16 replies to this topic

[Tracy]

I have recently read that the V angle of Renaults V10 engine will be 72 degrees, is this correct? As far as I know the universal consensus of opinion is that 90 degrees or close to it is the way to go for a generally desirable engine all round. Since renault have already been burnt by an 'unusual' engine config, wouldn't they be better to go with a standard config and exploit all there other chassis advantages.

[estoril85]

err its an upgraded supertec :

[scarbs]

One of the ideal configurations for a V10 is a 72-degree, this is down to crank shaft balance and loads of oily engine reasons I dont claim to understand. However the upside is the more balanced layout produces less vibration and hence components can be lighter for the same reliability (a generalisation I know).

The recent move to wider V angles has not been driven by engine designers (who hate them) but the chassis and to a lesser extent aerodynamicists. Most team adopt 90-degrees (Except Jordan and Minardi in 2003) with Renault being the odd one out at 106-degrees(reputedly). This placed the masses lower on the car to improve the CofG, it also brought the frontal area of the engine to well within the shadow provided by the fuel cellDriver etc. improving the aero. However wider engines also place their exhausts further outboard and this can impinge on the slim shape favoured by the aero guys at the rear of the car. Renaults early wide angle enginw famously suffered cooling issue related to space left at the rear of the sidepods. Renault also suffered a poor airbox shape created by the inlets being spaced for apart, necessating a tall ridge mouled into the airboxes base to provide the shape to produce similar accoustics to narrower engine airtboxes, the offset of a narrower airbox was the volume took up space in front of the rear wing, this has been offset by better design, Jordan has as low an airbox as any one in 2003.
also installation stiffness can be compromised, Renault installed a subframe as part of their design (& not an after thought) to compensate, this years car also had a broad steel sump to mount the bottom of the engine securely to the chassis and usefully to act as ballast.
All up engine weight is less of an issue now, instead CofG has been the pre-occupation, waisted cylinder heads appearing like shrink-wrapped castings around the valve tractscombustion chambers and camshafts have reduced these to the point of diminishing returns. Underweight cars can now compensate for heavy components mounted high up with ballast (or ballasted components i.e. sumps etc) and still leave weight for set-up tuning ballast.

So with overall engine height, CofG and weight not an issue, but installation width and reliability a key factor the 72 degree once agains becomes the better packaging option. With a narrower profile the 72-degree can place exhausts and anclillaries inboard to narrow the rear end.


Renault have excelled at this with their R24 for the 2004 season. The airbox and cylinder heads even protrude from the main bodywork underneath blisters creating a tightly waisted sidepods and engine cover beyond even ferraris F2003Ga which was still reqiured to package the wide 90-degree engine.



Even if it with a design borrowing from the older Williams Benetton RenaultMechachromesupertech design

[marion5drsn]

There are only three angles that a V-10 engine can use with a minimum of vibration and that is Zero, 72 and 144 degrees.
Any other angle and you will have some problems. Primary shake is dealt with by using ten Counterweights.
M.L. Anderson

[Chevy II Nova]

I love you Scarbs.

[FordFan]

Any news on the latest Cossie, Scarbs?

[Halfwitt]

I wouldn't discount 90 degrees for minimising vibration.... It mightn't be even-firing, but it's good for vibration, yes even for V10.

[Powersteer]

What about arranging the 10 cylinders like VWs style of W arrangement. VW has a narrow angle V5, having one on each bank might not shadow the side-pods well but the aero angle into the rear aero package would be very good. Also the short length and very compact casting nature of the engine might help weight while more ballast to be used undernearth. With the engine behaving like two V5s vibration would not be a problem when the angle of the V is widenened.


Just an probable addition or another 'maybe'.

[Double Apex]

I heard Renault will be starting the season with an updated version of their mid 90's engine and will be introducing their new engine at some point during the season. Anyone knows if there's any thruth in this?

[scarbs]

Theres some confusion as far as the Renault engine for 2004 being an old supertec, Bernard Dudot has said that the engine uses soem of the concepts of the old unit, but also incorporates the thinking and material from the current wide angle unit. Obviously the two engines have differing requirements based on their V-angle, so for example the new engine may not have the cam drive and counter balancer set up of the 2003 wide angle engine.

The limiting factor on (90-degree) engine output as I understand is now secondary vibration, the harmonics this creates affects the camshafts, which break under the load. Mercedes (Ilmor) had this issue with their first 90-degree engine (2002), so I guess although the primary balance of a 90-degree V might be OK, the secondary shake is the killer. Also the accoustics in airbox design are critical in delivering the right air pressure over the right cylinder at the right time. Cosworth I understand are using external accoustic analysts to understand if the effect on track matches that on the dyno.

I dont know about the W format, in terms of layout 10 cylinders into three banks (3-4-3 or 2-4-2..?) doesnt sound promising on the vibration front. The rule mandate 10 cylinders so a more balanced 9 cylinder wouldnt be allowed. Also the airbox design would be split with two banks sharing one airbox and one bank having its own, would limit tuning potential.

PS Chevy I Love you too...x.

[Wuzak]

I asked about the possibility of a "W" layout a while back.

Rather than 3 banks with 3-4-3 cylinder arrangement, the "W" engine as used by VW would be a 4 bank engine. Essentially it would be a W12, as found in the Bently Continental GT, amongst others, with two cylinders missing.

In the VW engines, the banks paired together have an angle of 15° between them. They carry a common head, and the inlet and exhausts from both banks exit from the same side - this is very convenient for transverse applications for the VR engines.

To achieve this narrow angle between the paired banks, the W (and VR) engines are smallish bore/long stroke with relatively long rods.

For a short stroke/large bore F1 engine the angle between the paired banks would have to be wider, making the head/inlet/exhaust a problem.

[Wuzak]

Scarbs, is the Renault definitely 72°? I thought they had confirmed 90° earlier in the year.

[Chevy II Nova]

They are still developing the 90.

Trust me, scarbs is sure.;)

[Wuzak]

Originally posted by Chevy II Nova
They are still developing the 90.

Trust me, scarbs is sure.;)

They are doing both?

[Chevy II Nova]

As far as I know, they are developing a 90 for later use.

[Wuzak]

Thanks.

[Powersteer]

4 banks, two banks has a very narrow angle V5. 2-3 and the on the other side another two banks making the total layout 2-3 and 2-3. I did a drawing and found the cylinder head would be too cramped for F1 style entry ports and exaust ports . Probably the end product might not be as light. It is still a curiousity to me whether a one piece head and block casting would make the V10 engine lighter. I think it would be strong and have less mountings which would save weight. If F1 teams has a robot to machine the deep combustion chamber and valve seat then blast the liners with coating this would be very strong and light.