SPRL fuel selector and gascolator install.

[schu]

Sooooo much variation to fuel system install. Makes it hard to compare fuel system issues between builders because every one is a one off, including mine, which looks nothing like any of these.

[PaulSA]

My install is very similar to Rob's. I didn't like the idea of cutting the stainless panel. I have fitted a door in the lower boot cowl extension to access the gascolator

[Nev]

I went ahead and cut an access panel this morning, in the stainless tunnel. I still need to make the cover. Problem is we are in a lockdown here in NZ so I can’t get supplies and I don’t have any stainless sheet. My question is, could I make the cover from .025 or .032 aluminium sheet ? Thoughts appreciated.

76E8EECA-DBBC-48F6-830B-7812BF7C1892.jpeg

[Paul Johnston]

I would- I think aluminum would be fine

[Mark Goldberg]

A piece of .032 aluminum would be OK I think also. Mark

[Nev]

Thanks gents, I’ll do that.

[Battson]

Surely the tunnel is made of stainless steel for a reason?

The tunnel has more direct airflow through into the cabin from that area where the hole is, so you want to ensure there is not any exhaust gas getting past the tunnel panel. and rising up past the pedals I would suggest a gasket.

[Nev]

Surely the tunnel is made of stainless steel for a reason?

Yes, hence my question. But I think given the proximity of the cover being aft and inside the exhausts the heat should be minimal. There’s .025 sheet aluminium 10mm further aft, followed by fabric all at a safe distance.

The tunnel has more direct airflow through into the cabin from that area where the hole is, so you want to ensure there is not any exhaust gas getting past the tunnel panel. and rising up past the pedals I would suggest a gasket.

This is a very relevant point given the fuel drain hole. The cover is easy to seal around the edges, but the drain hole not so much. Any suggestions appreciated.

Here’s where I’m currently at (the other hole is for the VHF aerial between the exhausts - it has a gasket) :

BD2F12A9-8116-450E-8E22-2978F4C78712.jpeg

7B050F80-A949-4EAF-847F-2756377B8A1F.jpeg

[Battson]

Perhaps a rubber plate across the back side of the cover plate?

[Paul Johnston]

Looks good Nev! Drain hole is ok as is

[Nev]

I might try making a small seal using red high temp silicon around the drain.

[Nev]

Following on from the above discussion, it does seems that exhaust is finding its way in around the gascolator drain valve. I've now sealed the top of the oleo struts pretty well, and also the top of the gear legs, and around the fire wall. I've been taping over the hole after draining fuel but I need a more permanent and functional solution.

One idea is to make a hinged flap with a rubber seal, held closed by a Camloc.

I'm wondering if a simple small gurney flap in front of the hole will cause cabin air to be drawn out (like the cowling exit cooling lip) rather than being forced in.

Thoughts ?

[Chris Werner]

Nev, I have a 250 comanche. The fuel strainer is in the belly and it has a little door that I open to access the drain. Here is a link to one on eBay so you can see what it looks like. Similar to an oil door on some cowlings only smaller.

https://www.ebay.com/itm/AIRCRAFT-AVIATION-HOMEBUILT-EXPERIMENTAL-ACCESS-PANEL-DOOR-FUEL-STRAINER-PIPER-/272042561781?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=711-127632-2357-0

[Nev]

Thanks Chris - exactly what I was thinking of.

[spinningwrench]

Lot of ways to plumb the fuel selector. This arrangement put the gascolator in a good position. I am using wood floorboards and split them down the middle under the pilots feet for easy access to all the plumbing and brake rigging.

Fuel Plumbing-1S.jpg

Fuel Plumbing-2S.jpg