Saving Old Seagulls

H all. Just wondering if any of you racers can tell me the best way
to marry a featherweight box to a 102 top end?
The waterpump housing of the featherweight doesn't
line up exhaust wise and if I use the waterpump housing
of the 102, the screw holes don't line up with the featherweight
box. Do I need to make an adapter plate, or is there an easier
way?
Any ideas appreciated.

Hate to say it but the easiest way is to get hold of the right gearbox...

Normally you'd be right, but my plan is to build an engine
capable of higher speeds. Apparently changing the
gearbox ratio is essential.
Appreciate the reply though.

Ah... I see now.

The other Charles will doubtless be along soon. I'm sure he will have some input here.

I imagine the exhaust diameter is the prime consideration.

Come on lads! Let the secret out!

I will be pleased when the other Charles explains because I have a featherweight box which would fit straight on (when I fit it)
He told me once why, and I have forgotten. Stupid . . .

Get the water pump housing off a Century 100,which has the 40 style gearbox, but with a large exhaust. Bolt up to the featherweight gearbox.

A Ha! Easy when you know how I suppose.
Thanks rosbullterier. Now I just have to convince "herself" that
I need yet another seagull.

PM me your landline number & I'll talk you through it.
There is a little bit more to it than RBT suggests, don't worry I'm on free calls to your place.
Charles

-it was Phil who gave the info - why not talk us all through it?

You could just fit the 102 and exhaust to a 40 driveshaft and gearbox (just overlap the exhaust at the bottom) and the water delivery pipe will need to be straightened and shortened.

You could fabricate a 102 to 40 exhaust pipe, and do as above.

I have as you see got both .... even by swapping props, it doesn't seem to make any difference

Nice bit of work Rob on the diameter change.

Which prop are you using?

Seagull's own figures show that the longshaft version of a motor produces 2% more power than the short, thats why we don't reduce the exhaust volume.

There are no bolt on performance parts for any of the Seagull powerheads.

Which prop am I using?

Any of the 'small' collection.

Very impressed with your metalwork but as Charles comments, your pipe also reduces the exhaust expansion chamber.

I don't understand - I thought the high ratio box was the Featherweight. If so, what advantage would the standard 40 box provide?

Wow! Nice work there Rob. The graduated exhaust certainly
looks great but I think performance would suffer. Charles
has set me on the right track ( thanks Charles) on this and
many other speed related issues. A goldmine of tuning tips.
All I have to do now is buy more seagulls and start experimenting!