Morris Minor Owners Club

Everything is painted, final hurdle is assembly with some custom thrusts to make up the small difference in main bearing width between the 948 and 1098 cranks/blocks.

Might have gotten carried away with the masking tape.

Do not know about the masking tape - but truly carried away with the paint

Looks very nice but you might want clean one of the lugs back to make sure you have a good earth.

kevin s wrote: ↑Tue Sep 14, 2021 9:30 am Looks very nice but you might want clean one of the lugs back to make sure you have a good earth.

That's a definite requirement otherwise we'll be here in a few months with electrics questions.

Monty-4 wrote: ↑Mon Sep 13, 2021 1:11 pm Might have gotten carried away with the masking tape.

Far from it, there needs to be a nice clean, bare metal contact on at least 1 of those mounting lugs, preferably both.
A circle of tape would not have gone amiss on that.
With good clean, metal to metal contact maintaining the earth path from generator, to bracket, to engine block, to gearbox, to bodywork.

Not just on classic cars, I've seen far too many people get carried away with making stuff 'pretty' when maintaining electrical continuity is actually essential. Sometimes for static dispersal on workplace equipment.
Personally I'd rather see bare aluminium on the Dynamo/Alternator end castings. I'm pretty sure the original Dynamo only had a painted centre section containing the windings, and that was probably black.
The end sections were bare casting.

Can't please everyone!

I didn't realise the alternator earthed through the block, the starter is painted similarly but with the mating face bare. A trivial matter to remove a little paint from the inside of the lugs though. Thanks.

Monty-4 wrote: ↑Tue Sep 14, 2021 11:39 am Can't please everyone!

I didn't realise the alternator earthed through the block, the starter is painted similarly but with the mating face bare. A trivial matter to remove a little paint from the inside of the lugs though. Thanks.

That's what I mean, where did you think the electricity went?
So many people forget about it because they can't see it.
Just removing a 'little paint' won't do it, you require a good metal to metal contact at every point in the circuit, as I explained.
It would actually be possible for you to remove all the paint from inside the lug holes, bolt it in and it not work.
Because without the mating end surfaces connecting you could have an air gap all around the mounting bolts.
Don't decry the idea, and think it must touch, because I've seen it done and wasted time chasing the snag before finding it.
At least you realised the starter needed bare mounting surfaces.
I have seen it so often where people get carried away with painting stuff, like mounting brackets...

The other favourite thing is using PTFE tape around electrical temperature senders, thinking the water will provide the earth path and wondering why the temp readings are way off.....

Haha, I do understand that the magic pixies need somewhere to go, I suppose I assumed it was one of the connectors.

Maybe I'll go the whole hog and make a little earthing strap for it.

Great looking paint job on the alternator! How did you do it - spray it or brush? I look forward to seeing it all completely assembled...

Just went to fit the main bearings and thrust washers - the centre main strap is flush with no cut-out so they can rotate 15-20 degrees in both directions. Useless.

The way I see it there are a few solutions;

1. Source a wider strap (1275?) and cut slots in it to locate the washers.
2. Add dowels to the current strap to hold them in place.
3. Cut a slot in the block and fit the thrusts upside-down.

Hmm!

I would suggest that there has been too much metal removed from the centre main cap. With the minimum removed (that is with a complete flat machined between and including the cap bolt seats) the tangs of the thrust washers will still be retained in the factory machined cut outs.
If you have had serious amounts of metal removed from the centre main cap I would suggest that the centre main cap is replaced.
By replacing the metal machined off the cap with a strengthening strap will have done little to improve the strength of the cap/strap assy.
Fitting a 1275cc bearing cap strengthening bar is not an option because the 1275cc cap bolt centres are further apart.

I don't think I'll be using that machine shop again, they claimed years of experience with all sorts of A-Series engines, ho-hum and bah-humbug.

Minded to pursue option 2.

would one of these with the slots for the thrusts work?

https://www.med-engineering.co.uk/med-9 ... main-strap


I read somewhere that this is a common problem on small bore blocks.

I see no reason that fitting the MED strap would cause any problems.
MED do recommend that the centre main cap is machined and ground prior to fitting the strap.
There is a MED you tube video regarding fitting the centre main strap.
https://www.youtube.com/watch?v=dlBqJqJFTgc

The two small bore blocks I have and the 998cc I built way back would not or did not incur any problems when fitting the centre main strap - providing care is taken in removing only sufficient metal to fit the strap.

If you have had serious amounts of metal removed from the centre main cap I would suggest that the centre main cap is replaced.

The above caught my eye - immediately, if not sooner, thinking that will need line boring, if one goes that route.

The blocks I have seen, which I knew had been line bored over-size, were all fitted with 15 thous. oversized bearing shells (end to end, not just the centre bearing).

Both had been supplied with the standard OD main bearing shells as replacements when rebuilt, resulting in very serious loss of oil pressure at low rpm.

Good find kevin s but best not to browse the MED website too often as one is liable to go bankrupt.

Interesting they sell pre-modified main bearing caps with the oil seal conversion... no... must resist.

A new centre main bearing cap will require line boring but that does not mean it requires the boring to be oversize. My 1380cc engine has a steel 4 bolt centre main cap and it is line bored to standard spec.

Monty-4 wrote: ↑Fri Oct 01, 2021 8:02 pm Good find kevin s but best not to browse the MED website too often as one is liable to go bankrupt.

Interesting they sell pre-modified main bearing caps with the oil seal conversion... no... must resist.

Yes it's like a toyshop for petrol heads.

I have ordered the MED piece and shall see how it works out - machining to achieve any of the other solutions would be at least as much - and I've have to use precious petrol to the machinists!

The good news is my custom made thrust washers leave me with 0.004" end-float.

Doh! This thread in the block is stripped and going over it with a tap didn't help.
Safe to drill out to 5/16" in that location?

Fit a helicoil insert?