Cowl Measurement

Kyle Boatright · #1 12-26-2017, 05:50 AM

I'm looking for a quick measurement.

What's the fore and aft length of the top cowl (installed), measured from the top center of the firewall to the flat area behind the spinner? Basically, the measurement along the the centerline of the cowl.

Thanks,

CJ in EP · #2 12-26-2017, 07:19 AM

Mine came out at 33 7/16". This is on a -9A, but I'm pretty sure the cowl for a 9A is the same as the 6A... that or Van's sent me the wrong cowl.

Good Luck

Phil · #3 12-26-2017, 07:47 AM

Kyle,

I don't have the measurement with me right now, but something you need to consider is the prop choice. (really just the spinner)

Van's spinner and ends flush with the backing plate, while my MT spinner has a flange that extends about 1/2" past the back of the spinner.

What that means is the cowling fitting to my MT spinner is about 1/2" shorter than the cowling of vans spinner.

If I were to switch over to a Hartzell and Van's spinner, I'd have to add about 1/2" of glass between the front of my cowling and the back of the spinner to get that nice 1/8" gap back.

Does that make any sense?

Phil

Kyle Boatright · #4 12-26-2017, 07:58 AM

I'll be using Van's spinner with a Hartzell prop for the RV-10.

Carl Froehlich · #5 12-26-2017, 08:43 AM

Quote:

Originally Posted by Kyle Boatright

I'll be using Van's spinner with a Hartzell prop for the RV-10.

If you are trying to fit the cowl without the prop and spinnner backing plate on the engine you might end up with a poor fit.

The prop hubs are different - thus the postion of the backing plates. I fitted the cowl using an identical Hartzell prop hub but no blades. A neighbor had one left over from a prop hit. If you don?t have the exact hub, then bite the bullet and mount the prop and spinner back plate before doing any cowl fit.

Another tip, when you add the spacers and washers to connect the spinner backplate to the hub, make sure you have at least one washer on each side of the backplate. This way you have some adjustment room when you are done.

Carl

Kyle Boatright · #6 12-26-2017, 09:00 AM

Don't over think this folks. It is a simple request. All I need is one dimension...

rocketman1988 · #7 12-26-2017, 09:05 AM

I made a plywood disk the size of the spinner on my MT prop/spinner then used the dimension from the spinner Back plate to the base of the prop hub to make nylon bushings. The bushings hold the disk exactly where the back of the spinner is located. I then fit the cowl. I can?t even imagine the PITA it would be to fit the cowl with the prop installed. I must have installed and removed that cowl a hundred times before it was finished...

RV10Pilot · #8 12-26-2017, 01:18 PM

From the top center of the spinner flat face of the top cowl to the foward fuselage skin is 40 3/4 inches. Add 5/8 inches for the flange to the fwf so the dimension you are requesting is 41 1/8 inches. At least that is what I have on my install.

Simple request simple measurement. Heed the warning above.

Kyle Boatright · #9 12-26-2017, 04:26 PM

Quote:

Originally Posted by RV10Pilot

From the top center of the spinner flat face of the top cowl to the foward fuselage skin is 40 3/4 inches. Add 5/8 inches for the flange to the fwf so the dimension you are requesting is 41 1/8 inches. At least that is what I have on my install.

Simple request simple measurement. Heed the warning above.

So, the cowl (the fiberglass part) is 40 3/4" front to back across the top?

RV10Pilot · #10 12-27-2017, 08:37 AM

Quote:

Originally Posted by Kyle Boatright

So, the cowl (the fiberglass part) is 40 3/4" front to back across the top?

Close, If it is just the fiberglass subtract 1/16 to 1/8" for the gap between the fiberglass and the forward upper fuselage. Also, my spinner is not on currently, I have about a 1/4" gap between the spinner and cowl, but you did not request that dimension.
Larry