RV-8 Horizontal Induction Snorkle Fit

I'm attempting to install Van's horizontal induction snorkle on a Lycoming Y10-360-M1B engine with a Bendix type RSA fuel injector. The Van's supplied alternator and bracket is interferring with the snorkle which will apparently necessitate a fiberglass modification to the snorkle. Has anyone else had this problem and any suggestions?
John

Hi John - Check out my Firewall Forward section of my log and this may help as it seems to affect most people. Some cut the snorkel in half and fit each end to servo/baffle and then glass the centre gap. You'll find what works best for your situation in time.

Hi Bob,
Thanks for your tip. Good to know that I'm not the only person experiencing this problem. I talked to a Van's tech yesterday afternoon and he suggested that heating and remolding the snorkel at the interference point may also work. He also indicated that they were talking to the alternator supplier and attempting to have them redesign the hardware for a better fit.
John

Yep, the Vans supplied Snorkel interferes with the Vans supplied Plane Power alternator if you have an RSA style fuel servo. I think this is a result of the fact that the PP alternator is new and the older alternator they supplied did not interfere (at least that's what I hope, because supplying two components that interfere this bad is just totally lame).

Vans also recommended heating the snorkel locally with a heat gun and deforming it to eliminate the interference, which I did. But after a few weeks, the shape crept back to it's original, interference condition. So I heated a larger area and made a larger deformation to increase the clearance even more, which also relaxed over several weeks time, resulting in the same interference. So in the end I had to cut out a big hole in the snorkel and glass a recess in - a big pain but it had to be done...

SHOCKER said:

He also indicated that they were talking to the alternator supplier and attempting to have them redesign the hardware for a better fit.

Click to expand...

Now that is funny. Rather than redesign the fiberglass part, which can easily be done with a minor mold change, they are suggesting that the ALTERNATOR MANUFACTURER change their design? Seems a little backwards to me...

Heating and deforming composites

Trying to warp or change the shape of a composite part by heating it is a waste of time. You will never be happy with the outcome in the long run.

Cut away what you need to, then glue a piece of styrofoam inside, sand to shape, glass over it with epoxy, then dissolve the styrofoam out with acetone or gasoline. Or, use modeling clay if you can reach in to pull it out after the glass cures.

Epoxy (and Polyester) are thermo-set, not thermo-plastic. This means that they cure, not just solidify. Heating it won't 'melt' it. It will soften, but as others commented on, it will try to creep back to its original shape. It also will probably have degraded mechanical properties.

filter box rv8a

I had to literally cut the top of air box to get it to fit under alt. & re-glass
Van's has known this for long time, it is not the only thing that doesn't fit properly from Van's FWF kit. I had lots of prob with TMP cables, sniffle valve, exhaust sys, baffle kit etc. I am very disappointed. It involved many hours of mods that should not be necessary. Van's has no interest in fixing prob, they just say " well those parts have to fit so many diff configs & airplanes" to which I reply BS

scsmith said:

Trying to warp or change the shape of a composite part by heating it is a waste of time. You will never be happy with the outcome in the long run.

Cut away what you need to, then glue a piece of styrofoam inside, sand to shape, glass over it with epoxy, then dissolve the styrofoam out with acetone or gasoline. Or, use modeling clay if you can reach in to pull it out after the glass cures.

Epoxy (and Polyester) are thermo-set, not thermo-plastic. This means that they cure, not just solidify. Heating it won't 'melt' it. It will soften, but as others commented on, it will try to creep back to its original shape. It also will probably have degraded mechanical properties.

Click to expand...

Steve,
I had good success with the reheat technique. In my experience, epoxy softening depends on what temperature the epoxy was originally cured at. If one raises the temperature above the original cure, it will soften and re-cure at that higher temp.
On my snorkel, there has been no relaxation or restoration to previous form in the year it was in the shop or in the 70 hrs flying time so far. In regards to degraded properties, Yeah, probably compared to a pristine layup but for the localized areas where reforming is useful, the degradation was not detrimental in my case. Different results may be an indicator of technique. If one overheats the epoxy, it can certainly be permanently damaged and need replacement via cutout and layup. Heat it the MINIMUM possible to make it formable with some decent force. I used my body weight on a round PVC pipe to create a cylindrical depression. If you heat enough to make it "floppy", its probably toast.
Start of Snorkel pages on webpage

Snorkel fit

I am not to this point yet as engine won't be delivered to next month but I was thinking of cutting out the offending area, turning over the part cut out and re-glassing this piece in place...has anyone tried that? seems like it should work with very little mess...

Cut Snorkel added dimple

LyCon IO-360 M1B, AirFlow Performance FM-150

Cut snorkel in half. Fitted up ends then reglassed back together. Ground off unused mounting tabs from Plane Power starter. Added dimple to eliminate interference with starter. 18 hours flown off in Phase One.







Good luck.

Dave Casey
Race 89

Different?

Your ramp/filter installation doesn't seem to have the typical screws and hold-down brackets. Did you create a different attachment mechanism not visible in the picture? Can you share the details?

Cut

Cut

Join together

Finished