Hurricane radiators - is there a tropical, or later type on the Mk.II and IV? And is there a different Canadian inlet shape?

[72modeler]

5 hours ago, gingerbob said:

So you could have two different cores that fit a common housing, which I think was true for the Spit V

That's why I was thinking that might have been the case for Mk 1 and Mk II radiators- same housing/fairing, but different cores for tropical use. For the Mk IV/V variants which had visibly deeper housings, or at  least inlets, the cores and most likely the oil cooler core as well, might have been  too big to fit inside of the normal radiator housing. Once again, I'm just making an unsubstantiated guess- is this a great hobby or what?  Twenty-eight years after the fact and there are still so many parties  interested in knowing the facts so they can get a plastic replica correct!  

Mike 

[StevSmar]

Here's the full excerpt from the Schedule of Spare Parts:

Since this is an excerpt from the Schedule of Spare Parts, all it shows is what parts could be demanded. To work out what parts go into each type of Hurricane, you need the side elevation drawings (as far as I currently understand).

 

What I find interesting is that it shows one radiator fairing (housing) for the MkI and two types of radiator cores, similarly for the MkII. Does this mean that the same housing was used regardless of whether it had a "regular" or tropical radiator "core"? Or does it mean that you couldn't demand a replacement for the tropical radiator fairing (housing)?...

[StevSmar]

10 hours ago, 72modeler said:

....That's why I was thinking that might have been the case for Mk 1 and Mk II radiators- same housing/fairing, but different cores for tropical use... 

You might be correct based on the full excerpt I posted above.

[72modeler]

I found these photos - they most likely won't answer answer any of the posted questions, but they are nice photos- I have no idea if they are captioned correctly, but hoping the resident Hurricane aficionados will know! (This is a re-post; hopefully the links will work.)

Mike

 

captioned as the radiator housing from the BBMF Hurricane

https://www.flickr.com/photos/sisaphus/4429664961/in/set-72157623970323344/

 

Looks to be a Mk 1, Mk 2a radiator at the Calgary Mosquito Society shop

http://www.calgarymosquitosociety.com/feature66/feature66.html

 

new-build radiator/oil cooler core for a Mk 1, Mk II Note the non-standard shape of the oil cooler core in one photo

https://www.replicore.co.nz/gallery/MK1-and-MK2-Hawker-Hurricane-radiator-and-oil-cooler-cores/20

 

Mk II radiator

https://www.largescaleplanes.com/walkaround/wk.php?wid=147

 

 

 

 

 

 

Edited January 12, 2021 by 72modeler
added links

[V Line]

8 hours ago, StevSmar said:

You might be correct based on the full excerpt I posted above.

Steve, I very much subscribe to the approach you have taken as it is granular, evidence based and is a sound basis for further research and reasoning.

 

Your view on radiators seems to be rather like mine on propeller blades as kit producers and publications so often get these wrong.

 

Coincidentally, I have just received a copy of the Franks book and to be fair, it is not altogether a waste of money. Having said that, on page 212, I see clear errors.

 

The NASM Hurricane Mk IIc is described as having ‘(Shwartz) metal blades.’ They are in fact Weybridge DR291 wooden types with a Schwartz/Rayoid or Rotaloid covering. Aside from the Mk I de Haviland blades, metal types were not fitted the Hurricane other than perhaps for trials etc. There also is a photograph caption of ‘the classic blunt Spitfire spinner’ which is actually a Rotol/CSA Hurricane spinner designed for that particular aircraft.

Nevertheless, Pages 216/7 are particularly useful re this current thread, as is the photo of the Mk IV engine armour plate on page 215(also in Mason p88). I should imagine that would contain/reflect heat in the engine compartment and in itself suggests a need for additional cooling, Merlin XX or not.

