V4 engine

[trinidefender]

For quite a while I have wondered why V4 engines have not become more popular in road going cars, spec race cars or even as an alternative to F1.

Let us start with F1. Before the layout and basic architecture of the latest generation F1 ICE units were set in stone (as far as regulations are concerned) there was a debate between having an inline 4 or something else. Various voice said that they did not like the idea because it was impossible or very difficult to make the inline a stressed member of the chassis. To cut a long story short, a decision was made to produce a V6 instead.

My question is why was a V4 not considered? Or if it was why did it not gain any real mention?

From what I can see having a 4 cyclinder 1.6L ICE has quite a fair few advantages over a V6.
1. The block will be both shorter and slightly wider making it more stiff for the same weight or lighter for the same stiffness.
2. Less cylinders means probably less production time will be spent on block manufacture as producing the cylinders and other moving parts are the most expensive and time consuming part of producing an engine block.
3. My knowledge in harmonics is highly limited so I could be totally wrong here but aren't V6's generally known for terrible harmonics?

V4's are sometimes used in motorbikes and have been used a few times in road cars. Why haven't they been used in road cars more? Yes an inline 4 will always be cheaper to produce than a flat or V engine as it has more than one piece as the block. However subaru is able to constantly be profitable producing flat engines yet a V4 gets over many of the problems that is encountered by subaru with their flat 4 engines. That problem is space. With the typical front mount engine in a road car the engine bay width is severely restricted. Hence why their engines have very short con-rods, generally tend to have a large bore and short stroke and tend to have wider valve angles then ideal to lower the height of the heads. All in an effort to place the engine in the small space a v4 is just as short as a flat 4 which helps to shift the CofG slightly rearwards yet will no be nearly as limited for space. This can allow a more ideal rod ratio. A more square bore and stroke ratio and better valve angles.

So for those more knowledgable than me:
1. Why were V4's not considered for F1?
2. Other than cost, why did they never catch on in road cars?

Do V4's have problems with harmonics?

Edit: yes I know the actual V angle plays a large part when it comes to harmonics but I am asking about it for anybody that can educate me.

[NL_Fer]

With aluminium blocks, turbo downsizing and cars getting bigger and heavier. Engine weight and cog, doesn't really matter that much anymore. At least not for 2.0l and smaller engine sizes.

[trinidefender]

With aluminium blocks, turbo downsizing and cars getting bigger and heavier. Engine weight and cog, doesn't really matter that much anymore. At least not for 2.0l and smaller engine sizes.

Tell that to Toyota and Subaru who specifically used a flat engine to get as low a C of G as possible in the GT86/BRZ. A V4 is very short helping for rearward C of G and has a lower C of G than a vertical inline 4 engine.

In F1 it seems to fit everybody's goals. I.e. Can be used as a stressed member of the chassis while going along with the whole downsizing/lower cylinder counts that is used by many road car manufacturers.

[NL_Fer]

AE86 is a niche car, not worth developing a complete unique engine for. It's also not needed for a Auris or Yaris, the high volume models.

As far as f1, probably nobody was interrested. Remember the need to market th concept, Renault, Merc and Ferrari don't sell v4 cars.

Only Porsche does, thats why they built a hybrid V4 for le Mans.

[Tommy Cookers]

the V4 will make a lot of vibration unless 90 deg (and counterweighted) or close
this near 90 deg will give uneven firing intervals and even induction intervals
or the other way round, but traditionally impractical
eg even firing intervals needs a crank with 4 throws at 90 deg, expensive to forge and making a bulkier engine
(traditionally) nbg for a road car, ok for a bike
the V4 was (is?) so bad for a car the flat 4 seemed quite good

Lancia produced car V4s from 1920 to 1985, but were staggered inlines eg 10-14 deg, the layout VW have reinvented in the VR5 etc
so balance and firing intervals were quite good
Lancia won WRCs with these Fulvias
there was in Italy a Lancia V4 single seater class

Ford in Europe had V4s 60 deg (for production with V6) with a balance shaft (also Saab used it)
Zaporozhet also (improvement on VW beetle?)

there is/was 'half-a-bigblock Chevrolet' type engines

a 90 deg V4 has about the same balance as a flat-crank V8
and about the same as a 90 deg V twin or a 90 deg V6- we've heard of those !!
because 90 deg V with ideal counterweight leaves secondary imbalance only, regardless of cylinder count

we could have 1 throw with 2 main bearings
2 throws at 180 deg with 3 main bearings
4 throws at 90 deg with 3 or 5 main bearings
all with the sameish balance but different firing intervals and (reciprocation) inertia force intervals

some MotoGP machines should tell us useful stuff

iirc I suggested a long time ago that the endurance Porsche could be about 120 deg maybe with 3 main bearings

[PlatinumZealot]

The prosche V4 had some vibration issues first time out:

The resulting car is powered by a 2-litre V4 engine, which has been extensively re-designed since it first hit the track in June, 2013. However, from the moment the car hit the track, a vibration issue with the V4 engine caused the interlinked suspension to break. A major redesign of the engine was commissioned early on, instigated by the Technical Director Alex Hitzinger. That engine, featuring a new crankshaft, was installed for the test in Portimao in which Mark Webber completed 600km.

