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Aviation Heritage => Restorations => Topic started by: JamesF on October 22, 2011, 04:39:19 AM



Title: Mk IX Carburettor Air Intakes
Post by: JamesF on October 22, 2011, 04:39:19 AM
Well have started (finally) with my Tamiya 1/32 scale Mk IX.  I recall from the SAAF Museum Mk XVI, that it had the longer intake, with a flap at the front, which closed it off, in this config', air would then be drawn down through a coarse cloth type filter, from inside the cowling, through the slotted top if the internal intake trunk.  (This system can be chosen for the model and has been beautifully re-produced by Tamiya).  Quite a clever setup and certainly would have been effective as an anti ice system.  Early Mk IX's however, have the shorter intake.  Was this directly open to the carburettor venturis?  Did it have any filter system?  I suppose any grass or dirt ingested during take off would have been turned into fine garden "mulch" by the supercharger!??  Johhnie Johnson's aircraft (which I've decided to do, seeing I've met him once at a SAAF Association Annual Bankquet, Wonderers Sports Club Johannesburg), has the early short intake as such.  Anyone out there know any tech details on the short intake?   


Title: Re: Mk IX Carburettor Air Intakes
Post by: Edgar Brooks on October 22, 2011, 08:40:16 AM
This is all I have; as far as I can tell, it only had the usual stone filter, which probably means that none of the early conversions went to the Med.
(http://i165.photobucket.com/albums/u79/EdgarBrooks/36138SHT5HAirIntakeContoursMkIX.jpg)
Edgar


Title: Re: Mk IX Carburettor Air Intakes
Post by: Jaybee on October 22, 2011, 09:03:04 PM
Certainly the standard Mk. V intake ( and presumably the MK. IX's converted from Mk. V's ) didn't have any filter, only the Vokes and Aboukir units contained filters.


Title: Re: Mk IX Carburettor Air Intakes
Post by: JamesF on October 23, 2011, 01:33:44 PM
Thanks for that, very interesting.  Nice drawings edgar, I should imagine you would need to be a dab hand at an english wheel sheet metal former, to make one of those!

So I guess the later larger intake with the internal built in filter, replaced the Vokes and the other temporary (for theatre) designs?  Interewsting only a stone guard...Stil raises the question of icing.  With the other system, drawing air from inside the cowlings that would solve the icing problem, but the shorter filter, I suppose would have had an alternate air source for anti ice? The Harvard had a carb heat selector in the cockpit, which if memory serves, drew warm air from the airflow through the oil cooler.  In a Harvard the bottom air intake is oil cooler air, the intake on the LH side of the cowl, is the carburettor intake.