 

I have wondered about Hurricane engine cooling for some time. Perhaps there was a general issue. Whilst the early de Haviland and CSA spinners extended the full width of the cowling collar, the ‘bullet’ Rotol and later de Haviland types were contained within the collar opening. Thus, there was an intermediate gap which wouldn’t do much for streamlining/performance but would allow an airstream to circulate around the engine.

 

In relation to the different radiators, the Spitfire provides some insights.

 

I found an interesting Supermarine drawing of  the Spitfire ‘close matrix Morris type Q.A. type’ radiator (35241/Sheet 1.C date 17.4.41 –Mod No. 411) which details an increase of the matrix area by 10%. This was achieved by increasing the depth of the radiator (not widening).

 

(I have a reference that the Spitfire Mk I was fitted with a ‘Gallay radiator Type E5’ (matrix facial area 1.88 sq ft approx) which may or may not equal that of the Q.A. type).

 

The original Q.A. type and the deepened version were, according to the drawing, ‘interchangeable.’ This suggests the fairing remained the same at that date.

 

However, the full Mod 411, for ‘Tropicalistion (Fitted to special Order Only)’ also specifies a complete new radiator fairing. For the avoidance of doubt this has different parts numbers to those of the Va/Vb. The ‘tropical’ radiator is listed as ‘Morris QCY’ with the drawing number as per the ‘Q.A.’ modification above.

 

At the same time, according to the Mk V parts list (AP 1565E & J Vol III April 1943) the Mk Va/b radiator is listed as ‘Radiator, Morris, Q.C.V.(Temperate) Group’ i.e. not the Q.A. so there is a question as to which version the latter was fitted. Perhaps it was an earlier/alternative model or prototype ‘tropical’ type.

 

It is important to note the term, ‘to Special Order’ used above, which replicates that used in the Hurricane parts list. This implies a less restrictive category than I originally suspected and could be read in each case as applying to all ‘tropicalised’ aircraft.

 

Extrapolating from the above, it seems that, as has been suggested that the tropical radiators for both aircraft were produced by deepening the cores so providing an increased matrix face and perhaps some design efficiencies. In the case of the Spitfire a new fairing was specified where the extra depth perhaps required it.

 

If you ever purchase the Mk IV spares manual it will be interesting to see what is listed in terms of fairing and radiator.

 

Finally there are some reasonable Mk II radiator views in the following video of Mk IId's in the desert. There are other versions but the film quality is pretty good.

 

https://www.youtube.com/watch?v=rrxT4Lc0W6E

 

 

 

 

 

[Graham Boak]

25 minutes ago, V Line said:

Whilst the early de Haviland and CSA spinners extended the full width of the cowling collar, the ‘bullet’ Rotol and later de Haviland types were contained within the collar opening. Thus, there was an intermediate gap which wouldn’t do much for streamlining/performance but would allow an airstream to circulate around the engine.

 

Not quite, as I understand it: the early Rotol types were too wide for the Hurricane cowling ring and a special nose had to be fitted to Hawker's own aircraft used for Rotol trials.  This makes for an interesting model and it appears to be a shame that it was not adopted - perhaps the promise of the later spinners counted against this.  When fitted to the production Hurricanes it was too wide, leading to oil leaks smearing the windscreen so the familiar oil spill ring was fitted.  As some Hurricanes were fitted with DH spinners sized for the Spitfire they are also beyond the limits of the cowling ring and these also leaked - it may even have been noticed first on the DH.  The later (pointier) DH spinner designed for the Hurricane and the "bullet" Rotols were sized to fit the Hurricane and would not have had any more than the same unavoidable gaps as on all other types of aircraft.

 

I am quite sure that the Franks book has contains much good information and is a useful buy for those with no other Hurricane references.   I however do, and though I would expect to find something new to be inside almost any book I am not certain of trusting his sources.

