Hot Start Tips

[urbanti]

Hi Shadrach

I'm not an engineer so unsure why IO-360 is so much easier than IO-520 to hot start.

Both planes are well maintained with properly adjusted magnetos, new spark plugs as necessary, new batteries kept on chargers, calibrated injection systems, and lots of advice from trained professionals.

Both planes will hot start, its just that the Lycoming seems to do it first time every time with no drama, whilst the Continental requires more operator sensitivity and mojo

Clarence, congratulations on your luck and skill with the IO720.

Tim

[Marauder]

Well, if it is any conciliation. When I was doing the Pilots n Paws flight on Sunday, the woman who brought the pups up from the south had a bear of a time getting her IO-550 started in her Columbia 400.

doesn't always buy you a hot start

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[Shadrach]

Hi Shadrach

I'm not an engineer so unsure why IO-360 is so much easier than IO-520 to hot start.

Both planes are well maintained with properly adjusted magnetos, new spark plugs as necessary, new batteries kept on chargers, calibrated injection systems, and lots of advice from trained professionals.

Both planes will hot start, its just that the Lycoming seems to do it first time every time with no drama, whilst the Continental requires more operator sensitivity and mojo

Clarence, congratulations on your luck and skill with the IO720.

Tim

I am not an engineer either. I was just curious. It seems that with the Continental's return line you have the ability to run the fuel pump at idle cutoff until you've purged the servo of all hot fuel and vapor. With a Lyc, the only place for all of that "preheated" fuel (from the mechanical pump forward) to go is out the injectors.

Can any other Continental flyers speak to this?

[urbanti]

Shadrach - yes you can run the pump with mixture set on idle cutoff and that is part of the hot start procedure, but even after doing so the IO-520 requires more technique to get it to catch - you can go on Beechtalk and read all the threads - pilots have different procedures they swear by and it appears that some 520's are just more cantankerous than others.

The BT crowd on thw whole is fairly well off, so hard to imagine its all about poorly maintained engines.

best

Tim

[carusoam]

A few challenges arise with the engine temperature...

1) boiling fuel causing bubbles in the line... (Boiling temp of 100LL.. 30-170°C according to Statoil)

2) boiling fuel pushing more fuel than expected forward into the engine... (Mixture out)

3) heated engine easily evaporates more fuel than a typical cold start... (Minimum use of priming)

4) cooling the fuel lines would go a long way....park into the wind and open the oil door

----------

The IO550 fuel system gives the opportunity to remove the first challenge. Recycling hot fuel back to the tank through the selector valve.

I know, Ross...you were clear. I tried...

I have an unused engineering degree that needed exercise...

Best regards,

-a-

[carl]

"Throttle approximately 1100 rpm
Mixture off
Boost pump on
Mixture full rich 6-8 seconds than off for cold starts (advance slowly when engine fires)
Mixture full rich 1-3 seconds than off for hot starts/warm starts (advance slowly when engine fires) "

 

Question ???? Boost pump on, advance mixture to full for 6-8 seconds , then mixture off. 

                           Do you turn off your boost pump , or leave it on before you crank?

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John

[carl]

"""I know every engine is somewhat different but I have never had a cold start/warm start/hot start issue since I started using this method.

Throttle approximately 1100 rpm
Mixture off
Boost pump on
Mixture full rich 6-8 seconds than off for cold starts (advance slowly when engine fires)
Mixture full rich 1-3 seconds than off for hot starts/warm starts (advance slowly when engine fires)""

 

well that didn't work for me. hot with boost pump on 

it did cold with boost pump on.

[carl]

LOOD said "Like all the advice above and to add something very important to that, STAY CALM AND DON'T RUSH THINGS!

 

Something else I picked up here on Mooneyspace, regarding a really hot start, like within 20 odd minutes after shut down, (always use the 1100 - 1200 rpm throttle setting on shut down):

 

Push both the throttle and mixture controls completely forward, count to ten and watch how your fuel pressure/flow gauge jumps around. After ten seconds, pull the mixture completely closed and start cranking"

 

 I will try this next . throttle and mixture full foward ,(boost pump on? yes?)count to ten. pull close mixture , ( where is throttle 1200 or full?) start cranking ( Boost pump still on ?) start cranking , (mixture in when it starts?)

