Why weren't flat engines experimented with more in F1? Why did Renault try a wacky 111° angle V instead?

[mzso]

Hi!

I was wondering what's inherently unattractive about flat engines such as boxers for F1 cars. It seems to me that they'd have inherent advantages of low center of gravity and little vibration.

I saw only one half-hearted attempt at a flat-12 in 1990.

[DiogoBrand]

As far as I know Ferrari used to make Flat 12 engines during the 70's, but they became a disadvantage once everyone started using ground effects and the engine didn't allow Ferrari to create the big tunnels underneath the car.
Before that I think they were quite common.

[jjn9128]

I'm pretty sure someone used a boxer in the late-80's early-90's as well...

[edit] missed that you mentioned the use in the 90's

[ian_s]

the problem with a flat12 is that either the inlet or exhaust manifolds have to sit underneath the engine, forciing the relatively heavy crank and block higher up, negating any CoG advantage of the flat layout. the only way i can think of keeping the engine low is to somehow have the inlet and exhaust on the top side of the head, and somehow keep 4 valves per cylinder.

[Big Tea]

the problem with a flat12 is that either the inlet or exhaust manifolds have to sit underneath the engine, forciing the relatively heavy crank and block higher up, negating any CoG advantage of the flat layout. the only way i can think of keeping the engine low is to somehow have the inlet and exhaust on the top side of the head, and somehow keep 4 valves per cylinder.

There is obviously a good reason for it, which I cannot bring to mind, but with turbo pressured inlet, why can not the spark plug and inlet valve swap places? Plug beneath, inlet center of the head exhaust straight up. Is inlet valve size so critical with so much push behind the incoming air?

I know it would not be as efficient as a cross-flow but what am I missing?

[ian_s]

the problem with a flat12 is that either the inlet or exhaust manifolds have to sit underneath the engine, forciing the relatively heavy crank and block higher up, negating any CoG advantage of the flat layout. the only way i can think of keeping the engine low is to somehow have the inlet and exhaust on the top side of the head, and somehow keep 4 valves per cylinder.

There is obviously a good reason for it, which I cannot bring to mind, but with turbo pressured inlet, why can not the spark plug and inlet valve swap places? Plug beneath, inlet center of the head exhaust straight up. Is inlet valve size so critical with so much push behind the incoming air?

I know it would not be as efficient as a cross-flow but what am I missing?

I am assuming by straight up you mean 'up' is the direction of travel of the piston, please correct me if I'm wrong.
how would the valve be accuated in this scenario?

[Big Tea]

the problem with a flat12 is that either the inlet or exhaust manifolds have to sit underneath the engine, forciing the relatively heavy crank and block higher up, negating any CoG advantage of the flat layout. the only way i can think of keeping the engine low is to somehow have the inlet and exhaust on the top side of the head, and somehow keep 4 valves per cylinder.

There is obviously a good reason for it, which I cannot bring to mind, but with turbo pressured inlet, why can not the spark plug and inlet valve swap places? Plug beneath, inlet center of the head exhaust straight up. Is inlet valve size so critical with so much push behind the incoming air?

I know it would not be as efficient as a cross-flow but what am I missing?

I am assuming by straight up you mean 'up' is the direction of travel of the piston, please correct me if I'm wrong.
how would the valve be accuated in this scenario?

Well, I would need to study things like this when I got funding to develop the prototype!

I'll get my coat then

[ian_s]

Well, I would need to study things like this when I got funding to develop the prototype!

I'll get my coat then

haha maybe I can give you my ideas now to help you. as you can see I am a professional CAD designer, my skills are unparalleled.
this is the only way I can see 4 valves per cylinder working without a crossflow head. it means ultra long valve stems, making the whole engine wider. On what would be the upper valve, the stem would have to go through 2 tracts, so to prevent sealing issues maybe the 'upper' and 'lower' tracts would have to be the same, either inlet or exhaust.
https://www.dropbox.com/s/vktcydt2on12j ... s.png?dl=0

[Big Tea]

Well, I would need to study things like this when I got funding to develop the prototype!

I'll get my coat then

haha maybe I can give you my ideas now to help you. as you can see I am a professional CAD designer, my skills are unparalleled.
this is the only way I can see 4 valves per cylinder working without a crossflow head. it means ultra long valve stems, making the whole engine wider. On what would be the upper valve, the stem would have to go through 2 tracts, so to prevent sealing issues maybe the 'upper' and 'lower' tracts would have to be the same, either inlet or exhaust.
https://www.dropbox.com/s/vktcydt2on12j ... s.png?dl=0

I thought of something like that, but you would have all sorts of sealing problems. I thought of rocker arms pivoted in the casting of the manifold, but the same there plus all the heat transfer it would bring.