[V Line]

1 hour ago, Graham Boak said:

Not quite, as I understand it: the early Rotol types were too wide for the Hurricane cowling ring and a special nose had to be fitted to Hawker's own aircraft used for Rotol trials.  This makes for an interesting model and it appears to be a shame that it was not adopted - perhaps the promise of the later spinners counted against this.  When fitted to the production Hurricanes it was too wide, leading to oil leaks smearing the windscreen so the familiar oil spill ring was fitted.  As some Hurricanes were fitted with DH spinners sized for the Spitfire they are also beyond the limits of the cowling ring and these also leaked - it may even have been noticed first on the DH.  The later (pointier) DH spinner designed for the Hurricane and the "bullet" Rotols were sized to fit the Hurricane and would not have had any more than the same unavoidable gaps as on all other types of aircraft.

 

I am quite sure that the Franks book has contains much good information and is a useful buy for those with no other Hurricane references.   I however do, and though I would expect to find something new to be inside almost any book I am not certain of trusting his sources.

I believe we have differed on this point on a previous thread. I would be very interested to know on what information your understanding on the spinners is based.

It is entirely possible there is something I have missed in my analysis.

 

[Graham Boak]

Looking at many photographs, it is quite clear that there is a step down behind the early spinners, usually known as the "Spitfire" ones, at least for the Rotol, and none behind the later spinners.  Photos of BoB Hurricanes with the wider "hemispherical" (they aren't quite) Rotol are fairly common, those with the "Spitfire" DH have been presented on this forum by Troy Smith.  The need for a new nose on the privately-owned Hurricane is again clear if the existing photograph is studied  This test example appears to be much the same as the later "Spitfire" spinner.  The Spitfire does have a greater nose diameter than the Hurricane, hence the difference in spinner sizes.  The Air Ministry made an early decision (possibly November 1940?) that the hurricane was to receive priority for the delivery of constant speed propellers (at this stage only Rotol) because of its inferior performance.  Hence the visible differences between the fit of the propellers on Hurricanes during the Bob.

 

The adoption of the oil spill ring was universal, for aircraft with both DH and Rotol spinners - as the two were interchangeable (given the right control systems) this is presumably a matter of standardisation covering both ease of production and ability of change the unit at any time without further modification.  

 

I don't believe that my views differ from the established story - or rather stories as there does not seem to be a single source covering the entire programme.  If you wish to argue that early spinners had the same diameters as the cowling ring, then we need to see the actual dimensions, for this is not what is visible.  Similarly for the later spinners not being of smaller diameter.

[dogsbody]

13 hours ago, 72modeler said:

I found this photo just now- looks like a Mk II radiator- doesn't answer any of the posted questions, but it's a nice photo.

 

0463ca53292c080905f9bc01cf5b81fd.jpg (2120×1560) (pinimg.com)

 

Here's a view you don't often see of the radiator housing from the BBMF Hurricane.

b2a0c9b1aadf7a1ba9557aae7f5a6fe2.jpg (1024×768) (pinimg.com)

 

Here's the radiator core with the space for the oil cooler in the center.

Hawker-Hurricane-5481-radiator-472x295.jpg (472×295) (warbirdsonline.com.au)

 

This looks to be a new-build radiator shell- note the different shape and style for the oil cooler matrix.

Hurricane--6-.jpg (800×600) (replicore.co.nz)

 

This is captioned as a Mk II radiator- obviously a  restored Hurricane, but the identity of the airplane  was not mentioned in the caption.

147-20.jpg (1555×1037) (largescaleplanes.com)

 

I hope these are useful!

Mike

 

 

 

 

Can't see your photos as there are no useful links to click on.

