1 1/2" carb. and manifold

[Captain flint]

Hi all,
First of all many thanks for all your comments on my previous post,ref,1275cc Midget engine mated to 5 speed Ford box.
This time I am asking if the 1 1/2" cast manifold and 1 1/2" SU carb.will be inferior to a four branch exhaust manifold
and an alloy inlet manifold? This is to fit my 1275cc MG Midget engine Minor.
O.K, I guess the answer is 'yes it is!'
The point I am trying to make is this,I am not a boy racer,much too old! but would like a few more horsepower
for the traffic light GP!
Without spending a fortune(poor old pensioner!) would this set up be suitable for my purpose.
All comments gratefully received.
I do not have the original carb and exhaust and the carb and manifold described are what I have in stock.
Many thanks for looking.
Martin.[frame][/frame]

[bmcecosse]

You'll only have a 4 branch exhaust if you fit an 8 port head? Is that the plan ??? Let's assume not - in which case a 3 branch exhaust is what you want, but on an otherwise standard engine - it will not show any great improvement (and maybe some low revs loss). The alloy unheated inlet manifold is very well worth having though - so start off with that. Get one designed for the larger 1 .75" carb (it will still take the 1.5" carb) and then later if you further improve the engine, it will be easy to upgrade to the larger carb.

[amgrave]

I think the 1 1/2" carb and manifold are the standard for a 1275 engine. You would gain a small amount of extra power by fitting a ally inlet manifold and not heating it and using the carb you have. You can pick up the 1 1/2" inlet manifold for around £35. BMC beat me to it as I was writing

[Captain flint]

Doh! yes I meant a 3 branch exhaust manifold,not4 !
Can I cut off the inlet part of the manifold shown and then get n alloy replacement?
What would be the designation of a suitable 1 3/4" SU?
Advice much appreciated!
Martin.

[bmcecosse]

Yes - just cut it off. And search ebay for a 'good buy'. This is one of the best designs - and I 'think' for the larger carb - but ask them -or just buy it - it's money in the bank and wil always hold the value. I used to get them for £5 !
http://www.ebay.co.uk/itm/Classic-Mini- ... SwO~hXIR8s

[Captain flint]

Many thanks BMC, got it!

[Captain flint]

With reference to my 1275 Midget engine transplant, I am now learning all things are not quite a they seem!
I have at present a ford type 9 gearbox,ford clutch fitted to a standard 1098 Minor engine.
Having taken all the kind advice,I have contacted David Manners and they will fix me up with a suitable flywheel.
BMC found me a Minisport manifold,see I do take all comments on board!
Oh,better get to the point before I bore you all to death!
I hadn't realised that the 1098 and 1275 back plates were different,what alternatives do I have to overcome this
conundrum?
One other thing,the Minisport manifold has a four hole fixing for a HIF carb,but the carb I have in stock is
a 1 1/2" HS4 two hole diagonal fixing,this seems to line up with two holes on the manifold,do you think I can use this?
Once again all comments appreciated.
Martin.

[bmcecosse]

Yes you use the 2 bolt carb - and yes you need a 1275 backplate - or you 'can' modify the 1098 backplate - but many will say don't do it.

[philthehill]

Reference rear engine plate:-
Purchase a rear engine plate from ESM

http://morrisminorspares.co.uk/shop/pro ... c448223fe3

Whilst some do modify the 1098cc rear engine plate to fit the 1275cc engine I personally would not do so as they can crack between the rear main cap aperture and the oil pump aperture.

The carb will be perfectly ok using just the two studs provided the carb and manifold holes line up.
Phil