Engine Rebuild

[izzi]

Hi MarkyB,

I was concerned, because when I had my crankshaft fully reground with new bearings I still had a oil leak from the rear of the engine. tried all the usual tips with engine in and out a few times. however there is always a small drip.

Being stuburn I refused to fit the modern type seals and the crank and breather conversion.

Now, when I see a crankshaft that needs attention, I would recommend these mods as to avoid hassle.

Hope this makes sense.

Roy.

[smithskids]

Hi, you need to hone to take the glaze off the bores as it helps the new rings to bed in, you can do it by hand with emery and a round piece of wood if you want.

[silloyd]

Thanks for the views all.

Looks lie an exchange crank is the way to go for me. (Pocket money permitting)

Bearing surface quality aside, I had thought that the rear oil seal scroll (helix) looked OK and unworn. I'm not convinced on the cost benefit of the revised rear seal because people's views on its effectiveness seem to be very polarised (perhaps what you might describe as a 'Marmite' mod ).

However, this project is still contingent on removing the Distributor housing (see original post) to remove the dizzy drive and therefore get the camshaft out to inspect it and its bearings. So far I cannot budge the beast by one iota at present, even after the application of Plus Gas and heat. At some point the casting is going to crack, I just know it.

Thanks for the clarification on honing. Have to say that 80 grit seems pretty coarse to me though (?) but I bow to those more experienced in these matters.

Incidentally, I eventually found the oversize markings on the bearing shells ... under several layers of grime. For the record, here are the pics:

Main:
[frame][/frame]

Big end:
[frame][/frame]

[silloyd]

More pics...

Camshaft:
[frame][/frame]
[frame][/frame]

Cylinders looking from the bottom:

1 & 2:
[frame][/frame]

3 & 4:
[frame][/frame]

From this view it looks to me like liners have been inserted (according to the engine number this was probably a 'Silver Seal' engine, i.e. reconditioned short engine)

Camshaft bearing surfaces in the block:

Front and middle:
[frame][/frame]

Rear:
[frame][/frame]

[MarkyB]

I was actually asking BMCecosse, I didn't know Izzi was a Roy too.
Cam and bearings look fine to me.
As there is no appreciable ridge on the bores I think the engine didn't too many miles after the reconditioning.

[silloyd]

Do I take it that these are 5 ring pistons?

[frame][/frame]

[chrisryder]

Do I take it that these are 5 ring pistons?

[frame][/frame]

Nope, only 4.

5 ring pistons have a fifth ring below to gudgeon pin to stop piston slap/scuff.

[silloyd]

Thanks. I couldn't work out whether the bottom ring (which seems to be made up of two thin rings interspersed with a serrated black ring) constituted one ring or not...even after reading the manual!

[bmcecosse]

The crank looks decidedly marginal to me - yes -you 'may' get away with it - but really a reground crank will be so much better, and if treated right - will last 'for ever'........ The bores have been linered - that's why they haven't worn! Liners are much harder than the original cast bores.

[silloyd]

I think I've resigned myself to the cost of an exchange crank now. Given that they come with a full set of bearings it's probably the most economic route but will check local prices for a regrind anyway.

I taking MarkyB's view that the camshaft is viable though (thanks for that).

Given that that the cylinders are lined, does the 'glaze busting' needs to be done in the same way that you suggested, i.e. 80 grit.

[IslipMinor]

Cam and bores both 'look' fine, but have you measured the crank journals? The shells are obviously worn, and would need replacing anyway, but you would need to measure the crank to be sure what to do.

[MarkyB]

Given that that the cylinders are lined, does the 'glaze busting' needs to be done in the same way that you suggested, i.e. 80 grit.

I don't think you do with liners, they are much harder than the block and would take a very long time to bed-in.

[silloyd]

Thanks MarkyB.


Richard, I did measure them and got the following (measuring at 8 points across and around each bearing using a digital vernier):

Mains:
Front 1.728-1.729
Centre 1.727 - 1.729
Rear 1.727 - 1.728

Cranks:
One 1.602 - 1.604
Two 1.602 - 1.604
Three 1.603 - 1.604
Four 1.602 - 1.604

I can post some close-ups of the surfaces if that helps.

[bmcecosse]

It's 2 to 3 thou wear pretty much everywhere - and the mains were down to the bronze - I strongly suggest a regrind/exchange crank - but you can of course fit shells and they will be ok for a few thousand miles. Maybe that's a few years for you ?? I would still run the 80 grit up and down the bores before fitting rings - but indeed I made that suggestion initially when we didn't know it had liners!

[silloyd]

After feeling slightly grumpy about the crank needing a re-grind, the gods of all things Morris Minor looked kindly upon me....

I just picked the following up on the bay of fleas:

1. a re-ground crank;
2. new matching main and big end bearings;
3. new thrust bearings;
4. a new oil pump;
5. a set of bottom end gaskets; and
6. a workshop manual!

For the princely sum of £85!! All I've got to do now is get them shipped to me, which will cost a good twenner but still a bargain.

Happy days!

I'm off to do the lottery now.......

[silloyd]

I've given the block a really good clean, including blasting water through all the oil and water galleries - now leaving it to thoroughly dry before I do anything else.

Just a thought, should I remove the core plugs to check/clean even further or leave them be?

[les]

I think I would having gone this far but some would say leave well alone. Incidentally, regarding cleaning the oilways, I went as far as knocking out the brass plugs at the end of the oil gallery on the last block I rebuilt, to clean it. Then tapping a thread each end for a brass plug. I'm glad I did as being dead ends, so to speak, there was quite a build up of sludge there!

[MarkyB]

If it ain't broke, don't fix it!
A picture would be good, but unless you have reason to think there is a problem I wouldn't bother.

[silloyd]

A picture would be good, but unless you have reason to think there is a problem I wouldn't bother.

What would you like to see a pic of? I guess the problem is that as this engine is of unknown origin then I don't know what lurks there. ("There are things we do not know we don't know." D. Rumsfeld)



Les - If I were to consider your suggestion, can you get replacements for those brass plugs rather than tapping the oilways?

[bmcecosse]

Drilling and tapping is the norm. I would NOT touch the core plugs........