## 3 cylinder engine.

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
Jolle
Jolle
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Location: Dordrecht

### Re: 3 cylinder engine.

wuzak wrote:
Fri Dec 22, 2017 12:33 am
Jolle wrote:
Thu Dec 21, 2017 2:07 pm
wuzak wrote:
Thu Dec 21, 2017 1:10 pm

Same boost = same pressure.

If they have the same air/fuel [mass flow rate] and boost, the 1L engine will need to have 7 times the rpm to take the volumetric flow rate.
I'm sorry, but that is not how a turbo engine works, that is how a NA works.

A turbo enige forces the air into the cylinder. For instance, if you have a NA 1L engine, at 10.000 revs, you have 0.5L of air (1 bar) per cycle, 10.000 cycles per minute is 5000 liters of air at 1 bar which will give for instance 150bhp.

If you turbocharge that with 2 bar at 10.000rpm you will have 1L of air per cycle at pushed into the engine (compressed into 0,5L) which gives 10.000 liters of air per minute which will double the power and gives you a theoretical 300 bhp.

To keep the combustion pressure the same, the compression ratio has to come down the same amount. lets say the NA engine has a ratio of 1:14, the turbo with 2 bar of pressure has a ratio of 1:7. This way the air/fuel mixture will be compressed the same, just with twice the amount of air/fuel in the cylinder, so twice the amount of energy.

So as you see, revs at a turbo engine is unimportant (in theory), it's all about boost. If you want more power, you turn op the boost and lower the compression ratio.
At the same RPM, a 1L turbo engine will require a pressure ratio of 7:1 to the the same mass of air into the cylinder as a 7L non-turbo engine. Assuming the same volumetric efficiency, which probably wouldn't be the case (and would bring down the PR required).

But you specified a 7L turbo and a 1L turbo engine, running the same boost. Same boost = same pressure ratio.
Jolle wrote:
Tue Dec 19, 2017 3:55 pm
First of all, you won't get higher revs in a turbo charged engine if you make it smaller. Power is a result of the amount of air/fuel you can get trough the engine. Boost pressure does this. In theory a 7l V8 will have the same power as a 1l 3L with the same boost.
My mistake, the same volume of air per second.

wuzak
wuzak
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### Re: 3 cylinder engine.

Jolle wrote:
Fri Dec 22, 2017 12:41 am
wuzak wrote:
Fri Dec 22, 2017 12:26 am
Jolle wrote:
Thu Dec 21, 2017 3:55 pm
why, if a low CR is not efficient, do the current F1 teams all go for lowest revs they can be which means the highest cylinder pressure and therefor the lowest CR?
Because the fuel flow rate is on a ramp, and lower rpm means less fuel, which means less power.

They are hardly running at low CRs. The rues had a maximum CR of 18:1 inserted into the rules last year. Which suggests that the manufacturers were working towards that sort of number.
Could be, could also be to rule out the use of diesel. Which has more energy per kg but isn’t very F1
Doubt Compression ignition will operate at 10,500rpm, the point at which maximum fuel flow is achieved.

Edax
Edax
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Joined: Tue Apr 08, 2014 9:47 pm

### Re: 3 cylinder engine.

wuzak wrote:
Thu Dec 21, 2017 1:30 am
graham.reeds wrote:
Tue Dec 19, 2017 9:03 am
You are forgetting that an I3 would be too small to become a stressed member.

I remember Adrian Newey saying that the small V6 was right on the limit.
The V6 should be better as a stressed member than the longer V8s and V10s.

The bank angle chosen was specifically for this reason.

Newey was opposed to the in-line 4 originally proposed, as it lacked strength in some directions.

The other side of the coin is the extended wheelbases the current cars have. This leads to a longer gearbox connection to the engine, which means that it is heavier to get the strength required.
Surprised that Newey was against this. If I look at the old BMW I4 engines, the engine is so much smaller that it leaves sufficient room (and weight) to apply additional reinforcements. The Brabham had additional struts around the engine.

For a guy who is aero oriented, and has coined the size zero philosophy I would have guessed that he would have fallen for the slimmer profile and the freed up volume (engine and exhaust manifold.)

