Lysander Discussion was Lysander mk II Cowling Question

[Graham Boak]

4+ shows 15mm for the Mercury, 13.5mm for the Perseus. Eyeballed from a scale rule.

I believe that the gills are cutback on the Mercury because of the forward fuselage slope down from the cockpit would otherwise foul the rear of the gills or at least excessively narrow the exit gap.

Edited May 6, 2016 by Graham Boak

[Dave Fleming]

Thinking about it, I might have the Matchbox kit somewhere, which would solve the problem......time to brave the depths of the garage

[Dave Fleming]

4+ shows 15mm for the Mercury, 13.5mm for the Perseus. Eyeballed from a scale rule.

I believe that the gills are cutback on the Mercury because of the forward fuselage slope down from the cockpit would otherwise foul the rear of the gills or at least excessively narrow the exit gap.

Thanks, that would seem about right.

[hendie]

This may not be any help other than to confuse matters more, but.... after hours and hours of searching, this was the only drawing of a Mk I & Mk II comparison that I could find.

I have no idea how accurate these drawings are or where they originated from but someone has gone to the trouble of creating them

Google led me to believe that the overall length of the Lysander was 30' 6" but I wasn't sure from where to where. I did find one drawing (Wylam?) which stated 28'6" from the front of the cowl to the tail light, so I used that as my reference. I drew a reference line on the drawing, then scaled that plus the drawing up to the 28'6" dimension.

It's difficult to see in this screen shot but... the propeller datums line up between the MkI & the MkII. The front of the cowls line up and the panel line just forward of the windscreen all line up perfectly.

However....

Mk I

Front of cowl to start of cooling grills = 842 mm

Front of cowl to rear of cooling grills = 1078 mm

Mk II

Front of cowl to start of cooling grills = 737 mm

Front of cowl to rear of cooling grills = 976 mm

The diameter of the MkI cooling grill came out at 1383 mm versus 1392 mm on the MkII but the original lines were a bit pixelated so they could very easily be the same diameter.

There's a 4 mm difference in the length of the cooling grills, again, the discrepancy easily put down to line thickness of the drawing.

The MkII exhaust is also shorter than the MkI in the drawing above.

Although I had read somewhere that the Perseus exhaust collector wasn't as deep as the Mercury collector, this drawing does not bear that out as both collectors are the same depth as far as I can tell.

If the 28'6" from front of cowl to tail light isn't correct - if someone can provide better data, I can rescale the drawing and see what figures come out of that.

So, if these drawings are to be trusted, then the MkII cowling is definitely shorter than the MkI & the MkIII by roughly 100 mm (4"), but appears to be essentially the same diameter.

I am tempted to trust what I find here. Someone has gone to all the trouble of drawing the two versions and there are minor differences between the two - which appear to be confirmed by what limited photographic evidence there is

(and if you take the above numbers and scale them by 1/72 - they match very closely to what Graham stated earlier with 15 mm and 13.5 mm)

Edited May 7, 2016 by hendie

[stevehnz]

A good effort on that hendie, that is pretty close to what I came to by scaling my Warpaint & 4plus plans, which both seemed to agree pretty much. I've long thought this is an under appreciated aspect of building Lysanders.

Steve.

[John Aero]

I wouldn't trust the dimensions on a Wylam drawing. Most of his drawings are awful. I have a Me 109 dimension-ed drawing of which the outline is nonsense. (Aurora made their ancient 1/48 kit to this drawing). I believe he dimensioned from the drawing rather than drew to dimensions. Many of his drawings were published early in the war when very few Americans had even seen a 109. A lot of the early Airfix kits were done from Wylam drawings. I was given the books by Airfix staff when Haldane Place closed.

John

[Dave Fleming]

Ok, I do have an MB Lysander, but it appears to be missing it's engine! If you are able John...

[Dave Fleming]

The MB cowling has the two small intakes at 9 and 3 o'clock. Those are on the Mercury but on the Perseus? Hard to tell.

[airjiml2]

Dave,

Not sure this helps much, but it is about the best Lizzie Mk. II cowl photo I have. (Photo is courtesy of the Canada. Dept. of National Defence/Library and Archives Canada.)

Jim

[tempestfan]

I'd hunch those Russian drawings are based on the Aeromodeller ones by Geoff Duvall. Ray Rimell built a Lysander for the "RAF Museum Collection" series in SMI way back when ('73 ?), but probably a cowling diameter difference of a fraction of a mm (would the diameter rather be 19mm in 72nd, I wonder ?) wouldn't have bothered him that much. Not sure which kit he used, in other words if the MB or the semi-new tool Airfix were already out by then, but both probably were.