 

 

 

Chris

[V Line]

2 hours ago, Graham Boak said:

Looking at many photographs, it is quite clear that there is a step down behind the early spinners, usually known as the "Spitfire" ones, at least for the Rotol, and none behind the later spinners.  Photos of BoB Hurricanes with the wider "hemispherical" (they aren't quite) Rotol are fairly common, those with the "Spitfire" DH have been presented on this forum by Troy Smith.  The need for a new nose on the privately-owned Hurricane is again clear if the existing photograph is studied  This test example appears to be much the same as the later "Spitfire" spinner.  The Spitfire does have a greater nose diameter than the Hurricane, hence the difference in spinner sizes.  The Air Ministry made an early decision (possibly November 1940?) that the hurricane was to receive priority for the delivery of constant speed propellers (at this stage only Rotol) because of its inferior performance.  Hence the visible differences between the fit of the propellers on Hurricanes during the Bob.

 

The adoption of the oil spill ring was universal, for aircraft with both DH and Rotol spinners - as the two were interchangeable (given the right control systems) this is presumably a matter of standardisation covering both ease of production and ability of change the unit at any time without further modification.  

 

I don't believe that my views differ from the established story - or rather stories as there does not seem to be a single source covering the entire programme.  If you wish to argue that early spinners had the same diameters as the cowling ring, then we need to see the actual dimensions, for this is not what is visible.  Similarly for the later spinners not being of smaller diameter.

Thank you Graham.

I am very conscious that you have great knowledge of matters aviation. 

 

The Hurricane nose is certainly an interesting shape.

 

Would you be kind enough to provide a photograph of the ‘privately owned Hurricane’ as I may not have seen it. I would certainly like to understand why there was a need for a ‘new nose.’ Any explanation you could add to the photograph, assuming you are able to post or link same, would greatly assist as you have no doubt made a reasoned analysis and I would not wish to have missed anything.

 

As to additional photographs, there are many and various posts and photographs on this site. Are there any particular ones you had in mind? Narrowing down some examples would be helpful in my understanding of where you believe I have erred. Waving in a general direction is not particularly helpful.

 

I do not have a reference to dH Spitfire spinners being fitted to Hurricanes. Again, it would be much appreciated if you could share your source(s)/links.

 

Thanks in anticipation.

[gingerbob]

 

15 minutes ago, V Line said:

Would you be kind enough to provide a photograph of the ‘privately owned Hurricane’

 

G-AFKX, one place to see the profile photo is p.37 of the "All the Hurricane Questions..." thread.

 

[Graham Boak]

Hawker's personal Hurricane was G-AFKX (ex-L1606) used as a test machine.  If you search for it, you'll find it has been discussed before on this site.  The difference is entirely (I judge) in the cowling ring, which tapers less to the spinner, meeting the diameter of the spinner.  There is a clear photo in Mason's The Hawker Hurricane published by Aston Publications (and again by another publisher more recently - Crecy?).  Despite some faults this book is still the best single account of the aircraft.  Photos of production Hurricanes with this Rotol spinner show a step down to the cowling ring.

 

I'm afraid that I don't keep an index of what is in the Hurricane posts on this site,  As a short cut to these you can search under Rotol or DH propellers,  adding Hurricanes of course!  Troy Smith has posted a number of useful posting about these matters (and many others) so including him in your search terms would help.  Perhaps the best thing to do is to go to the main Hurricane thread and work backwards,

 

Tanks Bob: our postings crossed.

[Troy Smith]

1 hour ago, V Line said:

I do not have a reference to dH Spitfire spinners being fitted to Hurricanes. Again, it would be much appreciated if you could share your source(s)/links.

DH Spitfire units were fitted before the DH Hurricane units became available from what I can see in the photographic record. 

 

Note the Hurricanes exported to Finland and Romania have the DH Spitfire unit,  as well as the first RAF Hurricanes with DH unit.

 

BUT, older Hurricanes initially fitted with the 2 blade wood prop mostly seem to have then been upgraded with the DH Hurricane unit,  so these are  far commonly seen on early Hurricanes.

 

this shows them in comparison, 

N2358 has the Spitfire DH unit, N2479 has the Hurricane DH unit.

As can be seen the Spitfire DH is wider and blunter, and overhangs the nose ring, the Hurricane DH is more pointed and is correct diameter.

