Advice on engine block inspection

[beno9962]

Ok so I have the engine fully stripped down now and I'm trying to come to a decision whether anything needs machining. Being a complete novice I'm planning on posting a few pics of the cylinder head/ crank on here to get some opinions. To get the ball rolling, i've noticed there is a small chip on the face of the cylinder head. it is nearer the edge than it is the cylinders, but I'm interested to know if this will have any affect? There are also a couple of holes that appear to be filled in (This is probably for a reason, but they appear to be rusted circles around 1/2" wide on the face of the cylinder head. I think two are filled in and the rest have threaded holes in. Can anybody tell me why this is?

[bmcecosse]

Well - we do need to see pictures........ The cylinder head normally has some holes in the face plugged with brass inserts. I haven't seen any threaded holes in the face of a head - maybe brass plugs have been unscrewed - or just rotted away - which would be unusual for brass........... Pictures will tell all!

[robedney]

Get a new head gasket and lay it down on the head in the proper position (the head, of course, being upside down on the bench). This will tell you immediately what holes matter. So long as the chip lies underneath a solid portion of the gasket it likely effects nothing. However -- as bmcecosse pointed out -- pics are ever so useful. Yup, the threaded holes make no sense -- pics please!

A couple of questions:

Why have you torn the engine down? Was it running badly, and do you know why? Are you planning on replacing the valves -- valve seats? How about the bearings in the bottom end -- crank and main? Even if you have nice shiny and clean surfaces, the crank may have been turned at some point, which means that off the shelf OEM bearings may not be the right ones. Ditto for the piston rings. Post lots of pics and ask lots of questions -- you can do it, and it's ever so much more fun to get it right on the first try.

[beno9962]

Cheers gents appreciate it! I'll. Have 'pictures for you ASAP. Watch this space...

I picked up the engine for £20 and challenged myself to rebuild it to standard. I'd like to find myself MM 1000 pick up in a couple of years ( the master plan), howeveri'm waiting to move house first.
Anyway, the engine has been sat in the back of a garage for 40 years, so has completely rusted over gaskets rotted away, and had parts missing (.rebuild clearly in need). I could just about turn it over by hand, but it got stuck 3/4 the way through it's cycle. I later found a fair bit of survived rust in number 1 cylinder. So that pistons was getting stuck. Fortunately the engine was still full of oil so the crank seems in good condition and rotates freely (minus the pistons).

[beno9962]

Here goes.. I polished the face up a bit with emery cloth so you can see the holes better. There appears to be 8 holes with with some kind of rusty insert in them. They then have small/ large holes drilled in them. I can't understand why there are only some drilled?

Also you can see the small crack at the top right that I mentioned.



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Here's a close up of one.

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Here's one with the gasket over so you can compare holes. Now i'm really confused!

The hole on the bottom right in the gasket has no corresponding hole. Also you can see the two inserts without holes in at the top left and middle appear as if they should..

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[MarkyB]

Are you sure that's a crack?
It looks more like a gouge mark from someone putting a screwdriver or something in there to lever the head off.
Apart from that it looks fine, the rusty holes are waterways, the not rusty holes carry oil or the push pods.

[beno9962]

Thanks Mark, You could be right about the crack, it seems to be where the edge of the gasket goes anyway. It's not sharp and doesn't have any burrs so I guess it could be a dint from someone bashing the engine.

With regards to the rusty holes (water ways) the bit that is confusing me is that only some are drilled out? And they appear to be random holes of different sized drilled. is there a reason for this?

[bmcecosse]

It looks fine - stop worrying! The gasket has a spare mirror image hole for the oil way to the rockers in case folks put the gasket on upside down.

[beno9962]

I'll stop worrying about the crack/dint/score.

I'm pleased to find out what the extra hole in the gasket it for.. I'm still a little confused about the waterways though?

[bmcecosse]

Nothing wrong - it's fine. The bores don't look too bad either..........

[beno9962]

That's good to hear.. a few more questions...

Any advice for cleaning this rusty oil way out? I've steam cleaned and washed out. It's just full of rust now.

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Any idea what these screws are for?[frame][/frame]

Cam bearing 1 (With insert) Opinions?

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Cam bearing 2

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Appreciate all the help.

Cam bearing 3

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Finally.. Any idea how to remove these inserts? One of them came out with the bolt.[frame][/frame]

[chrisryder]

the rusty bits on the block aren't 'bungs' or anything. it's just where an hole in the head (possibly to aid casting) has overlapped the block and the water has rusted the block face, making it look different to the rest.

some have holes in the middle as they are water ways between head and block.

if you were to cut a slice off the top of the block, you would find that once you're past the surface rust, it's solid below, not a bung or anything.

the inserts for the main caps on the bottom of the block are nothing to worry about. sometimes they stick in the block, sometimes they stick in the cap. they just help to align everything. and it can be helpful to make sure you get the centre cap back on the right way around!

you can remove them if you want to (not that you need to unless you're getting the block machined and need it to have a flat bottom) by gently twisting them out with some mole-grips.

[liammonty]

That's not an oilway! It's the water jacket (behind the water pump)- that's why it's rusty. Don't worry about it.

Can't see the cam bearings very well (blurred), but I think they're cheap enough, so if in any doubt just get them replaced.

[bmcecosse]

Cam bearings are fine - don't touch them! It's a specialist job to renew them.......

[beno9962]

Thanks Chris appreciate that, I understand now.

Apologies I meant to say waterway not oilway.

[liammonty]

If the waterway isn't full of loose, flaky rust, it's no problem- there's always going to be some rust on the surface. If it's got loads of flakes in it, it will need cleaning more though. I wouldn't worry unless it's a real mess. I should think you've already got any loose stuff out if you've washed it.

[chrisryder]

if you really want to get in and clean out that water jacket, you can remove any or all of the 3 core plugs along the side (and one at the rear) to gain access.

if the engine is an 'unknown quantity' i'd certainly be tempted to look in there myself. rusty sludge and sediment at the back of the block can lead to the back bore overheating. a little work now could save a lot of problems further down the line!

in case you don't know what they look like, here's one:
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[Alec]

Hello beno,

when I rebuild an engine, I replace the core plugs as a matter of course. They can corrode (from the inside) over time so it's worth ensuring that they are all good.

Alec

[beno9962]

Thanks for the advice gents. How do you remove the core plugs? Are replacements easy to source?

[bmcecosse]

Pierce the plugs with a sharp chisel and lever them out. Any Mini or Minor supplier will have the new plugs.