How wide is a 'coffeepot' expansion chamber ?

This topic has 7 replies, 4 voices, and was last updated 9 years, 10 months ago by Dripfeed.

Viewing 8 posts - 1 through 8 (of 8 total)

Author

Posts
14th November 2013 at 4:09 pm #3500

BRIAN MARSHALL
Participant

Hi, I’m starting to fabricate a ‘coffeepot’ front expansion chamber, as fitted to short-stroke Flyers from about 1929 to 1934, and I need to know the width of the basic steel chamber, not including the end caps. Could someone please give me that dimension ? Also, do the two inlet stubs enter the coffeepot on its centreline, or are they at a tangent ? Many moons ago I had a drawing, done by John Underhill, but I must have loaned it to somebody, never to be seen again…
Brian

14th November 2013 at 4:46 pm #11676

dave bushell
Participant

Hi Brian
Mine is 10 5/8″ to the edges of the cast ally end caps. Just How far they enter I don’t know, probably a 1/4″, I didn’t want to dismantle it on the bike and break the seal. The two stubs appear to enter on the centre line.
Dave

14th November 2013 at 5:59 pm #11677

BRIAN MARSHALL
Participant

Thanks Dave !

15th November 2013 at 10:49 am #11678

Ian Parsons
Keymaster

I have a complete coffee pot expansion chamber with end caps that I do not need. It was made by Ken Lack about 30 years ago and has had very little use. It was on my 1929 Flyer when I had a S/Stroke engine in it. I later fitted a L/Stroke engine so did not use it as the L/S engine has different exhaust port dimensions.

15th November 2013 at 1:05 pm #11679

BRIAN MARSHALL
Participant

Hi Ian, The one I am making is to go on 1929 TT3, WX179, which has a longstroke engine with the bigger exhaust ports, so yours would very unfortunately not be suitable. Many thanks anyway !
As more photographs of the 1929 Isle-of-Man Senior TT bikes are slowly coming to light, I have found that about half of them had ‘coffepot’ front expansion chambers, with the others having the 2″ left-hand siamesed pipes. Perhaps a matter of rider preference if they gave different performance characteristics. Sid Gleave even had a celluloid ( ? ) clear windscreen atop his front racing number plate.
Brian

15th November 2013 at 6:52 pm #11680

Dripfeed
Participant

Hello ian if Brian is not in need of your coffee pot I need onefor my S S flyer that is at present fitted with a l h Siamese pipe if for sale would you give me a shout .Regards D F.

21st November 2013 at 9:59 am #11681

Ian Parsons
Keymaster

I sent D/F a pm. have you read it?

21st November 2013 at 6:42 pm #11682

Dripfeed
Participant

Hello Ian . Yes received your message and have emailed you I guess that you did not receive it . I will have another try . Regards D F .
Author

Posts

Viewing 8 posts - 1 through 8 (of 8 total)

You must be logged in to reply to this topic.