Crankshaft Scroll Seal

[pgp001]

I recently bought a job lot of Morris Minor parts from a guy who had started an engine rebuild a few years ago and then decided to scrap the car instead !!. The main thing I was after was the newly reground crankshaft which I can use in my own spare engine rebuild.

There is also what appears to be generally a very good block still on standard bore, the problem is when he took it to bits there are some parts that have gone missing. The one that really concerns me is the upper half of the scroll seal has been removed from the block and subsequently lost.

I seem to remember reading somewhere that these are best left undisturbed, so where does that leave me.
Can I just find another and bolt it on, or is it a line boring job ?, or am I the proud owner of a scrap block ?

Does anyone on here happen to have a spare upper half casting they want rid of ?

Thanks
Phil

[philthehill]

The block is not scrap just because you do not have the top half of the return scroll.

Just find another and fit as per the Morris Minor workshop manual.

The Pt No: of the scroll top cover is Pt No: 2A51 & gasket Pt No: ARG240B (both part no's from MOSS parts list).

It does not have to be line bored as would the rear main bearing cap if replaced.

The upper half is best left alone and not disturbed but I have taken the top half off the block and refitted it as per the manual with no problems.

The three top half bolts are special and lock wired in place with the bolts drilled through the head for the lock wire.

The bolts are Pt No: 53K1028 (MOSS).

rear cover 1.jpg (508.34 KiB) Viewed 1199 times

Rear cover 2.jpg (532.94 KiB) Viewed 1199 times

I hope the above is of help.

Phil

[pgp001]

Thanks Phil

What do you reckon the chances of obtaining a spare one are ?
I did wonder about making one myself, I do have a chunk of cast iron that would do nicely.

Phil

[philthehill]

The chances of obtaining a good S/H scroll top cover are very good.

I would not attempt to make one unless you have the milling and turning capability and the ability to do the job yourself.

It is a precision piece of engineering (even though it does not look like it) and if not done correctly can lead to leaking from the rear scroll.

Someone on here must have a scrap 948cc engine block.

There again you may find it easier and cheaper to buy an engine block/short motor to get the scroll top half and the special bolts. Here is a cheap engine with scroll top half fitted:-

https://www.ebay.co.uk/itm/Morris-Minor ... SwYB5dJkWu

The remaining parts may come in handy during the engine rebuild.

[Declan_Burns]

Anybody who fitted a rear lip seal should have that part left over. I will have a look in my spares cabinet. If I find it you can have it for the postage costs ~4€.
The lip seal conversion is also an option. Try ringing Charles Ware-they probably bin them when they do such conversions.
https://www.morrisminorspares.com/engin ... cc-p830310
Regards
Declan

[pgp001]

Hi Declan

That would be great if you have a spare one you dont need please.
I am more than capable of making one myself and I also have a well equiped machine shop in my back garden for this kind of work.
However life is too short and if I can find a decent second hand one my time would be much better spent doing something else.

I keep hearing different opinions regarding the rear lip seal conversion, a few have said that they dont last very long and then the leak is even worse than with the scroll seal. I believe for it to be a success the flywheel boss on the crank would need skimming to give a uniform surface for the seal to run on ??

There is a USA supplier that reckons his is the only lip seal conversion that actually works reliably, but as of May 2018 the cost was an eye watering $440 US.

Thanks
Phil

[philthehill]

The biggest problem with the 948cc/1098cc seal conversion is that the seal is expected to run on the outer face of the flywheel mounting boss.

The outer face of the boss was never finished to a standard acceptable to have a seal lip running on it.

If the boss is cleaned up and has a perfect outer face the seal will work. That may mean machining the boss to give a perfect surface finish but at a cost of reducing the spring pressure on the seal lip.

If there is any imperfection on the boss outer face the seal lip will be ripped to pieces in seconds and then you are back to square one.

When BL produced the 1275cc Maestro engine the flywheel boss was designed, finished and made wider to run a lip seal on. The seal was mounted in its own rear engine plate.

Maestro rear engine seal plate.jpg (419.62 KiB) Viewed 1104 times

Personally I would rather stick with the original design of return scroll. If the Minor engine is assembled correctly there should be no leaks or problems.

[Declan_Burns]

Phil,
I am sure there is an SKF speedi sleeve available that would fit the crank boss. They come in many sizes and would save having to polish up the boss.
Regards
Declan

[pgp001]

I wonder if it is feasible to machine the flywheel boss down a bit to clean it up, and then loctite a hardened SKF Speedi-Sleeve onto it for the seal to run on. That way you could bring it back to its correct design diameter for the lip seal.

Phil

You just beat me to it Declan

[philthehill]

Declan/pgp001

Fitting the easy sleeve is a very good idea but the flywheel boss outer face would have to be cleaned up first.
I would not want to be fitting an easy sleeve to the two good 948cc crankshafts I have without cleaning up the outer surface of the boss.

If the boss is to be cleaned up my preference would be to grind the surface.

But by the time you have spent out on a easy sleeve and the cleaning up of the outer surface of the flywheel mounting boss it may be cheaper to buy a S/H engine to get what you want.

[pgp001]

So, what is the general concensus of opinion regarding the lip seal conversion idea. ?

For myself it would be very easy to machine or even cylindrical grind the flywheel boss and fit a sleeve etc as I have the equipment to do it, but do we think overall it is better to stick with the scroll seal and decent engine breathing, or go for a lip seal solution ?

This is for my spare engine project that I have the luxury of time to complete. So I can take as long as I want on this one.

Phil

[philthehill]

Unless you can provide a totally acceptable lip seal running surface I would give the lip seal conversion a miss.
If you have the machinery go for the easy fit sleeve.
If you do go for the easy seal conversion please post some photos on here of the machining operation.