The bulges on that one II cowling showing them are much further back than those on the I/III. Thinking about it, I'm sure I have seen that small round variety in pics before, but it could well have been the example shown above.

[John Aero]

The exhaust rings for the Mercury and Perseus though they look similar are different because of the exhaust porting difference of the sleeve valve.

I've also noticed that he cutouts in the Mercury exhaust are a standard production feature and coincide with the guns on Mercury powered single engined fighters, These are found on many types which do not have a requirement for guns firing between the engine cylinders such as the Lysander and Blenheim and Master II.

John

[gingerbob]

Nice shot, Jim- I've never seen a Lizzie with retracted gear before!

bob

[hendie]

........would the diameter rather be 19mm in 72nd, I wonder ?

1392 x (1/72) = Ø19.33333333 mm [ or Ø29.0 mm in 1/48]

1383 x (1/72) = Ø19.2083333 mm [ or Ø28.8125 mm in 1/48]

Given the vagueness of the line width, I'd feel comfy with a Ø19 mm in 1/72 and Ø29 in 1/48

Airjiml2 - that's the first/only photo I've seen of a MkII (or any other Mk) with the small cowls below the pilot position aft of the cooling gills. All the other photo's I have seen have this removed and showing some kind of vent

The MB cowling has the two small intakes at 9 and 3 o'clock. Those are on the Mercury but on the Perseus? Hard to tell.

Are you referring to the two small circular intakes inside of the collector ring ? If so, based on this photo, I'd say they are also present on the Perseus engined Lysanders

This photo also shows how narrow the cowling length is compared to the MkIII

[Dave Fleming]

Yes, and wow that is a fantastic photo

[John Aero]

The small intakes are the usually for the oil cooler. The small semi-circular cutouts are not present on the Perseus ring. I 'm guessing that the trunking visible here is for the cabin heating.

John

[Dave Fleming]

This is the cowl

Next point of interest is the wheels - the Matchbox wheels and tyres are the same diameter as the Airfix wheel hub!

[sloegin57]

.....and the tail plane is different on the Mk.II - check your inbox Dave

Dennis

[hendie]

Dennis - care to share that information ? As I am also building a MkII that information could be useful

[sloegin57]

Dennis - care to share that information ? As I am also building a MkII that information could be useful

Aeromodeller, December 1967. Drawn by G R Duvall, Traced by A A P Lloyd :-

HTH

Dennis

[hendie]

Thanks for that Dennis

[brewerjerry]

hi

Seconded thanks for the drawing.

Cheers

Jerry

[brewerjerry]

Hi

A link to an interested thread, on different sized whel spats on lysanders

http://forum.keypublishing.com/showthread.php?47723-Lysander-spats-shape

After i read it I wonder ...

did i read it right, does it imply .......

the Mk II also have different wheel spats ?

Cheers

Jerry

[dogsbody]

Thinking about it, I might have the Matchbox kit somewhere, which would solve the problem......time to brave the depths of the garage

I have one but it's 350km. North of me and it may be 2 weeks minimum before they start letting people back in.

Chris

[sloegin57]

Hi

A link to an interested thread, on different sized whel spats on lysanders

http://forum.keypublishing.com/showthread.php?47723-Lysander-spats-shape

After i read it I wonder ...

did i read it right, does it imply .......

the Mk II also have different wheel spats ?

Cheers

Jerry

There is nothing in the Aeromodeller drawings to indicate that but bearing in mind that the draughtsmen only had the RAF Museum's example to measure and sketch and that the drawings were constructed nearly half a century ago - who knows ?. A lot of research has gone under the bridge in the intervening years.

I assume that you all know that one was fitted with a four gun rear turret. Interesting "how to" conversion article in the October 1969 issue of Scale Models using the Frog Lizzie, Plasticard, the tail wheel from a Frog Me210 and Plastic Padding.

I wish I hadn't got these magazines out now. Revell 1/32nd Me109F, Spitfire I and P-40E going for 14 shillings and thrupence - 70p in Metric Money

Dennis

(who freely admits that the last two paragraphs are of absolutely no use to the topic in hand at all)

[Garry c]

When I was in school ,in the last century, we were practicing weight and balance calculations. One of the aircraft used was the deHavilland Otter.This aircraft had two different maximum weight ratings depending on the wheels and tires used.

I wonder if the Lysander with the different engines with different horsepower ratings has different wheels?

Garry c

Edited May 12, 2016 by Garry c