Cylinder head update - bad news

[eng622]

Took the head to be skimmed to remove what I thought was a shallow gouge between 1 & 2. They wire brushed around it and round the chambers and said it is cracked and scrap. Said the engine must have overheated. Not knowingly overheated in my short ownership, had been running fine until on starting one day ran lumpy so that was the start of the gasket going. Surprised that a cast iron head can crack so easily. So need another head.

[svenedin]

They don’t crack easily. Not at all. I suggest this was damaged prior to your tenure. Of course, cast iron is quite brittle. Drop a cylinder head and it might crack. Casting defects are also possible but that usually manifests itself quite quickly. My ancestors were bell founders. That is bronze of course but casting defects were found quickly. It does not ring true…..

The people on this forum are wonderful. They guided me through a job I had never done.

Stephen

[Maria1959morris]

What engine is it 1098 I have a head in shed from engine I got years ago complete engine was running when taking out nit shure if it been. Converted to hardend valves for modern petrol or not but know its not cracked your welcome.to it I'm.in north of scotland though prob could post might be worth it if u give it a refurb obv doesn't need skimmed but maybe other things like set new valves seals etc before fitting I have the complete engine and head forgot to say also was gold in colour most.likely. gold seal engine it's 1098 Cc my.car 948cc hope u get sorted thanks

[Maria1959morris]

There also completer engine in for sale section on her for 100 quid might be worth go not mines someone else selling maybe get u back on road

[olonas]

"My ancestors were bell founders. That is bronze of course but casting defects were found quickly. It does not ring true…"

Q. What stinks and sounds like a cracked bell?
A. Dung

[exlkrs]

"My ancestors were bell founders. That is bronze of course but casting defects were found quickly. It does not ring true…"

Q. What stinks and sounds like a cracked bell?
A. Dung

NURSE!!!!!

[eng622]

It has the 1098 cc engine. Spoke to a mechanic who has a good knowledge of classic and moderns and he says quite common for cast iron as well as ali heads to crack through overheating. I have noted that the rocker cover is coated on the inside with a thick layer of what looks like dirty mayonaise so must be emulsification of water and oil. Guess there was a water leak and engine overheated prior to my ownership. The oil now is clean of emulsification but rather dirty and level did not go up during my short drives.

[svenedin]

The mayonnaise is usually a blocked breather system and/or multiple short journeys but yes could be a water leak. I wonder whether it is possible to crack a cylinder head by brutally over-torquing it and not following the correct sequence for tightening (or loosening) the stud nuts?

[Bill_qaz]

The mayonnaise is usually a blocked breather system and/or multiple short journeys but yes could be a water leak. I wonder whether it is possible to crack a cylinder head by brutally over-torquing it and not following the correct sequence for tightening (or loosening) the stud nuts?

You would strip a thread before cracking the head, the sequence is more to do with even clamp load during compression of the head gasket.
Thermal cracking or shock load dropping the head or material defect in casting are most likely causes.