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1275 questions
Posted: Fri Nov 02, 2012 2:14 pm
by 54woody
I picked up a 1275 midget engine (12CDUHxxxxx) the other day which will be replacing Woody's current 948. The internal state of the 1275 is a bit of an unknown, although it looks quite decent from the outside. The head and most of the ancilliaries are currently detached from the engine. Chap I bought it from had purchased the engine in it's current state two years ago. He said the PO had told him that the head had been "redone", whatever that means. I'm sure I'll have all kinds of questions over the next little while as I check it out to determine how much freshening or rebuilding will be required.
First question is about carbs. The engine came with a pair of HS2's in unknown condition mounted on a standard midget inlet manifold. My goal is to keep the engine bay looking somewhat normal, so I'll probably retain the existing exhaust system and stick with a single carb. I'm thinking a 1.5". I have access to a 12g787 inlet/exhaust manifold (from an austin america I think) which accepts a single HS4. The diagonal mount on the manifold means that the HS4 fuel bowl would be on the rear side of the carb rather than the front side. Is that going to be a problem? Would I be better with an HIF38?
Re: 1275 questions
Posted: Fri Nov 02, 2012 3:17 pm
by bmcecosse
Clean up the useless HS2s and flog them. Note they are no use on a Mini (wrong angle) . Yes - much better with a big single -float bowl at the rear is ideal. And HIF 38 is a bit better from a surge point of view but no better on power. Well worth 'Vizardising' the carb - and now is the time to consider a camshaft upgrade to the engine before you install it. MG Metro or ~= 266 well worth having.
Re: 1275 questions
Posted: Fri Nov 02, 2012 3:36 pm
by brucek
HIF 44 probably a better carb than the HIF 38. 44 was fitted to the 1275 MG Metro

Re: 1275 questions
Posted: Fri Nov 02, 2012 3:52 pm
by bmcecosse
Yes - but not necessary unless fitting big valve head and fancy exhaust. The HS4 will be fine - better if Vizardised.
Re: 1275 questions
Posted: Fri Nov 02, 2012 3:56 pm
by 54woody
bmcecosse wrote:Yes - but not necessary unless fitting big valve head and fancy exhaust. The HS4 will be fine - better if Vizardised.
I do have a copy of David Vizards book but I'm not familiar with what you mean by "Vizardising" the carb.
Re: 1275 questions
Posted: Fri Nov 02, 2012 3:59 pm
by bmcecosse
Well - your bedtime reading is the section where he tells you how to improve the SU carb !!

Re: 1275 questions
Posted: Fri Nov 02, 2012 4:30 pm
by JOWETTJAVELIN
On the HS4 I presume this includes making some form of alteration to the float-bowl to prevent the annoying cutting-out on sharp bends at low speeds?
Re: 1275 questions
Posted: Fri Nov 02, 2012 5:37 pm
by bmcecosse
No - that's why you upgrade to the HIF.......
Re: 1275 questions
Posted: Fri Nov 02, 2012 5:46 pm
by JOWETTJAVELIN
Aye, but they cost money and condition can be unknown.
I'll put up with it stalling for now...
Re: 1275 questions
Posted: Fri Nov 02, 2012 6:18 pm
by bmcecosse
Make sure the fuel level is correct.
Re: 1275 questions
Posted: Sat Nov 03, 2012 1:47 am
by mike.perry
You can't beat a pair of HS2s for that classic 1960s tuned engine look
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Re: 1275 questions
Posted: Sat Nov 03, 2012 10:30 pm
by bmcecosse
Back in the days when they didn't know any better!

Re: 1275 questions
Posted: Sun Nov 04, 2012 3:29 pm
by 54woody
Does anybody know if the 12A191 exhaust manifold (see
http://www.moss-europe.co.uk/Shop/ViewP ... ndexID=998) as used on early midget will mate with standard minor exhaust system?
Re: 1275 questions
Posted: Sun Nov 04, 2012 5:00 pm
by IslipMinor
The Sprite/Midget/A30/A35/A40 are all common in general shape, but unfortunately the Minor is unique!
Re: 1275 questions
Posted: Sun Nov 04, 2012 5:23 pm
by bmcecosse
Just cut the inlet section off a Minor (or Mini) manifold. I suspect the manifold you show will be angled down too steeply - to put the exhaust tight down the side of the engine and then inside the chassis leg on a Spridget.
Re: 1275 questions
Posted: Sun Nov 04, 2012 5:55 pm
by IslipMinor
Should have said unique to in-line engines - the cast iron Mini manifolds will fit as well to a MInor.