Mounting Oil Cooler

flybill7 · #1 06-03-2008, 08:26 AM

Looking for advice about mounting the oil cooler on the #4 baffle. I’m using the stock Niagara oil cooler on a Mattituck TMX-360 and have the new RV-7 baffle kit. The new kit has pre-drilled holes and a pre-bent bracket fwd and above the oil cooler opening so you really don’t have any choice where – or how high – the oil cooler goes. I installed, fit and trimmed the baffles and didn’t think too much about the oil cooler.

But trial-fitting the oil cooler for the first time, I realized that only the upper half of the baffle rectangular hole is open to cooling air. The lower half is blocked by the #4 cylinder cooling fins. In addition, the cooling fins make it impossible to put a nutplate on the center bolt hole on the right side. The oil cooler is supposed to have two bolts on the left, and two on the right. I’m nervous about only bolting it on with 3 bolts.

Moving the oil cooler up a couple of inches would require new baffle parts, and a lot of effort. Since I just have a stock config and given the pre-drilled holes, I’m hoping somebody who has been through this has an easier solution. I’ve already had enough fun on the baffles!

Thanks in advance, Bill

asav8tor · #2 06-03-2008, 08:58 AM

True a nutplate will not fit but, you can disconnect the baffle and thread the bolt the other way.

The bolt head fits in there. The nut will go on the outside. You should use 6 bolts. Vibration transfer is spread out and reduces cracking to both the baffles and oil cooler mount flange when more bolts are used. 3 bolts and you will see stress cracks starting within a couple hundred hours.

Use the long bolts with the spacers so both sides of the oil cooler flange are supported or cracks will start prematurely.

And don't move it up. Stock location is the way to go or remote mount with scat tubing.

drill_and_buck · #3 06-03-2008, 09:58 AM

Hi Bill:

I just finished mounting my oil cooler with a similar setup. My baffle kit is about about a year old, not the latest.

On my initial setup I thought the the nutplate was going to be a problem. In the end it was not. My plans call for a .063 doubler between the rear bulkhead and the left rear sidewall. This helps a little bit but won't fix the problem.

What I found was that the alignment of the two rear left bulkheads play a big role in solving this problem. Initial fitting had the bottom of the inner rear bulkhead protruding from the mating part on the left outboard bulkhead. Making sure that these two edges are aligned (parallel) will push the nutplate back.

Clear as mud right?

Mike Draper
RV-8 Finish
TMX0360 CS Pmags
N468RV

bkilby · #4 12-10-2008, 09:44 AM

Anyone know off the top of their heads which long bolts and spacers I would need for the standard oil cooler? I need to install the long bolts to reach the rear bracket and wanted to pick some up at ACS before my next trip to the hanger.

allbee · #5 12-10-2008, 10:50 AM

Quote:

Originally Posted by bkilby

Anyone know off the top of their heads which long bolts and spacers I would need for the standard oil cooler? I need to install the long bolts to reach the rear bracket and wanted to pick some up at ACS before my next trip to the hanger.

An3-42A You will need to make spacers for them also from AT6-058x5/16

bkilby · #6 12-10-2008, 10:55 AM

Thanks for the quick reply!

N941WR · #7 12-10-2008, 11:08 AM

Quote:

Originally Posted by flybill7

Looking for advice about mounting the oil cooler on the #4 baffle...

Install it per the plans. There are thousands of RV's flying with the oil cooler down low, like you describe, and they don't have cooling problems.

Quote:

Originally Posted by allbee

An3-42A You will need to make spacers for them also from AT6-058x5/16

When you make your spacers, put an AN3 washer on both ends of the spacer. This will help spread the stress on the oil cooler flange and help keep it from cracking.

allbee · #8 12-10-2008, 11:16 AM

Quote:

Originally Posted by N941WR

Install it per the plans. There are thousands of RV's flying with the oil cooler down low, like you describe, and they don't have cooling problems.

When you make your spacers, put an AN3 washer on both ends of the spacer. This will help spread the stress on the oil cooler flange and help keep it from cracking.

Also along this line, put the oil cooler mounting as high as you can. Than put some of that black rubber stuff from the baffles inbetween the cooler and the bracket.