(I make the distinction between Genuine and Indian because there might be a difference)

I am needing to refurb by old CS cylinder head. Unfortunately at some time in the past, I suspect there has been a persistant head gasket leak which has allowed water into the combustion chamber resulting in erosion/pitting of the head, particularly around the mouth of the combustion port extending up to the edge of the cylinder gasket ring (IYSWIM). Skimming 40 thou would improve it a lot, 80 thou might just clean it up altogether BUT what is likely to be the safe machining limit?

If anybody has any practical experience to share I would be most gratefull.

Well, I removed the cylinder head from my new acquisition yesterday (It doesn't take long does it!  )

The top of the piston is (after wiping the gunge off) in perfect condition and the cylinder bore has only the slightest of ridge, and then only at one point. (I can just detect it with the edge of a fingernail a "Deglaze" hone would likely remove it completely!)

However

The face of the cylinder head seems to be somewhat pitted and eroded around the mouth of the injection cavity. At first I thought "Oh Pooh!" but photos I have seen on the web of Lister cylinder head faces suggest that they all look a bit like that.

What is "Normal" on a (Genuine. Not an "Oid") Lister? and if it is not normal, what is "acceptable" (I imagine that as long as it runs OK it is acceptable!    )  I am used to car/truck cylinder heads where these components are invariably machined smooth with no rough surfaces. 

On another note (though I haven't fully disassembled it yet) the valves seem somewhat receded. I don't imagine fitting new valve seats is too big a problem if it proves necessary (I know an engineering company that routinely does this sort of thing on car cylinder heads, especially on older cast iron ones that have been wrecked by unleaded petrol!)

My Lister service manual suggests that the valve faces should have a recess of betwen 5 thou and 100 thou. I am just wondering if their is any collective wisdom as to what one should aim for (IYSWIM) during a rebuild?

On yet Another note!  There is Sooo much limescale in the water galleries .  I am thinking of trying to dissolve it out with kettle descaler unless somebody has a better idea!

Thaks all!

Anubis

Well, I have done it.

I am now the proud owner of a complete CS 6/1 SOM.  (IE it includes the separate controll box that is so often missing!)

I bought it off E-bay (UK). some might think that I paid a bit over the odds but the difference between a "Fair" price and what I paid was only a couple of hundred quid at the most and in the great scheme of things I reckoned that it was more important to have a complete system. the real expense will come later as I restore it to reliable operation.

I only had a small trailer to recover it and I actually think I was Lucky that it didn't collapse under the weight getting it home   (No seriously! I had considered that the 6/1 was 330KG and the cast iron base not more than 150 KG. Now I read that the SOM engines are actually nearer 500KG owing to somewhat heavier flywheels. The weight of the base I do not know!  The generator was removed and put in the back of the landcruiser to reduce the load on the trailer but it still must have been somewhat more than the 500KG rated load capacity!)

Thus far I have not even got it off the trailer (This will be fun) It turns over smoothly but I am clearly not getting compression (My guess is that the exhaust valve is not seating owing to it spending the last 5 years open on the decompressor)

I have no real issues with getting the engine to work but I am more concerned about the SOM alternator and controll boxes. The controll boxes both require complete restoration/rewiring and the cables between the alternator and the top controll box are in poor condition (Insulation brittle and cracked)


I would be gratefull if anybody who has had experience of repairing the controll boxes and alternator would be willing to share their experiences.


Photos to follow!