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From: Ernest Christley <echristley@nc.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Sat, May 7, 2011 2:47:31 AM
Subject: [FlyRotary] I've got fuel pressure

I'll probably start rambling, but I've spent the past two days covered in gasoline, so I have an excuse.  Jumping in and out of the plane to turn fuel valves, try to bleed lines, or switch on pumps has me beat down.

The  first BIG mistake I made was to leave the wrapping on the oil-filter sized fuel-filter/water separator that I'm using.  You know, I wanted to keep it nice and pretty for when the plane is finished.  I had poured 2 gallons in yesterday, and it took about 15 minutes for me to hear the drip...drip....drip of fuel.  The filter sits about 6 to 8 inches below the tank and behind the back seat.  The belly fabric is already painted, so I was (am still) dreading the possibility of a gas stain (I've got the 2 cycle oil mixed in). I actually didn't do to bad with not spilling, but that was a big can.  I was able to screw it off, peel the plastic wrap, and screw it right back on.

I replaced the drain petcock on the filter with a 1/8"NPT to AN-3 adapter, and ran a 3/16" line to the rear of the plane.  That was the only way for me to get a reasonable downslope all the way to the drain point.

I have another 3/16" line that runs through a needle valve and up to the throttle body.  If the electrons get lazy someday, I'll open the valve and gravity feed fuel to the engine.  That was the plan.  Instead, I put the fitting on without tightening it down.  So after I got the filter back on, there was another drumbeat on the belly fabric.  Luckily, I had my wrenchs close and cinched it down quick.  I wiped it up as quick as I could, but the cockpit was now full of fumes, and it's probably going to stain anyway.

So, I figured the plastic was why my pumps weren't working.  I had the fuel line unhook from the injector rails, and I just stuck it in a bottle and flipped the switch to check the flow.  Wasn't any.  I ended up cracking every friggin' connection in that fuel system (but I was smart enough to tighten them back down, this time).  I ended up connecting a vacuum pump to the fuel line.  Stupid pump won't push the air out...DANG-IT, I"LL SUCK IT OUT!!

Did I happen to mention that I'd been breathing way to many gas fumes?  I had an isolation bottle, so I wouldn't suck gas into my buddies vacuum pump, which I did a couple of times anyway.  I did that for about three hours.  Suck the gas through till the isolation bottle is full.  Pour the gas back in the tank.  Suck another bottle full.

I jacked up one side of the plane to make sure the drain on the other side wasn't being uncovered, and to maybe give it a little more head.  I traced every line out and back in.  I tried setting the regulator to full stop.  On both ends.  I tried closing the valve on the return line to the tank.  I tried closing the supply to the pumps.  I cussed Walbro (whoever that guy is), Fred Wankel, John Dyke, and the guy that invented aluminum tubing.  I went outside to breath some fresh air, 'cause the fumes were getting kinda rough, ya' know.

Then I stopped.  Sometimes it is good to stop.  Think.  These pumps will prime themselves if there is a positive head.  I've got nearly a foot of head.  Are they pumping in the right direction?  I was careful to paint the flow direction on the side with a paint pen so that it would be obvious.  Well, let's look at them closer.  Ok, let's.

Crawled back in the plane with one of the wife's old make-up mirrors.  Those things are great for seeing around corners.  Now, let's see if we can see any markings.  Well there is a +, right next to this wire that is connected to the 1/4" fast-on tab that is connected to ground.

Pause......

Think about it....

And hear is a - next to a terminal that has a wire heading off to the switch panel.

Pause.....

Apologize to that guy Walbro, Fred Wankel, John Dyke, and...

That aluminum tube guy can still bite me.

OK, some cruel demon came in over the years and switched the wiring on my pumps.  They are under the tank, behind the seat along with the fuel filter.  Switching them around was one of those contortionist type jobs, and I was having to work with 8mm nuts.  My fat fingers don't work well with 8mm nuts.

I finally got them wired correctly.  Double checked that I had all the connections snugged back up.  Put the fule hose in a bottle and flipped the pump switch.  It gurgled.  It spat.  It flowed.  Switched it off.  The flow was interrupted by a few spits, but then it evened right out.  I connected the fuel line back to the injector rail, flipped the switch just for a second.  The pressure gauge jumped off the needle.

I have fuel pressure.

Noticed a few minutes later as I was cleaning up that one of the banjo bolts on the rail was leaking a bit.  I'm going to see if I can chase down Bruce Turrentine tomorrow.  He was still working and flying out of TripleW the last I spoke to him.  If I can get up with him, he may have one of those housing we've been looking for (and I can stop in and get some Aviator beer for lunch!!)


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