LASAR Oil Cooler Replacement and Guppy Cowling Mod

[hmasing]

Hey, gang!  The Aluminum Falcon (68 F) is coming up on annual time again in August, and I've been chasing high oil temps since my annual last year.  400 hours on the plane in that time, and my oil hovers around 200 degrees most of the time.  I've replaced the oil cooler, and that didn't help (it was cracked anyway).  I'm now considering moving the cooler to behind the baffling per the LASAR STC to move the cooler, and adding the cowling enclosure to help more.  

I'd like feedback from folks on these mods - worth it?  

If I do the oil cooler relocation, I'd like to add a second landing light in the hole.  Is this something my A&P can fabricate and get a field approval for?

Thanks!!

[MooneyMitch]

The LASAR cowl piece is aesthetics only..... this was told to me several years ago by Paul Loewen (creator of the item).

[hmasing]

Just now, MooneyMitch said:

The LASAR cowl piece is aesthetics only..... this was told to me several years ago by Paul Lowen (creator of the item).

I've heard it helps with cooling - not looking for extra knots (although those are always nice).  Thoughts on that aspect?  I've read that the guppy mouth creates a high pressure area in front of the prop, and that impacts laminar flow and airflow through the engine compartment out the cowl flaps.

[Marauder]

10 minutes ago, hmasing said:

Hey, gang!  The Aluminum Falcon (68 F) is coming up on annual time again in August, and I've been chasing high oil temps since my annual last year.  400 hours on the plane in that time, and my oil hovers around 200 degrees most of the time.  I've replaced the oil cooler, and that didn't help (it was cracked anyway).  I'm now considering moving the cooler to behind the baffling per the LASAR STC to move the cooler, and adding the cowling enclosure to help more.  

I'd like feedback from folks on these mods - worth it?  

If I do the oil cooler relocation, I'd like to add a second landing light in the hole.  Is this something my A&P can fabricate and get a field approval for?

Thanks!!

I have the lower cowl mod. I think it helps with cylinder cooling, but for me, in the wrong direction. My plane always ran cool and with the cowl mod, it runs even cooler. I doubt there was any real speed increase that you could measure. 

As for your oil temp, my F will run in the 170s (winter) to high 190s (summer). Is your temperature always in the 200 range regardless of time of year?

[MooneyMitch]

23 minutes ago, hmasing said:

I've heard it helps with cooling - not looking for extra knots (although those are always nice).  Thoughts on that aspect?  I've read that the guppy mouth creates a high pressure area in front of the prop, and that impacts laminar flow and airflow through the engine compartment out the cowl flaps.

 

27 minutes ago, MooneyMitch said:

The LASAR cowl piece is aesthetics only..... this was told to me several years ago by Paul Loewen (creator of the item).

Again, this was told to me by Paul, creator of the unit.  

[Bunti]

Hi, 200 degrees is not bad for the oil temp.

I have the Lasar relocation kit installed in my M20F. It did not change the temperature a lot.

My impression is that due to the new location behind cylinder 4, the airflow to the cooler is after the relocation more depended on the pitch of the airplane. Especially during the climb on hot Florida days, I have to lower the nose very soon and increase the speed to somewhere at about 115 to 125 KIAS to reduce the rising rate of the oil temp. Even with 120 KIAS, I sometimes end up with 215 F at the top of climb. Then the  oil temp usually drops a few degrees:. Depending on the outside air temperature at altitude and LOP or ROP ops, I see about 186F to about 206F in cruise.

The nose of the plane looks nicer. The new hoses to the engine are much shorter. I may have gained half a knot and the cooler does not collect dirt or so  anymore and stays in good shape.

[hmasing]

9 minutes ago, Marauder said:

Is your temperature always in the 200 range regardless of time of year?

Seems so - once I'm in cruise up high, it tends to run about 200 - even regardless of oil.  We've checked the probe, it reads accurately.

[bonal]

Looks like your trying to fix something that isn't broken. Honestly if 200 is your norm I would not worry about it.  I don't know at what temperature the water vapor cooks off but would think it needs to be relatively hot for that to happen.  It's nice to have things nice and cool but 200 is well below red line.  As for the lower cowl mod it does improve the look and remember it's not how you feel it's how you look that matters.

[Ragsf15e]

12 minutes ago, hmasing said:

Seems so - once I'm in cruise up high, it tends to run about 200 - even regardless of oil.  We've checked the probe, it reads accurately.

If it’s running 200+ during a Michigan winter, that’s pretty hot!  Actually, it’s still probably normal, I was sort of joking because it’s probably pretty cold oat... my F runs around 185 in cruise during winter (Washington state).  As @Marauder said though, it’s a noticeable increase in the summer.  I see about 200 depending on power setting, altitude, temp, etc.  Have you checked your Vernatherm?