 

I ve never had a IO before, but I would have never believed this is as hard as it is.

[EDNR-Cruiser]

That sounds like a routine for a Continental engine... - if that works on a Lycosaurus, please let us know...  

[ArtVandelay]

That sounds like a routine for a Continental engine... - if that works on a Lycosaurus, please let us know...

That's the last resort method, flood it and do the flooded start.

[Shadrach]

 

"Throttle approximately 1100 rpm

Mixture off

Boost pump on

Mixture full rich 6-8 seconds than off for cold starts (advance slowly when engine fires)

Mixture full rich 1-3 seconds than off for hot starts/warm starts (advance slowly when engine fires) "

 

Question ???? Boost pump on, advance mixture to full for 6-8 seconds , then mixture off. 

                           Do you turn off your boost pump , or leave it on before you crank?

John

 

For cold starts:

• 1) Full throttle.
• 2) Full Rich mixture.
• 3) Boost pump on for 6 to 10 secs (or more) depending on OAT. Ensure that fuel pressure is rising.
• 4) Mixture idle cut off.
• 4) Boost pump off. (almost simultanious with going to idle cut off) 
• 5) Throttle back to just .25" open.
• 6) When engine starts to fire go full rich (don't dilly dally, bit don't slam it through the fire wall either).

 

For hot starts one must remember to set throttle at 1000-1100rpm before shutting down (this is where an IO360 should be idled anyway).

• 1) Don't touch any of the knobs (leave throttle set and mixture at idle cut off).
• 2) Hit the starter.
• 3) When engine starts to fire go full rich (don't dilly dally, bit don't slam it through the fire wall either).

 

That is all I've ever needed.  If the hot start fails, use the cold start method, but with very little prime (2-4 secs).  As many have said, a high speed starter is preferable. 

[Shadrach]

That's the last resort method, flood it and do the flooded start.

and have fire extinguisher handy...

[mpg]

and have fire extinguisher handy...

 

I dont even know what Im talking about,,,,   BUT!!!

Dont EVER FLOOD your engine on purpose!!!

The chance of a flooded engine start is probably less than a FIRE!!!

[carl]

ok Ross , I have no problem with cold starts ,

For hot starts one must remember to set throttle at 1000-1100rpm before shutting down (this is where an IO360 should be idled anyway).
• 1) Don't touch any of the knobs (leave throttle set and mixture at idle cut off).
• 2) Hit the starter.
• 3) When engine starts to fire go full rich (don't dilly dally, bit don't slam it through the fire wall either).

 

What about boost pump on or off ? and no priming.

 

I will try this next .

carl

[Shadrach]

ok Ross , I have no problem with cold starts ,

For hot starts one must remember to set throttle at 1000-1100rpm before shutting down (this is where an IO360 should be idled anyway).

• 1) Don't touch any of the knobs (leave throttle set and mixture at idle cut off).

• 2) Hit the starter.

• 3) When engine starts to fire go full rich (don't dilly dally, bit don't slam it through the fire wall either).

What about boost pump on or off ? and no priming.

I will try this next .

carl

Do not prime, do not turn on the boost pump. The engine is already preprimed from the fuel that boiled out of the injectors. If it does not start on the first "don't touch anything" start attemp, then add a small amount of prime and try again.

[Shadrach]

ok Ross , I have no problem with cold starts ,

For hot starts one must remember to set throttle at 1000-1100rpm before shutting down (this is where an IO360 should be idled anyway).

• 1) Don't touch any of the knobs (leave throttle set and mixture at idle cut off).

• 2) Hit the starter.

• 3) When engine starts to fire go full rich (don't dilly dally, bit don't slam it through the fire wall either).

What about boost pump on or off ? and no priming.

