First and Second customer Mooney in for cowling mod.

[cctsurf]

1 minute ago, Marauder said:

My cooler's exit is on the lower side of the cylinders where air from the cylinders will mix with it from above,

Your placement is how it is on all of the early model mooneys, mine included.  The intake there is not in high pressure, it is in low pressure because of the air bending around the bottom of the cowl.  The pressure coming down past the cylinders is higher pressure (especially when the cowl flaps are closed).  The air often goes out through the oil cooler instead of in the assumed direction.  We don't need to see numbers, this placement is done on virtually all modern cowls on high performance planes.  It is better in many ways than our placement.

[Bob_Belville]

FWIW, supporting Chris' point about cowl flaps, my oil temp is what I'd call extremely sensitive to cowl flaps position. And I have the cowl flaps rigged 1/2" open when in the closed position. The queer thing to me is that the port side CHTs are low and the port side oil temp is high. That's in spite of the fact that these conflicting data share the airflow on the port side of the engine.

I am really, really, anxious to get David's "Van" baffles!

[Igor_U]

My understanding is that oil cooler relocation results in lower oil temperatures.

I bought my M20F with the cooler already relocated and never experienced high oil temps.

On my last flight past weekend, with temps 5C lower then standard, oil temps were 175F (on EI CGR30P). Prolonged climb over Cascades on a hot summer day would rise temps to around 200F.

this is with LASAR cowl mod... and  I would love to have Sabermech cowl on my plane.

Edited November 30, 2017 by Igor_U

[Browncbr1]

11 minutes ago, Marauder said:

Looking at these pictures of the relocated oil cooler, it appears about a quarter to a third of the relocated cooler is behind the cylinder. I would love to see some numbers from vintage owners who have done the relocation to see the before and after numbers. I'm sure it works, just curious how much warmer (if warmer) the oil gets. Bob's E may be an exception, but I never seen temps anywhere near his.

I believe Bob's oil temps are a function of a specific power and airspeed setting.   There seems to be a very specific airspeed/prop pressure that equalizes air pressure on both sides of the oil cooler.  Above this speed, air flows outward and cools the oil and below this speed the air flows inward and cools the oil...    Additionally, higher RPM is higher friction, causing higher oil temps... cowl flaps mitigate the stagnant air phenomenon and allow more air to flow out...   Bob seems to generally cruise at 2550... With the oil cooler being located on the high pressure side, of the baffle, air flow will not stop.  Air is not heated until after it has passed through the cylinder cooling fins, so hot air would not be going through the oil cooler.  just my opinion and thoughts..

[cctsurf]

1 minute ago, Browncbr1 said:

There seems to be a very specific airspeed/prop pressure that equalizes air pressure on both sides of the oil cooler.

That is an interesting idea, I never really thought of it that way, but my data supports your statement.  I always wondered why at a lower power setting my oil temps were higher than at a higher setting.  2300 and 23" gets me much higher temps than 2400 and 24" or even more.

[Marauder]

6 minutes ago, cctsurf said:

Your placement is how it is on all of the early model mooneys, mine included.  The intake there is not in high pressure, it is in low pressure because of the air bending around the bottom of the cowl.  The pressure coming down past the cylinders is higher pressure (especially when the cowl flaps are closed).  The air often goes out through the oil cooler instead of in the assumed direction.  We don't need to see numbers, this placement is done on virtually all modern cowls on high performance planes.  It is better in many ways than our placement.

It is being done on all higher performance planes and I am sure that it was done on the Js to gain some speed. My point is that on the older models that were flight tested with the oil cooler in the current location, they were designed this way and the mod introduces a new variable that may result in higher oil operating temps. Igor's example is a datapoint. I don't think I have ever seen my oil temps above 190. Even if climbing on a 95 degree day at Vx. My cylinders on the other hand will be close to the 380 degree range. I am not saying it doesn't work and the resulting temps are outrageous, I am just curious what a before and after looks like.

[cctsurf]

Just now, Marauder said:

I am not saying it doesn't work and the resulting temps are outrageous, I am just curious what a before and after looks like.

It's always good to have more data.  I guess what I'm saying is that it has been tested repeatedly and works better than what we have, so I don't believe it to be that much of a new variable.

[Marauder]

Just now, cctsurf said:

It's always good to have more data.  I guess what I'm saying is that it has been tested repeatedly and works better than what we have, so I don't believe it to be that much of a new variable.

It will be with David's mod. Bob has the Ari cowl, his temps are higher than mine (again not sure if the Ari mod has anything to do with it). With the exception of the SWTA, LoPresti & ARI mods, I suspect most oil cooler relocations were done on wide mouth Mooneys (with or without the lower cowl enclosure).  

