2 stroke thread (with occasional F1 relevance!)

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
Tommy Cookers
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Re: 2 stroke thread (with occasional F1 relevance!)

Post by Tommy Cookers » Mon Jul 16, 2018 11:15 am

the crosshead diesel is an accident of history
steam recips (designed of course by shipbuilders) had double acting cylinders and so were crosshead designs
these people then went diesel double acting and so crosshead
then single acting but kept the crosshead

the huge cylinder size gives relatively less surface area and so less heat loss to coolant - so raises efficiency
all been said before of course

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Re: 2 stroke thread (with occasional F1 relevance!)

Post by PlatinumZealot » Tue Jul 17, 2018 5:29 pm

gruntguru wrote:
Mon Jul 16, 2018 12:56 am
PlatinumZealot wrote:
Sun Jul 15, 2018 9:00 pm
A cross-head design means blow by . . .
You mean "reduced blow by"?
Yes!.. reduced.. typing from my phone
"The true champions are also great men. They are capable of making difficult decisions, of admitting their mistakes and of pushing harder than before when they get up from a fall."

- Ferrari chairman Sergio Marchionne

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Re: 2 stroke thread (with occasional F1 relevance!)

Post by PlatinumZealot » Tue Jul 17, 2018 5:29 pm

gruntguru wrote:
Mon Jul 16, 2018 12:56 am
PlatinumZealot wrote:
Sun Jul 15, 2018 9:00 pm
A cross-head design means blow by . . .
You mean "reduced blow by"?
Yes!.. reduced.next to none. typing from my phone
"The true champions are also great men. They are capable of making difficult decisions, of admitting their mistakes and of pushing harder than before when they get up from a fall."

- Ferrari chairman Sergio Marchionne

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Re: 2 stroke thread (with occasional F1 relevance!)

Post by PlatinumZealot » Tue Jul 17, 2018 5:32 pm

roon wrote:
Mon Jul 16, 2018 2:56 am
gruntguru wrote:
Mon Jul 16, 2018 12:56 am
PlatinumZealot wrote:
Sun Jul 15, 2018 9:00 pm
A cross-head design means blow by . . .
You mean "reduced blow by"?
Blow-by designed in, may be what he means. The piston doesn't need rings nor touch the cylinder wall. The volume beneath the cylinder can be used as a pump as a sort of forced induction. Blow-by would manifest as a sort of EGR, while being oil-free. The piston rod is what gets sealed from the crankcase, and also acts as the piston guide.
The pistons have monster sized rings! The rings look about 15mm thick. You still need rings to seal like a normal engine. There is a second type of oil called cylinder oil that is injected onto the rings to keep friction low and help the seal. The cylinder oil is burned off continuously and is extremely expensive. The mass flow rate is low so that helps keeps costs down.

The scavenge space is just like a plenum. The turbos blow into their from the air coolers and from there into the cylinders through the ports. There is no EGR. As the piston comes down to the port the boost pressure blows out the exhaust. It's important to keep the liners cool but not too cold... like 135 degrees celcius.
"The true champions are also great men. They are capable of making difficult decisions, of admitting their mistakes and of pushing harder than before when they get up from a fall."

- Ferrari chairman Sergio Marchionne

Pinger
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Re: 2 stroke thread (with occasional F1 relevance!)

Post by Pinger » Tue Jul 17, 2018 6:00 pm

PlatinumZealot wrote:
Tue Jul 17, 2018 5:32 pm
There is a second type of oil called cylinder oil that is injected onto the rings to keep friction low and help the seal. The cylinder oil is burned off continuously and is extremely expensive. The mass flow rate is low so that helps keeps costs down.

Any more info on the oil? Manufacturer and exact name, viscosity grade, etc?

gruntguru
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Re: 2 stroke thread (with occasional F1 relevance!)

Post by gruntguru » Wed Jul 18, 2018 1:43 am

PlatinumZealot wrote:
Tue Jul 17, 2018 5:32 pm
. . There is a second type of oil called cylinder oil that is injected onto the rings to keep friction low and help the seal. The cylinder oil is burned off continuously and is extremely expensive. The mass flow rate is low so that helps keeps costs down.
I hadn't heard of that oil being expensive. There are two main advantages to this system:
1. The rings are continuously supplied with new oil, without degraded detergency or solvency. This avoids buildup of carbon and varnish on the rings and bores. The consumption rate of this oil is no greater than if the cylinders were sharing the same oil as the crankcase.
2. The crankshaft assembly is lubricated by a separate system. The oil in this system is not being degraded continuously by exposure to high temperature and combustion gases, so it lasts much longer and can be designed for this more specialised task.
je suis charlie

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Re: 2 stroke thread (with occasional F1 relevance!)

