1275 marina engine

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Jackmansell
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1275 marina engine

Postby Jackmansell » Sun Mar 22, 2015 9:56 am

Hi all, so yesterday I nabbed myself a bit of a bargain (I think) a marina engine with gearbox, it only cost me 220. I came put of a marina with 78000 on the clock and the guy said it was a great runner hence why he kept it. Couple of questions, the clutch is hydraulic yes? How do I go about converting a moggy to that? Also the output shaft of the gearbox where it bolts onto the prop seems to be bent, is it fixable? Cheers
1969 Trafalgar blue minor saloon, cant ever see me parting with him and its my first car!

bmcecosse
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Re: 1275 marina engine

Postby bmcecosse » Sun Mar 22, 2015 10:05 am

It's not easy to use the Marina gearbox - and it's not a very good gearbox anyway. The normal conversion is to use the ribbed 1098 Minor gearbox, and the flywheel and clutch from the 1098 engine. The flywheel has to be modified slightly to fit the Marina crankshaft - but it's all 'do-able' .
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Jackmansell
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Re: 1275 marina engine

Postby Jackmansell » Sun Mar 22, 2015 10:07 am

This is the joint I'm talking about see how it's slightly bent?[frame]Image[/frame]
1969 Trafalgar blue minor saloon, cant ever see me parting with him and its my first car!

Jackmansell
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Re: 1275 marina engine

Postby Jackmansell » Sun Mar 22, 2015 10:09 am

Bmc, I keep hearing a 1098 gearbox isn't up to the extra strain of a 1300, especially the clutch. What makes the marina gearboxes not so good also?
1969 Trafalgar blue minor saloon, cant ever see me parting with him and its my first car!

bmcecosse
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Re: 1275 marina engine

Postby bmcecosse » Sun Mar 22, 2015 10:10 am

Use the Minor gearbox....
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philthehill
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Re: 1275 marina engine

Postby philthehill » Sun Mar 22, 2015 10:36 am

Firstly - get your self a copy of the Owen Burton Services 'Marina To Minor'. All you need to know is contained in the booklet.

http://morrisminorspares.co.uk/shop/pro ... 55698ce55b

If the output flange from the gearbox does not run true the gearbox is 'beyond economic repair'/scrap and the gearbox having had a real good thump on the output shaft who knows what other damage has been done to the gearbox.
If you want to run with a Marina gearbox it will be cheaper to get another.
Running with the 1098cc/1275cc gearbox is more than satisfactory with a 1275cc Marina engine otherwise the 1275cc MG Midget (similar engine to the 1275cc Marina) would not cope and I can assure you it does.
All the conversion parts required to fit/mate a 1275cc Marina engine to a 1098cc/1275cc gearbox are available from ESM or BullMotif.
It is a very easy conversion and a well trodden path for those wanting a bit more power.


chesney
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Re: 1275 marina engine

Postby chesney » Sun Mar 22, 2015 10:42 am

Jack,
The Ital box can be fitted, many also modify the box to fit a Triumph overdrive unit, but much more involved.
It differs from the Minor 1098 box in that it is a much stronger box, and has synchro on all gears.
It is far larger than the Minor box, to fit means a new prop shaft, gearbox mountings, engine needs mounting lower (to clear steering rack), starter motor fouls as standard so new backplate needed, gearbox casing needs modifying to clear and you'd have to convert to hydraulic clutch. See this post here - http://www.morrisminorowners.co.uk/view ... 47&t=10079 Midget is doing exactly as you describe, in fact I sold him some of the bits (custom prop, conversion OB backplate, gearboxes) to do the swap, though I believe he's using an Ital as a donor car too.
He's pretty approachable, and should be able to tell you what is needed.
The alternative is to source a Midget 1275 box and use an 1100 clutch, backplate, modified flywheel and clutch fork, which gives you a stronger box that drops straight in.

bmcecosse
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Re: 1275 marina engine

Postby bmcecosse » Sun Mar 22, 2015 11:31 am

A standard 1275 engine is not that much more powerful than a 1098 engine... Unless you plan wheel spin starts and 'racing' gearchanges - there is absolutely no reason why a 1098 gearbox (in decent condition..) should not handle the power. My own 1098 engine is modified to give more than a standard 1275 engine - and absolutely no problem with the gearbox. By all means persevere with the Marina box if you have the engineering facilities and deep pockets .....I certainly wouldn't.
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Jackmansell
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Re: 1275 marina engine

Postby Jackmansell » Sun Mar 22, 2015 3:49 pm

Okay so I'm thinking I'll get a backplate and modified flywheel to stick it into a 1098 box as mine is in nice shape. now, the engine itself, do I need to change it in any way? Ive seen talk of changing con rods etc,anyone had experience with that?
1969 Trafalgar blue minor saloon, cant ever see me parting with him and its my first car!

philthehill
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Re: 1275 marina engine

Postby philthehill » Sun Mar 22, 2015 5:34 pm

You do not need to do anything so serious as changing the con rods. :-?
The Marina crankshaft and con rods are more than adequate for normal and sane motoring :D
So long as you fit the modified back plate (ESM), the modified flywheel (ESM), the 7.5" clutch assy (ESM), the Minor front engine plate (you supply), block the Marina engine mounting bracket holes, you choose the manifold/carb & exhaust and off you go.
You may need a new spigot bush for the rear of the crankshaft (ESM to advise).
Of course the above is predicated on the engine being a serviceable unit and not requiring overhaul before installing in the Minor.


bmcecosse
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Re: 1275 marina engine

Postby bmcecosse » Sun Mar 22, 2015 5:44 pm

Who on earth tells you to change con-rods ?? Where do read this nonsense ?? !! Phil has pretty much listed it all above - it is possible to 'make do' of course if you don't want to be filling ESM 's tills with your hard earned cash......... :lol:
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Jackmansell
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Re: 1275 marina engine

