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.
marmer
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3 cylinder engine.

Post by marmer » Mon Dec 18, 2017 10:47 pm

Could F1 use a 3 cylinder really high reving engine to a similar power of current engines. Keep turbo hybrids alongside but have unlimited fuel flow just limit over the race the maximum amount of fuel usable.

As far as i can tell this would help reduce engine weight while the revs would help sound levels or would they still sound rubbish and rattle themselves to bits

Zynerji
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Re: 3 cylinder engine.

Post by Zynerji » Tue Dec 19, 2017 2:18 am

Wouldnt a 2 stroke I3 be similar in power to a V6?

graham.reeds
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Re: 3 cylinder engine.

Post by graham.reeds » 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.

marmer
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Re: 3 cylinder engine.

Post by marmer » Tue Dec 19, 2017 10:28 am

graham.reeds wrote: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.
Even with all the turbo and hybrid gubbins they would be too small?
To make it larger could you increase the size to 1 ltr per cylinder ImageImage

Jolle
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Re: 3 cylinder engine.

Post by Jolle » Tue Dec 19, 2017 11:31 am

Zynerji wrote:
Tue Dec 19, 2017 2:18 am
Wouldnt a 2 stroke I3 be similar in power to a V6?
In theory yes, but also uses twice the fuel (at least). Plus since motorbike racing went all four stroke, development is kinda slow.

But with a turbo, displacement of an engine is less important then NA, just turn op the boost...

MrPotatoHead
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Re: 3 cylinder engine.

Post by MrPotatoHead » Tue Dec 19, 2017 2:32 pm

marmer wrote:
Mon Dec 18, 2017 10:47 pm
Could F1 use a 3 cylinder really high reving engine to a similar power of current engines. Keep turbo hybrids alongside but have unlimited fuel flow just limit over the race the maximum amount of fuel usable.

As far as i can tell this would help reduce engine weight while the revs would help sound levels or would they still sound rubbish and rattle themselves to bits
But why would you want to?
You would get zero positive gains from this and would have an engine that sounded absolutely terrible.

Jolle
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Re: 3 cylinder engine.

Post by Jolle » Tue Dec 19, 2017 3:55 pm

marmer wrote:
Mon Dec 18, 2017 10:47 pm
Could F1 use a 3 cylinder really high reving engine to a similar power of current engines. Keep turbo hybrids alongside but have unlimited fuel flow just limit over the race the maximum amount of fuel usable.

As far as i can tell this would help reduce engine weight while the revs would help sound levels or would they still sound rubbish and rattle themselves to bits
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. That we have 10.500-12.500 rpm range in the current PU comes from the rule that the max fuel flow of 100l/h starts at 10.500. If that minimum wasn't there, the PU's would probably just do around 5000-8000 rpm.

Second, the idea of having no fuel flow limit sounds wonderful, until you start thinking how racing would be. This would be all about saving fuel to have the most fuel for the last few laps. Unlimited fuel flow means, depending how strong your engine is, unlimited power. This would mean nobody wants to lead the race because there will be 19 cars right in his gearbox saving fuel. The race will probably end at the first pit-stop, where everybody will wait in his box until someone will take the lead. If a driver does want's to take his chances and go for max pace over the whole race, everybody will just follow him as close as possible and overtake him in the last lap.... from 1st to 20th....

if it's the old sound you want back, you need old engines.

Tommy Cookers
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Re: 3 cylinder engine.

Post by Tommy Cookers » Tue Dec 19, 2017 4:13 pm

if what you said was true a 7 litre 8 cylinder engine would make no more power than a 1 litre 3 cylinder whether boosted or NA

roughly - massflow depends on induction pressure ('boost') x total valve area x rpm

Jolle
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Re: 3 cylinder engine.

Post by Jolle » Tue Dec 19, 2017 4:16 pm

Tommy Cookers wrote:
Tue Dec 19, 2017 4:13 pm
if what you said was true a 7 litre 8 cylinder engine would make no more power than a 1 litre 3 cylinder whether boosted or NA

roughly - massflow depends on induction pressure ('boost') x total valve area x rpm
I meant when they are both boosted. It’s about how efficient you can make the engine handle the same amount of air/fuel

Tommy Cookers
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Re: 3 cylinder engine.

Post by Tommy Cookers » Tue Dec 19, 2017 4:25 pm

surely ? ......
the 1 litre engine will need to run about 60% more rpm than current engines to use the same fuel and air at the same boost
or 60% higher 'boost' to use the same fuel and air at the same rpm

you just won't get 60% higher boost without a 2 stage compressor
Last edited by Tommy Cookers on Tue Dec 19, 2017 4:32 pm, edited 1 time in total.

Jolle
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Re: 3 cylinder engine.

Post by Jolle » Tue Dec 19, 2017 4:31 pm

Tommy Cookers wrote:
Tue Dec 19, 2017 4:25 pm
surely ? ......
the 1 litre engine will need to run about 60% more rpm than current engines to use the same fuel and air at the same boost
or 60% higher 'boost' to use the same fuel and air at the same rpm
The cillinder pressure just goes up by 60% if you want the same rpm, that is how a turbo engine works. The lower the revs the higher the pressure and probably how more efficient the engine.

Tommy Cookers
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Re: 3 cylinder engine.

Post by Tommy Cookers » Tue Dec 19, 2017 4:36 pm

increasing the cylinder pressure by 60% means dropping the CR to avoid detonation and failure - dropping the ICE efficiency
unless CI

yes, turbine recovery would increase
with CI allowed you are inventing a more heavily compounded engine that the current 'light compounding' rules allow

Jolle
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Re: 3 cylinder engine.

Post by Jolle » Tue Dec 19, 2017 4:52 pm

Tommy Cookers wrote:
Tue Dec 19, 2017 4:36 pm
increasing the cylinder pressure by 60% means dropping the CR to avoid detonation and failure - dropping the ICE efficiency
unless CI

yes, turbine recovery would increase
with CI allowed you are inventing a more heavily compounded engine that the current 'light compounding' rules allow
It’s all about how efficient you can transfer the energy from the fuel into the piston. There probably is a sweet spot with pressures, boost, capacity, revs and compression ratio. It might just be a two cilinder 1.1L at 3000 rpm :P there is no simple way of telling because of all the opposing forces. With a NA engine it’s simple: more revs = more air = more fuel = more power.

By the way, the compression ratio doesn't drop, it's the same because of the increased boost. So if you're are at 1:14 with 1 bar (NA) and at 1:7 ratio for the engine at 2 bar, the effective compression ratio is still 1:14

Tommy Cookers
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Re: 3 cylinder engine.

Post by Tommy Cookers » Tue Dec 19, 2017 5:40 pm

as far as the ICE is concerned the effective (in-cylinder compression/expansion) ratio has dropped
as I said, this is moving to heavier compounding
that is the turbine-recovered power being about as large as the crankshaft power

Jolle
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Re: 3 cylinder engine.

Post by Jolle » Tue Dec 19, 2017 6:42 pm

Tommy Cookers wrote:
Tue Dec 19, 2017 5:40 pm
as far as the ICE is concerned the effective (in-cylinder compression/expansion) ratio has dropped
as I said, this is moving to heavier compounding
that is the turbine-recovered power being about as large as the crankshaft power
there is logic in that yes, but still, all current PU's run with high cylinder pressure and the lowest revs possible. If low cylinder pressure with a higher compression ratio was more efficient, they would just run to 15.000 rpm.