Post by gruntguru » Wed Jul 18, 2018 1:55 am

Pinger wrote:
Tue Jul 17, 2018 6:00 pm
PlatinumZealot wrote:
Tue Jul 17, 2018 5:32 pm
There is a second type of oil called cylinder oil that is injected onto the rings to keep friction low and help the seal. The cylinder oil is burned off continuously and is extremely expensive. The mass flow rate is low so that helps keeps costs down.

Any more info on the oil? Manufacturer and exact name, viscosity grade, etc?
You can Google "Marine Diesel Cylinder Oil".
Nothing fancy. This product from Castrol is SAE 50 with a high "Base Number" (TBN 70) to neutralise the acids formed by high sulphur fuels. https://msdspds.castrol.com/bpglis/Fusi ... ASW6UD.pdf
je suis charlie

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Re: 2 stroke thread (with occasional F1 relevance!)

Post by PlatinumZealot » Wed Jul 18, 2018 2:20 am

gruntguru wrote:
Wed Jul 18, 2018 1:43 am
PlatinumZealot wrote:
Tue Jul 17, 2018 5:32 pm
. . There is a second type of oil called cylinder oil that is injected onto the rings to keep friction low and help the seal. The cylinder oil is burned off continuously and is extremely expensive. The mass flow rate is low so that helps keeps costs down.
I hadn't heard of that oil being expensive. There are two main advantages to this system:
1. The rings are continuously supplied with new oil, without degraded detergency or solvency. This avoids buildup of carbon and varnish on the rings and bores. The consumption rate of this oil is no greater than if the cylinders were sharing the same oil as the crankcase.
2. The crankshaft assembly is lubricated by a separate system. The oil in this system is not being degraded continuously by exposure to high temperature and combustion gases, so it lasts much longer and can be designed for this more specialised task.
The cylinder oil is very expensive in relative terms compared to the fuel oil and crank case (lube) oil.
Its formulation is of course very special to protect the liners and rings since in two stroke engines there is no "rest period" unlike four stroke engines as you know. Not to mention the engine runs on very agressive and "dirty" fuel like heavy fuel oil.

There is also a special timing mechanism to inject the cylinder oil. And the injection rate is adjusted based on conditions as well.

Very interesting engines - Slow speed diesel engines.. Really changed my view on two strokes. The form factor is very tall too so that might be a drawback on centre of gravity.. But then again the single exhaust valve is hydaulic.. So some weight savings up top. Lol.
"The true champions are also great men. They are capable of making difficult decisions, of admitting their mistakes and of pushing harder than before when they get up from a fall."

- Ferrari chairman Sergio Marchionne

Tommy Cookers
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Re: 2 stroke thread (with occasional F1 relevance!)

Post by Tommy Cookers » Wed Jul 18, 2018 8:57 am

of course
this was the only type of CI engine that could correctly be called a diesel or Diesel
ie the heat is added at notionally constant pressure

does this still apply ie with this type of engine as currently or recently produced ?
the crosshead engine over a century having been both increased in displacement and confined to speeds below 100 rpm
(one can now run for at 10% power at 7 rpm - and with direct drive of the ship's propeller of course)
or confined in displacement and increased in rpm to the low hundreds

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Re: 2 stroke thread (with occasional F1 relevance!)

Post by PlatinumZealot » Wed Jul 18, 2018 11:59 pm

Pinger wrote:
Tue Jul 17, 2018 6:00 pm
PlatinumZealot wrote:
Tue Jul 17, 2018 5:32 pm
There is a second type of oil called cylinder oil that is injected onto the rings to keep friction low and help the seal. The cylinder oil is burned off continuously and is extremely expensive. The mass flow rate is low so that helps keeps costs down.

Any more info on the oil? Manufacturer and exact name, viscosity grade, etc?
Chevron. Taro Special HT. Different grades available.
"The true champions are also great men. They are capable of making difficult decisions, of admitting their mistakes and of pushing harder than before when they get up from a fall."

- Ferrari chairman Sergio Marchionne

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Re: 2 stroke thread (with occasional F1 relevance!)

