I just watched this great video on offset cylinder engines vs traditional Zero offset cylinder engines and it got me wondering if this is
A/ legal in F1
And
B/ worth doing in race car applications.
Yes. While the advantage is of reduced piston side thrust and longer duration (greater than 180 degree) intake and power stroke. The penalty is of variation in inertia forces.
Tommy Cookers wrote: ↑26 Mar 2023, 17:53offsets were used in steam engines - but were then rather un-invented to enable double-acting
presumably illegal in F1 - or engine supplier swaps would be more difficult
with V engines offsets are usually used for package reasons - ie 'handed' displacing of cylinder bores VR5/6 Lancia Morini
if used for performance reasons 'handed' offsets would be beneficial on one bank but dis-beneficial on the other bank
this would negate eg benefits from to better piston motion on the power stroke
"Presumably illegal in F1'' I do not know it if is illegal or not in F1 and neither if it was always illegal. What I know but not at what time, is that cylinder offset is claimed as having been used in F1 (taken advantage off). The Lancia Fulvia (narrow angle VEE FOUR the crankshaft has offset crankpins double the angle of the VEE. The centerline of the crank is not actually at theoretical apex of the VEE. The 1298 version (77*69.7) the angle 12 degrees 40 minutes. The 1600 version (82*75) 11 degrees 20 minutes.
just to be clear .....saviour stivala wrote: ↑27 Mar 2023, 00:10Yes. While the advantage is of reduced piston side thrust .....
saviour stivala wrote: ↑27 Mar 2023, 07:38Tommy Cookers wrote: ↑26 Mar 2023, 17:53offsets were used in steam engines - but were then rather un-invented to enable double-acting
presumably illegal in F1 - or engine supplier swaps would be more difficult
with V engines offsets are usually used for package reasons - ie 'handed' displacing of cylinder bores VR5/6 Lancia Morini
if used for performance reasons 'handed' offsets would be beneficial on one bank but dis-beneficial on the other bank
this would negate eg benefits from to better piston motion on the power stroke
"Presumably illegal in F1'' I do not know it if is illegal or not in F1 and neither if it was always illegal. What I know but not at what time, is that cylinder offset is claimed as having been used in F1 (taken advantage off). The Lancia Fulvia (narrow angle VEE FOUR the crankshaft has offset crankpins double the angle of the VEE. The centerline of the crank is not actually at theoretical apex of the VEE. The 1298 version (77*69.7) the angle 12 degrees 40 minutes. The 1600 version (82*75) 11 degrees 20 minutes.
Neither do I know if VEE engines were in use in F1 when cylinder offset was claimed to have been used (taken advantage off) but I assume they were. As to the Lancia Fulvia (narrow angle VEE FOUR) my point was the two versions discussed the cylinders were actually not offset from the crank main bearings centerline, but the crankpin was, which gives the same effect, same as offset piston pin, of which I suspect what was used in F1 re the claim that offsetting was taken advantage off in F1.
I've just skimmed through the regulations, and I can't find anything that say that the axes of the cylinders has to meet with the axis of the crankshaft at any point.
I don't think the balance is such an issue with a race engine.
Isn't that an angular offset of the crankpin, rather than the cylinder being offset from the crank centreline?saviour stivala wrote: ↑27 Mar 2023, 07:38The Lancia Fulvia (narrow angle VEE FOUR the crankshaft has offset crankpins double the angle of the VEE. The centerline of the crank is not actually at theoretical apex of the VEE. The 1298 version (77*69.7) the angle 12 degrees 40 minutes. The 1600 version (82*75) 11 degrees 20 minutes.
Exactly. That (what you saying) has been explained yesterday 27 Mar 12:59 6 posts back on this same page. The offsetting of cylinder/s centerline to that of the crankshaft main bearing centerline (desaxe cylinders) was and is more widely used than one can think including in formula one racing engines. The offsetting of cylinders and or other such intended designs to achieve one of its more than one aimed effects can be achieved in more ways than one, including not actually moving the cylinder/s and or crankshaft main bearings centerlines apart. The original scope of gain of the 'desaxe' cylinders was solely aimed at mechanical leverage. With the advent of the aluminum pistons the unpleasant piston rattle when road going ICE was cold, pistons pin offset started to be widely used, this was one of the variant of 'desaxe'. The other was 'pulling down (by design) cylinders in the block in relation to crankshaft horizontal centerline on ''VEE ENGINES'' ''INCLUDING IN F1 RACING), This design actually pushed cylinder banks of a VEE ENGINE not only lower, but further apart and out of main bearing centerline. One VEE ENGINE desaxe incorporated design which is still talked about today was the FORD MODEL A V8, Ford moved both cylinder banks the same amount and together off crankshaft main bearing centerline. (cylinder blocks were moved both the same amount 'sideways' (to the driver's side).wuzak wrote: ↑28 Mar 2023, 01:51Isn't that an angular offset of the crankpin, rather than the cylinder being offset from the crank centreline?saviour stivala wrote: ↑27 Mar 2023, 07:38The Lancia Fulvia (narrow angle VEE FOUR the crankshaft has offset crankpins double the angle of the VEE. The centerline of the crank is not actually at theoretical apex of the VEE. The 1298 version (77*69.7) the angle 12 degrees 40 minutes. The 1600 version (82*75) 11 degrees 20 minutes.