The very short V4 engine means that there is a very large carbon fibre bell housing ahead of the transmission (also carbon fibre).

http://www.racecar-engineering.com/cars/porsche-919/

[Facts Only]

For road cars.... Twice as many camshafts, heads, manifolds, belts etc etc so more expensive in terms of parts and build compared to an I4. Also the Standard FWD transverse road car layout is better suited to a tall thin engine.

For racing... Harmonics and probably development costs.

[bdr529]

For road cars.... Twice as many camshafts, heads, manifolds, belts etc etc so more expensive in terms of parts and build compared to an I4.

The same goes for motorcycles, I ride a Honda VFR400R and it cost more to service then an Inline 4cyl. for those very reasons twice as many of everything, excluding belts, the bike has gear driven cams, that's a whole different kind of expensive $$$
But disregarding the extra cost, the bike is as smooth and vibration free as anything I'v ridden. even after a 2 hour ride my hands & arms are not numb, just my butt

some MotoGP machines should tell us useful stuff

You got me thinking of the 2 stroke bikes of the 80's, Yamaha had a V4 500cc, Suzuki had a square 4 500cc and Honda a V3 500cc
granted not one of them vibration free nor were the street versions, it still shows there's more then one way to skin a cat

[gruntguru]

I think we will see a lot more inline 3cyl as downsizing takes hold. The inline 3 has no inertia torque (IL4 is terrible) and good balance without balance shafts. At less than say 1.2 litre capacity, 3 cylinders is more efficient than 4.

[Tommy Cookers]

there's a lot of inline 3s around and they all seem noisier and more vibratory than 4s
a few years ago they all seemed to have a balance shaft - maybe not today ?
and (to my understanding) the motorcycle 3s seemed to be less smooth than the 4s

yes, Aprilia said their 3 that replaced their V4 was far cheaper to make (far less time for machining)

the 3 has moment imbalance at engine frequency - this seems quite hard to isolate
compared with the smallish force imbalances of the 4 - presumably because these are at twice engine frequency

iirc Greg Locock had some experience of these difficulties in development of a 3cyl-equipped new design


btw wasn't there a road RG 500 ?

[Cold Fussion]

How much does the transverse FWD layout of most 4 cylinder cars affect the choice of an IL4? Perhaps RWD cars like the Audi's etc could benefit from the V4, but they also are designed to accommodate V8's so I guess the length of an IL4 is not an issue.

[riff_raff]

With most production auto engines, cost is king. The I4 only has one cyl head and one exh manifold. Plus it is easier to machine with all of its features in-line.

[Facts Only]

More new design 6 cylinder engines seem to be I6 rather than V6 these days, certainly the brand new JLR engine family has gone for I6 Petrol and Diesel rather than a V6. Probably again due to reduced cost because of simpler machining and a smaller number of parts.

[Gettingonabit]

More new design 6 cylinder engines seem to be I6 rather than V6 these days, certainly the brand new JLR engine family has gone for I6 Petrol and Diesel rather than a V6. Probably again due to reduced cost because of simpler machining and a smaller number of parts.

Its my understanding the I6 is the best balanced having both primary and secondary imbalance cancelled out - that must be a serious consideration as well.

[Tommy Cookers]

Its my understanding the I6 is the best balanced having both primary and secondary imbalance cancelled out - that must be a serious consideration as well.

there would still be vibratory forces from the valve motion
conventionally this is ignored ....
but Mr Duckworth said (of the DFV) these forces were greater than the well-known 2nd order imbalance of a flat crank V8

V6 balance will be very close to the straight 6's if it has 6 crank throws positioned such that a full number of proper webs is needed
so producing a longer and heavier engine than we would want ie the old Ford UK 60 deg Essex and similar Cologne engines
there is a small 2nd order rotating couple but no 2nd order rocking couple

since, V6s had larger bank angles allowing overlapping throws, eliminating webs and giving shorter crank to match natural block length
overlapping or near overlapping throws won't avoid the 2nd order rocking couple
the larger bank angle might help a bit, its main benefit is to even firing order without the length and weight of the old Ford
and less engine height of course

anyway imo the V4 is better in a racing car than in the road car, but is a bit downmarket to give F1 gloss to car makers