Oil Cooler - Again (Just comments)

[scard]

That is the "standard" Vans "SW like" cooler that they ship with FWF kits.

[asav8tor]

I had the SW cooler and my oil temps were too cool (150-170). No oil squirts. Very mild OATs ( Pacific NW ). Changed to the Positec and now my temps are 170-190. So it really depends on your situation if the SW is an advantage irrespective of price. Two data points from my aircraft.


And NO that picture is NOT a SW type cooler.

http://www.aircraftspruce.com/pdf/20...l/Cat08298.pdf

Top left is the SW 8406R is the RV size, ( $531.00)

Bottom of the page right side is the type in the picture and the one in the FWF kits

They also sell a 8406R. ( $293.95)

They are NOT the same.

[Bubblehead]

Thanks for all the great information. I've saved the page and noted the two coolers for future reference.

John

[Rick6a]

Originally Posted by Bubblehead

Here are two pictures of the oil cooler on my 180 hp IO-360 RV-8 built by someone else.

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In 100 degree air I can crusie climb and oil temp gets up to 220 or so, and oil pressure drops to the low end of the green arc. It's manageable but I'd like to see a little lower temp so I could climb faster when I need to or just keep temps down for engine life......

Your pictures illustrate the very same problem I encountered.

RV's are not of one design. The engine's relationship to its mount and its physical clearance to the cowling can vary... and sometimes quite dramatically. Van's own literature tells us when baffle mounting the oil cooler "higher is better." What I was easily able to do in my -6A (and it tends to overcool) is physically impossible in the -8. Look how low on the left rear baffle I was forced to locate the very same oil cooler in the -8. I scrapped several baffle parts learning that lesson. Note from the picture that I still had to remove a portion of the upper left corner of the oil cooler doubler plate just to provide marginal clearance with the upper cowl.

If flight testing proves the location untenable.....well then I'll just have to move it, but I'll worry about that later.

Those builders who are given to issuing blanket statements about the overall superiority of one oil cooler design over that of another manufacturer may well be missing a very important point.

[Bubblehead]

Rick,

Do you have a picture looking at the baffle from the front? I'd like to see where the cooler opening sits in relation to the cylinder.

I agree that there are lots of variables that effect oil cooler effectiveness like position on the baffle. What cooler are you planning to use?

Thanks for the information in your posting.

John

[Rick6a]

Originally Posted by Bubblehead

....Do you have a picture looking at the baffle from the front? I'd like to see where the cooler opening sits in relation to the cylinder......

John,
Here's the relevant pics...nothing like a picture to illustrate a description. I had to seriously modify the newer style baffling and fastener callout and orientation in this area to get the FWF supplied oil cooler to fit.

[robertahegy]

I used the Van's oil cooler and baffle kit on my 7A with an 0-360. No problems with install, cooling, cracking , or leaking. I think a lot of cooling problems may be due to higher HP engines or poorly fitting baffle seals. Cracking and leaking could also be due to baffles too close to the cowl causing the baffles and/or cooler to hit the cowl. And vibration from a multitude of problems cold also cause cracking.

I have never had oil or cylinder head temp proplems. I run EI instrumentation and have calibrated it to ensure accuracy. I have never had any of the baffling fail either. Everything is as rock solid as the day it was built. I have the old baffle kit from 2003.

Roberta

Originally Posted by Rick6a

Your pictures illustrate the very same problem I encountered.

RV's are not of one design. The engine's relationship to its mount and its physical clearance to the cowling can vary... and sometimes quite dramatically. Van's own literature tells us when baffle mounting the oil cooler "higher is better." What I was easily able to do in my -6A (and it tends to overcool) is physically impossible in the -8. Look how low on the left rear baffle I was forced to locate the very same oil cooler in the -8. I scrapped several baffle parts learning that lesson. Note from the picture that I still had to remove a portion of the upper left corner of the oil cooler doubler plate just to provide marginal clearance with the upper cowl.

If flight testing proves the location untenable.....well then I'll just have to move it, but I'll worry about that later.

Those builders who are given to issuing blanket statements about the overall superiority of one oil cooler design over that of another manufacturer may well be missing a very important point.

I encountered exactly the same thing on my RV-8. I mounted it as high up as possible, but half of it is still blocked by the cylinder fins. I think the RV-7 upper cowl doesn't slope down as abruptly in this area, so the -7 builders are able to get the cooler higher up on the baffle without interference.

After a few hours of flying, I swapped my Niagra 20002A for a Stewart Warner 8406R. If I were to do it again (or remake the baffles), I'd go with a wider cooler. A fellow RV-8 builder I know used the wider (5" centers on the bolts) Niagra cooler, and he's never seen a temperature over 200F. I think having a not-top-of-the-line cooler that's wider gives much more cooling capacity than a top-of-the-line cooler that's narrower. Unfortunately, since I didn't want to remake my baffles, I had to spend the money for the latter option. It ended up lowering my oil temps 10-15 degrees.

Anyway, here is a pic from the initial installation that shows how tight the clearance is.




-Geoff

[Rick6a]

Originally Posted by Geoff

....I think the RV-7 upper cowl doesn't slope down as abruptly in this area, so the -7 builders are able to get the cooler higher up on the baffle without interference.....

Geoff,

Your statement is absolutely dead on and here's dramatic proof. The photo on the left is of Roberta's installation in a -7 series. Notice how high on the baffle Roberta was able to locate the cooler. The next photo shows the baffling I scrapped when I attempted to install the cooler in about the same place as Roberta's is. In this case the oil cooler protruded so high, I would have had to mold a blister on the upper cowl to allow clearance between it and the cowl and the area circled in red would have almost certainly failed anyway.

[robertahegy]

WOW!! I did not know that there was that much difference in the 8 cowl. That could surely account for cooling issues and the necessity to alter the placement of the cooler or enlarge it. Good Job Rick.

Roberta