Baffling/Oil cooler

[RV7Guy]

Well, I got the oil cooler install done as well as the baffling. I ended up using 3" SCAT tubing because of space. Also I don't believe the SW 8432R's size will allow it to be baffle mounted. I'm going to attempt to attach some pictures.

Darwin N. Barrie
Chandler AZhttp://img53.imageshack.us/img53/9241/engineinstallbaffling0141rf.jpg
http://img211.imageshack.us/img211/9...ling0124tm.jpg

[RV7Guy]

[avpro56]

Darwin:

Not sure how well that will work in AZ temperatures. The problem with those Scat hoses is that they are rather poor in efficient air transfer. Van's duct is adapter is not so well designed either, with a round flange simply attached to a flat plate. The way the long EZ guys do it is with a divergent, smooth duct.

Here's my setup, (scat hose removed) but bear in mind that I have since changed to a Stewart Warner oil cooler, which was identical in size to the Niagara it replaced:

http://img365.imageshack.us/img365/6066/image216lz.jpg

Your SW oil cooler has more capacity than mine, so I think that you might be OK. But the air you will get going through it may not be enough under certain flight conditions. It would be more efficient to have a better duct, perhaps made out of high temp epoxy resin and fiberglass. You can see that my duct is an attempt to make the attachment somewhat divergent in shape.

My setup works OK, but on hot days long steep climbs can put me up near the redline. I also see an increase in oil temps as I slow down to pattern speeds. This tends to make me think that the climbing temps are more air volume related than oil cooler capacity related. I intend to replace the 3" scat hose with a smooth, larger duct, and use a homemade flexible duct to attach it to a rectangular flange I will place behind the #4 cylinder.

In general, I think a 4" duct would be better.

Best Regards,
Jon

[RV7Guy]

Originally Posted by avpro56

Darwin:

Your SW oil cooler has more capacity than mine, so I think that you might be OK. But the air you will get going through it may not be enough under certain flight conditions. It would be more efficient to have a better duct, perhaps made out of high temp epoxy resin and fiberglass. You can see that my duct is an attempt to make the attachment somewhat divergent in shape.

Hi Jon,

Thanks for the input. The adapter on the cooler was made by me. I used a foam block cut to the exact size of the oil cooler. I sanded it to shape and used the flange as the top dimension. Several layers of fiberglass were used and the interior finished to eliminate any square corners.

I wanted to use 4" SCAT but there was no room. The 8432R is quite a bit larger than the stardard Van's unit and won't work on the baffling.

I'm also making a low pressure ramp on the bottom of the cowl to help pull the air out. I am hoping the additional size of the oil cooler will make up for the use of a little more tubing than I wanted. As I noted, my neighbor has an 8 with IO360 and the same set up with a smaller cooler and he only has temp problems in the most extreme AZ days. Hoping for the same.

Darwin N. Barrie
Chandler AZ

[avpro56]

Originally Posted by RV7Guy

Hi Jon,

Thanks for the input. The adapter on the cooler was made by me. I used a foam block cut to the exact size of the oil cooler. I sanded it to shape and used the flange as the top dimension. Several layers of fiberglass were used and the interior finished to eliminate any square corners.

I wanted to use 4" SCAT but there was no room. The 8432R is quite a bit larger than the stardard Van's unit and won't work on the baffling.

I'm also making a low pressure ramp on the bottom of the cowl to help pull the air out. I am hoping the additional size of the oil cooler will make up for the use of a little more tubing than I wanted. As I noted, my neighbor has an 8 with IO360 and the same set up with a smaller cooler and he only has temp problems in the most extreme AZ days. Hoping for the same.

Darwin N. Barrie
Chandler AZ

Darwin:

Sounds good. I had considered the 4" duct myself, but realized as you did that the 4" was too large to fit the cooler adapter. I plan on a rectangular duct with a home made rectangular rubber flex tube.

I'd like to see the details on your cooling ramp.

Jon

[caryr]

Darwin

I have just about the same setup on mine. Same sw oil cooler. I run rather warm on hot days on climbout.

I have a van's alum adapters on both ends of the scat tube.

I am going to build a cone shaped inlet and a somewhat cone shaped outlet of glass to see if I can shove more air thru.

cary r

[RV7Guy]

Cary,

I'm going build another fiberglass plenum for the oil cooler that is larger and more funnel like. Now that I know my dimensions I can be a little more creative. I'll test it at a later date or sooner if necessary. I think things will work.

Regarding the low pressure ramp, I had a giant scale aerobatic RC plane with a 150CC twin cylinder engine that was having some cooling issues. Keep in mind, on the models we can make a pretty large exit hole. I didn't want to butcher the cowl anymore so I built a ramp on the exit and dropped the temps 25 degrees. Should work on the 1:1 scale stuff too.

Darwin N. Barrie
P19

[caryr]

darwin

I have a 'good intentions' list to do also.


I have a difficult time getting to any of them. Heck cool weather is just around the corner and I won't have to worry about hot oil soon.

I may just change the oil and put the cowl back on and go fly.


cary