Jolle
Jolle
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Joined: Wed Jan 29, 2014 9:58 pm
Location: Dordrecht

### Re: 3 cylinder engine.

Edax wrote:
Fri Dec 22, 2017 9:44 pm
wuzak wrote:
Thu Dec 21, 2017 1:30 am
graham.reeds wrote:
Tue Dec 19, 2017 9:03 am
You are forgetting that an I3 would be too small to become a stressed member.

I remember Adrian Newey saying that the small V6 was right on the limit.
The V6 should be better as a stressed member than the longer V8s and V10s.

The bank angle chosen was specifically for this reason.

Newey was opposed to the in-line 4 originally proposed, as it lacked strength in some directions.

The other side of the coin is the extended wheelbases the current cars have. This leads to a longer gearbox connection to the engine, which means that it is heavier to get the strength required.
Surprised that Newey was against this. If I look at the old BMW I4 engines, the engine is so much smaller that it leaves sufficient room (and weight) to apply additional reinforcements. The Brabham had additional struts around the engine.

For a guy who is aero oriented, and has coined the size zero philosophy I would have guessed that he would have fallen for the slimmer profile and the freed up volume (engine and exhaust manifold.)
I think it has to do with the beautiful symmetry of a V6, with all the piping in all the right places. A 4l is a bit weird, especially the inlet, that would be pointing up and to the side. Or it would be mounted like a V8, with one bank missing but then there is a very strange void on one side.

Edax
Edax
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Joined: Tue Apr 08, 2014 9:47 pm

### Re: 3 cylinder engine.

Jolle wrote:
Fri Dec 22, 2017 9:58 pm
Edax wrote:
Fri Dec 22, 2017 9:44 pm
wuzak wrote:
Thu Dec 21, 2017 1:30 am

The V6 should be better as a stressed member than the longer V8s and V10s.

The bank angle chosen was specifically for this reason.

Newey was opposed to the in-line 4 originally proposed, as it lacked strength in some directions.

The other side of the coin is the extended wheelbases the current cars have. This leads to a longer gearbox connection to the engine, which means that it is heavier to get the strength required.
Surprised that Newey was against this. If I look at the old BMW I4 engines, the engine is so much smaller that it leaves sufficient room (and weight) to apply additional reinforcements. The Brabham had additional struts around the engine.

For a guy who is aero oriented, and has coined the size zero philosophy I would have guessed that he would have fallen for the slimmer profile and the freed up volume (engine and exhaust manifold.)
I think it has to do with the beautiful symmetry of a V6, with all the piping in all the right places. A 4l is a bit weird, especially the inlet, that would be pointing up and to the side. Or it would be mounted like a V8, with one bank missing but then there is a very strange void on one side.
It looks a bit weird, but I think you can build a competitive engine out of it.

Anyway I like these bold designs like the Nismo 3 cilinder. F1 could do with a bit of garage 56 spirit.

marmer
marmer
1
Joined: Fri Apr 21, 2017 5:48 am

### Re: 3 cylinder engine.

Edax wrote:
Jolle wrote:
Fri Dec 22, 2017 9:58 pm
Edax wrote:
Fri Dec 22, 2017 9:44 pm
Surprised that Newey was against this. If I look at the old BMW I4 engines, the engine is so much smaller that it leaves sufficient room (and weight) to apply additional reinforcements. The Brabham had additional struts around the engine.

For a guy who is aero oriented, and has coined the size zero philosophy I would have guessed that he would have fallen for the slimmer profile and the freed up volume (engine and exhaust manifold.)
I think it has to do with the beautiful symmetry of a V6, with all the piping in all the right places. A 4l is a bit weird, especially the inlet, that would be pointing up and to the side. Or it would be mounted like a V8, with one bank missing but then there is a very strange void on one side.
It looks a bit weird, but I think you can build a competitive engine out of it.

Anyway I like these bold designs like the Nismo 3 cilinder. F1 could do with a bit of garage 56 spirit.