Post by PlatinumZealot » Thu Jul 19, 2018 12:03 am

Tommy Cookers wrote:
Wed Jul 18, 2018 8:57 am
of course
this was the only type of CI engine that could correctly be called a diesel or Diesel
ie the heat is added at notionally constant pressure

does this still apply ie with this type of engine as currently or recently produced ?
the crosshead engine over a century having been both increased in displacement and confined to speeds below 100 rpm
(one can now run for at 10% power at 7 rpm - and with direct drive of the ship's propeller of course)
or confined in displacement and increased in rpm to the low hundreds
The speed is just above 103 rpm to 125 rpm at full load for the slow speed engines ( power generation - I am not familiar with their use on ships, but ships require variable operating loads and speeds). You can hear each explosion when you stand beside the cylinders.
"The true champions are also great men. They are capable of making difficult decisions, of admitting their mistakes and of pushing harder than before when they get up from a fall."

- Ferrari chairman Sergio Marchionne

gruntguru
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Re: 2 stroke thread (with occasional F1 relevance!)

Post by gruntguru » Thu Jul 19, 2018 12:19 am

PlatinumZealot wrote:
Wed Jul 18, 2018 2:20 am
The cylinder oil is very expensive in relative terms compared to the fuel oil and crank case (lube) oil.
In other words cheap as manure compared to oil you put in your car. :lol:
je suis charlie

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Re: 2 stroke thread (with occasional F1 relevance!)

Post by PlatinumZealot » Thu Jul 19, 2018 12:20 pm

You typically burn 1kg per Megawatt hour of the cylinder oil.

So in F1 terms, over the race you would burn about a kilogram of this oil over two hours if the engine design requires a second oil only for clylinder lubrication.
"The true champions are also great men. They are capable of making difficult decisions, of admitting their mistakes and of pushing harder than before when they get up from a fall."

- Ferrari chairman Sergio Marchionne

manolis
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Re: 2 stroke thread (with occasional F1 relevance!)

Post by manolis » Fri Aug 03, 2018 6:46 am

BOEING / Gofly contest: Oh, BOEING


Hello all.

On Ausust 1, 2018 GoFly / Herox / BOEING (the big sponsor) deleted the Forum wherein the contestants of the GoFly / BOEING contest presented their opinions and their complaints.

GoFly’s / BOEING’s best response to contestants’ questions, was to shut down the annoying forum . . .

Each one of the contestants has paid 250 or 500 USD to GoFly / BOEING.
In return, all they took from GoFly / BOEING is the list with the ten winners.
No scoring, neither ranking, neither justification from the "97 judges"; just the ten winners alphabetically.


Take a look at http://www.pattakon.com/GoFly/index.html wherein some of the Open Forum Discussions have been “partially” saved and presented:

IS BOEING TRAPPED? : http://www.pattakon.com/GoFly/IS_BOEING_TRAPPED.html

20 minutes OR 20 miles? - Page 1 : http://www.pattakon.com/GoFly/20_minute ... miles.html

20 minutes OR 20 miles? - Page 2 : http://www.pattakon.com/GoFly/20_minute ... age_2.html

20 minutes OR 20 miles? - Page 3 : http://www.pattakon.com/GoFly/20_minute ... age_3.html

Note: the “20 minutes OR 20 miles” thread had in total 11 pages.

Design Discussion - Page 3 : http://www.pattakon.com/GoFly/Design_di ... 3Page.html

Design Discussion - Page 4 : http://www.pattakon.com/GoFly/Design_di ... Page4.html

Design Discussion - Page 5 : http://www.pattakon.com/GoFly/Design_di ... age_5.html

Debating Results of Phase I : http://www.pattakon.com/GoFly/Debating_ ... ase_I.html


The above discussions are indicative and show the appreciation, the trust and the confidence of the contestants for the GoFly / Herox / BOEING contest.


When you have time to spend, read the http://www.pattakon.com/GoFly/Posts_to_GoFly_Forum.htm and give your comments / questions.


Image

Image

Thanks
Manolis Pattakos

PlatinumZealot
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Re: 2 stroke thread (with occasional F1 relevance!)

Post by PlatinumZealot » Tue Aug 07, 2018 3:38 am

:D
The portable flyer looks like the best design. It doesnt look as far developed as the other designs though. Its only in 3D model stage it seems.
"The true champions are also great men. They are capable of making difficult decisions, of admitting their mistakes and of pushing harder than before when they get up from a fall."

- Ferrari chairman Sergio Marchionne