1275cc upgrade to 1971 Minor van

[philthehill]

Thank you for posting the pictures.
From what I see and the size of the valves I am 95% sure that you have the MG Metro big valve head.
Phil

[bmcecosse]

Yes - that's the big valve head. When the 1275 engines went unleaded the inlet valve size was reduced to allow for insertion of a hard seat for the exhaust valve. So later MG Metros just had that standard unleaded head. They didn't reduce the claimed HP of the engine though!

[Spikesdriver]

Gents
As I gradually get my head around the various bits and bobs, I wonder what the unused bolts were for on the Marina "A" block.
See attached.
Also, do I need a clutch from a 1275 or is my new 1098 clutch going to be OK?
Thanks
Tom[frame][/frame]

[philthehill]

The unused bolts are where the Marina engine mounts were attached to the block.
If the holes are blind i.e. have bottoms the bolts can be dispensed with. The holes are sometimes drilled right through to the crankcase and if the bolts are not fitted will invariably leak oil. Check that 4th hole not circled.
As regards the clutch it all depends upon what flywheel you have fitted.
A picture of the flywheel would be appreciated so as to positively confirm what clutch is or can be fitted. Also please include a picture of the flywheel mounting bolts/arrangement as there are several possible flywheel scenarios.

Note: I would advise against using the oil filter shown especially as it has a nasty crease in its case. A source for possible leakage / failure.

Phil

[Spikesdriver]

Thanks again Phil
One of the engine mount bolt holes went right through so that is now blocked, the others were blind.
The flywheel is from a 1275 MG Midget. Next to the block it has the metal cut away to lighten it.
I have a brand new 1098 clutch to use unless I need a clutch from a 1275.
As regards the dented oil filter, it will work fine as there are no weaknesses in the metal. I plan to use it just for the first few miles while the engine beds in then swop it for a new one.
I received a new Accuspark electronic dizzy today and some new silicone ht leads. The carb is all back together and I have a new air filter.
The angle from the thermostat outlet is different from the 1098 engine. It points slightly rearwards. Do you know of a top hose that will fit without kinking?
Thanks again for your helpful advice.
Tom[frame][/frame]

[philthehill]

Tom
Many thanks for the photo.
Looking at your photo - you will have to use a 1275cc Midget clutch as the pitch of the holes to secure the 7 1/2" clutch cover are at a different and larger radius.
Edit: Looking very closely you appear to have the one locating dowel for the flywheel. The other dowel hole is vacant.
The Midget flywheel is normally located by a register and two studs and secured in place by the 6 bolts - I would be interested to see photos of the engine side of the flywheel and the rear end of the crankshaft with the flywheel removed.
For future reference:-
You can get the 1275cc Midget flywheel faced off and index drilled to accept the 7 1/2" clutch.
Photo of a spare faced off and indexed drilled 1275cc Midget I have on the shelf.
Phil[frame][/frame]

[bmcecosse]

Top hose - cut the curved section out of a bottom hose and use that.

[Spikesdriver]

bmcecosse, thanks for the tip ref the top hose. That saves a lot of aggro.
Tom

[Spikesdriver]

Gents
Not much done on the 1275 recently but I am back in the groove again with some more questions for the "ones who have done it all before!".
My HIF6 carb is from a 1700 Ital, it will be mated to an in/out combined manifold from a MG Metro. Sadly I do not have the appropriate abutment plate that holds the end of the throttle cable. Any ideas where I can find one?

Ref the clutch, I have a Midget 1275 flywheel so have ordered a 1275 Midget clutch - that must be a wise choice! Question - will the Minor thrust release bearing match up to the Midget clutch?

Ref exhaust, my MG Metro exhaust manifold has a much larger outlet so I guess it will be too big to match the standard Minor van exhaust down pipe. So it looks like I will need a larger bore exhaust or at the least, modify the downpipe. Any comments on this? Where would I go to get a large bore exhaust?

Thanks chaps[frame][/frame][frame][/frame]

[philthehill]

The Midget clutch release bearing Pt No: GRB107 (MOSS) should be fitted when installing the 1275cc Midget clutch assy.

[Spikesdriver]

Well, the Marina A 1275 is finally in and running.
Some questions for the brains out there.

1. To get the timing correct, the vacuum piece on my new Accuspark 45D4 electronic dizzy need to be so far anticlockwise that the edge of the vacuum unit needs to be about 1cm inside the oil filter! Temporarily I have tapped a small dent in the filter casing to help out but it needs to go further. Can I change the orientation of the dizzy so the vacuum part is at 2 oclock ish??

2.The new dizzy has a vacuum advance outlet but my Carb, an HIF6 has no vacuum outlet. Do I need to fit one to the carb? I guess it would mean drilling a hole and fitting a pipe fitting.

3. The oil breather pipe from the front of the engine (the small cylinder) fits on to the carb but when it is removed the engine runs smoother. Can I just route the breather pipe out beneath the car and leave the pipe sticking out the carb open to the air? Or do I need to block of the carb pipe?

BTW, I lengthened the arm on the clutch release mechanism and the Midget clutch is much less stiff. My electric cooling fan on the engine side of the radiator is clear of the oil breather cylinder so without a fixed fan blade, I did not have to slice a bit off the cylinder.

Here's a new one for me......I had oil leaking from the rear of the rocker cover even though the two bolts were tight. Poking with a screwdriver I could see the cork gasket was moving and not sealing. After some head scratching I found that the rear vertical stud that holds the rocker cover was bent thereby not allowing the top bolt to travel all the way down the threads!

Thanks chaps
Tom