just thinking

[wreckless]

in f1, we all know that renult use the 110 degree v angle on their engines, just what are the advantages and dissadvantages of this over the 72 degree angle engines?

[alfasud]

Lots of different issues to consider.... wider angle V gives lower centre of gravity. The crankshaft is the same distance above the ground, but the cylinder heads are mounted lower.

This idea is nothing new... Ferrari used a 120deg V6 in the early 1960's. The boxer engine is sometimes considered the extreme example (i.e. 180deg V engine), but can have problems routing the exhaust below the cylinder heads which are already very close to the ground, so sometimes it is a bit of a compromise, where the crankshaft of the boxer is higher than could be achieved with a V engine.

On the over hand, the normal way to choose the V angle for best balance is some multiple of 2*360deg/n where n is the number of cylinders. e.g. 2*360/12 = 60deg V12, 2*360/8 = 90deg V8 and 2*360/10 = 72 degrees V10 (144deg might also work?). Therefore, for a V10, 72deg should be better balanced than 110deg.

A major factor in F1 is aerodynamics... how the airflow is routed around the engine - a low angle V could be an advantage or disadvantage, depending on the rules that apply on a particular year.

I'm sure there must be other factors I haven't listed.

[boyracer]

And the disadvantages were outlined by the team manager of Renault in RaceCar Engineering about two months ago (?)
These include rigidity problems, a wider airbox that changes the harmonics of the intake system and also needs to be made stiffer to stop from flexing.
The idea was based on a simple principle, get the weight lower, but there were a few more problems than first appeared. The team manager admitted the problems but also said the aerodynamic gains achieved more worth the hassle, for this chassis. He did hint that next year there would be a re-think on the chassis strategy that could mean going back to the normal V-angle, especially as next year the engines will have to last a lot longer than this year.