Zuldarin
Well Known Member
Let me start with a little background on my engine and why I think I was having oil temperature issues. I have an RV-9A with an IO-360 but its not just any IO-360, its got a few "modifications" that are pertinent to this discussion.
First, the bottom end of the engine is actually from a 200hp angle valve IO-360 which means it has piston oil squirters. This feature squirts oil up against the bottom of the piston which removes heat from the cylinder...hence better CHT control. I rarely if ever have issues with my cylinder head temps getting over 400 degrees.
Second, I have a Superior cold air induction sump. This means I get cooler air into the engine but it also means I have one less heat extraction path for heat in the oil pan.
Third, I have dual P-Mags (electronic ignition) which, as I understand it, means hotter temperatures in the cylinder due to better efficiency and advanced timing. Those hotter temperatures combined with the piston oil squirters means more heat to the oil.
Ok, now on to the story. As you might suspect during my original build I expected to have higher than normal oil temperature from the piston oil squirters, or at least more of a heat load in the oil system so I purchased a SW 10599R oil cooler from DanH hoping it would be enough. I also mounted the oil cooler on the firewall and fed it with 4" scat/ducting.
I've been flying for a few years now and in the summer I have to be very careful with high RPM's. If I keep my RPM above 2400 for more than a few minutes my oil temps get into the 220+ degree range which is much hotter than I am comfortable with. Yes I am aware that Lycoming allows up to 240 degrees but I'm not comfortable with those temps myself. Once I level off and things stabilize I can run anywhere from 185-200 degrees which is acceptable but it does require lower RPM's. High RPM's always mean high oil temps.
That said I decided to try again to resolve the high oil temp temp at high rpm issue so this year when I took the airplane down for the annual condition inspection I decided to make a change to the oil cooler. This time I decided to go with the Airflow systems 2007X 15 row oil cooler...the same one I plan on putting in my RV-10 when its done. That required a bit of work on plenum, baffles, and the oil cooler inlet duct since the oil cooler was about an inch bigger than the original.
I have completed the conversion and I have done a few flight tests including a full throttle 2500 RPM climb from sea level up to 8000' MSL and the results are excellent! I couldn't get my oil temps over 190 on that climb! I'm happy.
I think the hardest part of the process, or at least the most work was involved in creating a new inlet duct for the oil cooler. I am pretty happy with the results so I thought I would show my process in case anybody else out there has a similar issue with this engine configuration. There were more steps than outlined below but for the purpose of this post I think these steps are the most important.
First step was to design the new oil cooler inlet duct. To do this I took a few measurements of the oil cooler and then fired up Solidworks to design a duct that takes a 4" scat hose and converts it to a rectangular shape that fits the oil cooler. Here is the result of that process:
Next up was to use my 3D printer to print up the duct. To tell the truth I actually printed up 3 different ducts trying to get the right fit and form. The duct below is the final iteration.
I added a 3/4" aluminum ring to the inside of the duct to act as a hard point for the hose clamp pressure that will be applied later.
Next up was to use a couple layers of carbon fiber glass cloth, some "poor mans vacuum bagging" and a little peel ply to wrap the 3D printed duct.
Then, I did a little sanding, a final thin coat of epoxy, and this is the result.
Then it was simply install and seal.
And thats it! Using the 3D printer to form the base of the duct was such a huge step forward from the foam I formed with knives and files on my first duct.
First, the bottom end of the engine is actually from a 200hp angle valve IO-360 which means it has piston oil squirters. This feature squirts oil up against the bottom of the piston which removes heat from the cylinder...hence better CHT control. I rarely if ever have issues with my cylinder head temps getting over 400 degrees.
Second, I have a Superior cold air induction sump. This means I get cooler air into the engine but it also means I have one less heat extraction path for heat in the oil pan.
Third, I have dual P-Mags (electronic ignition) which, as I understand it, means hotter temperatures in the cylinder due to better efficiency and advanced timing. Those hotter temperatures combined with the piston oil squirters means more heat to the oil.
Ok, now on to the story. As you might suspect during my original build I expected to have higher than normal oil temperature from the piston oil squirters, or at least more of a heat load in the oil system so I purchased a SW 10599R oil cooler from DanH hoping it would be enough. I also mounted the oil cooler on the firewall and fed it with 4" scat/ducting.
I've been flying for a few years now and in the summer I have to be very careful with high RPM's. If I keep my RPM above 2400 for more than a few minutes my oil temps get into the 220+ degree range which is much hotter than I am comfortable with. Yes I am aware that Lycoming allows up to 240 degrees but I'm not comfortable with those temps myself. Once I level off and things stabilize I can run anywhere from 185-200 degrees which is acceptable but it does require lower RPM's. High RPM's always mean high oil temps.
That said I decided to try again to resolve the high oil temp temp at high rpm issue so this year when I took the airplane down for the annual condition inspection I decided to make a change to the oil cooler. This time I decided to go with the Airflow systems 2007X 15 row oil cooler...the same one I plan on putting in my RV-10 when its done. That required a bit of work on plenum, baffles, and the oil cooler inlet duct since the oil cooler was about an inch bigger than the original.
I have completed the conversion and I have done a few flight tests including a full throttle 2500 RPM climb from sea level up to 8000' MSL and the results are excellent! I couldn't get my oil temps over 190 on that climb! I'm happy.
I think the hardest part of the process, or at least the most work was involved in creating a new inlet duct for the oil cooler. I am pretty happy with the results so I thought I would show my process in case anybody else out there has a similar issue with this engine configuration. There were more steps than outlined below but for the purpose of this post I think these steps are the most important.
First step was to design the new oil cooler inlet duct. To do this I took a few measurements of the oil cooler and then fired up Solidworks to design a duct that takes a 4" scat hose and converts it to a rectangular shape that fits the oil cooler. Here is the result of that process:
Next up was to use my 3D printer to print up the duct. To tell the truth I actually printed up 3 different ducts trying to get the right fit and form. The duct below is the final iteration.
I added a 3/4" aluminum ring to the inside of the duct to act as a hard point for the hose clamp pressure that will be applied later.
Next up was to use a couple layers of carbon fiber glass cloth, some "poor mans vacuum bagging" and a little peel ply to wrap the 3D printed duct.
Then, I did a little sanding, a final thin coat of epoxy, and this is the result.
Then it was simply install and seal.
And thats it! Using the 3D printer to form the base of the duct was such a huge step forward from the foam I formed with knives and files on my first duct.