IO360 starting

[jwpatton3]

Would like suggestions on both cold and hot starts with the above engine in an RV6. Thanks. John

[Bubblehead]

search the threads. There are lots and lots of posts but the general procedure I use on the IO360 in my -8 is:

cold:
mixture full rich
throttle idle
boost pump on for 5 seconds
crank engine and open throttle a little when it starts firing until it smooths out, then reduce to idle

hot:
mixture full rich
throttle full open
boost pump on for 5 seconds (this purges the fuel line and makes sure your engine is flooded)
mixture idle cutoff (this ensures that when you start cranking the rich condition becomes just right and then goes lean)
throttle REMAINS full open
crank engine and smoothly close throttle when it starts firing and bring mixture up until it smooths out.

The last step happens fast and I'm not sure how much of each I do when but it's basically pulling the throttle back and then putting mixture in to keep the engine going.

[DEWATSON]

COLD

Mixture rich, throttle cracked, run boost pump for about 5 seconds and then start cranking with boost pump on. When it fires, turn off boost pump and reduce throttle.

HOT

Mixture full lean, run boost pump for about 10 seconds then go mixture rich for last 2 seconds and crack throttle before turning the pump off. Open throttle over half way and start cranking. When engine fires, reduce throttle.

The reason for running the boost pump with the mixture full lean when hot is to force vapor in lines back to the tank and replace the vapor with cool liquid fuel. Two seconds of boost pump with the mixture rich provides ample fuel for a hot start (probably more than needed). This almost floods my engine, but after about 5 blades it fires and clears it's rich condition in a few seconds.

This works for me......I'm sure there are other ways to crank one when hot.

[DanH]

Originally Posted by jwpatton3

Would like suggestions on both cold and hot starts with the above engine in an RV6. Thanks. John

For Bendix or Airflow?

[Toobuilder]

This is funny? Seems everyone has ?the? method?.
Here?s mine that works 99.9% for a IO-360, Bendix, no purge valve:

Cold ?
1. Mixture rich
2. Boost pump on
3. Throttle wide open for 2-5 seconds (depending on OAT), then closed.
4. Boost off
5. Crack throttle and crank engine

Hot ?
1. Mixture lean, throttle off
2. Crank engine and advance throttle to full
3. Engine will start, accelerate and start to die
4. Push mixture in before engine dies, when it catches again, retard throttle to idle
5. Run boost pump to smooth out fuel pressure on taxi

[Sig600]

Originally Posted by Bubblehead

search the threads. There are lots and lots of posts but the general procedure I use on the IO360 in my -8 is:

cold:
mixture full rich
throttle idle
boost pump on for 5 seconds
crank engine and open throttle a little when it starts firing until it smooths out, then reduce to idle

hot:
mixture full rich
throttle full open
boost pump on for 5 seconds (this purges the fuel line and makes sure your engine is flooded)
mixture idle cutoff (this ensures that when you start cranking the rich condition becomes just right and then goes lean)
throttle REMAINS full open
crank engine and smoothly close throttle when it starts firing and bring mixture up until it smooths out. The last step happens fast and I'm not sure how much of each I do when but it's basically pulling the throttle back and then putting mixture in to keep the engine going.

I've got probably a thousand hours behind the IO-360 instructing in Florida summers, and this hot start procedure worked every time. Only difference was I would crack the throttle about an inch, and when it fired, feed in the mixture and then retard the throttle (prevents the engine from running up if you stumble, also saves wear/tear prior to the oil flowing).

[David-aviator]

Originally Posted by jwpatton3

Would like suggestions on both cold and hot starts with the above engine in an RV6. Thanks. John

Here's my simplistic view on the subject, John.

When the engine is cold, some fuel is needed in the intake manifold to get the thing running.

When the engine is hot it starts best with no priming.

I have the AFP 200 system. About 5 seconds of prime for a cold engine and no prime for the hot engine.

The only time I have had trouble this past season is when preheat was applied over night. The engine is somewhere between cold and hot and it seems about 2 seconds of prime works best. Five seconds definitely is too much.

With a Bendix system you will have to play with the mixture to gets things right. With AFP, for starting, the mixture is always full in and fuel flow is controlled with the purge valve. Either way, start with a plan of your own. If it works remember it, if it doesn't, try something different.

In the beginning with AFP, I had some problems but they were solved by
(1) electric pump on always
(2) always hit the starter with the mixture or purge valve off but introduce fuel immediately when hitting the starter, cold or hot
(3) if it doesn't pop off in 3 or 4 blades, stop, cut fuel flow and try something different.

If the engine doesn't start it either has too much fuel or not enough. If it is just right it will start almost instantly every time, but it will quit if fuel is not on the way quickly, that's why I introduce fuel when hitting the starter.

Eventually you will figure it out and feel confident. At least that's the goal.

[Toobuilder]

The "flooded" hotstart can give you big problems. It seems that every airframe/engine combination is unique - but with my Hiperbipe and a -B1E, if you even touch the boost pump, you get raw fuel dumping overboard out the exhaust stack. This is followed by a fireball, which ignites the puddle of fuel on the ground. It's very exciting to be strapped in at the fuel island when fire burns the fabric off the belly of the airplane and starts licking at your bare legs! Using this as a learning experience, I use the same start technique on the 200 horse RV-8

Anyway, no intentionally "flooded" hot starts for me. If the existing fuel cooking in the lines and spitting out the nozzles is not enough of a "prime", then my technique will clear the engine and return it to a known lean condition. From here, I can do the ?cold? start. That said, I can count on one hand the times ?my? hotstart did not work the first time.

[David Z]

When I would do a hot start on a certified AEIO-360-A1B6, I would just run the boost pump until the fuel pressure needle moved. This basically primed the injector lines. Other than that, it was the same as a cold start.

Mixure rich
prime as required
mixture ICO
throttle as required [800rpm once started]
START
mixture rich

[jwpatton3]

Thanks michael, will try your technique. I live in sw colorado with high density problems. John