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First engine start!

Amazon-1

Active Member
This morning, I started my brand new IO-390 Thunderbolt engine for the first time.

After doing the pre-tasks including pre-oiling, draining preservative and verifying oil pressure, I took it out to the run up area and fired it up.

It started without difficulty and ran well.

I do have a handful of questions to research:

Cylinders 1 and 2 ran cooler than 3 and 4. The front two were about 200F cooler (EGT)than the back two (900F vs 1100F) at idle. The CHTs were also lower by about 50F. When I ran it up to 1500 rpms, the two front cylinders registered similar temps to the back two. BTW, I ran it with the cowlings off.

An experienced A&P friend of mine said that was not especially problematic.

I don't think the fuel flow transducer is set up correctly - it reads 6.3 gph at 1000 rpms (I expect it to read about 2 to 3 gph), drops slightly to 5.3 gph at 1500 and then goes up to 7 gph at 2100 rpms.

The system voltage as reported on the G3 is 13v, this is with both the primary and standby alternators switched on. I expected the system voltage to be 14.1v. The current as reported by the G3 was 0.0 though the VPX showed all of the loads with their correct values. I am wondering if I have to configure the G3X for my setup or possibly if the primary alternator is not putting out any power.

I have to adjust the FM-150 to get the proper idle mixture and idle rpms.

Overall pretty happy. Hope to be flying in about 3 weeks.

bruce
 
Hi,

I started my IO-390 on Thursday afternoon for the first time also. Caught on the 5th blade. We ran for two minutes to do a quick leak and sensor check. My setup similar with a Mag/PMag combo with the FM150. The alternator was not selected on and the cowling was off. We need to adjust the idle and mixture as well. The photo was about 30 seconds after start.

I should be ready for final inspection in 2-3 weeks and first flight in early November. Great to see the end!

Cheers Jim
 

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If these are new engines, don’t run them for very long on the ground. You don’t want to glaze the cylinders before break-in. :eek:
 
Three more quick runs before first flight. One for Fuel flow, Mag check and the final for the Inspector. I expect the engine will run less than 10-15 mins before first flight.

Jim
 
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I did the first start of my stock 390 yesterday. My temp numbers were very similar to yours. My FFT registered between 2 and 4 at 1000rpm and 5.75 at 1800. If you haven’t done it download Your history file and load it into Savvy Analysis.
 
To the earlier posters who did engine starts this week. What was your fuel pressure without and without boost pump? Mine shows 40 psi which seems high. I have the new style Kavlico sensor that had a range of 0-150. Oil pressure and fuel use the same sensor.
 
My figure 32.9 PSI was just the engine driven pump running. When I first primed prior to start the boost pump read above 40 PSI.

Jim
 
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