LSE/Cowl/IO-360 Help Please

[phapp]

Hi,
Working on the cowl. Aerosport Power IO-360. The clearance between the cowl and the LSE ignition module & spark plug leads is very close. (Picture 1).

The plans call for 1/8" spinner to upper cowl but they don't indicate in which direction. My guess is 1/8" high or low? I'm all the way up to double that, 1/4" (Picture 2) to have some clearance for the LSE module and wires.

What have others done?

Thanks for any advice.

 

[BobTurner]

Hi,
Working on the cowl.
The plans call for 1/8" spinner to upper cowl but they don't indicate in which direction. My guess is 1/8" high or low? I'm all the way up to double that, 1/4"

Thanks for any advice.

The 1/8" is the fore-aft gap between the back of the spinner and the front of the cowl. Vertically there should be a smooth flow from the spinner to the top of the cowl, although some builders with fresh engine mounts position the cowl slightly high, figuring that the mounts will sag 1/8" with time.

Edit: high-low confused, see below.

 

[Mel]

The 1/8" is the fore-aft gap between the back of the spinner and the front of the cowl. Vertically there should be a smooth flow from the spinner to the top of the cowl, although some builders with fresh engine mounts position the cowl slightly high, figuring that the mounts will sag 1/8" with time.

I think you meant to position the cowl slightly low so that the engine will settle down to it.

 

[Guy Prevost]

I agree with the other posts about cowl spacing. I moved my ignition coils aft of the fuel distribution spider to answer your other question.

Best,
Guy

 

[phapp]

Thank you Guy. That's what I was looking for and what I was thinking. Move the coils aft. I wish Aerosport would keep track of these things and configure accordingly. I'll send them a friendly note to help the next person.

The engine has been mounted for a 3 months, and the prop for 1 month (yes, a very slow build, quick build). So hopefully I have some sag already.

DWG 48 shows 1/8 top, 1/8 - 3/16 bottom vertical. I have a 1/8 cowl to spinner spacer in place per the build manual.

My understanding is that the vertical position is relatively important for air flow / cooling. If I get the 1/8 vertical, the cowl will sit on, or within 1/16 of the LSE ignition module and leads. Flexing, vibrating, rubbing. Not good for aircraft.

 

[BobTurner]

I think you meant to position the cowl slightly low so that the engine will settle down to it.

Uh, yes. Everyone, read what I meant, not what I say!

 

[rvbuilder2002]

The engine has been mounted for a 3 months, and the prop for 1 month (yes, a very slow build, quick build). So hopefully I have some sag already.

Not likely.

I have found that engine sag occurs slowly as a result of engine shake/vibration once put in service. It usually is pretty settled in after the first 100-150 hrs.