RV-7 Oil cooler question

[ghatch]

Does anyone have a picture or series of pictures of the successful mounting of a SW-8432R or SW-10599R or SW-8406R on an 360 powered RV-7 ? I have been struggling with way too high oil temps and plan on using one of the above oil coolers but room and mounting techniques ate at a minimum and would love some ideas.

thanks, Gerry

[billgill]

Gerry,

Which engine do you have?

Bill

[elippse]

Originally Posted by ghatch

Does anyone have a picture or series of pictures of the successful mounting of a SW-8432R or SW-10599R or SW-8406R on an 360 powered RV-7 ? I have been struggling with way too high oil temps and plan on using one of the above oil coolers but room and mounting techniques ate at a minimum and would love some ideas.

thanks, Gerry

One of the best things you can do is to mount your cooler to the firewall, if possible, and supply it with a separate inlet and a rear-facing outlet, That way you won't be stealing engine cooling air and can fabricate a duct that starts with about a 3 sq. in. inlet and then expands to the oil cooler, and then on the outlet side have a duct that contracts to about a 4 sq. in. outlet that points to the rear 'Almost no drag and excellent cooling. That's how I did mine.

[Jim P]

Gerry, what's "way too high?" Also what engine model? Straight O-360 or IO?

[ghatch]

To answer some above questions:

I have an Aero Sport Power IO-375. Cruise (21"/2300rpm) temps at 7500' run 205+ with OAT in 40's. At 9500 with everything else the same 215+,
I've seen 250 at 4000-5000 after temps got to 230s after NOT max performance takeoff. Noticing the 230 temps I pulled power back to 15" and temps still rose to 250. Remaining at 15" for 10+ min got the temps down to 241. OAT in the 50's.

Pictures of possible solution would be appreciated. The current plan is to install a SW-10599R cooler on the rear baffle at cyl 4 using a 1/4 spacer to create a gap between the cylinder fins and the oil cooler. The 10599R is 1.1" wider and the same height as the std Vans oil cooler with two more oil and two more air channels and much higher quality construction and corresponding cost.

[David-aviator]

Gerald,

I am not at home at this time so no pictures are available. But this is how I how I did it and the cooling results are excellent. (will send pictures later if needed)

The cooler is a SW-8432R and it is mounted as per the RV-10 using a 4" scat duct from aft of #4 cylinder for cooling air connected to an aluminum box over the cooler. The 4" scat attach flanges are hard to find but Vans has them. Do not use a 3" duct, 4" is much better. The bottom of the cooler is open with no special treatment. Air simply goes down and out the exhaust opening. You may have a problem finding space for the SW-10599R on the aft baffle or at the fire wall. I believe Van's has a kit for the firewall mounted cooler with the RV10 although I made my own from scrap aluminum angle.

There is a butterfly air flow shut off valve between the aft baffle and the cooler. I tried the Vans shutter device mounted below the cooler but it had little effect in cooling one way or another. It definitely does not provide for warm oil temps in the winter and in the summer, closing it will increase oil temp about 10F. It has been reported it works better mounted on the inlet side of the cooler but I never tried it there. For $60 the duct valve is available from one of our builders and it is of very hight quality. I don't have the source here but can also provide that later is needed.

Good luck. There's no greater pain the the butt than inadequate oil cooling.

[Rick of Austin]

Since the oil flow through the cooler is controlled by the vernatherm how can closing off the airflow to the oil cooler effect oil temps? I know vans doesnt design and create parts without good reason and I have always wondered what the air cutoff mechanism that he sells really does.
thanks

[647jc]

My undestanding is that even when the vernatherm is closed, a small amount of oil is still allowed to flow through the oil cooler. This is to prevent oil from congealing in the cooler and causing a total blockage. The Lycoming manual does not really quantify the amount of oil that flows to the cooler when the vernatherm is closed other than saying a small amount. So, the effect of blocking air flow through the cooler to increase oil temps is really difficult to quantify. My experience is that unless oil temperature is warm enough to cause the vernatherm to open significantly, blocking off air flow through the cooler will have little effect increasing oil temperature.

[David-aviator]

Originally Posted by Rick of Austin

Since the oil flow through the cooler is controlled by the vernatherm how can closing off the airflow to the oil cooler effect oil temps? I know vans doesnt design and create parts without good reason and I have always wondered what the air cutoff mechanism that he sells really does.
thanks

The vernatherm only controls oil flow to the cooler in a sense that it closes the engine port at a Y in the system. Oil can flow through the cooler on a cold day because the oil cooler port is never closed. The vernatherm closes the engine port when it expands, otherwise both ports are open.

That's why certified aircraft have an oil cooler air flow blocking plate installed in winter months and it is the basis for the Vans air flow shut off device. But mounting it at the cooler outlet does not seem to work too well, at least not for me.

[RV7Guy]

Hi Gerry,

Check your PM's.