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 Friday, July 30 2010 @ 08:51 PM EDT

Engine Start - Finally!

   

Final Assembly

Success! The engine runs, finally.

I took the afternoon off to make yet another engine run attempt. I put the new battery charger on the battery for 90 minutes to make sure it was fully charged. Then I did a fuel flow test to be sure that I had adequate fuel flow at the fuel injector. I disconnected the fuel line at the fuel injection servo, and put it in a gas can. I ran the boost pump for one minute, and used a calibrated fishing scale to determine the weight increase - 4.5 lb, which equates to a fuel flow of 45 USG/hr. Way more than enough. I need to do the official fuel flow test later, with the fuselage pitched up to the maximum climb angle - but I am certain that it will make the requirement of 125% of the fuel flow required at take-off.

Then I pulled the aircraft out of the hangar and chocked it. The engine caught on the second cranking attempt. All the engine indications looked good, except the alternator load meter - it showed 5.2 amps load with the alternator switch OFF. I need to review the settings in the EIS for that one. The bus voltage did not increase when I selected the alternator ON, but I later discovered that the alternator field fuse was not installed, which almost certainly explains this snag.

After warming the oil, I ran it up to 1800 rpm and cycled the prop. It took a whole bunch of back and forth on the prop control before the rpm would respond. But, that was expected, based on reports from other builders.

The engine ran smoothly on the electronic ignition only, and with both the magneto and electronic ignition ON. But it ran a bit rough on magneto only, and the EGTs were higher. It seems probable that the mag timing is too retarded. Talking with Ron M. (Aircraft Maintenance Engineer based at Smiths Falls), it seems that perhaps I erred by trying to do the mag timing without having the pin that Slick calls for to lock the mag internals in place. I had assumed that as long as the mag breaker box light goes on and off at the correct crank angle, that everything would be OK. Ron gave me a spare Slick mag timing pin, and I’ll have another go at setting the mag timing tomorrow.

Life is good - I flew the mighty C182 this morning, I got the first engine run in this afternoon, and now I’m sipping a glass of wine and watching the first Canadian Football League game of the season (real men only need three downs to get it done :).

Thanks to everyone who e-mailed and phoned with advice on starting procedures. I appreciate your support.




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Engine Start - Finally! | 2 comments | Create New Account
The following comments are owned by whomever posted them. This site is not responsible for what they say.
Engine Start - Finally!
Authored by: kitplane.solutio on Saturday, June 28 2008 @ 12:09 PM EDT
Hi Kevin
Sean White down in kingston (I used to work with Ron) I have used the Lightspeed and mag. combination 5 times now and the EGT rise and the rough running on the mag only is normal. You are correct that it seems the timing is retarded as the EI can wind the timing out to 40 degrees at idle so going back to the fixed 25 degrees seems like someone put a tractor engine out front. You may also find when you do the idle mixture set up that you might not see a 50 rpm rise (50 rpm is the norm. but may differ buy engine model) when running on both the EI and the mag again becuase the EI will fire a very lean mixture. It is worth do a mixture rise check with the mag only. I have just started test flying a Rebel amphib out of Carp I'm three flights in once I beat up the slow flight card I'll take a run down Smith Falls is with in the test area.

Sean
Engine Start - Finally!
Authored by: Kevin Horton on Saturday, June 28 2008 @ 01:31 PM EDT
Hi Sean - For the first engine run, I had the manifold pressure line disconnected
from the Lightspeed ignition, so it should have been firing at 16 deg BTDC.
The mag seemed to be firing quite a bit after that, rather than the 20 deg BTDC
it should have been at.

---
Kevin Horton

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