Nose Oil Cooling

Overview

Oil cooling seems to be a chronic problem, so I'm going to try to capture some of the better ideas on how to control oil temperatures as well as background data that can be useful along the way.

The oil lines running to the nose are 1/2" 3003 AL tubing, mated to Aeroquip #8 stainless steel braided and firesleeved hose in under the cowling. Some folks have reported good additional cooling by adding [NACA_VG_Installation|vortex generators] ahead of their cooling inlets.

As you can see from the series of pictures of Rene Dugas' airplane, he has a significant bump on the bottom of his Velocity that creates a low pressure zone and allows for good airflow through the cooler. He says that he can fly WOT at low altitude with good temperatures with this setup.

Minimum vernatherm extension is .160" according to the below Lycoming information. I found a thread here that gives these approximate overall dimensions. I've also found that you can by a replacement online at Sacramento Sky Ranch. It is to be torqued to 300 in-lbs. The current model number is 53E22144, but you may find these older models in the field (53E19600 ; AEL19600 ; SL53E19600 ; 75944).

I found a couple different measurements, but haven't found the specs yet
cold: 3.800" hot:4.031"

diff: 0.231 (3/16" = 0.1876")
The Vernaterm should extend at least 0.160" Between 150 F and 185 F (the temperature stamped on the Vernatherm 85 C ).

Relevant articles and documents.

Curves on Ariflow Performance Coolers
Kitplanes article on Cooling
Lycoming IO-540 Operating Limits
Lycoming Operations Flyer
Lycoming Oil Cooler Troubleshooting
Aircraft Maintaince - Piston Engine Troubleshooting

Oil Cooler Conversions

Niagra Cooler Model	Applicable Engine	Positech	Stewart Warner
200002A	IO-360, O-360, O-320	P20002C	8406R
200006A	IO-360, O-360K, IO-540	P20006C	10611R
200008A	IO-360, O-360K, IO-540, V-6, V-8	P20008C	10614R
200009A	IO-540