Alt air problem

Hello Gents,
I've just modified the snorkel for my RV-7 with an IO-375 (aerosportpower) engine.
Big disapointement when I checked the alternate air : the alt air door doesn't open fully because it is restricted by the oil pipe coming from cylinder 2
Please refer to the pictures below:







Question: with the opening which is a bit less than 3/4 of an inch would this be enough for the engine to breathe properly (ie enough air to the injection intake) if I need to activate the alternate air??

Thank you.
Alain (in France)

First thought was to change the direction of rotation, second thought is to change the oil line. It looks like you could rotate that 45-degree oil fitting more to the horizontal and fab a new aluminum line to just miss the door?

Moving the hinge point to the top would do it, I think.

Thanks for these quick replies.
I believe the alt air door can only move aft if positionned at this location on the snorkel because of the tight fit of the cowlings. That is as it is positionned now.
As Airguy said moving the oil line would solve the issue, but I'll have to check if that is doable.
Another painful solution would be to change the location of the door to the forward face of the snorkel, but that would require major surgery on the fiberglass...

I'd like to know if the open area when the door is open is enough for the engine to function normally if I ever have to use alt air?

Waiting for more advice before I change anything.

Thanks

Looking at it again, I believe moving the hinge point (screw) forward 1 to 2 inches would allow it to clear the oil return tube.

HOLD ON A SEC

I recognized this problem early in the fabrication of the alt air system.

Similar to what Ray said above, it can be alleviated by rotating the assembly clockwise such that the door moves downward quicker due to a forward pivot location.

This was how I located mine. Despite the admonition in the instructions that this is a one way operating valve that must be reset by removing the cowl, mine works both ways with the cable (meaning it re-engages the ramp "latch")

You may notice the use of a nutplate and screw to create a stud for the cable. It is finished with a metal locking nut such that the curled cable end is not in a bind




The rest of the fabrication can be found here:

Start of bypass fabrication

A bit more fiberglass

rzbill said:

I recognized this problem early in the fabrication of the alt air system.

Similar to what Ray said above, it can be alleviated by rotating the assembly clockwise such that the door moves downward quicker due to a forward pivot location.

This was how I located mine. Despite the admonition in the instructions that this is a one way operating valve that must be reset by removing the cowl, mine works both ways with the cable (meaning it re-engages the ramp "latch")

You may notice the use of a nutplate and screw to create a stud for the cable. It is finished with a metal locking nut such that the curled cable end is not in a bind

The rest of the fabrication can be found here:

Start of bypass fabrication

Click to expand...

That is the best solution.

And here I go for a little bit of fiberglass work

Thank you very much for your replies.

Alain

I tightened the drain fitting a couple degrees and tweaked the drain tube. Easy.

Alt air

I moved the oil return line on my -8. It was very easy to do.