1275 mini engine covert for morris

Discuss mechanical problems here.
Forum rules
By using this site, you agree to our rules. Please see: Terms of Use
Post Reply
andrew.searston
Minor Addict
Posts: 687
Joined: Sun Apr 19, 2009 8:55 pm
Location: kenilworth
MMOC Member: No

1275 mini engine covert for morris

Post by andrew.searston »

Hi everyone
I’ve been offered a 1275 a series mini engine but curious how easy it is to swap crank to convert for inline what’s same and whats needed, is it a easy worth while thing todo or look out for another engine, I’d rebuild whatever engine I get anyway
Thanks
[sig]9671[/sig]
philthehill
Minor Maniac
Posts: 10767
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: 1275 mini engine covert for morris

Post by philthehill »

It can be done but not easy.

For a taster and not the complete process:-

New rear main bearing cap required with top half oil catcher. Line boring required.

Oil pick up is different and needs to be resolved.

Changing the crankshaft requires the corresponding rods and pistons. Plus the flywheel & clutch.

To be honest with the machining costs and replacement crankshaft/rods and pistons etc - unless I was using a cooper S 1275cc block I would not undertake the conversion.

Using the 1275cc Cooper S block in a Minor has been done before and the car was successful in autocross.

Personally I consider that it is much easier to obtain and convert a Marina/Ital or Midget/Sprite engine.

Phil

callyspoy
Minor Legend
Posts: 1110
Joined: Sun Jun 24, 2007 10:00 pm
Location: Sunny Portsmouth
MMOC Member: No

Re: 1275 mini engine covert for morris

Post by callyspoy »

Aye up,
Pretty much a no go with the Mini engine. Too many differences to get it to work, i am sure there was once a conversion, but it is not a thing i have ever seen.
You can strip a 1275 Mini engine of its components to fit to your engine (cylinder head, alternator, carburettor, cam) and you'd have a good upgrade to a standard Minor engine, but probably not cost effective.
Quite a few 1275 Marina/Midgets popping up on ebay at the moment though.
callyspoy
Minor Legend
Posts: 1110
Joined: Sun Jun 24, 2007 10:00 pm
Location: Sunny Portsmouth
MMOC Member: No

Re: 1275 mini engine covert for morris

Post by callyspoy »

Ha, posted same time as Phil. He knows his onions 👌
philthehill
Minor Maniac
Posts: 10767
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: 1275 mini engine covert for morris

Post by philthehill »

Please note:
No onions were harmed in the prognosis of the conversion. :roll:

The Miller Minor also used a Cooper S block.
img087.jpg
img087.jpg (637.24 KiB) Viewed 1340 times

ManyMinors
Minor Legend
Posts: 2752
Joined: Tue Nov 11, 2014 9:41 am
MMOC Member: No

Re: 1275 mini engine covert for morris

Post by ManyMinors »

Yes, but that was in the days when you could buy a Cooper S 1275 engine without having to re-mortgage your house first! Even Midget 1275 engines (probably the best option) are becoming scarce and expensive now.
philthehill
Minor Maniac
Posts: 10767
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: 1275 mini engine covert for morris

Post by philthehill »

Everything is relative and nothing gets cheaper.

If you do not mind doing some work how about this:-

https://www.ebay.co.uk/itm/MG-MIDGET-MO ... :rk:1:pf:0

and not expensive.

The thrust of the question was - can a Mini engine be converted to be used in a fore and aft orientation in a Minor - yes it can but at a cost and the only transverse engine worth converting to a in line configuration against cost is a 1275cc Cooper S otherwise a Marina/Ital or Midget/Sprite is more than suitable.

The 1275cc Maestro engine (with rear crankshaft seal) can be converted but they are possibly even rarer than the Marina/Midget and conversion parts are now very limited if available at all.
Maestro engine 4..jpg
Maestro engine 4..jpg (315.28 KiB) Viewed 1301 times
Phil

oliver90owner
Minor Legend
Posts: 1653
Joined: Thu May 12, 2016 6:33 am
MMOC Member: No

Re: 1275 mini engine covert for morris

Post by oliver90owner »

Phil,

That advert says missing the head. With all those pics and other gaff, one might hope they mean only the manifold is missing, not the head. A difficult one for epay to sort out if the buyer finds they have been done over!
philthehill
Minor Maniac
Posts: 10767
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: 1275 mini engine covert for morris

Post by philthehill »

This is my thinking behind suggesting the Midget engine in the link above.
If the OP has been offered the 1275cc Mini engine and it is complete the missing parts from the Midget engine i.e. head etc can be replaced by utilising parts from the 1275cc Mini engine.
That is one good thing about the 'A' Series many of the parts are interchangeable.
The OP has stated that they intend to rebuild what ever engine they acquire.
Fitting any other 1275cc engine that is Marina, Ital or Maestro it is going to cost money for conversion parts and machining.
The Midget engine in the link above may not be perfect but it is a start and having the engine number tag still in place is a good indicator that the engine has not been re-bored.
Not being able to turn the engine over is not the end of the world.
The OP can always send the seller a message asking for further details and the engine is open to offers as well.
Phil

Post Reply