mistergrumpy
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| posted on 24/1/09 at 05:56 PM |
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Cylinder Marks
Whaddya reckon to these marks I've noticed inside my cylinders?
 
Cylinder Pitting2
 
CylinderPitting1
On the second picture there's a slight scratch which you can just feel but in general there is a very slight sort of pitted effect. Its not very
prominant and you can't even feel the 'pits' but there is a slight raise there. I've tried cleaning them with thinners by the
way.
I suppose my uestion is what problems are these likely to cause if any?
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MkII
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| posted on 24/1/09 at 05:59 PM |
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very difficult to tell from pics but if the bores are not excessivley worn i would try honeing them and see if the marks are just on the surface
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mistergrumpy
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| posted on 24/1/09 at 06:31 PM |
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I've just thought as to the cause. The engine was sat under a tarp for a while when I bought it and had a bit of water in the cylinders then but
not sure about that slight scratch.
I'm thinking of honing them down the line but I may try something like some fine paste or polish first. Any suggestions.
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Paul (Notts)
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| posted on 24/1/09 at 06:41 PM |
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Are the pics looking down into the cylinder or up from underneath the cylinder.
If looking down the cylinder then the circular scratch mark could be a ware line where the piston rings getdown to but not any lower.
Paul
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austin man
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| posted on 24/1/09 at 07:01 PM |
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hone the bores and fit new cored rings that should be okay. Just honing and using the same rings may allow oil to pass
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mistergrumpy
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| posted on 24/1/09 at 07:09 PM |
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Hey I like your thinking there Paul. The view is from the top looking down. Both marks are coincidentally 40mm from the top and the whole cylinder is
90mm.
I've just measured the pistons and there's a 40mm difference in the rings 
Are these wear marks normal then?
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omega 24 v6
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| posted on 24/1/09 at 07:13 PM |
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I'd have said definately water marks.
If it looks wrong it probably is wrong.
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mistergrumpy
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| posted on 24/1/09 at 07:16 PM |
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I'm inclined to think that too not sure whats caused the very slight scratch that you can see in the second picture though.
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omega 24 v6
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| posted on 24/1/09 at 07:21 PM |
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Is it definately a scratch?? could it be where the ring was rusted to the bore and a bit has come away?? I presume you mean the dark mark around the
centre of the bore?
If it looks wrong it probably is wrong.
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mistergrumpy
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| posted on 24/1/09 at 07:52 PM |
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I mean the line through the dark mound. I suppose its possible that that was the bit protected by the piston ring and rust marks have formed around
it, so yes.
I'm beginning to think its not much to worry about now thanks to Pauls suggestion.
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owelly
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| posted on 24/1/09 at 11:34 PM |
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Use a three stoned honing unit. Use the springy ones in a drill and don't pull the decise out until it's stopped spinning!!
I definately looks like the pistons were sat at. There will probably be a pair of cylinders the same. One and four or two and three.
At that point in the bore, the surface has to be spot on as that's the 'turnaround land' that gets the most wear from the rings. The
bores get the most wear from lateral wear midway when the rods are pushed at an angle to the bore line.
http://www.ppcmag.co.uk
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