 

The linked thread needs editing and tidying up,  as it has had a few revisions over the years. (including your input on the ES/6 spinner from the CM/1 vs ES/9 spinner thread) 

 

 

[Graham Boak]

One area I meant to address above (but dinner was called) was the general undesirable nature of open spaces facing into the wind.  These cause drag.  Plus the air that goes in needs to come out again, so some vent/exhaust is required.  There does not seem to be any such on the Hurricane.  Further, just having the wind blowing freely past the outside of the engine would be a very inefficient way of cooling the internal fluids, and is not seen on other inline engines.  There are specific examples of small vents, such as the examples on the Bf109F and G, where small amounts of air are directed at specific parts of the engine accessories, but these are just that: small and specific.  Not an entire ring around the outside of the spinner.

 

PS  The Hurricane does seem to have two small vents, on the low sides of the cowling ring (other than early Mk.Is).  However these are actually bulges to cover the vacuum pump for the instruments and the Constant Speed Unit, but the full tear-drop shape would stick out ahead of the cowling ring, so they are cut short.  These are present on most production Mk.Is, even before the actual equipment was fitted, because the mountings for them came as part of the Merlin III, and the production was standardised early.  That's why the early production machines ended up back at Hawkers early for refit with the two-part cowl ring and Merlin III rather than earlier single piece example, which must have been more awkward to make.   Also how L1606 became conveniently available for Hawkers to buy back.  Also the two-cannon example?

[V Line]

3 hours ago, Graham Boak said:

Hawker's personal Hurricane was G-AFKX (ex-L1606) used as a test machine.  If you search for it, you'll find it has been discussed before on this site.  The difference is entirely (I judge) in the cowling ring, which tapers less to the spinner, meeting the diameter of the spinner.  There is a clear photo in Mason's The Hawker Hurricane published by Aston Publications (and again by another publisher more recently - Crecy?).  Despite some faults this book is still the best single account of the aircraft.  Photos of production Hurricanes with this Rotol spinner show a step down to the cowling ring.

 

I'm afraid that I don't keep an index of what is in the Hurricane posts on this site,  As a short cut to these you can search under Rotol or DH propellers,  adding Hurricanes of course!  Troy Smith has posted a number of useful posting about these matters (and many others) so including him in your search terms would help.  Perhaps the best thing to do is to go to the main Hurricane thread and work backwards,

 

Tanks Bob: our postings crossed.

The test Hurricane photograph which Bob kindly referenced, I have seen before and studied.

 

Mason (p36/pictured p37) states that the first tests of a 10ft 6ins dia. constant speed Rotol airscrew on the Hurricane was undertaken from January 1939 using G-AFKX (formerly L1606).This aircraft to was from the first production batch with the one piece cowl collar purchased back from the War Office and re-fitted with a Merlin III engine.

 

I believe it was around this time that the production 2 piece version was being introduced. It clearly wasn’t fitted to this aircraft at the time of the photograph. The pictured cowl collar (‘widened nose’) is clearly a bespoke modification and would allow for the vacuum pump and constant speed unit. This, I believe, explains the ‘need for a new nose’ which is not the reason you suggest. 

 

Careful examination of the photo suggests to me there is no cowl bulge at 8 o’clock, as was found in the production version (perhaps you saw it differently but it is an important point).It should accordingly be expected to be consistently wider toward at least a section of its outer edge for that reason alone. Thus, it is logical that the cowling form was not determined entirely by the airscrew spinner. There would probably have been an attempt at streamlining but note also the large ‘step’ below the spinner.

 

It seems to me like a typical ‘test’ cowling for new installations.

 

In any event, I very much doubt the spinner was a Hurricane ES6 as put into service. This certainly applies to the blades (probably magnesium) and probably other elements of the airscrew. I believe Rolls Royce were leading the airscrew development at this stage when there was still work underway on selecting the preferred blade root size for the airscrews which seemed to be the primary engineering concern at the time.

