Gas & Oil HOBBS 2699.0 hrs

Last Sunday, it was finally time to add some fuel to the airplane for the first time. In getting prepped for this, I realized in some cases it isn't easy to get fuel in a new airplane. Our airport, KBJC, wont allow you to drive out to the self serve fuel pumps. They also wont deliver to a plastic gas can...only an actual airplane. We've had a lot of wind lately, so pushing the plane out to get it fueled was kind of a pain. I ended up going out to KFTG, a more low key airport near my house, to fill up two 5 gallon cans at their self serve pump. No one even questioned me...and I hauled the fuel back to the hangar.

 

 

Away we go, first I flushed the tanks with a couple gallons through the sump to try and remove any construction debris. I did this twice on each tank and got nothing...apparently the tanks were pretty clean? Or the debris just didn't dislodge?

 

I then disconnected my fuel line going into the fuel injection servo, hooked up a homemade hose and fed it into a painters bucket. If you look closely, I also made an attempt to ground the system....not sure how effective it was? I wasn't too crazy about doing this in the hangar and opened the doors while I did it. Once I got this setup, I turned on my fuel boost pump and pumped fuel through the system. The pump self primed in a few seconds and it was readily apparent by the change in sound when it was pumping fuel.

 

Again, I did this a couple times and then used a paint filter/strainer to clean the fuel as I dumped it back into the tank (rumor has it a coffee filter will also work). Although I didn't get a picture, there was debris in the filter...alum shavings, so watch for this.

 

 

Now it was time for a fuel flow test. I put the tail up in a level flight attitude...turned on the pump, started my iPhone stop watch and pumped for exactly one minute. The top picture shows the right tank and the one above shows the left tank. As you can see, they are essentially identical, as you'd expect with a good flowing system with no blockage. If I estimate 110 oz. and do some math, this give me roughly 51.6 gph. Well above anything the engine could burn at WOT.

 

 

 

The two videos (although they are kind of useless to see the readings on this post) above show my engine instruments during the fuel flow test. The fuel flow was topping out at anywhere from 54-56 gph, so slightly higher than my calculated figure of 51.6. Not sure if I should be worried about that, but the bottom line is, we are getting more than adequate fuel in a level flight attitude.

 

These two shots show the unusable fuel left in the tanks when I sumped them. As you can see, there is really just a mere ounces left, which surprised me. The procedure was to turn on the pump until it went dry. Then drain the remaining fuel in the tank...this is what I got. Van's says 1 gallon, my guess is that is a very conservative figure to account for varying build style on the fuel tanks.

 

Here is a gotcha to look out for with the Andair fuel selector. The assembly comes with the fittings loose...so you can orient them as needed for your install. I was aware of this a year ago, but forgot to address it then. I should have just taken care of it at the time.

 

I had done my fuel flow test and had no leaks...even at the selector. I realized I had the right and left tank plumbing switched up, so I went to unscrew my hose to swap it over and off popped the fitting!! It was only then I realized I hadn't installed the screws. Let your imagination go through a scenario of you missing this until your first flight...that could be ugly. BE SURE TO ADDRESS THIS!

 

Its really not Andair's fault either, they clearly tell you this in their instructions. Also notice they want you to use a punch to stage the screw heads. I've never done this before, but I just used the other screws as an example.

 

Next came the engine oil, but first I drained the preservative oil. I let this drain while I went to lunch since it was relatively cold and the oil was thick. Quick drain plug worked great too.

Close up the drain, check all the oil fittings and the oil filter. Start adding oil, SAE 40 mineral oil. Why mineral oil? Well, the ashless dispersant oil has anti-wear additives. During engine break in, we actually want to encourage wear to seat the rings properly, so we remove the anti-wear additives by burning straight mineral oil. For the first 25 hrs I will use mineral oil. I put 7 qts in, 6 plus one for the accumulator. I can add more later if needed, but that should be sufficient.

 

Once I got the oil in, with a few messes to clean up from an ill fitting funnel. I decided to hook up the starter for the first time, clear the prop, ensure the mags were off and crank over the engine to see if I could get oil pressure. Most recommend not going more than 30 seconds on the starter. I read this guideline somewhere: 30 seconds on, two minutes off, 30 seconds on, 30 minutes off. I didn't follow that to the letter, but just be careful not to burn up your starter. You'll also need a battery charger or you'll likely drain that down. You can also do this by hand, but I figure...work smarter, not harder...and its a good test of other systems.

 

First attempt...I conservatively cranked about 20 seconds...nothing, no oil pressure. I waited a couple minutes...tried again, this time about 25 seconds...again, nothing...dangit. I was bummed. I then checked my oil pressure transducer and the plumbing and wiring to see if everything looked good. It did, everything checked out. I waited about 15 minutes, checked to see if the starter was warm and tried a third time. About 25 seconds once again, nothing...I stopped in frustration, dejected, ready to leave it for now and do some research before proceeding. But...I glanced down at the EFIS to notice, right at the end of the start cycle, I got about 3 psi!

 

Now I knew the system was alive, it just took a while to prime, and that was cool. I waited another 15 mins and decided to see if I could get anything on my fourth try. Sure enough, the oil pressure slowly ticked up to about 25 psi...heehaw! After that session, I noticed a pretty good oil leak near the firewall. It didn't show itself sooner, because there wasn't any oil pressure. Before starting, as I mentioned, I checked all of the fittings...but one. The connection to the oil accumulator. The reason I didn't check it was, it is hard to get to and I thought, because of that I had tightened it before mounting the accumulator to the firewall. Nope! It was only finger tight. I got a wrench on it and tightened it up.

Later in the day, I did another cycle to check once again for leaks.  This time it achieved 30 psi. Doing another visual of the engine, I found some small drops up near the alternator. At first, I was puzzled as to the source of the leak. Tracing it upward...I noticed my oil line that feeds the prop was not even hooked up! Sheesh! I had it off for plenum fitting work and forgot to hook it back up. I didn't even think to check that during my initial oil line checks.

Oh well, definitely good to catch these now, before engine start. For now, that's all I will do prepping the engine. Fuel and oil systems seem to be working as designed. Next test will be the first engine start this weekend.