Oil cooler location

I'm at the stage where it's time to mount the oil cooler.

When I trail fit the cooler in the recommended location (mounted on the left rear baffle ) it appears that the rear cylinder will block most of the airflow to the cooler. Is this ok i.e work adequately ?

Or should I be looking at other ways to mount the cooler that will allow more air to flow through the cooler.

Mount it as high as you can without hitting the cowl. What do you have there? RV4? A high mounting should expose at least 1/2 of the OC fins. If you can install a 1/2 inch spacer between the baffle and the cooler, with an aluminum peace (baffle) against the back of the cylinder fins on #4, you'll get full exposure on your oil cooler. Worked great on my RV8.

I mounted mine at a slight angle. I've seen several others mounted this way. Opens up the area between the cylinder and the "face" of the cooler.

Cool it!

Derek said:

I'm at the stage where it's time to mount the oil cooler.

When I trail fit the cooler in the recommended location (mounted on the left rear baffle ) it appears that the rear cylinder will block most of the airflow to the cooler. Is this ok i.e work adequately ?

Or should I be looking at other ways to mount the cooler that will allow more air to flow through the cooler.

Click to expand...

G'Day Derek,

Oil cooling in the RV4 is challenging as you're not so much pushing air into it but drawing it through. With the tight confines behind the engine, as you know, it's a challenge. On my Four, I mounted the cooler in front of and underneath the left front cyllinder baffle. Worked well for extended climbs and aerobatics. For rear mounted coolers you need to strengthen the rear baffling as cracks will ensue after the first 100 hours.

The best setup I have seen (I inspect alot of RV4's) is to fabricate oil cooler mount brackets and connect them to the engine mount with Adell clamps, with the cooler angled back about 30 degrees. Then fabricate baffle material to connect the cooler to the rear engine baffle. This way the air draws well through the cooler and exits out of the lower cowling with no weight on the engine baffling. Here is a great thread on this very subject with photos: http://www.vansairforce.com/community/showthread.php?t=19960

Fair dinkum
V/R
Smokey
[email protected]
PS: you'll find "there are no new questions, just new members"

Exactly what Smokey Ray said. Get the cooler weight off the rear baffle.
Here are some pictures of an RV-8 sample that will give you an idea of what he is talking about. Not a 4, but the concepts are exactly the same.

Thanks for your replies.

Thanks everyone, lots of great responses.

Looks like mounting the cooler will be slightly more work than first anticipated, no surprises here

I did what G-IKON did, and it was easy. He has had great results, and there is no additional stress on the baffles. I just finished my baffles and don't want to have to do them again.

Oil cooler

Derek said:

I'm at the stage where it's time to mount the oil cooler.

When I trail fit the cooler in the recommended location (mounted on the left rear baffle ) it appears that the rear cylinder will block most of the airflow to the cooler. Is this ok i.e work adequately ?

Or should I be looking at other ways to mount the cooler that will allow more air to flow through the cooler.

Click to expand...

This is a photo of another builders oil cooler solution which I copied exactly. It has a plenum so that air can reach all of the cooler fins.

Something different.

http://rv-4builder.blogspot.com.au/2010/04/firewall-forward.html

I adopted a completely different approach. I haven't flown it yet so don't know if it works well.

On a different matter make sure you put in the oil pressure fitting before you do up the mount bolts.

like hcccs did

i have 500 hrs on a very similar type of setup I live in michigan so made a cover to block front opening into plemiun for winter but had to pull cowl everytime it warmed up. got sick of this and in vans catalog is a cover for the oil cooler that you can move with a cable from the cockpit. I put this between the plenuim and the cooler works great. In the picture you see the side and back of this baffle is reinforced with thicker material. at the back of the engine in my o-320e3d is a spot towards the center of the engine were if you extent the thicker plate at the back of the baffle you can add another bolt to secure this plate to the engine. I was concerned about the weight on baffle so looked for every way to beef up this mount.

Michael Henning said:

I did what G-IKON did, and it was easy. He has had great results, and there is no additional stress on the baffles. I just finished my baffles and don't want to have to do them again.

Click to expand...

Here is a link to G-IKON.To date I have still never seen the oil get to 200F. If doing it again I would put a shutter on the cooler to limit the airflow. The alternative would be to reduce the exit area of the lower cowl. It sucks too hard is my intuitive belief. The arrangement I have is organised so the cooler sts on 3 Adel clamps which ensures it is not stressed.

PS It perhaps looks a little more complicated in the pictures because I take cabin air from the cooler....I dont like CO....but thats another story.

My hangar neighbor, and my son Peter (both RV-4) have their oil cooler centered on top of the engine block, mounted in front of the baffle. Gets plenty of straight in air flow.

Mine is very much like Steve's. I did make a butterfly shutoff with a push-pull cable for cold weather operations.

ACS used to have a plenum made for this exact purpose. The scat hose is smaller but like Steve, I have never had high oil temps.

I also have a very similar set up, but my cooler is nestled in between the mount tubes, also mounted via 3 Adel clamps. The cooler is fed off the back of the baffles via a fabricated aluminum duct. The baffle opening is rectangular, 3" x 5". Cooling is very efficient using a positech 2002 cooler with max temps in the 205 F range only on very hot days during climbs.

I like Steve's cooler location outside of the engine mount much better than mine. This eliminates ducting interference from the mount tubes, which I had to work around. It does require the use of SCAT/SKEET or a more complex fabricated duct to direct air from the back of the baffles to the cooler.

I suspect (but have no data to back this up) that some of the efficiency of this setup comes from the possibility that the cooler exit in this general area is in a relatively low pressure area of the lower cowl, facilitating good mass air flow through the cooler.

I use a hinged door in my duct to cut off airflow during cooler temps and need it often, even in the summer time.

I'll try to post a pix.