[Sabremech]

I installed one of the LASAR oil cooler relocation kits on an F and was disappointed in its fit. Mounting the plates per the instructions actually had the cooler hitting the engine mount. I ended up modifying the plates to clear the engine mount. 
David

[Prior owner]

I am in the middle of dealing with warmer oil temps in my D model, and from what I am seeing online, there are 4 different coolers that fit my plane: 

Harrison, Stewart Warner, and 2 different coolers from Aero Classics (a 6 row and a 7 row).

It’s like comparing apples to oranges.... the pictures I have seen of the Stewart Warner cooler show that it is most definitely a larger cooler than Aero Classics cooler that I have. It is thicker (when measuring the distance from the face to the back of the cooler). It has to make a difference. If you guys are running wit great oil temps or high oil temps, please post which cooler you are running- There might be something to this..!

The cooler in this C model [Edit] looks deeper than mine:

 

Edited July 29, 2020 by PilotCoyote

[carusoam]

Gravity button.... On!

-a-

[carusoam]

Heat exchangers typically get a few details with their spec page...

overall surface area...

The tubing flow pattern...

Amount of heat rejection expected under ideal set conditions....

If you can find the spec sheets for the oil coolers, make a chart... Compare the similar specs, line by line...

Post them here... we can all take a look at them.

Mechanical engineers often have this in their experience bag...

Best regards,

-a-

[Prior owner]

Just now, carusoam said:

Heat exchangers typically get a few details with their spec page...

overall surface area...

The tubing flow pattern...

Amount of heat rejection expected under ideal set conditions....

If you can find the spec sheets for the oil coolers, make a chart... Compare the similar specs, line by line...

Post them here... we can all take a look at them.

Mechanical engineers often have this in their experience bag...

Best regards,

-a-

Here’s one which graphs the heat rejection performance of the Aero Classics cooler that is normally specified as the part number replacement for the oil cooler in the C & D

[Prior owner]

Still looking for more info on the Harrison and Stewart Warner coolers...

[carusoam]

One interesting detail... so it seems...

The oil cooler depends on the amount of air flowing through it...
 

The more air that flows through the oil cooler... the better the OilT will be...

That air is competing with the cylinder cooling air...

The more air that flows through the cooler at the back of the cowling....

The less air is available to get pressed down through the cylinders...

Air flowing through the oil cooler is now by passing flowing down through the cylinder fins....
 

This can make choosing by the charts and graphs a bit more challenging...

Keep an eye on CHTs after install...

If you get good oilT and lousy CHT... adjusting airflow through the cooler may be an option...

PP thoughts only, not a mechanical engineer...

Best regards,

-a-

[Prior owner]

But if the cooler is at the front of the Lower cowling, as it is in the C & D models, then maybe the considerations are a little different?

With the cowl flaps closed, is the pressure inside the lower cowling impeding air flow through my oil cooler at cruise speeds due to all the air flowing into the lower cowling from above the cylinders? Moving the cooler to the back of the upper cowling solves this (but steals cooling air from the cylinders, as you pointed out), but as we already know, that mod is not available on the C & D.

[carusoam]

Interesting, Similar challenge...

Air that flows through the cooler mounted up front... dumps air/pressure below the cylinders...  again not very helpful for cylinder cooling...
 

It would help if we had a few pressure sensors to put in various locations around the cowl...
 

I think David had to demonstrate everything working in concert during his cowling development phase...

Early days of the guppy mouth... air was known to form eddy currents above the cylinders, some air would come back out, throwing dripped oil back out and on the windscreen...

Fortunately what we have works over a wide range of conditions...

In deep cold, Ovations have a plate that blocks half of the oil cooler at the back of the IO550.... A similar balance of air flow exists here as well...  except Os don’t have cowl flaps to close...

Lots of variables...

Air flow through the cooler...

Oil flow through the cooler...

OAT...

OilT...

Where the waste air, pressure and temp, goes....
 

How well the Vernatherm is working... if it doesn’t work properly, less oil gets pushed through the cooler...

Makes that... always leave the flaps 1” open, make a lot of sense....  more sense today, than ever before... 

 

PP thoughts only...

Best regards,

-a-

[brndiar]

Hi.

Climbing from cca 3000 ft to 8000 ft yesterday. At the airport (cca 1300 ft was 30 grad C), full power, solo.

The engine is 30 Hours after overhaul, new oil cooler, installed Lasar cowl fairing.

P.s. never had problems with high oil temperatures with my M20C before repair.

