Mating a 1275 A+ engine to 948cc ribbed gearbox

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sam.bullen
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Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by sam.bullen »

I have currently got a 1275 A+ engine from an Ital which is being rebuilt. My long-term aim is to upgrade to a Type-9 5 speed gearbox, but in the meantime I need some advise as to what I need to change/modify to mate the 1275 engine to the 948cc ribbed gearbox/clutch which is currently in 'Ruby'.

Thanks
bmcecosse
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by bmcecosse »

If it's a ribbed gearbox - it's not from a 948.. You'll need to redrill your old flywheel very precisely to fit on the Ital crank, and then check you have enough release bearing movement to work the clutch - and check that the starter motor bendix clears the ring gear.
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sam.bullen
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by sam.bullen »

It is definitely a 948 and the gearbox is definitely ribbed. It is 1962, so one of that late ones.
bmcecosse
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by bmcecosse »

The ribbed gearbox is from a 1098 (or perhaps a 1275 if lucky...).
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philthehill
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by philthehill »

Basically you need the engine back plate Pt No: 10M002
and the flywheel Part No: 10M001 from ESM.
http://morrisminorspares.co.uk/shop/pro ... 3fcc729851

http://morrisminorspares.co.uk/shop/pro ... f1a7596ine

Fit a Minor front engine plate for the front engine mountings.
Blank off the Ital engine mounting holes (some holes are drilled right through the block wall).
Blank off the Ital fuel pump apature.
Check the first motion shaft bearing in the rear of the Ital crank shaft is correct for the Minor first motion shaft.
Obtain the correct clutch for the modified flywheel. The 1098cc clutch assy will fit your ribbed gearbox and the modified flywheel.
and off you go.
A well trodden conversion path and relatively simple to do and complete.
I have just obtained a spare 1275 'A' plus engine and will be doing similar to the above.
I have already done similar to the above with my 1380cc Ital 'A' plus fitted to my Minor and mated to Ford RS 2000 (Quaife) gearbox.
As regards the type 9 - the bell housing for the Minor/Type 9 conversion will fit the above but just check the fitment of the Type 9 first motion shaft where it fits into the rear of the ital crankshaft/bearing. You will have to change the clutch centre plate to suit the Ford first motion shaft.
Attached is a photo of the modification required to fit a Ford box first motion shaft to the rear of a MG Midget crankshaft.
There is a spacer available (see:- http://frontlinedevelopments.com/produc ... 75cc.shtml) which may be suitable for the Ital crankshaft. Have a chat with them and they are very helpful. Fitting instruction are available through the link.
Phil[frame]Image[/frame][frame]Image[/frame]
Last edited by philthehill on Sat Jan 03, 2015 8:43 am, edited 2 times in total.

irmscher
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by irmscher »

Some really good information there :)
BLOWNMM
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by BLOWNMM »

G'day to all and a happy new year!
Phil - re the RS2000 Quaife box you have fitted - is it a 4 or 5 speed box?
Cheers Bob
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philthehill
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by philthehill »

Bob
Happy New Year to you and all down under.
The Ford RS 2000/Bullet/Quaife box fitted to my Minor is the 4 speed version converted to Quaife clubman C/R, S/C spec with alloy casing / top cover and with Quaife quick-shift. The Ford 4 speed was the only gearbox available for the CS Autoclassics conversion at the time. I am not sure that the type 9 was available. It certainly was not offered as an option. All I can remember is that there were other Ford gearboxes available but non that could be converted to S/C, C/R without spending a fortune. Anyway it works for me and is a superb gearbox. The only limiting factor is the main shaft which is on a plain bearing and Quaife only recommend its use up to 7500rpm. When the engine was first installed it would regularly exceeded those revs as nothing happened below 5000rpm and would easily rev to way way beyond the 7500rpm limit. So to make the engine a bit more useable I replaced the Kent race cam with a 649 cam and installed a rev limiter set to 7500rpm. But that has brought its own problems as whilst I have plenty of bottom end power which is good for speed hill-climbing I can feel that it is running out of breath at about 7000rpm. I have now purchased a new Kent can with valve timing/lift half way between the race and 649 so should see am improvement all round.
Phil

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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by BLOWNMM »

G'day Phil
The reason I asked what box you were using was to see if it was a QBM1M inline 4 speed with drop gears. Did you consider this box when making a choice? I contacted Quaife re a box for my Minor that would handle 70 to 80 HP and was not close ratio. This is because my car is blown at a little over 15 psi and although it will freely rev to 7000 it is a waste of time going much over 5500 partly due to the low down grunt the blower gives but mainly because the side valve box synchros are hopeless at anything over about 3000 requiring double declutching, and on upchanges even with more that 2.6 Kg. removed from the flywheel it takes forever for the revs to die down. Quaife came back to me suggesting their QBM1M. It looked good upuntil I saw the price tag. When you refer to S/C spec what does this mean? I would have thought this box would have been perfect for your car especially with a selection of drop gears to enable ratios to be matched to the track you were using. I guess it doesn't hurt to dream.
Cheers Bob
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bmcecosse
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by bmcecosse »

Drop gears?
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les
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by les »

Straight cut gears! You should know that Roy, drop gears are the primary gear line up on Minis. :D

philthehill
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by philthehill »

Drop gears - a bit like the rear of a Hewland gearbox where you can fit what ever ratio you want to suit the driving conditions.
S/C means that the gears do not have single helical teeth, they are cut straight at right angles to the gear. Having S/C gears removes any power loss caused by using single helical gears as there is no side thrust. The result is a very noisy transmission which sounds very much as if a supercharger is fitted.
The gearbox fitted to my Minor was and still is available with a choice of gear sets and I chose what I considered would be the best set and it has worked out well.
The Quaife clubman gearbox will cope with well in excess of 150bhp. My BMC S/C - C/R could not cope with that sort of power and that is why I decided to fit the Quaife box.
As regards costs - to fit and upgrade the gearbox fitted to my Minor was in the region of £4.5k all in - so not cheap.
My next transmission upgrade will be to fit a 4.8 - 1 rear axle ratio which I have already purchased. The lower ratio will allow me to make better use of the available engine revs.
This is the link to the Quaife QBMIM gearbox:-

http://shop.quaife.co.uk/quaife-in-line ... drop-gears
Last edited by philthehill on Sun Jan 04, 2015 9:45 am, edited 1 time in total.

bmcecosse
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by bmcecosse »

les - I'm well aware of drop gears and indeed s/c gears on a Mini. Both my Rally and Autocross Minis had s/c boxes. All Minor owners are also familiar with s/c gears - 1st and reverse gear is straight cut on all Minor boxes....hence the noise. And yes - 'drop gears' in the back of Hewland etc boxes of course - but drop gears in a Ford Type 9 ????
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BLOWNMM
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by BLOWNMM »

Roy
It is not a Ford type 9 box I was refering to - see link

http://shop.quaife.co.uk/quaife-in-line ... drop-gears
Cheers Bob
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philthehill
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by philthehill »

Change facility just like a Hewland

bmcecosse
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Re: Mating a 1275 A+ engine to 948cc ribbed gearbox

Post by bmcecosse »

If you can afford ! Seems a lot for a miserable 70/80 bhp........ :roll:
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