Fibreglass layup for air filter mount on Snorkel?

Has anyone used fibreglass to make the air filter mounting flanges on the top of the snorkel?

I'm working the VA-132-1 snorkel on my IO-360-M1B that puts the air filter in the baffle floor in front of no. 2 cylinder.

I've fitted the bottom end of the snorkel just fine but the top end is too far forward and interferes with the bottom cowling inlet area. To make it fit in the baffle floor I need to cut the snorkel in half and move the top half as far back as I can, which means positioning it close to the cylinder underneath the baffle floor support angle that is screwed to the no. 2 cylinder. As a result, the profile of the top edges on the sides of the snorkel are no longer straight. The filter is pretty flexible and can form to that shape so that won't be a problem.

However, in the above circumstances it is tricky to make up the air filter mounting flange using the VA-132-1A & B 'W' angle that came in the FAB-HORIZON INDUCTION-1 kit (there isn't even any room really for much of a flange at all along the aft edge of the snorkel). I'm thinking it would be simpler to make the complex shaped filter mounting flange that I need using fibreglass.

Grateful for any similar experiences or thoughts on this idea, for or against?

CUT IN HALF

G'day Steve,

We had to cut the snorkel in half, fit both halves, trim them substantially, and then rejoin with glass. Seal the air inlet first.

The fit for the filter was tight: fore, aft, left & right.

Also, we had to add about 25mm of 90mm diameter plumping pipe to shift the filter bypass door to the left so that the cable and door would clear the oil line to/from No 2 cylinder head.

We suggest that you do not make the diagonal bend on the baffle inlet floors as shown in the baffle kit. Well, not unless you have to, after several trial fits.

Regards,

G'Day Bob, Thanks.

That all sounds very familiar. I reckon I have about one inch of play left-to-right and at most 1/4 inch fore-aft play when the snorkel is placed flush with the sidewall baffle. There's no fore-aft play at all when I move it to the most inboard position possible (which is where it sounds like you have yours).

Your bypass door extension addressed another concern I had. Thanks.

Too late I have already made the diagonal bend in the baffle floor which does complicate things. I figure I can rebend it. Most will be cut out anyway.

Still thinking I'll go with the fibreglass molding for the filter mount lip. I have cut the snorkel in half already so am committed to a whole bunch of fibreglass work anyway. I figure I will be much happier with the precision of the fit if I go for the glass filter mount.

Cheers,
Steve

FURTHER

I meant to add that we used the standard aluminium angle edges as flanges to attach the top of the filter to the baffle inlet floor. We used fibreglass to seal the corners and to provide a support for the front of the filter next to the cowl inlet.

Adding the baffle material has made fitting the bottom cowl tight but manageable with the prop and spinner fitted. With hindsight, probably I would increase the clearance between the spinner and cowl from 4/18 to 5/16" to ease fitting the bottom cowl.

RV-7 with Aerosport IO-360-M1B, circling first engine start. Aircraft painted and re-assembled - tip-up, Hartzell BA.

Regards,

Thanks Bob,

I too have 1/4" gap between spinner and cowl. Fitting is just about ok at the moment (though no paint to mess up yet) and hopefully will get a bit easier when I open up the gear leg cutouts in the bottom cowling for the brake lines.

Although I am not keen on doing it, I also have the option of cutting back the edge of the inlet on the bottom cowling. That would enable me to get away with a bigger baffle floor, resulting in more room to fit the snorkel/air filter into.

Problem Solved!

Problem solved, I think.

A mate came round and had a look. The lip on the bottom cowling left inlet was longer than the one on the right inlet. Never even occurred to me that the cowling inlet lip would be too long, but it was. Always helps getting a second pair of eye to look at it.

Trimming half an inch off the lip of the bottom cowling inlet will make the space needed to move the snorkel/air filter forward wholely onto the flat area of the baffle floor.

Now, if only I'd not messed up one of those 'w' angles trying to make all fit further back against the cylinder. Live and learn

Done in metal

Here's mine. Done in metal, with all fasteners hidden underneath. The filter pulls out the front for cleaning (its a K&N).



The duct is about 4 plies of 6oz e-glass:


The fastening of the duct is done from below, and not visible from above:


There's more to this than meets the eye. Hiding all the fasteners underneath was a trick. I used nutplates turned around backwards as surface mounting points.

exactly

Bob Redman said:

G'day Steve,

We had to cut the snorkel in half, fit both halves, trim them substantially, and then rejoin with glass. Seal the air inlet first.

The fit for the filter was tight: fore, aft, left & right.

Regards,

Click to expand...

Sounds like exactly what I did on the '8. Frankly, much easier just to deal with the 2 parts separately, then glass'em together.

very pretty!

Bill Wightman said:

Here's mine. Done in metal, with all fasteners hidden underneath. The filter pulls out the front for cleaning (its a K&N).

The duct is about 4 plies of 6oz e-glass:

The fastening of the duct is done from below, and not visible from above:

There's more to this than meets the eye. Hiding all the fasteners underneath was a trick. I used nutplates turned around backwards as surface mounting points.

Click to expand...

Bill, I want one of those! I am just down the road from you and could pick it up anytime. How does tomorrow sound?

Ok, just kidding on picking it up tomorrow. Seriously though, that looks beautiful. I have the same snorkel setup and wrestled a great deal with the baffling to get it to fit. It finally fit in place but I know anytime I have to remove the filter I am going to have a bear of a time getting all the screws back in place.

I would be very very very, yes very interested in talking with you about making one of these for my airplane. Please PM me if you are interested. Or, maybe you could come out and visit. I just had my airworthiness inspection Monday (forum post here: http://www.vansairforce.com/community/showthread.php?t=58903). I would love to have you come out and "eyeball" it closely before I fly.

Actually, that last invitation stands for anyone in the OKC area. I would really like to have anyone and everyone look over my airplane with a very CRITICAL eye. If interested in doing so please PM, email, call me anytime. I really want to have as many eyes on the airplane as I can find.

Well, anyway, Bill I would love to talk with you about the snorkel/baffle mount. That looks awesome!

Hey Steve - actually tomorrow would be just fine! It could be replicated; lets take a look at your setup. I'm off this week and next... will call you tomorrow.

Bill