What model is this?

[Keith.P]

Circa early LS?

I would agree with that, or was it the SJ.

[seagull101]

Just had another look, it must be a hinged tiller otherwise the throttle would be visable.

[Charles uk]

So shall we see what we do have,

One SJ series crankcase that is decidedly weird, this appears to be a 2 stud SJ crankcase, the visible stud is in the expected place but the slope which in an SJ case, is in the corners without a stud, in this crankcase is under the stud, so a completely different casting.

Now the cylinder seems to be totally missing the tell tale part of the casting, but the head seems to have room on the outside of it's retaining bolt (which looks very close to hitting the bore) to almost get one in.

The transom bracket seems to have very long legs.

Am I "over thinking" or could this just be an artist's impression?

[Oyster 49]

I did ask the question earlier, is this a photo or an artists graphic? If so then we could be discussing something that did not actually get produced, even as a one off

[Keith.P]

I did ask the question earlier, is this a photo or an artists graphic? If so then we could be discussing something that did not actually get produced, even as a one off

You could be right, the FVP add was not the same motor they sold and I know of one other that never made it to production.
http://www.britishseagullparts.com/40Minus.htm

[headdownarseup]

I wonder if there's any pictures around of the prototype "air cooled" 40. I remember seeing something quite a while ago now which could be along the same lines as this. We might be able to compare one against the other and spot what's different.
Difficult to pinpoint with any accuracy due to the picture quality, but i would think the cylinder on this "thing" probably had a water outlet in the usual place. The shadowing in the picture makes it difficult to see for sure.
Is it an artist's impression or is it another grainy old photograph taken against a white background. Easy enough to do in a photographic studio i would think. Are there any professional photographers on this forum that could perhaps cast a glance over this and give us their ideas about this.(bloody good if it is an artist's drawing)

Interesting all the same in it's unique way

Jon

[Oyster 49]

As per previous questions raised earlier in the thread, is it a photo or artists work? I'm now thinking that it is an artist impression, with a bit of artistic licence thrown in for good luck. I've always found seagullparts.com to be a useful website.

[Charles uk]

Then explain the crankcase Jon.

Oh and the 4 bladed cloverleaf on a featherweight box on the British Seagull parts pic.

[Janzip]

Hi everyone,
isn't it obvious, that is a picture of a secret prototype of the factory, a four-stroke! That peculiar cylinder head has two tiny little valves and rockers!
The push rods were placed in the left and right hand side upper water channels in the cylinder and the camshaft is hidden under the magneto! Brooom!!
Happy new year
Janzip

[Charles uk]

At Last!

A genius in our midst!

Good thinking!

[Hugz]

Four-stroke?

f31d5bf1-1e5e-4a00-8813-6f8eb0c4b736.png (91.8 KiB) Viewed 1006 times

[Oyster 49]

Ah yes the original Marston twin.. What a nice looking engine

[Charles uk]

Sorry to disappoint you, the above Seagull twin was created by Septics not Brummies!

[Keith.P]

What a Marston twin looks like.

[headdownarseup]

4 stroke yeah right. Why didn't we see that one coming
Another nice old advert Keith. Nice one

One thing i can answer with complete confidence Charles is the prop. Yes it really is a real prop fitted to a seagull minus gearbox.
I've got one EXACTLY the same. It's currently fitted on my early SJM. Very cute little prop it is too. Same as a 3 bladed FV prop but with 1 extra blade. I actually acquired it from Jeremy earlier this year, and if it's wrong somehow you can ask him if you like but it is definitely a real prop and NOT a fake. If you look at Jeremy's list of the "little 40" engines, even his own LM which would slightly pre-date what we're talking about here has the same prop just in case you were wondering.


