SonexBuilders.net

I would recommed doing this mod while building your Onex with and AeroVee engine for oil cooling purposes.
Brent
Onex 77

Being a sonex builder and not a onex builder I'm not on the onex yahoo group. Has anyone flow without and then with that mod? I'm having a hard time seeing how it benefits cooling. The same ammount of air passes through the cooler with or without that rear duct. The only thing the duct does is make the air that passes through the cooler go out the back of the baffles instead of down over the rear cylinders. I'm not saying it doesn't help, just looking for an explanation of the benefit.

Keith
#554

What you have is a pressure differential guiding the air through instead of around the cooler. The higher presure air will go through the cooler and out the back seeking the lower pressure air behind the fence. Without the duct the cooling eould be less because instead of going through the cooler a proportion would go around the cooler and down. I don't think it will significantly affect flow over the cylinders as the air would mostly be that over the crankcase but only measurements would determine that or its efficiency at increasing oil cooling. You also need to remember that the hottest part is going to be the heads and not the cylinders. This mod shouldn't affect the head air flow.

Is this the standard mod for Onex aerovee's ? Im putting a top mounted cooler on my Waiex and was wondering if this is a mod or a factory setup. What does the Onex plans show for routing the cooling air thru? I would really appreciate it if someone could give me more info on this cooling duct. Thanks Tim Waiex 0146

The top mounted oil cooler is the factory standard for the Onex. Early on Sonex changed the baffling cooling duct for the oil cooler exit to help pull more air threw the oil cooler during the summer months.

I have an Aerovee that I plan to install in my Sonex . To make room for the eventual installation of the Turbo, I plan to use the top-mounted oil cooler. Kerry says there are as yet no drawings to enable me to do this, so if any one on the forum has installed the top mounted cooler in the Sonex standard cowling, I'd like to hear more. I gather I have to remove some material from the bottom and possibly the top of the oil cooler, and I am keen to learn about any necessary changes to either cowling or baffles.
Tim Mobbs
Sonex #1555 Aerovee #0672

Tim,
Mike has done it. The thread is below:
viewtopic.php?f=7&t=606

I have just started my Aerovee I am doing the top mount and installing in my Sonex. You can check my builders log soon to see what I hav done. I hope to start on the cowl during Christmas vacation.
Here is a link to my web site. http://websites.expercraft.com/gripdana/?q=home

tmobbs wrote: To make room for the eventual installation of the Turbo, I plan to use the top-mounted oil cooler. Kerry says there are as yet no drawings to enable me to do this, so if any one on the forum has installed the top mounted cooler in the Sonex standard cowling, I'd like to hear more.
Tim Mobbs
Sonex #1555 Aerovee #0672

Hi Tim,

As Bryan has pointed out, I have been flying my Waiex with the top mounted cooler for a year now. Overall I'm very happy with the setup and have had no issues. When you install the cooler, follow the AeroVee instructions on removing portions of the bottom flange so the cooler will fit over the cooler mount. Also, there is a flange on the "top" of the cooler (when mounted) on the forward/prop side that you will need to file away. This should give you sufficient clearance for the stock Sonex or Waiex cowling, but some individuals have needed to file a little extra off the outer housing for cowling clearance. The "tight" spot is where the cowling hinge is located so be ready to file the cooler or remove a hinge lug.
If you have any questions, please let me know!

Mike < have you installed the rear baffling duct to let the air thru the rear fence? I would love to see the pictures if you have any > i just started fitting the top cooler and it fits just as you say. I am now trying to figure how to make that duct. Thanks< Tim Koehler Waiex 0146