rslandys3 Posted June 17, 2007 Share Posted June 17, 2007 After skimming my cylinder head on my 2.25 I bolted everything back together and all was well for ten minutes then the thing wouldnt run. I checked the compression and it was way off so took the head off again to find the faces of the block and head covered in a mix of oil and water. The head and block are fine, not cracked or anything. Does anyone know what I may have done wrong when I put the thing together. I used a cheap copper head gasket which might have had something to do with it. Any help would be good as I have to get the thing running again asap. Quote Link to comment Share on other sites More sharing options...
hattymender Posted June 17, 2007 Share Posted June 17, 2007 After skimming my cylinder head on my 2.25 I bolted everything back together and all was well for ten minutes then the thing wouldnt run. I checked the compression and it was way off so took the head off again to find the faces of the block and head covered in a mix of oil and water. The head and block are fine, not cracked or anything. Does anyone know what I may have done wrong when I put the thing together. I used a cheap copper head gasket which might have had something to do with it. Any help would be good as I have to get the thing running again asap. Would this be the head you just took 2.75mm off? Have the bolts bottomed out before they pull down the head? Not seen a copper gasket in some time, the ones I've used tend to be a composite with steel inserts around the bore. Sounds very much like a gasket leak especially in conjunction with your compression being all over the place but the oil and water could just be normal disassembly leakage? I've been following your progress, Hatty's head came off this afternoon with a view to a valve grind and skim tomorrow. I took all possible care to drain as much as possible but there was still quite a spill as it came off. Did you get a high pitched 'twittering' when you ran it? Going back a lot of years but it was always a sign of gasket leakage on old British bikes with copper gaskets. The combustion pressure would push past the gasket until the head warmed up and sealed. A cure was to heat them up to about 300 degrees C and let them cool slowly to soften them up. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 17, 2007 Share Posted June 17, 2007 You can put the head gasket on the wrong way round on a 2.25 engine - perhaps you did this without noticing? As hattymender says - maybe the bolts bottomed out. A clean head bolt hole should be fine with the skim, but over the years they get a layer of crud in the bottom of the bolt hole and although they torque down, in relaity they are not actually clamping the head to the deck. Easy way to check is leave the gasket off and torque the bolts down and see if the head is still loose. (I know there are 18 of them, but you probably need the exercise ) Les. Quote Link to comment Share on other sites More sharing options...
keithjh Posted June 17, 2007 Share Posted June 17, 2007 Believe it or not i had the same thing today, used a copper gasket, low compression afterwards, after much cursing and threatening to burn the heap, i put on a composite gasket i found in the workshop, hey presto now running perfect, all i can put it down to is the cheap copper gasket. regards Keith Quote Link to comment Share on other sites More sharing options...
Stewart Posted June 18, 2007 Share Posted June 18, 2007 Believe it or not i had the same thing today, used a copper gasket, low compression afterwards, after much cursing and threatening to burn the heap, i put on a composite gasket i found in the workshop, hey presto now running perfect, all i can put it down to is the cheap copper gasket.regards Keith Was that the head of me? Every thing ok? Quote Link to comment Share on other sites More sharing options...
Betsy Posted June 18, 2007 Share Posted June 18, 2007 I had fitted a copper gasket when I rebuilt my engine 2 years ago. A few months back it failed between pots 3 and 4. It started off sounding like the engine was 'pinking', it got worse over a period of about 10 miles then stopped completely. I replaced it with a composite gasket, and its been fine ever since. Quote Link to comment Share on other sites More sharing options...
rslandys3 Posted June 27, 2007 Author Share Posted June 27, 2007 OK, my head bolts are bottoming out. Shortening them without a lathe is impractical so what do I do? Quote Link to comment Share on other sites More sharing options...
VERY OLD DISCO Posted June 27, 2007 Share Posted June 27, 2007 OK, my head bolts are bottoming out. Shortening them without a lathe is impractical so what do I do? Thick washers ? geoff Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 27, 2007 Share Posted June 27, 2007 Put a bolt back in, measure the protrusion with it tight (feeler guages), then remove twice that amount with a bench grinder. Where the cut-end is, grind the end of the thread 45-deg so it 'starts' in the thread ok still. Les. Quote Link to comment Share on other sites More sharing options...
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