The crankcase after much back and forth i think falls squarely into the SJM/SJP camp with its tilting tiller, but also seeing the way in which the powerhead is attached to the drive tube via 2 bolts in the conventional manner for a 40 series engine made from the SJ series onwards and NOT like anything in the F/FV/FVP/LS camp. Originally i thought it might have been a fixed tiller but as the quality of the picture is fairly poor it's quite difficult to be absolutely sure. The attachment of the cylinder head has me a bit puzzled though. 2 bolts instead of 4? One idea that's rattling around inside my head at the moment with this is it might have been a development motor from perhaps during the SJM run but definitely post LS etc.From what we can see in these images of Keith's so far we can pretty much narrow things down to around 1955/6. SJM's come into production somewhere around here so this has to have been at least developed somewhere in 55/6 going by the powerhead attachment. As this is an image of what appears to be one of the smaller seagulls that we know and love, as Keith has mentioned earlier it probably never got put into full production for quite obvious reasons. If this particular engine really did exist even as a prototype it would need to have a specially fabricated cylinder in order to attach a cylinder head as we see in these images. Quite a costly thing for BS to do even if it was just for testing purposes, but as Keith mentioned a while ago the money for some of this development work possibly came from some time before this, perhaps even from the SD order during the war of 10,000+ units. Nice little earner for somebody with an outboard motor company wanting to develop new motors wouldn't you say.
Fins on aluminium cylinder heads is something that Jeremy and myself have tried to get to the bottom of. If we were to look at any typical "classic" 40 or century series motor that was made they all seem to have fins on the cylinder head. Do these fins actually serve a purpose at all considering the design of the engine's cylinder itself is watercooled? Are they just there to look pretty? Why do all of the classic square block cylinder heads all have fins? Is it possible these fins do actually provide some benefit by air cooling to some degree rather than relying completely on watercooling?
Hear me out here.
Some of us might be thinking that the cylinder head in these images could possibly be watercooled (because there's no fins that we can see) Maybe, then again maybe not but how's this for my interpretation of an LM. Liquid cooled Minus.... gets you thinking doesn't it! After all, the images clearly show all of the components we'd associate with a 40 minus of the time, with the exception of this strange looking cylinder head! In all honesty these images could be anything from BS's development stage that perhaps a photograph or two found its way inside an advertising brochure by mistake back in the day. I still think this is a print taken from an original photograph, just that it's been "tidied up" a bit by not having any unnecessary clutter in the background like anyone with some skills in a photographic studio could easily do back in the day. These images (in my opinion) are far too neat to be an artists hand drawn rendering for my liking. Quite a lot of these earlier seagull adverts seem to have a similar theme in them with plain uncluttered backgrounds, some even against a plain white backdrop if you look. From what i've seen of older adverts,(not just old seagull adverts either) printers ink will begin to fade after some time (depending upon storage conditions of the originals from which these images were reproduced) and i think what we're seeing in these images is possibly a printed copy taken from an older photograph rather than anything an artist would spend a lot of time reproducing. If this really is an artist's rendering then i have to say it's very well done indeed. There are of course a few later adverts that are clearly hand drawn and they're fairly obvious to spot.
Seagull artwork in general is something i've been looking at a lot recently. Cobb and Groves springs to mind, but their "style" is very different to what we see in most of the commercial advertisements.
Here's a good example of what i'm talking about between an artist's rendering and a printed photograph. Artwork at the top of this advert is clearly hand drawn, no question about that, but the image of the Marston seagull is a perfect example of a printed photograph similar to what looks to be in the images of this "experimental" 40. Images become fuzzy after a while, especially where printing is concerned, and from my viewpoint this is what i mean by a printed photo and not necessarily a good reproduction done by an artist.
http://www.saving-old-seagulls.co.uk/ma ... ge%202.jpg

I could ask my father-in-law what he thinks about these images of the "experimental" 40. He used to be a semi-professional photographer back in the late 60's-early 70's and did everything himself including developing all of his negatives in a dark room.
I could also ask a friend who works in the printing industry. He might be able to shed a bit more light over this debate.

Interesting little thing all things considered.


Right, i'm off next door to get drunk with the neighbour. Happy new year all.




Jon