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-   -   How to start the engine (https://vansairforce.net/community/showthread.php?t=118162)

mlwynn 10-03-2014 01:48 PM

How to start the engine
 
Okay folks, I may be having an 60's flashback, but I somehow got it in my mind that the starting sequence for my IO360 M1B with AFP fuel injection and dual Plasma III ignitions was supposed to include hitting the starter for a couple of blades and then turning on the ignition. Can't find anything about that in the Lightspeed documentation nor in the AFP documentation. Did I imagine this?

flightlogic 10-03-2014 01:53 PM

Haven't done that trick since I flew the Pratt and Whitney round engines on Beavers. I would stick with the normal... prime if you have it.
Crank and crack if you don't. 1/4 cracked throttle...
Judicious pump of the throttle if needed. If it backfires... keep cranking.
If the ambient air is really cold....figure a way (lots avail.) to warm the sump prior to starting... good for the life of the cylinder barrels too.
Nick

N427EF 10-03-2014 03:20 PM

Lots of info on getting an engine started, have not heard of what you are describing at least not for an IO-360 with dual plasma and AFP injection.

In most cases your engine will be running before you get a chance to look at the second blade:). that is, if you turn the ignition on before cranking like most everyone else.

I see you are in San Ramon, is your RV located in Concord or Livermore?
Hope to meet you, lots of RVs on both of those airports.

DanH 10-03-2014 03:29 PM

Quote:

Originally Posted by mlwynn (Post 921832)
starting sequence for my IO360 M1B with AFP fuel injection and dual Plasma III ignitions

With or without purge valve?

mlwynn 10-03-2014 04:37 PM

Starting
 
With Purge valve.

David-aviator 10-03-2014 06:08 PM

I prime the engine 5-6 seconds with purge valve, WOT, reset throttle to about a quarter inch open, engage starter and push purge valve in at the same time.

Same procedure with hot engine except no prime.

Engine usually starts with a couple blades swung, sometimes more with hot start.

It's an art, getting the engine started. In time you come up with what works for you.

Amount of prime takes practice, priming with throttle closed does not work for me. Bypass flow rate is too slow. With WOT it is at least three times and gets fuel up there in 5-6 seconds. Do the same thing with throttle closed and my engine won't start.

xblueh2o 10-03-2014 06:13 PM

I haven't seen a recommended procedure to motor the engine with mags off on a horizontally opposed engine. Doesn't mean it isn't out there but I haven't seen it. Different story on round engines.

Kevin Horton 10-03-2014 06:51 PM

Quote:

Originally Posted by mlwynn (Post 921832)
Okay folks, I may be having an 60's flashback, but I somehow got it in my mind that the starting sequence for my IO360 M1B with AFP fuel injection and dual Plasma III ignitions was supposed to include hitting the starter for a couple of blades and then turning on the ignition. Can't find anything about that in the Lightspeed documentation nor in the AFP documentation. Did I imagine this?

Older Plasma ignitions don?t do well if the voltage goes too low when the starter cranks the engine. If the voltage gets too low, the ignition may fire at the wrong moment, leading to kick back. I have experienced this.

Permanent magnet starters in particular draw a very large amount of current at low rpm. The current decreases as the rpm increases, which means the voltage goes very low when you first hit the starter, then it comes back up as the engines starts to turn. So, if you have a PM starter, and an older Plasma ignition (as I do), the recommended procedure is to hit the starter button with the ignition off, then turn the ignition of after a couple of blades. My kickback issues went away when I adopted this start technique.

Apparently the newer Plasma ignitions have a design change that makes them more tolerant of low voltage, in which case it is proably OK to have the ignition on before you start cranking.

billdianne 10-03-2014 10:56 PM

I've heard of people with lightweight props doing that to prevent kickback.

pierre smith 10-04-2014 05:22 AM

Quote:

Originally Posted by flightlogic (Post 921838)
...
Judicious pump of the throttle if needed. If it backfires... keep cranking.
.
Nick

Pumping the throttle on a fuel injected engine does nothing but wear out the linkage :)

Best,


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