurner BobTurner is offline
 
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Any chance #2 is running lean? Look carefully for any air leaks in the induction.
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  #3  
Old 08-02-2018, 02:46 PM
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RV8JD RV8JD is offline
 
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Quote:
Originally Posted by RicoB View Post
... with a O-320 E3D... I have already removed the front dam completely. also my oil temp is running about 210-215, my oil pressure is at 60psi at running temps, if i raise the oil pressure the oil temp goes up, if i lower the oil pressure down to 45 it runs around 185-190.
Just a note: 60 psi oil pressure is the Normal Operating Minimum. You'd usually want it higher than that, and certainly not any lower.

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  #4  
Old 08-02-2018, 02:54 PM
BillL BillL is offline
 
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How many hours on your plane? Is this a newly flying or newly acquired?


Awaiting better understanding . . . I think my 7 cools pretty well (180 hp/mags) with a nice plenum and sealed tightly. But . . . I can get a CHT over 400 if left at full throttle, high RPM, and climbing at low speeds with high VS. The oil temp does not get over 190 unless KIAS drops (w/altitude) as VS begins to back off. No cooling jets on the pistons. (yours?)

So - the back of #3 and front of #2 have some restricted fins. That would help, but the elevated oil temps indicate a lower than ideal upper chamber pressure. My Vans cooler is quite adequate. Checking for engine baffle leaks is in order, esp around the inter cylinder baffle. Mine had 1/4" leak around the perimeter. Edit: Also look where the rubber meets the cowl, make sure there are no wrinkles and/or gaps.

One more item, some have had issues with the o-320 carb being too lean in full power climb. What is your full power take-off fuel rate - other 9 owners can compare and give a comparison.

edit 2: Here is how I modified the baffles for better cooling on #2. A friend drilled 5 #30 holes there to get more cooling, he got 10 deg.
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  #5  
Old 08-02-2018, 03:48 PM
Reformed SeaSnake Reformed SeaSnake is offline
 
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Rico,

First, is this a fairly new problem or has #2 always run hot? If it has only recently been running hotter than the others that implies (as Bob pointed out) that #2 is running lean. If you have EGT you can check this by leaning the engine in flight and noting which cylinder peaks 1st. If #2 peaks 1st OR never peaks and just goes down in temp as you lean, this would confirm that #2 is running overly lean and an air intake leak is worth looking for. If one of the other Cylinders peaks 1st, the problem is probably more related to cooling than fuel/air mixture.

If #2 has always run hot, it could be running too lean or it could be a cooling issue. Check for gaps around the #2 cylinder baffles.

The oil temp issue is only partly related. As you already know the Lyco uses an adjustable pressure relief valve to regulate operating pressure. Excess oil is diverted back to the sump to maintain pressure. The higher you set the operating pressure the more oil goes to lubricate and cool the engine. The lower you set the pressure, the more oil is recirculated back to the sump without being heated by the engine. So, the higher oil temp with a higher pressure set point is normal.

If it were me, I would fix the cylinder #2 temp issue 1st. If you bring #2 CHT down, either by enrichening the mixture to that cylinder or improving cooling airflow, oil temp should also come down (at least a few degrees). If oil temp remains higher than you’d like, then you can look at oil cooler airflow.
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  #6  
Old 08-02-2018, 05:08 PM
RicoB RicoB is offline
 
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So let me describe a lil more. Thanks so far for all of the info. It’s just a lil over 40hrs, I am running dual p-mags (the jumpers are not cut)
So the EGT on #2 will peak before the rest if I am leaning. I checked compression few hrs ago and that shows good, 80/80
On take off my fuel flows shows 11.3 I am still working on the accuracy of the red cube.
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  #7  
Old 08-02-2018, 06:06 PM
BobTurner BobTurner is offline
 
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So you confirmed #2 is running leaner than the others. Check all those induction hose clamps for leaks.
Your take off fuel flow, if correct, is too low.
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  #8  
Old 08-02-2018, 07:02 PM
RicoB RicoB is offline
 
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So what fuel flow should I be having at take off ? It’s a 160hp.
Could the P-mags at the 35 degree curve be cause of any extra heat? (Oil temp)
Also someone and the book mentioned the 60psi is low for pressure, what are the average pressure everyone is running on a O-320 -160hp
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  #9  
Old 08-02-2018, 07:20 PM
BobTurner BobTurner is offline
 
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Quote:
Originally Posted by RicoB View Post
So what fuel flow should I be having at take off ? It’s a 160hp.
Could the P-mags at the 35 degree curve be cause of any extra heat? (Oil temp)
Also someone and the book mentioned the 60psi is low for pressure, what are the average pressure everyone is running on a O-320 -160hp
Assuming your CS prop is at redline, takeoff fuel flow should be around 15 gal/hr (check Lycoming spec sheet for exact number). 35 deg advance will also raise CHT.
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  #10  
Old 08-02-2018, 09:28 PM
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Toobuilder Toobuilder is offline
 
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Quote:
Originally Posted by RicoB View Post
... Could the P-mags at the 35 degree curve be cause of any extra heat? (Oil temp)
P-mags are known to have an aggressive curve at high MP. It very certainly could be a contributor. Easy to check though- just retime the ignitions a few degrees after TDC and fly. The timing process on Pmags is so easy it should take you 5 minutes to make the change.
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