Finally, again and importantly, as regards the matter at hand, the cowling collar was not the production two-piece version with its nuanced contours. The photograph does not support a view that the service Hurricane spinner was ‘too wide’ as there is no like for like comparison.

 

I believe my assessment to be properly researched, logical and in accord with the photograph.

 

I am afraid you took my speculative point on the later spinner/engine cooling off on a tangent in company with some red herrings but I note your comments below. I do not disagree about the downsides which I alluded to in my post. No time now, but I will get back to the spinners at a subsequent point.

 

I have read that Hurricanes were notorious ‘flamers’ when hit due to the draught flowing into the cockpit. Probably down to the cockpit/wing opening/wing tanks.

 

[V Line]

2 hours ago, Troy Smith said:

DH Spitfire units were fitted before the DH Hurricane units became available from what I can see in the photographic record. 

 

Note the Hurricanes exported to Finland and Romania have the DH Spitfire unit,  as well as the first RAF Hurricanes with DH unit.

 

BUT, older Hurricanes initially fitted with the 2 blade wood prop mostly seem to have then been upgraded with the DH Hurricane unit,  so these are  far commonly seen on early Hurricanes.

 

this shows them in comparison, 

N2358 has the Spitfire DH unit, N2479 has the Hurricane DH unit.

As can be seen the Spitfire DH is wider and blunter, and overhangs the nose ring, the Hurricane DH is more pointed and is correct diameter.

 

The linked thread needs editing and tidying up,  as it has had a few revisions over the years. (including your input on the ES/6 spinner from the CM/1 vs ES/9 spinner thread) 

 

 

I believe there were two dH types, both Hurricane versions. I will return to this when I have some time. 

[Graham Boak]

I agree entirely with your first three paragraphs up to the step below the spinner, which I do not see.  The new shape may indeed include the two bulges on the standard cowl ring, as would be sensible to at least minimise these, but the streamline shape is simply to meet the diameter of the spinner.  You may well be right about the blade: I am not certain about the shape of the early magnesium ones, but suggest that the size of the spinner was dictated by the internal mechanism (and the diameter of the Spitfire's cowling) rather than the external shape of the blade.  Otherwise it is difficult to understand why it took Rotol so long to come up with the "bullet" spinner designed for the Hurricane.  The magnesium blades were used on one Spitfire squadron at the time of Dunkirk, presumably with this shape spinner.  If it differs slightly from the final shape(s?) seen on the Spitfire and Hurricane with the wooden Rotol blades I would not be surprised but this must be marginal.

[ClaudioN]

A few Hurricane Mk. II radiator housings.

 

https://www.worldwarphotos.info/wp-content/gallery/uk/raf/hurricane/Hawker_Hurricane_assembly_radiator.jpg

 

Square intake

Mk. IIB

RAF FIGHTER COMMAND 1939-1945. © IWM (HU 107414) IWM Non Commercial License

HURRICANE (HAWKER) MARK IIB. © IWM (CH 3525) IWM Non Commercial License

 

Mk. IID

ROYAL AIR FORCE FIGHTER COMMAND, 1939-1945.. © IWM (CH 18134) IWM Non Commercial License

 

Mk. IV

THE HAWKER HURRICANE MARK IV. © IWM (MH 4942) IWM Non Commercial License

 

Rounded intake

Mk. IIB

https://www.worldwarphotos.info/wp-content/gallery/uk/raf/hurricane2/Soviet_Hurricane.jpg

 

INDIAN PILOTS TRAIN FOR THE INDIAN AIR FORCE. © IWM (IB 1330) IWM Non Commercial License

 

Mk.IIC

ROYAL AIR FORCE FLYING TRAINING COMMAND, 1939-1945. © IWM (CH 10090) IWM Non Commercial License

Edited January 12, 2021 by ClaudioN

[Graham Boak]

Thanks Claudio, but I see the Mk.IId example as being round rather than flat-sided.  We've now seen clear examples of both on Mk.IIs, and not necessarily Canadian ones.

