Engine ID

[rocco]

Love it. That's absolutely brilliant info Phil, thanks so much. Will definitely be buying the suggested seals and guides unless I have them already fitted and they're still in order. I'll know by the weekend if the spring compressor gets delivered on time.

[philthehill]

One other thing to consider. The thickness of the standard head is 2.75". If the head has been skimmed the thickness will be less than 2.75".

[rocco]

I cleaned up the valves yesterday with some scotchbrite and a drill. The method worked quite well but the results show some nasty pitting.

Valvesx8.jpg (308.26 KiB) Viewed 5776 times

So new guides (with the groove for the top hat seals) makes sense and may as well go for new valves too.

And just to be sure, the bigger valves are the inlets, right?

[philthehill]

Those valves have come up well
The inlet valves are the larger valves.
I would recommend replacing the 4 exhaust valves, much easier than trying to grind the pitted exhaust valves to the head seat.
These are the exhaust valves for the 12G202 head
https://www.morrisminorspares.com/engin ... ls-p830104
Are the exhaust valve seats in the head pitted?

[rocco]

I finally got to pop down to ESM last week and pick up a small box of bits including new valve guides and a complete set of valves - so cleaning up the old ones was a bit pointless.
Do I need to get the valve guides machined or are they already a perfect fit for the valves? How about knocking out the old ones, how can I measure exactly where the new ones need to be? The inlet valve guides seem to be longer and sit proud in the chamber above the valve seat. The exhaust valves are flush. On the stem seal side (top), all the valves guides are the same height.
Is this one of those jobs that makes sense to give to a specialist to do?
In case anyone make a trek to ESM, I can recommend The Bell in Ticehurst for coffee or a pint, depending on whose driving. It's quite an interesting pub.

[philthehill]

The valve guides can be considered to be a perfect fit in the head, but I would recommend that after knocking in the valve guide a reamer is passed down the valve guide to ensure that the valve stem has the correct clearance - inlet clearance 0.0025", exhaust clearance 0.003".
Once the valve guides are fitted the valve seats should be ground concentric to the valve guide.
Have you fitted the shorter special valve guides from ESM with the top hat seal groove which are suitable for the 12G202 head? The 1275cc valve guides are slightly longer.
The top of the valve guide should sit 19/32" above the valve spring seat.
You should be able to do the job yourself but if in any doubt pass the head to a specialist engine reconditioning company.

[rocco]

I bought the valve guides that you recommended to me Phil, with the groove. Also a set of those top hat valve stem seals and will only use them on the inlets, as you also recommend.
I'd have fewer concerns about giving a UK-based engine specialist the job but some reservations about asking a German firm to do it. Unless I give them some exact specifications.
I would like to replace the guides by myself but will need to buy some measuring tools. No idea what a reamer is nor how to accurately measure 19/32" above the spring seat on all the guides.
So as usual I am torn between having a go myself and shelling out to get it done by a pro. I'm starting to lean towards the latter though.

[philthehill]

This is a reamer:-
https://www.ebay.co.uk/itm/294023901930 ... R7T3iYyVYQ
The size of reamer I use is 9/32" which is most suitable for use with unleaded fuel as it gives a little more clearance alleviating the possibility of valve stem to guide pick up leading to stuck valves.
The reamer ensures that the hole through the guide is accurately sized and straight.
After you have fitted the valve guide and the valve stem drops through the valve guide without hindrance the valve to guide clearance will be about right so no need for a reamer. I am just over fussy and strain to get things perfect.
If you replace the valve guides one at a time and place a straight edge over the tops of the guides, you can get the height correct without measuring equipment.
As regards ensuring the seats are concentric to the valve guide you can attain the concentricity by grinding in the valves, but it may take much longer than machine grinding or cutting.
I would recommend that you do the work and get that warm glow of knowing that you have done the job yourself.

[kevin s]

As I learnt the hard way if you fit the later guides and stem seals they need to be pressed around 2mm further into the head than the minor ones.

