Interesting manifold and carb…

[Henry Harris]

The Lotus manifold.....

   

https://www.flickr.com/photos/henryharri...6/sizes/l/

[John Cornforth]

Hi

The carb looks like it is a progressive type. ( Nothing to do with 1970's music ! )

At low airflow just one barrel is used, to keep the air speed up and give good atomisation. When the first throttle butterfly gets to about 2/3 rds open, the linkage (or sometimes a vacuum capsule) rapidly opens the secondary barrel to cope with increased airflow. Both throttles end up fully open at the same point. Often the cold start choke flap is only fitted to the primary barrel.

As such, it is designed to feed all 4 cylinders.

The airflow capability is probably way in excess of even a tuned 747 cc engine, so it would be quite happy on just the primary barrel.

[Lowespeed]

I used the exhaust manifold for a while with 11/8th downdraught SU. Seemed to work just as well as the steel tubular type. However the one I had, had been welded up at the outlet end and looks quite thin at that point. Probably broken at some time where it narrows in.

[Duncan Grimmond]

Never come across 11/8th before...is this some arcane nomenclature?

[Tony Griffiths]

Never come across 11/8th before...is this some arcane nomenclature?

No, just the difficulty of writing, in digits, one and one-eighth inches. It can be done, but not on our standard page. But, when starting a new thread, if the four green 'arrows' tab on the top toolbar is clicked, the page becomes 'PHP' (Hypertext Preprocessor) where, among the new toolbar tabs across the top of the page, you'll see a capital A with a red arrow. Click that and the font size can be changed e.g. 11/8  This is getting bigger and bigger Then, changes made, click the 4-green arrows box and you are taken back to the standard page.
It can also be done by writing in Word or similar where there's access to changes in font size and then copied and pasted. 11/8"

[David Stepney]

That all sounds a bit complicated, Tony. IfI want to use Imperial measurement ('Proper Christian measurement' as my first boss would say) , I simply put a space between the integer and the fraction thus: 1 1/8.

[Tony Griffiths]

That all sounds a bit complicated, Tony. IfI want to use Imperial measurement ('Proper Christian measurement' as my first boss would say) , I simply put a space between  the integer and the fraction thus: 1 1/8.

Indeed, a far better solution. Long live Imperial! Amusingly, I receive many requests for belts with dimensions in both metric and inch e.g. 3.2 cm wide and 4 feet long. Or, even better, "A round belt 5 mm in diameter and 30 mm long" - where the 30 mm should be 300 or even 3000 mm. Old dogs, new tricks, eh!