My questions will be answered when Matt does his flight test. I'm hoping for a 10 knot speed increase, 40% lower fuel burn and no change in temps. 

[Browncbr1]

8 minutes ago, Marauder said:

It is being done on all higher performance planes and I am sure that it was done on the Js to gain some speed. My point is that on the older models that were flight tested with the oil cooler in the current location, they were designed this way and the mod introduces a new variable that may result in higher oil operating temps. Igor's example is a datapoint. I don't think I have ever seen my oil temps above 190. Even if climbing on a 95 degree day at Vx. My cylinders on the other hand will be close to the 380 degree range. I am not saying it doesn't work and the resulting temps are outrageous, I am just curious what a before and after looks like.

I've found oil temp is not an issue in climb because you're below that specific airspeed that I mentioned in my previous post.  It seems to occur in cruise, at higher airspeed, and lower power setting than climb.     Perhaps you haven't had OT issues because you're cruising faster than this specific airspeed?   I recall you run around 75% power with some pretty good speeds?  

[Bob_Belville]

9 minutes ago, Browncbr1 said:

I believe Bob's oil temps are a function of a specific power and airspeed setting.   There seems to be a very specific airspeed/prop pressure that equalizes air pressure on both sides of the oil cooler.  Above this speed, air flows outward and cools the oil and below this speed the air flows inward and cools the oil...    Additionally, higher RPM is higher friction, causing higher oil temps... cowl flaps mitigate the stagnant air phenomenon and allow more air to flow out...   Bob seems to generally cruise at 2550... With the oil cooler being located on the high pressure side, of the baffle, air flow will not stop.  Air is not heated until after it has passed through the cylinder cooling fins, so hot air would not be going through the oil cooler.  just my opinion and thoughts..

I came back from MA to NC Monday - a pretty cold day OAT 7C - over 600 nm and headwinds so I flew at 8000', 2350 RPM, 8.1 gph LOP, 61% power. OilT was 195F with cowl flaps in trail. (CHTs were not much over 318/315F on the port side and 341/361F on the starboard.

[Bob_Belville]

3 minutes ago, Browncbr1 said:

I've found oil temp is not an issue in climb because you're below that specific airspeed that I mentioned in my previous post.  It seems to occur in cruise, at higher airspeed, and lower power setting than climb.     Perhaps you haven't had OT issues because you're cruising faster than this specific airspeed?   I recall you run around 75% power with some pretty good speeds?  

My OilT usually gets to 215-220 or even higher in climb. But CHTs are fine, below 380 in climb.

FWIW, I do run the engine at 6 quarts. More oil would no doubt keep oil cooler. I also run straight weight (AS W100) oil with CamGuard.  And I have my oil pressure set on the high side - it is over 90 psi on initial start up and until temp gets up to normal. Nuff variables?

[Marauder]

Just now, Bob_Belville said:

I came back from MA to NC Monday - a pretty cold day OAT 7C - over 600 nm and headwinds so I flew at 8000', 2350 RPM, 8.1 gph LOP, 61% power. OilT was 195F with cowl flaps in trail. (CHTs were not much over 318/315F on the port side and 341/361F on the starboard.

Since I don't know what the apples to oranges comparison is (you flying LOP and me ROP), I'm not sure it is comparable. On a 7C day, my temps would be in the low 180s flying at 8000', 2500 RPM, 100 degrees ROP.

[Browncbr1]

Just now, Bob_Belville said:

I came back from MA to NC Monday - a pretty cold day OAT 7C - over 600 nm and headwinds so I flew at 8000', 2350 RPM, 8.1 gph LOP, 61% power. OilT was 195F with cowl flaps in trail. (CHTs were not much over 318/315F on the port side and 341/361F on the starboard.

You're definitely running hotter than my OEM cowl F.  I guess you're ARI cowl has some unique factors on oil temp and definitely on CHTs.

At that setting and OAT, my CHTs would be between 275 and 305 with cowl flaps closed and OT around 180.

[Marauder]

Just now, Bob_Belville said:

My OilT usually gets to 215-220 or even higher in climb. But CHTs are fine, below 380 in climb.

FWIW, I do run the engine at 6 quarts. More oil would no doubt keep oil cooler. 

I never have seen anything that high. I always run at 6 quarts as well. 

[Marauder]

Just now, Browncbr1 said:

You're definitely running hotter than my OEM cowl F.  I guess you're ARI cowl has some unique factors on oil temp and definitely on CHTs.

At that setting and OAT, my CHTs would be between 275 and 305 with cowl flaps closed and OT around 180.

That is in the ballpark with mine. 

[Browncbr1]

1 minute ago, Bob_Belville said:

My OilT usually gets to 215-220 or even higher in climb. But CHTs are fine, below 380 in climb.

