G

ghatch

Active Member
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
 
ghatch said:
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
Click to expand...
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.
 
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.
 
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.
 
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
 
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.
 
Rick of Austin said:
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
Click to expand...

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.
 
Mags or Electronic Ignition?

Do you run ROP, at peak, or LOP?

Is the engine broken in? (how many hours)


Have you tried running it LOP yet? I'd expect a significant drop in temps (both oil temp and CHTs)


Just lookin' at some photos from a recent trip... at 10,500.. OAT 34 degrees... oil temp 168... highest CHT 330 (lowest 310)... This is with a firewall-mounted SW 8406R...
 
All flight have been rich of peak. There was about 45hr on engine when previous temps were measured. I have not run LOP because I haven't done a GAMI spread check(s)

Gerry
 
647jc said:
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.
Click to expand...

I do have the Van's cooler shutter. It needs to be mounted in front of the cooler, and it works very well. Mine is cable operated from the cockpit.
I installed this last fall, after getting tired of taping the cooler front with metal duct tape for winter months.

L.Adamson -- RV6A
 
ghatch said:
What hose size are you guys using to and from the oil cooler? -8 or -6 ?Gerry
Click to expand...

Now there's an interesting technical issue to explore.

As David said....the vernatherm is retracted and the oil cooler bypass port is open when the oil is cold. Oil flows through the cooler AND through the bypass. The vernatherm extends as the oil gets warmer, eventually closing the bypass port and forcing all flow through the cooler. Extends hot, shrinks cold....guys should be able to remember this familiar principle ;)

The system is driven with a positive displacement pump. With the oil hot and bypass closed, the only available path is through the cooler and hoses......and hose size should make no difference. Both the -6 and the -8 hose should flow the same volume of oil because a positive displacement system doesn't allow it to be any other way. The smaller -6 will result in higher oil velocity in the hose and higher pressure between the pump outlet and the cooler return fitting.

Things get interesting with the oil cold. Remember, the vernatherm is open so the oil can flow through both the cooler and the bypass. The volume split will be in proportion to flow resistance in each path. In theory, a smaller hose should result in less flow through the cooler and more through the cooler bypass, making the -6 a better choice for cold weather operations.

So, theory seems to suggest the -6 is a better choice; same oil volume through the cooler with oil hot and vernatherm closed, less volume through the cooler with oil cold and verntherm open.

Is it really the better choice? Darned if I know. Practical details can trip up a good theory. For example, right angle fittings could be a larger potential problem with -6 oil plumbing; the velocity increase could make them more prone to cavitation. More theory really, but all fun to think about.
 
I do believe the standard is -8 hose for oil plumbing with a Lycoming. Whether or not -6 matters I don't know but it would seem logical if what Dan says is true, -4 would work also. But it is not done. This has been discussed before but I don't think anyone has gone to the trouble to prove it.

Dash 8 works, why not stick with it? If Gerald is running with -6, change it to -8, maybe it will make a measurable difference.
 
Thanks guys for your responses. I have decided to go with a SW-10599R cooler mounted on the plenum behind cylinder 4 with an offset of 1/4" behind the plenum away form the cylinder fins to allow more air to get to the oil cooler fins. I will use 45 deg -8 fittings. It will be a tight fit. As previously stated, any pictures of your setup will be appreciated.

Gerry
 
DanH said:
Now there's an interesting technical issue to explore.

The system is driven with a positive displacement pump.
Click to expand...

Careful Dan. Someone will be on here talking about filling up his swimming pool again! I wouldn't mind but he has not paid me the 6-pack of Shiner from the last time!
 
L.Adamson said:
I do have the Van's cooler shutter. It needs to be mounted in front of the cooler, and it works very well. Mine is cable operated from the cockpit.
I installed this last fall, after getting tired of taping the cooler front with metal duct tape for winter months.
Click to expand...

Today............. Van's cooler shutter temps, fully shut. Outside temps 29-34 F. at 10,500' msl. Oil temps from 190 to 195, and 212 in a climb.
 
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