Adam,

My experience is the same as yours. I often found/drained water out of my ol= d Cherokee tanks, and MANY rental airplanes as well. All were parked outside= , and I think avgas came with a certain amount of =E2=80=9Cwater added=E2=80= =9D in the old days=E2=80=A6 L

I=E2=80=99ve never found any water in the gascolator o= f my IV-P, so the fuel doesn=E2=80=99t have/collect any water=E2=80=A6or it=E2= =80=99s going through the engine and being vaporized--which I think unlikely. I know the gas caps= are MUCH better than the old Cherokee =E2=80=9Cstoppers,=E2=80=9D and I rar= ely park the Lancair outside these days.

Like you, I was meticulous in cleaning/keeping the fue= l tanks/lines clean during fabrication and through flight test. I still collected some small amounts of carbon fuzz, and a few bits of alum= inum in the gascolator during testing, and at the first two condition inspec= tions. Almost undetectable bits of something for the last three, not enough t= o even identify when poured onto a piece of white paper=E2=80=A6 So the gascolator/filter is probably n= ot serving a useful function today=E2=80=A6but deleting it would be like thr= owing away the spare tire in my car, IMHO=E2=80=A6 I carry a few critical sp= are parts in my airplane for the same reason=E2=80=A6

Bob

From: Lancair Mailing List [mailto:lml@lancairon= line.net] On Behalf Of Adam Molny
Sent: Thursday, July 24, 2014 1:30 PM
To: Lancair Mailing List
Subject: [LML] Re: Gascolators and fuel lines.

Hi Mark =E2=80=93

Our planes are kept in a heated h= angar so there=E2=80=99s no opportunity for water in the system from rain or= condensation. Back when I was renting Cessnas and Pipers I did occasionally drain water from the gascolator. Those planes were kept ou= tside.

The lowest point in the Legacy f= uel system is the fuel selector valve, but it=E2=80=99s not designed to capt= ure water or sediment like a gascolator. Your notion that the fuel flows too fast for water to settle out is difficult to prove or dispro= ve. I always envisioned tiny globs of water flowing out of the fuel tanks an= d coalescing into a large glob of water in the gascolator. The real test wou= ld be to pour a cup of water into one wing tank, run the engine at high power, and see where the water e= nds up (in the gascolator, out the tailpipe, or back to the fuel tank). Howe= ver, deliberately adding water to the fuel system seems like a bad idea so I= =E2=80=99m not going to try it.

I think you are saying you want f= uel filtration but there=E2=80=99s no point in having water separation since= a gascolator won=E2=80=99t work. Can you be 100% certain that you will never get water in your system? What about flying through rain with a loose= fuel cap? What about being parked outside at Oshkosh for a week? If you do g= et water in the system, where will it go? I hate to fall back on the =E2=80=9C= It=E2=80=99s always been done that way=E2=80=9D argument, but gascolators exist for a reason.

For all the Legacy drivers out t= here: Have any of you ever discovered water in the gascolator?

Good discussion!

-Adam Molny

From: Mark Sletten [mail= to:mwsletten@gmail.com]
Sent: Thursday, July 24, 2014 9:15 AM
To: Adam Molny
Subject: Re: Gascolators and fuel lines.

Adam,

I wasn't questioning the value of fuel filtration, ju= st whether a gascolator is the best choice. As I understand it, the gascolat= or provides a means to filter the fuel and a low point to catch water that m= ay have gotten into the fuel system. There are several arguments against using one for the Legacy.

In the L= egacy the gascolator is not the lowest point in the fuel delivery path from t= he tank to the engine, so water in the tank should not flow to the gascolato= r before turning on the pumps. (I believe the same is true of the RV. Has your wife ever drained any water from her g= ascolator?)
Given th= e high fuel flow rate and recirculation of unused fuel to the tank, it's unl= ikely the gascolator will remove any water with the engine running.
The gasc= olator in the engine compartment provides a large surface area to add heat t= o the fuel which can contribute to vapor lock. Lancair combats this with a h= eat shroud and blast air, adding weight and complexity.
The gasc= olator requires numerous fittings and breaks in the fuel lines, adding to co= mplexity, weight and the possibility of fuel leaks.

Since the gascolator appears to be rather useless at r= emoving water, it's primary function for the Legacy is filtration. With so m= any other filtration options available, it seems illogical to put a gascolat= or in the engine compartment.

What do you think?

--Mark

On Thu, Jul 24, 2014 at 7:12 AM, Adam Molny <Adam@validationp= artners.com> wrote:

Mark =E2=80=93

The gascolator provides a large reservoir for c= apturing water and sediment. It also contains a fine screen with a fairly large area that acts the final filtration element to keep jun= k out of your carburetor or injector(s).

Case in point: my wife=E2=80=99s RV6-A started s= howing small amounts of debris when sumping the fuel tank drains and gascolator. We opened up the gascolator and found a small amount of deb= ris at the bottom of the bowl, and the screen was about 5% blocked. There wa= s no immediate danger, since the bowl would have to completely fill with deb= ris and the screen would have to be 100% blocked in order to kill the engine. It turned out to be bits of= fuel tank sealant flaking off.

My point here is that the gascolator acts as a b= uffer and gives you lots of warning and lots of time to head off any potential fuel contamination problem.

What is the argument for omitting the gascolato= r on fuel injected engines?

-Adam Molny

Legacy N181AM 255hrs

From: Mark Sletten [mailto:mwsletten@gmail.com]
Sent: Wednesday, July 23, 2014 7:35 AM
Subject: Gascolators and fuel lines.

Gang,

First: Gascolators. There is a great deal of debate around the web o= n the benefits of a gascolator in fuel injected systems. What's the consensu= s among Lancairians?

Second: I'm considering making my own engine compartment fuel lines.= I plan to build them up from scratch including the fire sleeve (or not if t= he hose is sufficiently fire resistant). Anyone have a recommendation on the type of hose to use?

--Mark