I will try this next .

carl

Do not prime, do not turn on the boost pump. The engine is already preprimed from the fuel that boiled out of the injectors. If it does not start on the first "don't touch anything" start attemp, then add a small amount of prime and try again.

[Shadrach]

I dont even know what Im talking about,,,, BUT!!!

Dont EVER FLOOD your engine on purpose!!!

The chance of a flooded engine start is probably less than a FIRE!!!

You don't need to tell me. I don't intentional flood any engine, nor do I advocate doing so. However, for some it's SOP for a troubled hot start. I've seen too many fires. It's usually no biggie if the plane starts. The fire goes lean and blows out. It's when you have a fire and the plane doesn't start that you need a fire extinguisher.

[carl]

ok ross that is my next attempt ,

[Shadrach]

ok ross that is my next attempt ,

Look forward to you reporting back! Hope it works well!

[oldn0tded]

I struggled for the first year with my F to find the right hot start procedure. What works for me 99% of the time is to leave the mixture out and to slowly advance the throttle while cranking. At some point during the throttle advance it will catch and I move the mixture in and the throttle out.

I've had my F for 2 plus years now and just recently discovered this technique, in combination with the 1100 RPM shutdown. I would emphasize advancing the throttle SLOWLY. My working theory is the gasoline VAPORS (from boiling in the lines)is creating a flooded condition, when you advance the throttle you change the air/fuel ratio by adding air until curing the flooded condition.

I can generally get mine to fire within a couple of blades by using this technique. The key is:

1. Slowly advance the throttle and

2. It wont take much, maybe a 1/4 inch of movement.

My two cents worth.

Oldn0tded

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[carl]

Ross

he is my update; 

today I flew a 30 minutes flight , landed straight in ,but slowed it down, 75 over the numbers , full flaps, held it off ,.... touched down good, but no stall warning buzzer, maybe a little fast.

 

taxied back to the hanger ,shut down,  sat around like I was letting some one off, maybe 5 minutes.

 

True hot start

did not touch anything. boost pump off , mixture closed,  throttle left at 1100, where i shut down at .

 

master on, turn key to crank , it catches and i go mixture full in, then i have to ease the throttle in a bit and then that is too much so back out with the throttle .   IT worked well. 

 

thanks for the help 

 

carl 

[carusoam]

Nice detailed follow-up, Carl.

Best regards,

-a-

[MyNameIsNobody]

Ross

he is my update; 

today I flew a 30 minutes flight , landed straight in ,but slowed it down, 75 over the numbers , full flaps, held it off ,.... touched down good, but no stall warning buzzer, maybe a little fast.

 

taxied back to the hanger ,shut down,  sat around like I was letting some one off, maybe 5 minutes.

 

True hot start

did not touch anything. boost pump off , mixture closed,  throttle left at 1100, where i shut down at .

 

master on, turn key to crank , it catches and i go mixture full in, then i have to ease the throttle in a bit and then that is too much so back out with the throttle .   IT worked well. 

 

thanks for the help 

 

carl

No need to go full rich. Just get mixture in from idle cut-off, but keep it leaned for ground ops

[Shadrach]

Ross

he is my update; 

today I flew a 30 minutes flight , landed straight in ,but slowed it down, 75 over the numbers , full flaps, held it off ,.... touched down good, but no stall warning buzzer, maybe a little fast.

 

taxied back to the hanger ,shut down,  sat around like I was letting some one off, maybe 5 minutes.

 

True hot start

did not touch anything. boost pump off , mixture closed,  throttle left at 1100, where i shut down at .

 

master on, turn key to crank , it catches and i go mixture full in, then i have to ease the throttle in a bit and then that is too much so back out with the throttle .   IT worked well. 

 

thanks for the help 

 

carl 

I'm glad it worked out well for you!  As Scott..ahem...I mean MyNameIsNobody says above no need to leave it full rich for ground ops, lean it back aggressively to where it just runs smooth for taxi power.  This will help keep your plugs clean and make it impossible for you to inadvertently take off with the mixture leaned.