Various Start up

[Potenz]

Short video with various engines start ups

 

[media]https://www.youtube.com/watch?v=xOeGgf5ZMFo[/media]

[pilotpierre]

Excellent, thanks for posting.

[Fifi]

Tons of smoke, but not that much flames...

[Bando]

Great to watch that. Some planes make some strange noises, like firing a bullet or so...

 

Thx

[BeastyBaiter]

I'm pretty sure the F8F backfired. That thing just didn't want to run. Anyways, those must all be newly rebuilt engines, normally they aren't that smokey on startup from what I've seen.

[Fifi]

Great to watch that. Some planes make some strange noises, like firing a bullet or so...

 

Thx

 

Some radials engines have starting cartriges firing up to launch engine, just like a gun detonation!

[MarcoRossolini]

No wonder the Po-2 was nicknamed the sowing machine...

 

 

(Note to 777/1C, please, please, please, make the Po-2) 

[peregrine7]

Fantastic video, especially the backfire on the hellcat! If we could have complex startups like the videos suggest I would be a happy man. Perhaps if the condition of the plane is sub-standard..?

[Sternjaeger]

I'm pretty sure the F8F backfired. That thing just didn't want to run. Anyways, those must all be newly rebuilt engines, normally they aren't that smokey on startup from what I've seen.

 

It's actually a Hellcat, not a Bearcat, and yes, it did backfire, but it's not that uncommon among radials with high hours, especially if they've been sitting unused for a while.

 

Engine smoke occurs for different reasons, but the oily kind is more common on radials because gravity and older piston rings means that the bottom cylinders get oil seepage into the combustion chamber.

 

An engine with low hours will be less smoky because the piston rings are much newer and allow for less oil seepage. Some engines smoke a lot on startup regardless (the Russian ASh-82 is a classic example of that), but as the engine heats up the piston rings expand just that much to ensure a better seal. 

 

As an example, the maintenance manuals of the Alfa Romeo and Fiat radial engines in WW2 recommended to remove the bottom spark plugs in between flight and connect a pipe to drain the seeping oil out!

 

Flames are caused either by overpriming or by poor spark plugs, but basically what happens is that the first cycle doesn't burn, the one right after does, and the hot exhaust of the second one ignites the mixture that has just been expelled. When it goes BANG it's because when the mixture ignites it's still inside the exhaust manifold, so it's almost exclusive to radials.

Edited December 6, 2013 by Sternjaeger

[BeastyBaiter]

Hellcat indeed, I didn't look very closely.

[Sternjaeger]

Hellcat indeed, I didn't look very closely.

 

no worries man, it's just me being a pedantic ass 

Edited December 6, 2013 by Sternjaeger

[OBT-Psycho]

hep Sternjaeger, 

you seem to know one bit or two about warbirds, so I have a question in my mind since I read all your comments about oil in radial engines. Every body feel free to answer though.

 

On start up routines, you often see mecanician turning the prop several cycles before starting the engine. Someone told me it was because of the conception of the radial engine. Because of gravity, oil tends to accumulate on the lower cylinder and starting up the engine as it is would imply accelerated wear of the engine. Therefore mechanics would rotate a few time the system and so if will be more equaly distributed, lubricating the entire engine. 

 

Is that the main reason or is there another one that I don't have figured out yet?

[JtD]

Nice video, thanks for posting. I hope the developers see this.

 

 

 

Is that the main reason or is there another one that I don't have figured out yet?

I think you're spot on. I attached snippet from an F6F manual, it essentially says the very same thing you said.

Edited December 6, 2013 by JtD

[J4SCrisZeri]

So beautiful. Those ladies are kept with love, look at the engines: the mechanics looks like if they had left the factory yesterday.

[-MG-Cacti4-6]

that 109 sure did put out a ton of smoke. good thing the epa wasnt around for that lol

[Sternjaeger]

hep Sternjaeger, 

you seem to know one bit or two about warbirds, so I have a question in my mind since I read all your comments about oil in radial engines. Every body feel free to answer though.

 

On start up routines, you often see mecanician turning the prop several cycles before starting the engine. Someone told me it was because of the conception of the radial engine. Because of gravity, oil tends to accumulate on the lower cylinder and starting up the engine as it is would imply accelerated wear of the engine. Therefore mechanics would rotate a few time the system and so if will be more equaly distributed, lubricating the entire engine. 

 

Is that the main reason or is there another one that I don't have figured out yet?

 

There are different reasons to manually swing a propeller: 

 

1) basic aircraft like Tiger Moths need that to manually prime the combustion chambers in that way.

2) radial engines do indeed accumulate oil on the bottom cylinders, and there's the risk of doing a fair amount of damage if you don't drain that oil from the chambers: if you just hit the starter and there is a significant amount of oil trapped in the lower cylinders (hydraulic lock) you are likely to bend/break the pushrods or rockers, or even pop the cylinder off the crankcase or the cylinder head off the cylinder, since oil is incompressible and if pressed it will not compress like mixture, but try and push its way out. 

Edited December 6, 2013 by Sternjaeger