Filling a engine with oil...Max or not?

[Refueler]

Take this ........
RR Merlin in the spitfire had an ingenious lub system that meant it could fly inverted .....as and when the pilot required ....thinking dog fight with a ME109 .
Additionally ...a semi forced induction system on the carbs so they could function inverted ......as long as the pilot requires .

ME109 ....no such adaptations.......Jerry could only momentarily invert for fear of engine conking out ,

Gross oversimplification and in error anyway.

The Merlin had carbs ... it biggest problem was negative G in a push over into a dive - the lean mixture when the float bowl ran out of fuel due to neg Gs caused engine to stall, if the engine did not stall completely then the rich mixture cut-out when the a/c went inverted and the float fell to the top of the bowl allowing an unrestricted flow of fuel to the cylinders.

A War Office Lady - Ms Tilley - came up with a restricted orifice ring to partly overcome this - so the Spit could roll and then dive ...

The ME109 though had injection fuel system and did not suffer this and in fact the engine was mounted inverted and could fly inverted straight from level flight .. could go into negative G without engine cutting out as did the Spit.

Fighters such as these were never intended to fly inverted for longer than a minute or so anyway - but the ME109 pilot would always be looking to force that negative G factor ...
In most other factors - the Spit had the advantage of greater climb rate ... tighter turn ... greater speed at height ... and in later Mk's when they got rid of the early cockpit hoods - better visibility.

 

[Portofino]

Gross oversimplification and in error anyway.

The Merlin had carbs ... it biggest problem was negative G in a push over into a dive - the lean mixture when the float bowl ran out of fuel due to neg Gs caused engine to stall, if the engine did not stall completely then the rich mixture cut-out when the a/c went inverted and the float fell to the top of the bowl allowing an unrestricted flow of fuel to the cylinders.

A War Office Lady - Ms Tilley - came up with a restricted orifice ring to partly overcome this - so the Spit could roll and then dive ...

The ME109 though had injection fuel system and did not suffer this and in fact the engine was mounted inverted and could fly inverted straight from level flight .. could go into negative G without engine cutting out as did the Spit.

Fighters such as these were never intended to fly inverted for longer than a minute or so anyway - but the ME109 pilot would always be looking to force that negative G factor ...
In most other factors - the Spit had the advantage of greater climb rate ... tighter turn ... greater speed at height ... and in later Mk's when they got rid of the early cockpit hoods - better visibility.

Yes I vaguely remember reading something of a simple float chamber mod and something about partial forced induction .....sure with carbs , could have been icing up mitigation as well but I think it was the inverted thing mostly?
The book was written by an Italian engineer after the war Enzo Ferrari sent across to study the Merlin .
In a nut shell they miniaturised it for there road cars sans the inverted kit

sorry for the TD folks .

 

[A_8]

Seems to be a hot topic and generally you want as much oil in the engine as possible (without over filling obviously) for the simple reason that whatever crap the engine dumps in the oil or general degradation will be less in relative terms the more oil you have.

 

[PCUK]

All which points back to how I said oil changes should be done. i.e. fill by required quantity, use the dipstick as a daily check guide.

Absolutely, so why are we arguing.

 

[Ian MacAulay]

Thanks everyone for the input, seams quite mixed reviews on this subject and a lot more than a straight cut answer,