Very nice looking just looked it up 400hp and only 88 pounds.

Jolle
Jolle
132
Joined: Wed Jan 29, 2014 9:58 pm
Location: Dordrecht

### Re: 3 cylinder engine.

marmer wrote:
Sat Dec 23, 2017 11:38 am
Edax wrote:
Jolle wrote:
Fri Dec 22, 2017 9:58 pm

I think it has to do with the beautiful symmetry of a V6, with all the piping in all the right places. A 4l is a bit weird, especially the inlet, that would be pointing up and to the side. Or it would be mounted like a V8, with one bank missing but then there is a very strange void on one side.
It looks a bit weird, but I think you can build a competitive engine out of it.

Anyway I like these bold designs like the Nismo 3 cilinder. F1 could do with a bit of garage 56 spirit.

https://www.wired.com/images_blogs/auto ... 6-1500.jpg
Very nice looking just looked it up 400hp and only 88 pounds.
Beautifully simple indeed. But just imagine the intake and exhaust on that, and you have a rather difficult shape. Newey likes to love the symmetry, looking at all the RedBulls of the recent years, even the radiators are a mirror image of each other

wuzak
wuzak
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Joined: Tue Aug 30, 2011 2:26 am

### Re: 3 cylinder engine.

Edax wrote:
Fri Dec 22, 2017 9:44 pm
wuzak wrote:
Thu Dec 21, 2017 1:30 am
graham.reeds wrote:
Tue Dec 19, 2017 9:03 am
You are forgetting that an I3 would be too small to become a stressed member.

I remember Adrian Newey saying that the small V6 was right on the limit.
The V6 should be better as a stressed member than the longer V8s and V10s.

The bank angle chosen was specifically for this reason.

Newey was opposed to the in-line 4 originally proposed, as it lacked strength in some directions.

The other side of the coin is the extended wheelbases the current cars have. This leads to a longer gearbox connection to the engine, which means that it is heavier to get the strength required.
Surprised that Newey was against this. If I look at the old BMW I4 engines, the engine is so much smaller that it leaves sufficient room (and weight) to apply additional reinforcements. The Brabham had additional struts around the engine.

For a guy who is aero oriented, and has coined the size zero philosophy I would have guessed that he would have fallen for the slimmer profile and the freed up volume (engine and exhaust manifold.)
The limiting factor for width is the mandatory cockpit opening size and the cockpit protection.

The V6 fits within that width and height comfortably.

A L4 will be taller, unless it is canted to one side or the other, in order to lower CoG. Once it is canted, the width advantage disappears.

The V6's sump should fit in the step in the floor, while a canted L4's would not, so gaining a CoG advantage to the V6.

marmer
marmer
1
Joined: Fri Apr 21, 2017 5:48 am

### Re: 3 cylinder engine.

wuzak wrote:
Edax wrote:
Fri Dec 22, 2017 9:44 pm
wuzak wrote:
Thu Dec 21, 2017 1:30 am
The V6 should be better as a stressed member than the longer V8s and V10s.

The bank angle chosen was specifically for this reason.

Newey was opposed to the in-line 4 originally proposed, as it lacked strength in some directions.

The other side of the coin is the extended wheelbases the current cars have. This leads to a longer gearbox connection to the engine, which means that it is heavier to get the strength required.
Surprised that Newey was against this. If I look at the old BMW I4 engines, the engine is so much smaller that it leaves sufficient room (and weight) to apply additional reinforcements. The Brabham had additional struts around the engine.

For a guy who is aero oriented, and has coined the size zero philosophy I would have guessed that he would have fallen for the slimmer profile and the freed up volume (engine and exhaust manifold.)
The limiting factor for width is the mandatory cockpit opening size and the cockpit protection.

The V6 fits within that width and height comfortably.

A L4 will be taller, unless it is canted to one side or the other, in order to lower CoG. Once it is canted, the width advantage disappears.

