Spitfire mk.I: anti-spin parachute fin guard and strange exhausts?

That does possibly look like the same “early” style exhausts. Hard to be sure from that angle but the first chamber does look quite a bit longer. Cheers. I’d be just as interested to know what the story is behind these early attempts.

[ATTACH=CONFIG]239290[/ATTACH] This early pre war colour photograph clearly shows the elongated leading exhaust stub. It would be interesting to find out what advantage the restyled exhaust stub had over this one.

You can always rely on Forum members for exhaustive details..thanks for making this place special.

To my eye it seem that the exhaust shown in the two b&w photos of K9795 I posted above is different to the colour example on the right of P9374. Both seem to show the familiar Triple Ejector (nozzle type). However the stubs seem to come out at steeper angles than the exhaust on P9374, even more so with the front chamber. I don’t have Andy’s book to hand (it’s in a box since moving house) so perhaps the matter is discussed in there, but I’m just surprised no one has answered with an affirmative or even countered my claim suggesting I’m crackers and seeing things.
The patent Schneiderman posted suggests that the exhaust on the early Spits might have been an intermediate design before the commonly shown Triple Ejector Exhausts – not exactly like what is shown in the patent, but not the final design seen on P9374 either.

PS. If this is too firmly in the rivet counting arena then I’ll get my coat 🙂

The patent design will just be the principle rather than an exact specification for the Spitfire. All the Spitfire exhausts I have seen photos have 2 outlets per box and dont merge before the box.
The front engine compartment curves in to match the spinner so the front exhaust will be slightly more exposed. Also because of the curved panels enclosing the engine views from below this may make it difficult to determine exact angles from a photo,
Andy Saunders fine book “Spitfire Mark 1 P9374” that records its restoration has on page 102 a photograph of some reverse engineered ejector type exhausts that may prove of interest.

I think that patent may point to the answer here. I think these early Spits had a slightly different shaped exhausts than we’re used to. One difference I think I can see with the patent and the first photo on the left is that the last two outlets merge in to the last chamber independently rather than converging first, which the patent suggests. But the more steeply angled rake is very similar.

I was hoping there might be a bit more information out there on this apparent early design? Or indeed for someone to suggest I’m seeing things.

The left hand photograph provided by Matty has what appears to be quite distinct lines on the exhaust stubs possibly caused by weld lines or just reflections. I have been unable to locate close up photos of very early Spitfire exhausts.

So do any of the preserved Mk1s have the early form of the exhaust, where the front chamber has the almost hemispherical leading edge, or are they all as in Robert’s post?

K9942 at Cosford. However your photo of K9795 seems to have an opening at the front.
The Science Museum P9444 and R6195 at the IWM have fishtail exhausts which were fitted later in their service.

And the answer is…
Rolls Royce patent GB506333