[StevSmar]

On 1/10/2021 at 4:39 PM, Gomtuu said:

...Now you can this 2 ways - you can take it literally and have a 2.07" parallel section of profile OR adjust the front loft profile to account for the increased depth. I would suggest maybe UK did it one way and Canada the other?...

That is possible. If you look at the glare shields it seems that Canadian Hurricanes have them fitted "upside down", so sometimes the drawings are not quite clear...

 

So if Hawkers never produced a drawing for the MkII radiator and just relied on the shops to adjust their production jigs accordingly (maybe Canada did do it the correct way and the UK's are all incorrect- with tongue in cheek of course)

[ClaudioN]

10 minutes ago, Graham Boak said:

Thanks Claudio, but I see the Mk.IId example as being round rather than flat-sided.  We've now seen clear examples of both on Mk.IIs, and not necessarily Canadian ones.

After using the magnifier feature in the IWM web page ('+'), I'd disagree with you on the Mk. IID.

 

Concerning Canadian Hurricanes, we should perhaps try to agree on what we mean by this. Do you take "Canadian" to be only a "Mk. XII serving in Canada with the RCAF", or could it also be a "CCF-manufactured Mk. IIB, whatever its eventual fate, including dispatch to SEAC, Russia and conversion to Mk. IIC"?

In the latter case, possible candidates are more than twice the number and, at the moment, I'd feel we do not have enough evidence to rule out entirely a Canadian connection.

 

Restored warbirds are a different matter and, from what I can see, AE977 and BW881 have the squarer intake, 5481 and some other one have the rounded one. All of them are Mk. XII.

[Graham Boak]

I was referring to Troy's suggestion that there was a different radiator shape on Canadian-built Mk.IIs, and that this was the more curved one.  On the Mk.IId, I see the shape outside the port undercarriage kleg as being more curved.

 

One other source of a difference could of course be Hawkers or Glosters.  However getting clear views of the front of the radiator housing and the serial is difficult.

[ClaudioN]

43 minutes ago, Graham Boak said:

I was referring to Troy's suggestion that there was a different radiator shape on Canadian-built Mk.IIs, and that this was the more curved one.  On the Mk.IId, I see the shape outside the port undercarriage kleg as being more curved.

 

One other source of a difference could of course be Hawkers or Glosters.  However getting clear views of the front of the radiator housing and the serial is difficult.

I agree getting a clear view is difficult indeed. I made a quick search through all IWM photos and those I posted are the least ambiguous, still the Mk. IID is proving less convincing than others.

The "squared" intake appears to be the norm to me, so unless an intake looks "positively round" I am still assuming it to be the "standard" (i.e., "squared") shape.

 

About "Canadian" I was taking Troy's suggestion, too.

"Rounded" intakes seem much harder to find and the three examples I posted might all conceivably come from a Canadian production line. Many of the Mk. IIB (Canadian) went to the USSR and several reached India. Photos of both the Russian and the Indian one show the row of rivets ahead of the windscreen that is associated with the anti-glare shield, a feature that was common in Canadian-built machines and often removed later. Some Mk. IIB (Canadian) were converted to Mk. IIC in Britain and retained there. Such minor details do not "prove" the Canadian connection, but might suggest some care in dispelling it.

 

How I'd love to see a clear front view of a FAA Sea Hurricane during Operation Torch.

Edited January 12, 2021 by ClaudioN

[Gomtuu]

1 hour ago, StevSmar said:

 

 

So if Hawkers never produced a drawing for the MkII radiator and just relied on the shops to adjust their production jigs accordingly (maybe Canada did do it the correct way and the UK's are all incorrect- with tongue in cheek of course)

That drawing is for the mk.ii and the mk.V and shows the side elevation

[dogsbody]

Claudio's photos from above, but larger:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Chris