On my Zenair Zodiac experimental UL  I was trying years ago to solve marginale oil temperatures (of course Rotax engine with water cooled heads, engine with gearbox and dry oil sump...). I  changed all available oil coolers, from small to large  (available 3 types S,M, L) without significant success. The best result was achieved, wenn I modified the airflow around the oil cooler with deflectors. The airflow around cowling is without sensors ``known unknowns" and is sometimes not according to our ideas. 

Hopefully not off topic. 

 

lg,m

Edited July 29, 2020 by brndiar

[Greg Ellis]

13 hours ago, MooneyMitch said:

The LASAR cowl piece is aesthetics only..... this was told to me several years ago by Paul Loewen (creator of the item).

 

13 hours ago, hmasing said:

I've heard it helps with cooling - not looking for extra knots (although those are always nice).  Thoughts on that aspect?  I've read that the guppy mouth creates a high pressure area in front of the prop, and that impacts laminar flow and airflow through the engine compartment out the cowl flaps.

I have a 1963 C Model and I have the enclosure and it did nothing for cooling or speed.  Just aesthetics only.  The biggest bang for the buck that I got with any speed change was the flap gap seals, aileron gap seals and reversing the brakes so they are out of the slipstream.  Cooling came by replacing the dog house with a new one that sealed better.

My oil temps have never really been a problem with the oil running about 190 on climb in the heat of the summer and cooling off to the upper 170's in cruise, also in the middle of Texas summer.  I think what this shows is that every plane is different even within models and one thing that may work for one plane may not work for another.

 

[cctsurf]

3 hours ago, Greg Ellis said:

Cooling came by replacing the dog house with a new one that sealed better.

I was really hoping that I could accomplish 2 goals with @Sabremech's new cowling.  New baffling and better aerodynamics...  Haven't heard much recently.

My doghouse is in pretty bad shape.  I plugged a number of holes recently and things cooled down significantly.

[Greg Ellis]

21 minutes ago, cctsurf said:

I was really hoping that I could accomplish 2 goals with @Sabremech's new cowling.  New baffling and better aerodynamics...  Haven't heard much recently.

My doghouse is in pretty bad shape.  I plugged a number of holes recently and things cooled down significantly.

I got my new doghouse from Airforms Alaska.  When I purchased mine 8 or 9 years ago they had it for the C model.  They only list the E and J now but you may want to give them a call.  But it fit incredibly well and mechanic that installed it said it fit much better than original.  I noticed an immediate difference when it was installed.  It has held up well also over the years.

I think that if I ever need to make an exterior cosmetic change I would go with Sabremech's cowling.  It looks great and hopefully helps with overall cooling and aerodynamics.

[Sabremech]

3 hours ago, cctsurf said:

I was really hoping that I could accomplish 2 goals with @Sabremech's new cowling.  New baffling and better aerodynamics...  Haven't heard much recently.

My doghouse is in pretty bad shape.  I plugged a number of holes recently and things cooled down significantly.

Hi cctsurf,

Its coming along slowly. I had a little set back on the upper cowling fitting correctly at the very front. It’s back at the composite shop being reworked along with the mold when we get the fit just right. 
I’d like to post more often but I feel I run the risk of the typical aviation product promises syndrome and don’t want that.

Thanks,

David

[cctsurf]

2 minutes ago, Sabremech said:

I’d like to post more often but I feel I run the risk of the typical aviation product promises syndrome and don’t want that.

I appreciate that, David, at the same time, I think we all know you are the real deal.  You headed up the gear lock blocks and we've seen your work on the cowl both in pictures and at the air shows and they looks GREAT.  I'd go for a few more updates, like, "Hey, we had a setback."  Maybe you posted it, but I didn't see it and I've been watching pretty closely.  It is sometimes difficult to watch what you are doing amidst the excitement when you post from other users.  It'd almost be nice if on these forums people like you who are progressively doing something to have a post to which you alone could post updates...  Anyway, Thanks!  I'm not certain I will be able to pay the price when you are finished, but I hope so and I don't want to do drastic things to the baffling until I find out.

[MooneyMitch]

4 hours ago, Greg Ellis said:

I got my new doghouse from Airforms Alaska.  When I purchased mine 8 or 9 years ago they had it for the C model.  They only list the E and J now but you may want to give them a call.  But it fit incredibly well and mechanic that installed it said it fit much better than original.  I noticed an immediate difference when it was installed.  It has held up well also over the years.

I think that if I ever need to make an exterior cosmetic change I would go with Sabremech's cowling.  It looks great and hopefully helps with overall cooling and aerodynamics.

Information......I spoke with Airforms about a year ago regarding baffling for the C model.

At that time, they no longer offered the system for the doghouse C. 

Again, the phone call was about a year ago....... things could have possibly changed since then.