manifold with 'flats' and threaded inserts ?

[AnimalJack]

I was wondering if anyone knew what the threaded inserts would be for on this manifold .Ive not come across the 'flat' bits before either (Apologies for the spark pug bung-temporary measure )
there is also a breather on the front engine plate which has no hose - but there is no connection on the carb - so I was wondering if that should be running to the air filter connector .[frame][/frame]

[andypocock]

I'd guess it was to suck in the oil fumes from the rocker cover / timing chest vents

Handy if you want to add a brake servo too.

Andy

[bmcecosse]

Nothing significant! Don't worry about them....

[philthehill]

The central threaded fitment (blocked by spark plug) is where the Pollution Control Valve (PCV) (Pt No: 13H5191) fits.
The other non drilled/tapped bosses are for a servo take off and other pollution control fitments.
The PCV valve connects to the crankcase or cam follower cover by a pipe and takes fumes on overrun via the carb to be burnt in the combustion chamber.

[bmcecosse]

Or it can be servo take off as already mentioned.

[AnimalJack]

Thanks !
I was thinking of splitting the in and out - using another standard one ,
but I didn't want to cut this if it was a rare one .

[philthehill]

The manifold is not particularly rare.
The extra connections to the manifold were for additional pollution controls as required for the North American and Japanese markets.
Those requirements were not needed in the UK home market.
B/L produced common/generic manifolds and just added the additional connections as and when required.
Therefore I would have no qualms in splitting the manifold.

[bmcecosse]

There's certainly nothing 'rare' or 'valuable' about it... As ever - a separate inlet manifold - ideally a better shape than the standard one - is worth 2 or 3 extra BHP by eliminating the Hot Spot.

[philthehill]

Whilst I agree with you to it not being rare or valuable it is not currently specifically listed in any parts catalogues that I can find so I am unable to put the designated part number against this manifold.
Currently the nearest I can find is manifold Pt No: 12A1097 with fitments/studs suitable for HS2 carb but does not appear to have the front boss.
The manifold may have originally been fitted to a 850cc Mk 1 Mini as there is one for sale on 'e' Bay which has the three bosses and the central one has the PCV valve fitment and has Pt No: 12G1514 cast onto it.

There again the manifold may be more valuable than first thought

See 'e' bay item No: 141382769018 and take a sharp intake of breath.

[aupickup]

http://www.ebay.co.uk/itm/141382769018? ... 26_rdc%3D1

[bmcecosse]

Oh but that's been 'Downton' modified! And the magic words 'Special Tuning' too in the advert... Although what evidence (or advantage..) there is in any of that I can't really see......

[aupickup]

of course

[AnimalJack]

Thanks again........... If anyone wants to swap it for a standard one just let me know .....I probably wont do the surgery until the weekend

[bmcecosse]

Why are you contemplating surgery? Do you have a better exhaust to fit? Or a an alloy inlet manifold?

[AnimalJack]

...it was just to eliminate the hot spot .
Ive held on to my Mr Grumpys * old kit for the reservoir shield and the petrol pipe coming off the pump , so I thought I would separate the inlet/exhaust aswell . you can just about see them * on the photo

[AnimalJack]

HOLD THE BUS ! Ive just seen the one you mean on Ebay .........that's a bit steep in it !?

.........on second thoughts ......

does anyone want to make me an offer on an extremely rare manifold !!!!!!

[bmcecosse]

Is it stamped 'Downton; or 'ST' ??

[philthehill]

Or even Les Ryder

[bmcecosse]