Postby Jackmansell » Tue Mar 24, 2015 3:51 pm

so, essentially, if i get the backplate from esm, and either myself or my mechanic wholl be fitting the engine (and who has also fitted a marina engine with all of these modifications) to modify the flywheel, all ill need to do is swap out the front plate and clutch from my current engine? and block off mount points etc
1969 Trafalgar blue minor saloon, cant ever see me parting with him and its my first car!

bmcecosse
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Re: 1275 marina engine

Postby bmcecosse » Tue Mar 24, 2015 4:39 pm

More or less....your 1098 backplate is also easily 'modified' if you have a small angle grinder....
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philthehill
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Re: 1275 marina engine

Postby philthehill » Tue Mar 24, 2015 5:27 pm

If you use your original 1098cc engine back plate you must take into consideration that the 1275cc oil pump cover hole in the engine back plate and 1275cc oil pump cover may of a larger diameter than the 1098cc.
The 1098cc engine back plate and oil pump cover can be made to fit but whatever you do you must ensure that there is adequate clearance around and at the rear of the oil pump.
For my money and less hassle a modified engine back plate from ESM or BM ensures that it all goes together correctly and with adequate clearance.
For information:-
The 1275cc oil pump hole in the engine back plate is 93.5mm ID and the oil pump cover is 25.6mm deep with a raised dimple 30mm OD x 1.5mm H in the centre.
Do not forget the bush in the back of the crankshaft!
Best of luck with your conversion.
Phil


chesney
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Re: 1275 marina engine

Postby chesney » Tue Mar 24, 2015 6:42 pm

I modified a 1098 backplate as BMC describes to an Ital A+ engine and did not have to do anything to the pump cover on the backplate?

les
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Re: 1275 marina engine

Postby les » Tue Mar 24, 2015 7:42 pm

From memory, the backplate pump hole centre is offset by a few degrees, and in my case needed altering, the difficulty (relatively speaking) was reproducing the shallow recess for the cover flange. I've got a feeling I worked on the starter motor hole as well as opening the crankshaft appeture to give clearance. It's nice to make all modified openings nice and square to the face of the backplate, looks like a factory job then! Oh dear, what am I like? :-?


bmcecosse
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Re: 1275 marina engine

Postby bmcecosse » Tue Mar 24, 2015 8:08 pm

If you use the 'right' oil pump - it fits fine within the cover. The hole where the crank comes through needs to be opened up - 2 minutes with the angle grinder (I didn't worry about it being 'square'...) . The top dowel hole needs to be opened out slightly - but the starter hole should be just fine - nothing to do there.
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philthehill
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Re: 1275 marina engine

Postby philthehill » Tue Mar 24, 2015 8:20 pm

Chesney
You are right in that according to the BMC parts catalogue the 1098cc 10V and 1275cc 12V engine oil pump covers are both Pt No: AEG553 so there should be no problem in using the 1098cc oil pump cover when fitting the 1098cc 10V rear engine plate and oil pump cover to the Marina 12V engine.
However not withstanding the same part number I have found that there are slight differences in some of the oil pump covers and I have had to pick and mix the oil pump covers to suit the specific application i.e. rear engine plate/oil pump.
Now looking at the current MOSS parts list the oil pump cover fitted to 10CG and 10CC and some other 1098cc engines is part number 12G276 and that cover is slightly different.
For that reason I was careful to say 'IT MAY' and also gave the measurements of the 1275cc oil pump cover and hole in the rear engine plate which accommodates the oil pump cover so that the rear engine plate could be checked.
When grinding the 1098cc rear engine plate so as to clear the 1275cc rear bearing cap great care has to be taken not to remove too much metal. There is very little metal between the space created to clear the 1275cc rear bearing cap and the hole for the oil pump cover.
Also do not when grinding get the rear engine plate too hot in the area of the grinding as if overheated could cause a stress point resulting in the plate cracking.
One of the major problems with the 1275cc 'A' Series rear engine plate Pt No: AEG552 is that it has a tendency to crack between the rear main cap opening and the oil pump opening so the need for care when grinding the 1098cc rear engine plate. I have seen this cracking happen on several occasions and that is why there is a good market for S/H 1275cc 'A' Series rear engine plates which S/H are costing in the region of £75 - £85 plus. http://www.ebay.co.uk/itm/MG-MIDGET-127 ... 419239370d
Therefore it is nearly as cheap to fit the 1275cc alloy rear engine plate from MOSS at £122.95 which is claimed to be stronger and less likely to crack.
I have one of the alloy rear engine plates ready to fit to my 1380cc (marina blocked) engine.
So in conclusion It may be better to purchase a ready modified rear engine plate and it aint going to break the bank either :D
Phil


bmcecosse
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Re: 1275 marina engine

Postby bmcecosse » Tue Mar 24, 2015 8:56 pm

I think it's more to do with choice of oil pump - the 'steel back' pump is highly recommended as being the 'best' pump - and I found it fits easily under the 1098 cap. Remember also on a 1275 engine you need the 'long shaft' pump...
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philthehill
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Re: 1275 marina engine

Postby philthehill » Tue Mar 24, 2015 9:31 pm

Both of the standard oil pumps fitted to a Marina 1275cc 12V engine - Hoburn Eaton Pt No: 12G 2790 and Concentric Pt No: 12G 1128 are driven by spider Pt No: 12G729. So you have little choice what oil pump you can use unless you change the camshaft or oil pump drive.
See:

http://www.minispares.com/search/classi ... 0pump.aspx

The trend nowadays is to favour the slot drive.
A note in the Kent Cams booklet indicates that all cams will now be supplied only with slot drive.



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