It would have to be something other than a poppet valve really. Rotary or sleeve possibly with the outer part as the casting.

No, I think I will slink away and hope no one who know me notices I said anything.

[mzso]

As far as I know Ferrari used to make Flat 12 engines during the 70's, but they became a disadvantage once everyone started using ground effects and the engine didn't allow Ferrari to create the big tunnels underneath the car.
Before that I think they were quite common.

I only remember V12-s from Ferrari.

the problem with a flat12 is that either the inlet or exhaust manifolds have to sit underneath the engine, forciing the relatively heavy crank and block higher up, negating any CoG advantage of the flat layout. the only way i can think of keeping the engine low is to somehow have the inlet and exhaust on the top side of the head, and somehow keep 4 valves per cylinder.

Is it that bad? By looking at the Subaru 1235, it doesn't seem like such a serious problem.

[DiogoBrand]

As far as I know Ferrari used to make Flat 12 engines during the 70's, but they became a disadvantage once everyone started using ground effects and the engine didn't allow Ferrari to create the big tunnels underneath the car.
Before that I think they were quite common.

I only remember V12-s from Ferrari.

Just look it up, the 312T for example, was one of Ferrari's cars from the 70's that used a flat 12 engine.

[Dr. Acula]

Hi!

I was wondering what's inherently unattractive about flat engines such as boxers for F1 cars. It seems to me that they'd have inherent advantages of low center of gravity and little vibration.

I saw only one half-hearted attempt at a flat-12 in 1990.

As far as i know in todays aero driven formula 1, they are considered as to wide. If you look at the back end of the side pods of the cars, you see this undercut coke bottle design. With a Boxer or Flat engine you could never made the undercut that extreme as we see it now with the V engines because simply the cylinderheads would take away some of the space needed to do that. The aerodynamic gain of a clean overflowed diffusor outweights simply the lower center of gravity.

Also if i remember correctly Renault had problems with the stiffnes of their 111° V10 engine. In many Formula cars the engine as a whole is a load bearing part. The Gearbox and so the rear suspension is connected to the chassis only via the engine. The 90° and smaller V-engines are generally stiff enough to carry these stresses without much additional strengthening or a sub frame. That's not the necessarily the case with a flat engine design. Which results in adding material to the engine to make it stiffer which also makes it heavier or using a subframe which also adds unwanted weight. If you look a bit through the hystory of Flat engines in racing, they are often considered as fairly heavy for its time and power output.

One further point is the plumming. You still need to get the air in at one side of the cylinder head and the exhaust out on the other side as some other people already pointed out. That means that at least one of them needs to be located under the cylinderhead which also means you can't mount the engine as low as you actually would want to because you need some space under the cylinderheads.

[Bandit1216]

There is an engine design which has an inlet from the "top" of the head; Lancia triflux

[saviour stivala]

I do not recon there ever was a flat-12 engine used in F1 or sports car racing made in ‘boxer’ configuration.
A flat engine which is not a ‘boxer’ configuration is regarded as a 180 degree vee engine.
The problem of a flat-12 used in F1 was always its wide and exhaust ground clearance.
V-engines with exhaust out from in-between the 2 cylinder banks were made and races.
V-engines with inlets in-between the 2-cams of each cylinder bank were made and raced.
The only ‘boxer’ configuration engine I know off that raced in F1 was the 1955 Porsche 547 1.5-litre Flat-4.
Flat-12 racing engine for use in F1 and sports racing cars:- Porsche 360 Cicitalia of 1949. FERRARI 512. Alfa Romeo F1-117/33tt12/33sc12. Porsche 917. Motori Moderni 1235F1. Tecno F1-Flat-12. Mercedes-Benz M291. Non of these flat-12’s were boxers.

[till.a.fischer]

I can only speak for Ferrari-engines:
Flat 12s were used in following F1-cars:
1964-65 Ferrari 1512 (sometimes referred to as 512), 1,5 litre
1970-74 Ferrari 312 B, B2, B3
1975-80 Ferrari 312 T, T2, T3, T4, T5

While 312 T4 won the Championship in 1979 its successor T5 failed miserably.
Two reasons made Ferrari abandon the flat12 concept:
There was no room under the car for a diffuser / ground effect.
Turbo-Technology was on its rise and dominated the 1980s.