The V6's sump should fit in the step in the floor, while a canted L4's would not, so gaining a CoG advantage to the V6.
Box 4 would be shorter and not much wider while losing alot in height compared to a V6 would give us very different looking cars but lower center of gravity would be nice.

rscsr
51
Joined: Sun Feb 19, 2012 12:02 pm
Location: Austria

### Re: 3 cylinder engine.

marmer wrote:
Sun Dec 24, 2017 11:51 am
wuzak wrote:
Edax wrote:
Fri Dec 22, 2017 9:44 pm

Surprised that Newey was against this. If I look at the old BMW I4 engines, the engine is so much smaller that it leaves sufficient room (and weight) to apply additional reinforcements. The Brabham had additional struts around the engine.

For a guy who is aero oriented, and has coined the size zero philosophy I would have guessed that he would have fallen for the slimmer profile and the freed up volume (engine and exhaust manifold.)
The limiting factor for width is the mandatory cockpit opening size and the cockpit protection.

The V6 fits within that width and height comfortably.

A L4 will be taller, unless it is canted to one side or the other, in order to lower CoG. Once it is canted, the width advantage disappears.

The V6's sump should fit in the step in the floor, while a canted L4's would not, so gaining a CoG advantage to the V6.
Box 4 would be shorter and not much wider while losing alot in height compared to a V6 would give us very different looking cars but lower center of gravity would be nice.
A flat engine (180° V engine) has a pretty high cog because you can't have the crankshaft as low. The Audi LMP1 engine has a 120° bank angle and it seems it is pretty much at the limit without compromising the cog height.

wuzak
wuzak
467
Joined: Tue Aug 30, 2011 2:26 am

### Re: 3 cylinder engine.

marmer wrote:
Sun Dec 24, 2017 11:51 am
wuzak wrote:
Edax wrote:
Fri Dec 22, 2017 9:44 pm

Surprised that Newey was against this. If I look at the old BMW I4 engines, the engine is so much smaller that it leaves sufficient room (and weight) to apply additional reinforcements. The Brabham had additional struts around the engine.

For a guy who is aero oriented, and has coined the size zero philosophy I would have guessed that he would have fallen for the slimmer profile and the freed up volume (engine and exhaust manifold.)
The limiting factor for width is the mandatory cockpit opening size and the cockpit protection.

The V6 fits within that width and height comfortably.

A L4 will be taller, unless it is canted to one side or the other, in order to lower CoG. Once it is canted, the width advantage disappears.

The V6's sump should fit in the step in the floor, while a canted L4's would not, so gaining a CoG advantage to the V6.
Box 4 would be shorter and not much wider while losing alot in height compared to a V6 would give us very different looking cars but lower center of gravity would be nice.
A boxer engine loses stiffness in the vertical plane. An upright L4 loses stiffness in the horizontal plane.

A vee engine is not as stiff as either in their strongest direction, but is stronger in their weakest direction.

Tommy Cookers
Tommy Cookers
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Joined: Fri Feb 17, 2012 3:55 pm

### Re: 3 cylinder engine.

maybe a 3 cylinder arrangement with 3 banks at 60 deg and a 2 (or 3) pin crank (and 2, 3, or 4 main bearings) ?
(like a 3 cyl radial but the 'vertical' cylinder moved 180 deg with its own pin at 180 deg to the pin angle of the other 2 cylinders)

firing intervals ideal for the turbo
structurally good
balance good or good enough ?

Big Tea
99
Joined: Sun Dec 24, 2017 7:57 pm

### Re: 3 cylinder engine.

Could the 3 cyl, or indeed the Nismo shown above, not be mounted transverse and canted forward?
When arguing with a fool, be sure the other person is not doing the same thing.

Jolle
Jolle
132
Joined: Wed Jan 29, 2014 9:58 pm
Location: Dordrecht

### Re: 3 cylinder engine.

Big Tea wrote:
Sun Dec 24, 2017 8:01 pm
Could the 3 cyl, or indeed the Nismo shown above, not be mounted transverse and canted forward?
At the moment it isn't permitted by the rules, but it would make the most sense.

Zynerji
110
Joined: Wed Jan 27, 2016 3:14 pm

### Re: 3 cylinder engine.

It would be interesting to see a v3 in the VR6 layout.