[JV69_BADA]

No M63 in42, the first series appear in squadrons begin march43, most ot the first-build airframes goes to the MTO. :wink:

[Davew]

Thanks Davew.
Yes we've found that one - its got performance curves for the merlin 61, 66, and 70 spits but we(I) haven't found the equivalent for the merlin 63 spit

~S~ Redcanuck

Yeah I saw that, also the horsepower ratings are off compared to most other sources I've seen. The extent of the variation in aircraft with the same engines is interesting though.

Btw, reflected, that site was http://www.flightglobal.com/imagearchiv ... =FA_18402s

gotta love this shot too... though it might be a little short on detail...

[Zorin]

The first release will be the 61 as it was the one being used on the first batch of IXs to enter service, which is actually the time frame we need this bird for.

[GBrutus]

@Davew,

Great shot there. Just had a quick look at that site and there are some fantastic photos on there. The aerial shots of the Tiffie are superb. BTW, that John Vader book arrived yesterday and is a great read.

I've finally got around to making a proper start on the 3d work. I've been kept busy with work up until recently and just haven't had any spare time at all. I should hopefully have an update in the next couple of days and I'll post some screenshots.

[I/JG27_Waggel]

The difference between both graphs is the performance in some regions. The character of the performance is nearly the same.

What is the meaning of "BF274" and "BS428". Is this somethig like a production number?

Edit:

Source of the yellow line: http://home.epix.net/~cap14/spit9v109g.html

Source of the gree line: http://www.spitfireperformance.com/spitfire-IX.html

The RAF pictures are great! hock:

Edit2:

Something wrong with the green line. This line does not belong to the "BS428" but to the "BS354". This plane was also in the report but I mentioned it as the "BS428". The "BS354" had a merlin 70 install and a Mk. XII rudder.

The "BF274" is a "BS274" but it was painted incorretly .

I will check the performace data of the "BS428"

[Davew]

Yeah, BF274 and BS428 are the serial numbers of the aircraft. As far as i can determine, they provide a number of aircraft with the same specifications to basically generate an idea of an 'average' performance. Removes the odd abberation of an exceptionally high or exceptionally low performing aircraft.

GBrutus - Yeah, always enjoyed that book. Annoyed that I can't find my copy. Gotta love those Whirlwind shots on that site though. If you're interested in Typhoons, another book you could look for is I think called Mosquito, Typhoon, Tempest. But I can't remember who wrote it. Wing Commander Beamont is one of the authors in any case. Can have a look who wrote it when i get home if you like. Some awesome shots of Typhoons in particular in that book.

[Davew]

Oh, btw, GBrutus, couple nose shots of an early IX


save you trawling through all those images



Note that the landing gear and oleo legs are also of the earlier MKV type...

[Zorin]

We still need more data on the Spitfire F IX with Merlin 61.

These aircraft have already been analyzed:

BS 428
BS 274 (wrongly labeled as BF 274)
BS 354

If you have any further reports on other aircraft for further refinement of the FM, please post a link or contact Waggel via PM.

[JV69_BADA]

Don't forget that the M61 used a carburator like the one on the Mk5, with anti-overfloat and not a full G capable like the one on the M66.

[Davew]

Don't forget that the M61 used a carburator like the one on the Mk5, with anti-overfloat and not a full G capable like the one on the M66.

It did use one like the MkV, but it still allowed negative 'g' manoeuvres. A diaphragm across the float chambers was fitted as standard from march 1941 allowing negative 'g'.
Following that, a modified version of the SU carburettor was fitted from 1942 to single stage and two stage merlins - the anit-g version. And then in 1943 the Bendix-Stromburg carburettor was fitted which basically provided direct injection.

I cannot find specific dates for the introduction of each modification though, so the very early IXs may have had either the diaphragm or the modified SU carburettor. Either way, all versions of the MKIX were capable of negative 'g' without the engine cutting out. At least as far as I am aware...

[JV69_BADA]

indeed, it allows the engine to continue to work through neg G, but it doesn't allow the engine to develop the needed potential, read power, or it doesn't allow the needed response on the pilot's input (if input on throttle was done), the engine starves for fuel with always a risk of engine cut (depending on the pilot's actions)->see last sentence of the attachement.

here,just a little copy from the original RAF rapport on the A3 evaluation against the spit9. I think it was the BR980, delivered to squadron 64 the 04-08-42, doing the same month the trials against the A3 and beeing killed by a 190 the 04-09-42
how ironic :twisted:

[Redcanuck]

Well I still can't find anymore data on the merlin 61 engine or anything useful for the merlin 63 engined spit IX; however I did run across a report that says that the F MK VIII and the F MK IX spits with the merlin 63 engine had basically identical performance.
http://www.spitfireperformance.com/spit8tac.html

So if you run across any F MK VIII performance tests with the merlin 63 engine it would be useful data.

So I dug into the info on the MK VIII in spitfireperfomance.com and discovered this:
http://www.spitfireperformance.com/jf934level.jpg
http://www.spitfireperformance.com/jf934climb.jpg
http://www.spitfireperformance.com/jf934time.jpg

Now the main text of this test refers to the tested ac being JF 934 with a merlin 66 engine but it is also called a F MK VIII not a LF. :?
That serial number for a MK VIII is probably a later LF but still one can hope

An opinions?

~S~ Redcanuck

[JudgeMingus]

It should be noted that even direct injection does not make the engine totally immune to negative-G problems even though it does allow the engine to run under a short period of negative-G.

There is still the matter of supplying oil to the engine and fuel to the injector/carburettor - generally these are drawn from the bottom of their respective tanks. Sustained negative-G will at some point cause supply reduction or interruption and thus problems with engine starvation or damage.

[GerritJ9]

Not necessarily- it depends on the internal design of the fuel/oil tanks. One would asume that the oil/fuel tank designers were aware of the contents of the tanks being flung around during violent manoeuvres in combat, and added baffle plates to prevent or at least minimize te risk of fuel/oil starvation. The latter would spell DEATH to nearly all engines. Plain bearings desperately need a constant and copious supply of oil to survive- interrupt that supply, even for a few seconds, and your bearings are seriously damaged if a load is applied to them. Ball and roller bearings are much less sensitive in this respect though they, too, need oil to lubricate and cool them.

[Carnagexxx]

Little Off topic

someone thinks about Spit Mk1b with 2 Cannons and Mk2 ?

Also was there an 4 cannon version of the MK IX ?

I hate that we only got 1 4x20mm spit