[February 3, 2009]

OK, tonight I think I finally figured out how the plenum is supposed to fit. I haven't seen too many pics of this online, so I figured I'd over-photo document this. Here is the right side. The plenum pretty much touches the ring and is perfectly aligned top-to-bottom.

Left to right alignment is perfect too.

I used the sparkplug hole on the baffle to align the rear. The top of the plenum is even with the bottom of the oval hole.

The left side of the plenum is offset aft about 1/4" from the top of the ring.

It is also offset left. I think I might need to chop-n-glass this side to get the alignment better. No biggie.

Aft alignment for the left side is the same as the right side.

Here is a generic view of the plenum. With this fit, there seems to be about 5/8" of upward movement on the front of the plenum before it hits the cowl. I really can't get it any better as it stands. My thought is to proceed with his it sits now, and if it does rub, I will cut out the interfering section of the plenum and reglass it lower. I am kind of stuck with the alignment I have now.

The oil cooler recess needs to be chopped-n-glassed. No real big deal.

Sam James recommends angling the oil cooler 15 degrees. He claims it adds tremendously to the cooling. Here the Stewart Warner (read: $$$$) oil cooler is at 0 degress.

Somewhat decent clearance from the engine mounts.

Now this is about 15 degrees.

Tons of interference issues. A local RV-8 recently completed by Jack Savage used the plenum and the angled SW oil cooler. jack says his oil cooler is blocked off significantly to keep the oil temps up. The way I see it is I don't need all that much cooling. I have the super-nice oil cooler. I am not going to angle it back. If I do have cooling issues, then I will contemplate putting it at an angle. But not now.



Last Modified: June 5, 2023