LASAR Oil Cooler Replacement and Guppy Cowling Mod

[brndiar]

On 7/29/2020 at 10:48 AM, brndiar said:

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

On the first picture is my idea how to improve the air flow around oil cooler.

Picture 2- Important is seal the gap around the starter.

lg,m

 

 

[carusoam]

Seals around the starter and alternator go missing over the decades...

There was a tradition for using felt and stapled in place....

There may be some updates made from silicone rubber...

Something our silicone seal guy may be familiar with....  @GEE-BEE

Best regards,

-a-

[Prior owner]

On 7/29/2020 at 1:48 AM, brndiar said:

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

What is the manufacturer and part number for the new cooler you have? Looks like a real improvement over the old one...

[brndiar]

27 minutes ago, PilotCoyote said:

What is the manufacturer and part number for the new cooler you have? Looks like a real improvement over the old one...

[Prior owner]

9 hours ago, brndiar said:

Thank you!

[JimB]

5 hours ago, PilotCoyote said:

Thank you!

McFarlane makes a nice oil cooler. Just make sure you get the one that is eligible for installation on your aircraft. For a D model it looks like one of these would work:

https://www.mcfarlaneaviation.com/products/product/8000075/

https://www.mcfarlaneaviation.com/products/product/8001602/ 

[podair]

since installing a Lasar cowl mod my CHTs are more evenly spread. My cylinder 3 was always hotter by 30 or so degrees. Now cyl 3 is in line with number 2 , they are routinely within 5 degrees of  295 ish for cyl 1 , 320 cyl 2 325 cyl 3 , 310 cyl4 in cruise, and rarely above 365/370 in the climb. I used to aim to keep 3 under 400 in the climb now 370 is the hottest it gets. 

I did not really get a significant TAS benefit, maybe a couple knots but proper rigging is probably more effective.

Still, very happy with the mod, nicely installed flush mount when the aircraft was repainted and very happy with the CHTs.

[Marauder]

since installing a Lasar cowl mod my CHTs are more evenly spread. My cylinder 3 was always hotter by 30 or so degrees. Now cyl 3 is in line with number 2 , they are routinely within 5 degrees of  295 ish for cyl 1 , 320 cyl 2 325 cyl 3 , 310 cyl4 in cruise, and rarely above 365/370 in the climb. I used to aim to keep 3 under 400 in the climb now 370 is the hottest it gets. 
I did not really get a significant TAS benefit, maybe a couple knots but proper rigging is probably more effective.
Still, very happy with the mod, nicely installed flush mount when the aircraft was repainted and very happy with the CHTs.

I forgot about the benefit of uniform CHT temps. I am seeing the same thing. #3 is now in line with the rest of the cylinders.




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[Skates97]

When I replaced the cooler hoses a year ago I had the cooler replaced too. It looked pretty good from the front, but as you can see the fins on the back side had disintegrated in places. Moral of the story, don't just look at the condition of the fins on the front of your cooler, take a look at the back as well.

[MooneyMitch]

1 hour ago, Skates97 said:

When I replaced the cooler hoses a year ago I had the cooler replaced too. It looked pretty good from the front, but as you can see the fins on the back side had disintegrated in places. Moral of the story, don't just look at the condition of the fins on the front of your cooler, take a look at the back as well.

Excellent information, thank you.