[philthehill]

The 1275cc valve guide with top hat seal should be pressed into the head so that the top of the valve guide is 13.72mm above the valve spring seat.
The 803cc, the 948cc & 1098cc valve guide with the normal 'O' ring seal should be pressed into the head so that the top of the valve guide is 15.08mm above the valve spring seat - so a nominal difference of 2mm, saying that I have never come across a situation before where the spring cap fouls the top hat seal when the ESM grooved valve guides are fitted when fitted/used in conjunction with a standard camshaft.
kevin s. you state in an earlier post/thread relating to valve guides and top hat seals that you have fitted a Kent Cams fast road cam. I do not know what camshaft number you have fitted but it could be that you have more valve lift which results in the valve spring cap being pressed further down which required the guide to be pressed down by a further 2mm.

[kevin s]

It's a pretty mild cam, but yes the lift is about 1mm higher. BL must have had a reason to drop it on std engines when they fitted the seals though.

[rocco]

The reamer ensures that the hole through the guide is accurately sized and straight.

I put the new valves through the new guides today and they fit well so reaming the guides wouldn't be necessary, right?
I'm going to visit a "zylinderkopf" specialist this week because I have learned that whacking the guides out with a hammer is a bad idea and I don't want to buy a press. I've almost spent as much on new tools and parts as the entire car cost me!
I'll get them to cut the seats and make it a proper job, seems silly not to when I have all the other new parts.

[philthehill]

If the valve drops through the valve guide without hindrance you should be alright.
It is better if you have a press to fit the valve guides. See photo below of me pressing valve guides being into a 12G940 head using a hydraulic press and limit stop tube. The tube ensures that the guiders are all set to the correct height.
The valve seats do need to be ground concentric to the valve guide so it may be best if you get an engine specialist to do the job for you.

Valve guide tool 2.jpg (85.42 KiB) Viewed 5543 times

[kevin s]

I didn't find the guides too difficult to knock in with a drift (you need a stepped drift with the small part the diameter of the valve stem), to make it easier the head can be heated ( an A series head fits in a domestic oven) and the guides frozen.

[rocco]

Was drafting an email to a head specialist this morning and then started to wonder if I could cut the seats myself.

This guy makes it look fairly straight forward, assuming I can get the right cutter type/angle.

https://www.youtube.com/watch?v=G2hKcEQ_Qbc

This this the method you would use Phil?

[philthehill]

You can cut the seats yourself if you have the right tools.
The method I use is the same and the tools I use are a Sykes Pickavant valve seat cutter which is similar to the tool used in the 'You Tube' clip if the seats are not hardened or if they are hardened, I use a Sykes Pickavant valve seat grinder.

valve seat grinder.jpg (26.05 KiB) Viewed 5161 times

With the valve seat grinder kit is the jig for refacing the stones. Typically, I had to buy three used (but cheap) Sykes Pickavant valve seat grinder kits to make up a full kit. The stones are available from India, but I had to make up a replacement diamond tip dresser from a Machine Mart diamond tipped grinding stone dresser.
Here is a used Sykes Pickavant valve seat cutter for sale on 'e' bay.
https://www.ebay.co.uk/itm/195493978446 ... R4jzlJicYQ
Here is a Sykes Pickavant valve seat grinder kit for sale on 'e' bay.
https://www.ebay.co.uk/itm/195493954158 ... R5iclJmcYQ
Unfortunately, the tools are not cheap even S/H and it may be easier and cheaper to get your local engineering firm to do the job.

[dustybinmercer]

Would anyone be able to help with my engine ID please? It's a late 2 door saloon.

10V/189E/H59555

Are there any resources that would help me find out if it's the original engine?

Many thanks!

[geoberni]

Would anyone be able to help with my engine ID please? It's a late 2 door saloon.

10V/189E/H59555

Are there any resources that would help me find out if it's the original engine?

Many thanks!

Basically it's a post 1969 Minor engine.
See this past almost identical question: viewtopic.php?p=609508#p609508

You can apply for a heritage certificate from the BMM: https://www.britishmotormuseum.co.uk/ar ... rtificates

[dustybinmercer]

Thank you! I’ll do exactly that.

[rocco]

Short update, I finally got the head back from the shop last Monday. Surface has been done, not sure if he skimmed it or blasted it. Valves seats cut, new bypass adapter, new valves and guides.

Well pleased with it and will be lapping valves and putting it all back together this weekend.

20231113_080746_.jpg (137.53 KiB) Viewed 4436 times