FWIW, I do run the engine at 6 quarts. More oil would no doubt keep oil cooler. 

That's pretty dang hot...   I've also found more oil cools better... and it is as if fresh oil cools better than 25 hour oil.  (maybe less friction?)

[Bob_Belville]

4 minutes ago, Browncbr1 said:

That's pretty dang hot...   I've also found more oil cools better... and it is as if fresh oil cools better than 25 hour oil.  (maybe less friction?)

Does anyone suppose the CamGuard has an effect?

I also have a PowerFlow Exhaust.

I'm suspecting your F model cowl flaps are bigger and a big factor. 

My CHTs were a good bit higher when I first got this plane. I've replaced baffle seals and tweaked the baffles and used at least 2 tubes of Red RTV.

[Browncbr1]

Just now, Bob_Belville said:

Does anyone suppose the CamGuard has an effect?

I also have a PowerFlow Exhaust.

I'm suspecting your F model cowl flaps are bigger and a big factor. 

My CHTs were a good bit higher when I first got this plane. I've replaced baffle seals and tweaked the baffles and used at least 2 tubes of Red RTV.

I've not compared cowl flap size between the two models, but with OAT of 7c and power settings like you mentioned, I would have them completely closed and never get above 315 CHT and 185 OT.  In the hot summer, I would have cowl flaps cracked though.    I use Exxon Elite with Avblend.  OEM exhaust. 25DBTDC and generally fly at peak up high and 25LOP down low with Hanks 47 principle. 

[cctsurf]

That's really the trouble, we're trying to compare apples to oranges to bananas:  What oil do you use?  What mods have you done to your plane?  Powerflow?  Cowl Closure?  What method of measuring these temps are you using?  Original gauges or modern ones?  What model is your plane?  C, E, F, G...  

[Browncbr1]

Just now, cctsurf said:

That's really the trouble, we're trying to compare apples to oranges to bananas:  What oil do you use?  What mods have you done to your plane?  Powerflow?  Cowl Closure?  What method of measuring these temps are you using?  Original gauges or modern ones?  What model is your plane?  C, E, F, G...  

67 F, OEM cowl and exhaust, EDM 830 with tanis collar probes, Exxon Elite (7qts)

[Raptor05121]

For you guys with digital engine monitors- where are your oil temp sensors in relation to the oil cooler?

I have the stock Garwin gauges and my oil temp needle sticks at 180, with barely any movement. As has been explained to me, the vernatherm is basically like a thermostat- opening and closing to maintain one temperature. I've never seen mine move far from 180.

[N6758N]

2 minutes ago, Raptor05121 said:

For you guys with digital engine monitors- where are your oil temp sensors in relation to the oil cooler?

I have the stock Garwin gauges and my oil temp needle sticks at 180, with barely any movement. As has been explained to me, the vernatherm is basically like a thermostat- opening and closing to maintain one temperature. I've never seen mine move far from 180.

Alex, as you said the vernatherm maintains the temp. The amount of oil in the engine should have no effect on oil temp (unless there is so little it causes other issues...) The oil temp is still in the stock location above the filter, just a different probe needed for the JPI.

[Raptor05121]

3 hours ago, Bob_Belville said:

FWIW, supporting Chris' point about cowl flaps, my oil temp is what I'd call extremely sensitive to cowl flaps position

 

3 hours ago, Igor_U said:

On my last flight past weekend, with temps 5C lower then standard, oil temps were 175F (on EI CGR30P). Prolonged climb over Cascades on a hot summer day would rise temps to around 200F

 

2 hours ago, Bob_Belville said:

 OilT was 195F with cowl flaps in trail.

 

2 hours ago, Bob_Belville said:

My OilT usually gets to 215-220 or even higher in climb.

Granted I have the stock Garwin gauges, I've never seen my needle move half a tick mark hotter or colder than 180F. Cowl flaps don't make a lick of difference in my IAS, CHTs, oil temp, etc. (again stock gauges probably aren't sensitive enough to notice it).

If the vernatherm operated like I said, it should be full-open with you guys having 200*F oil temps. I think oil only accounts for like 15% of engine cooling so it should be shedding that quite rapidly.

[Marauder]

51 minutes ago, Raptor05121 said:

For you guys with digital engine monitors- where are your oil temp sensors in relation to the oil cooler?

I have the stock Garwin gauges and my oil temp needle sticks at 180, with barely any movement. As has been explained to me, the vernatherm is basically like a thermostat- opening and closing to maintain one temperature. I've never seen mine move far from 180.

According to the installation manual, it is where the factory probe goes. Wonder if the one on the front of the case is the oil pressure one?

[Raptor05121]

So is it reading oil temp before it goes into the cooler or after it comes out?