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Re: Mercedes Power Unit

Posted: 29 Aug 2016, 10:33
by nevill3
I would guess that the customer teams would take a new ICE for Monza unless they are trying to get through the season on four engines to save money.

Five races per engine would mean waiting until Malaysia or stretch it to include possible updated engine in Japan?

Re: Mercedes Power Unit

Posted: 29 Aug 2016, 16:15
by Drica
Has anyone ever wondered why all the Mercedes powered teams have some big smoke coming out of the exhaust when they rev them for the race start and after fire up? I know that that is normal when the engine hasnt been run for a while and some oil gets into the combustion chamber and so on, but i havent noticed it on any other PU apart from Merc. Any known reason for this?

Re: Mercedes Power Unit

Posted: 29 Aug 2016, 16:38
by PlatinumZealot
They probably spray some sort of oil in the intake before the start to oil the top side of the piston rings? hmm

Re: Mercedes Power Unit

Posted: 31 Aug 2016, 11:49
by Blackout
Image

Re: Mercedes Power Unit

Posted: 31 Aug 2016, 12:27
by ME4ME
PlatinumZealot wrote:They probably spray some sort of oil in the intake before the start to oil the top side of the piston rings? hmm
Paddy Low has explained this before. Some oil escapes initially before all seals start fuctioning properly.

Re: Mercedes Power Unit

Posted: 08 Sep 2016, 11:00
by Facts Only
ME4ME wrote:
PlatinumZealot wrote:They probably spray some sort of oil in the intake before the start to oil the top side of the piston rings? hmm
Paddy Low has explained this before. Some oil escapes initially before all seals start fuctioning properly.
The question for me is not why does the Mercedes PU emit a puff of smoke but why dont the other engines. I'd love to K is how they have sealed the area in question

Re: Mercedes Power Unit

Posted: 08 Sep 2016, 11:18
by FW17
Does anyone have the thermal image video of the car running and is it possible to make out when the waste gates are operational?

Re: Mercedes Power Unit

Posted: 08 Sep 2016, 14:08
by Agerasia
Does Mercedes supply the MGU-H to customers?

Re: Mercedes Power Unit

Posted: 08 Sep 2016, 14:16
by wuzak
Agerasia wrote:Does Mercedes supply the MGU-H to customers?
Um, yes, as it is integral with the power unit and if they didn't the customers would experience turbo lag measured in tens of seconds.

Re: Mercedes Power Unit

Posted: 08 Sep 2016, 17:33
by godlameroso
Facts Only wrote:
ME4ME wrote:
PlatinumZealot wrote:They probably spray some sort of oil in the intake before the start to oil the top side of the piston rings? hmm
Paddy Low has explained this before. Some oil escapes initially before all seals start fuctioning properly.
The question for me is not why does the Mercedes PU emit a puff of smoke but why dont the other engines. I'd love to K is how they have sealed the area in question
Maybe their oil control rings are designed to purposely let some oil in the chamber. Burning oil is an easy way to lower octane, which would let you run a little leaner. I've seen plenty of cars with engines that burn oil be otherwise strong engines with healthy compression and good power.(Case in point the Porsche GT3 burns a healthy amount of oil, some up to a liter every 2,000km(FRM cylinder liners))

http://www.6speedonline.com/forums/997/ ... g-oil.html

Maybe the coatings they're using don't hone properly but do wonders for friction and the ability to run leaner is an after thought. It could just be their PCV system has a generous vaccum, but that doesn't make sense they could just as easily use an air oil separator if they were trying to control oil entering the chamber. I think they're allowing some on purpose, but not sure why exactly.

If it is seals leaking why would you want your pneumatic valve spring seals to leak?

Re: Mercedes Power Unit

Posted: 08 Sep 2016, 20:58
by Muulka
godlameroso wrote:
Facts Only wrote:
ME4ME wrote:
Paddy Low has explained this before. Some oil escapes initially before all seals start fuctioning properly.
The question for me is not why does the Mercedes PU emit a puff of smoke but why dont the other engines. I'd love to K is how they have sealed the area in question
Maybe their oil control rings are designed to purposely let some oil in the chamber. Burning oil is an easy way to lower octane, which would let you run a little leaner. I've seen plenty of cars with engines that burn oil be otherwise strong engines with healthy compression and good power.(Case in point the Porsche GT3 burns a healthy amount of oil, some up to a liter every 2,000km(FRM cylinder liners))

http://www.6speedonline.com/forums/997/ ... g-oil.html

Maybe the coatings they're using don't hone properly but do wonders for friction and the ability to run leaner is an after thought. It could just be their PCV system has a generous vaccum, but that doesn't make sense they could just as easily use an air oil separator if they were trying to control oil entering the chamber. I think they're allowing some on purpose, but not sure why exactly.

If it is seals leaking why would you want your pneumatic valve spring seals to leak?
Or they could be deliberately burning some oil to effectively get a little bit of extra power...?

Re: Mercedes Power Unit

Posted: 08 Sep 2016, 23:16
by PlatinumZealot
You lose power by burning oil.

Re: Mercedes Power Unit

Posted: 08 Sep 2016, 23:30
by Muulka
PlatinumZealot wrote:You lose power by burning oil.
I'm not so sure; it's more combustible material in the air-fuel mix, and even if it doesn't burn as well as the usual fuel, in this era of fuel flow limit, it will give some gain. It'd be less efficient, yes, but if you're only doing it on a quali run who cares!

Re: Mercedes Power Unit

Posted: 09 Sep 2016, 00:14
by hurril
The merc engines seem to be more responsive in the low to midrange area. They always leave curves with a very fine-tuned power onset. None of the others seem to have this the same way.

Re: Mercedes Power Unit

Posted: 09 Sep 2016, 01:02
by godlameroso
Muulka wrote:
PlatinumZealot wrote:You lose power by burning oil.
I'm not so sure; it's more combustible material in the air-fuel mix, and even if it doesn't burn as well as the usual fuel, in this era of fuel flow limit, it will give some gain. It'd be less efficient, yes, but if you're only doing it on a quali run who cares!
The thing is they seem to burn oil everywhere, it's not noticeable when the engine is powering away(although I'm guessing you can smell it), but whenever they stop and idle for a bit it smokes like a badly rebuilt engine.

Anyway gasoline has ~46MJ per KG, and IIRC motor oil burns similar to vegetable oil so ~37MJ per KG, I'm sure the properties of the lubricant will change this figure.