New Univair Cowling

[IowaJ3]

Has anyone replaced their PA18 cowling with one from Univair? I replaced boot cowl forward and the fit is terrible. It appears that the cowling doesn’t fit properly on the nose cowl and the rest of the cowling (top, sides and bottom)won’t make the circumference. Very tight fit and cannot latch both side cowls.

I spoke with them about the nose cowl and another was sent to me. It fits the same exact way. I even tried to fit it while on the ground and it still won’t make it all the way around the nose cowl.

Been dealing with this a while and getting frustrated. Was told that this was just the way it is and they haven’t had any complaints before. Someone else at Univair is working on it now and waiting to hear if I get the same answer again.

And I Know before you say it, I should have just built it myself.

[Dan Gervae]

I ran my cowl side through an English wheel and made it match the fiberglass nose bowl better. If you know someone who has one it worked surprisingly well on my build. Not perfect but acceptable to me

[180+cubs]

I ran my cowl side through an English wheel and made it match the fiberglass nose bowl better. If you know someone who has one it worked surprisingly well on my build. Not perfect but acceptable to me

i Had the exact same problem. Impossible to get a decent fit. I removed the material that was glued to the edges of the cowling and bent the serated edges inward and still wasn't able to get a fit. Extremely tight trying to get the cowling latched. Very very poor fit. Thought it was my lack of expertice, but I talked with a very highly renowned and respected cub builder, and he had the exact same problems. Can't live with it the way it is, so next step is to contact Unavair and see what the problem is. They need to completely scrap what they have been using to form this piece .

[KJC]

There’s nothing wrong with any of those parts. How can you possibly be trying to fit the nose bowl and cowls without the flywheel installed. You will likely need to trim the front edges of all the sheet metal pieces to achieve a nice fit.

Put the flywheel on and temporarily bolt it so it stays tight to the crank.
Use some 3/8 to 1/2 inch felt or other material as a spacer between the flywheel and nose bowl. It’s a tight fit.
Clamp the bowl to the flywheel. Make sure it’s straight.
Next, make the cowl support Channels the proper length. I think this is your problem now.

Start there and send more pictures and I’ll help you thru the rest.

[IowaJ3]

There’s nothing wrong with any of those parts. How can you possibly be trying to fit the nose bowl and cowls without the flywheel installed. You will likely need to trim the front edges of all the sheet metal pieces to achieve a nice fit.

Put the flywheel on and temporarily bolt it so it stays tight to the crank.
Use some 3/8 to 1/2 inch felt or other material as a spacer between the flywheel and nose bowl. It’s a tight fit.
Clamp the bowl to the flywheel. Make sure it’s straight.
Next, make the cowl support Channels the proper length. I think this is your problem now.

Start there and send more pictures and I’ll help you thru the rest.

The cowling won’t even fit with the cowling support channel not even on it. There is just not enough cowling to go around. Would you be happy with the way this top cowl fits?

[wireweinie]

I've never seen any panel on a Cub type airplane that did not need fitting. Even the original short instrument panels don't fit the same in all aircraft. If the doors/panels don't fit far enough forward, check the screw hole locations in the brackets that the cowl support channels fasten to. If the nose bowl is 'to big around', remove the chafe strip first and check the fit. The cowling, nose bowl, and associated brackets are not things that are fitted according to a drawing. They need the engine weight and accessories in place and then hand fit them to your aircraft. Even the latches themselves need some adjusting.

Web

[bob turner]

With Web on this - there are all kinds of interconnected adjustments. Big pain in the neck even with factory cowls.

I watched a pair of CC mechanics trim factory doors to better fit the nose bowl - when screw and latch adjustment would have done the same thing.

The latches are the worst. Adjustment is with washers!

that said, were you able to compare the circumference with a good stock nose bowl?

[ak49flyer]

I’ve never understood how they can sell those parts and expect them to fit-I always make my own top and sides at rebuild and half the time you’d be better off making a new bottom too. There’s just too many variables, especially with the side doors. I agree the pics look a little wonky, but seriously, it’s basically meaningless without being mounted on the airplane/engine. You’d be surprised how much things change when they’re screwed tight/braced in place. There’s a ton of slop in those southco fasteners. I’m curious on the circumference question...? I did hear from stoddards that univair was having some issues with nose bowls earlier this year, but I didn’t hear what specifically was wrong. Can you compare to the old one and post pics of differences? Fit each new piece with your old pieces and see which are different? (Old cowling might not have been “right”, so not necessarily reliable)

[supercrow]

I build the top, bottom and sides to fit from new material. I have found that the flange on most of the glass nosebowls has a decided tilt to it instead of being flat. That doesn't help. And it would do no good to pattern the ones I build. I build each one to fit as no 2 will be exactly the same.

[Steve Pierce]

So this fitting is not on the aircraft? The latches are adjusted by varying the washers under them. I have never been happy with the fitment of new Univair cowling but they fit like most original Pipers did, production parts don't meet a lot of our standards. I spent 5 years working for a sheet metal magician and that made me more picky I guess. I put the cowl seals on the doors and form, cut and fit my own doors which is a laborious task. There are so many factors that effect the fit starting with the boot cowl, firewall flatness, cowl channel angles etc. etc.

[bcone1381]

I just built a boot cowl for my experimental. Engine cowl will be in my future. When I read post #1, I wondered how Univair could offer a cowl and have a nice fit. I figured they would all be custom made for a good fit. I'd start by fabricating a poster-board template. Then I cut the AL piece about an inch oversize, then match drill it into place. I also put some curvature into the sheet before I match drill. Draw out curvature onto your template, then onto your stock.

I build because I like to build. Its not fast. I don't count the hours when I'm having fun. If I dont like the piece I built, I chalk it up to learning and start over. But that is experimental. Maybe the certified folks are stuck.