change to 1275 midget engine/gerabox

[LASSE46]

I have an 1275 engine/gearbox which I would like to install in my Traveller from 1963. What to think of? Changes needed? Which problems will occur? I would be greatful for all tips and ideas how to make the change.

[bmcecosse]

There are many threads on the subject - but if you change them as a pair, it's pretty straightforward. However the Spridget clutch is hydraulically operated - so you would need to use the mechanical clutch fork from a 1098 gearbox..and you may find the clutch action 'abrupt' - but again there is an easy fix for that... The heater tap will foul too - but that's easily over come. And the top radiator hose will need to be changed - an old bottom hose can be cut to do the job. You will probably want to change the final drive ratio...but it's not essential.

[814XUW]

If the front plate has a canister type breather fitted, these need to be adapted if using the standard Minor fan by cutting and welding flat, or 'bashing' it.
You may also want to consider changing the starting handle dog/crank pulley bolt from the Minor to the Midget engine, so you can turn the engine easily by hand. Retain the damped pulley though.
You may also wish to consider using the reverse light switch standard to Midget gearboxes too, while it is accessible.

[philthehill]

Personally I would not bash the oil separator canister attached to the front of the timing chain cover as you may fracture a weld which could subsequently leak oil.
Yes cut and weld or use a fan spacer to give adequate clearance.

http://www.minispares.com/search/classi ... pacer.aspx

You could use a later Minor timing chain cover with the lip seal instead and use the mechanical fuel pump aperture to facilitate a crankcase breather.
For an example see the link below.
http://www.morrismania.com/part/C-2A265 ... p-Mounting.

Or even use one of these breathers fitted by use of an adapter plate to the mechanical fuel pump aperture.

http://www.minispares.com/product/Class ... ~2~27|Back to catalogue

[mike.perry]

The bracket on the engine end of the stabiliser will require a notch cut out of it to fit around the base of the heater tap which is at an angle on the 1275 head. An adapter an be made to re align the heater tap if you are using the Minor 1098 heater valve[frame][/frame][frame]
As said, fan spacer washers which have a flat on one side will give clearance without cutting the canister but it is important that the engine breathing system is correct to avoid excessive oil drips.
The 1275 head is slightly longer than the 1098 head which can restrict movement and access to the rear of the engine and the gearbox slightly.
As the 1275 clutch is a diaphram unit, not the spring unit on the 1098 and is a smaller diameter and the flywheel has 6 mounting bolts it is easist to use the complete flywheel and clutch assembly from the 1275 together with the linkage from the 1098 with a small modification to the clutch relay shaft. For further refinement you can fit the roller bearing thrust bearing which should improve the life of the clutch linkage

[LASSE46]

Thanks all for valuable information. I will study it before starting the job. It seems to be a fairly straightforward job though.

[millerman]

I can never understand why the back edge of the fan is not cut to clear the breather [frame][/frame]

[bmcecosse]

Exactly - don't bash the can ! If there is Duplex inside - it WILL cause the cover to be rubbed by the chain. Other option of course is an electric fan - but that cut-down blade is perfectly adequate.

[philthehill]

If the fan blades are cut to clear the timing chain oil separator it is an absolute imperative that the fan blades are balanced.
If the fan blades are not balanced a harmonic vibration may be set up and ultimately one or both fan blades could fracture and separate from the water pump hub with predictable results
If it was that simple why would BMC/BL fit have fitted spacers to overcome any interference between fan and oil separator?

[bmcecosse]

When that engine was used in the Spridget - it had a completely different multi blade plastic fan - and of course that remains an option in a minor - but do check fan/radiator clearance.... That fan is also very much an overkill in a Minor with it's relatively large radiator.

[brucek]

I can never understand why the back edge of the fan is not cut to clear the breather [frame][/frame]

If you just place 4 spacers behind the fan blade - no more than the thickness of a standard sized nut, the blade does not foul the breather can, you don't need to bother about cutting it down and everything works without damaging other parts. The ONLY time modifying the breather can becomes an issue is when you fit an electric fan on the back facing edge of the rad. Then the breather assembly does tend to get in the way. Other than that it's an easy swap.

I have the 1275 Midget drive train in my convertible and it is a really enjoyable swap whilst maintaining the look of originality Good luck with your project

[philthehill]

Just a pointer as regards fitting spacers as recommended above:-
The fan does need to be fully flat against the water pump pulley or fan spacer (as per my link above) and not just around a nut or washer sized spacer.
The fan was originally fitted with out the capping plate (the RED plate in the above photo) and cracks started to appear around the fan mounting holes. to cure the problem BMC/BL fitted the capping plate.
Personally I would not fit anything other than a full size plate.

[chesney]

Having seen a fan (modified to fit a Midget engine) split and bury itself into the crossmember not 1/8" from the brake line, I would avoid attempts to alter the fan altogether, but each to their own!

[philthehill]

Midget 1275cc fan:-

http://www.ebay.co.uk/itm/MG-MIDGET-FAN ... 1563522991

[jagnut66]

Hi,
I fitted this heater tap:

[frame][/frame]

It works really well and seems a lot less messing about than altering the original. As used on the Austin Healey, MG Midget, Sprite.
Link below.
Best wishes,
Mike.

http://www.ebay.co.uk/itm/MG-MIDGET-AUS ... 43d85f774c

[IslipMinor]

I carry a spare 2-bladed fan in the boot for emergencies, and have modified the oil separator on our 1380 by cutting the front off and welding a flat plate to reduce its thickness.

A 9" Spal fan ref: VA07-AP7/C-31S 3010.0339 will fit in between the radiator and the grille with no modifications at all - use the standard Spal pin kit to attach it to the radiator. Has looked after our 1380 in temperatures up to 40°C (~104°F) on a number of occasions (including 38°C on the M25 near Heathrow when the highest temperature in the UK was recorded there a few years ago!). I have fitted a thermo switch into the header tank, which is wired into a fused 'permanently on' supply.

During normal running it does not come on, but in traffic will cycle on/off as it should. We have an 88°C thermostat all year round, and the fan cycles between 90/92°C and 86/88°C. It frequently kicks in after the engine has been switched off and the residual heat rises to the top of the radiator. If it was on an ignition-fed supply, it would not be able to respond to this.

After disconnecting the fan bullet connectors at the bottom of the radiator, and with no standard steel fan on the water pump pulley, the complete radiator + fan + thermo switch can be removed all together, without any need to split it, remove the grille or move the front panel in any way.

[mike.perry]

My Midget engine installation has the special washers with a flat side mounted behind a 4 blade fan (two double blades at right angles) with the plate on top. There is sufficient bolt thread to secure the assembly to the water pump pulley

[philthehill]

Mike
Would you please be so kind as the post the special washer part number/description and source on this thread.
Many thanks in advance
Phil

[bmcecosse]

A completely flat single washer with 4 (+centre..) holes is the best option - such a thing was fitted on some Mini engines. Note it is 'required' if there is a breather can timing cover....

http://minispares.com/product/Classic/C ... 0to%20shop

[philthehill]

bmc
I agree and the spacer was one of two referred to and link to them given in my post of the 02 March.
Mike Perry refers to 'washers' in his post above so was interested to know what the/those 'washers' were.
Phil