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Cylinder Bore Pitting


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#1 country clubman

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Posted 10 April 2018 - 02:35 PM

I have slight pitting in one of my cylinder bores, does anyone know if this will cause any problems?

 

27495065088_8341ff6363_z.jpg

 



#2 mini13

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Posted 10 April 2018 - 02:36 PM

I'd say its been stood with moisure in the bore



#3 country clubman

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Posted 10 April 2018 - 02:41 PM

I'd say its been stood with moisure in the bore

Wow quick response there, it might well have been, it is just one I picked up off ebay, and seller said all cylinder bores are good. The only problem when you can't collect in person you can't check these things out till it's too late.



#4 mini13

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Posted 10 April 2018 - 02:54 PM

I would say that far down the bore it will likley be ok for a std build.

 

it looks like there is no real depth to it and its more "stain" that pitting. but hard to tell from a photo.



#5 Northernpower

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Posted 10 April 2018 - 03:11 PM

Can you actually feel it or is it just discoloration.



#6 Cooperman

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Posted 10 April 2018 - 03:27 PM

Take the piston out and try cleaning it up with a 3-legged de-glazing tool in an electric drill at a slow speed. If it cleans up easily it should be OK. 

Or have a machine shop hone all the bores and then fit a new set of piston rings. That way you will have a good engine which should not smoke or burn oil.

 

It is always wise to strip and do a re-assembly of any newly acquired engine with new rings, main and big-end shells, new thrusts and a new oil pump.

 

It saves a lot of possible issues sooner rather than later.



#7 Northernpower

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Posted 10 April 2018 - 03:33 PM

Is it an unrun rebuild?



#8 country clubman

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Posted 10 April 2018 - 04:49 PM

Ok, thanks for all the replies, you can feel it slightly so it isn't just stain. So sounds like it'll be best taking it to a machine shop and av them look at it.



#9 HUBBA.HUBBA

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Posted 10 April 2018 - 05:33 PM

I had the same with mine. Bought a 'sound engine' found 2 of the bores full of water! Was well rusty. Told the seller and he gave me a part refund which i was happy with. The rebore to +40 sorted it

Edited by HUBBA.HUBBA, 10 April 2018 - 05:34 PM.


#10 Cooperman

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Posted 10 April 2018 - 08:21 PM

I never trust an engine that I haven't had to pieces and put back together myself.

 

I once bought an Innocenti with, allegedly, a fully rebuilt engine done by a fairly well-known local company.

 

I took it to pieces and it had 21251 low compression pistons and the block had not been decked to suit. The CR was very low and the pistons far from ideal for hard use. It had to be honed and 21253 pistons fitted. Even then the block needed 0.015" skimmed from the block deck. The oil pump was also suspected as not having been renewed, so it all got re-assembled correctly with a properly timed-in cam.

 

Trust no-one and you won't be disappointed!



#11 mikal

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Posted 10 April 2018 - 10:58 PM

The honing pattern looks odd....



#12 Spider

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Posted 11 April 2018 - 12:51 AM

The honing pattern looks odd....

 

It does look very 'flat' but doesn't always photograph too well.

 

I wouldn't be mucking about with it. Bore and new Pistons.



#13 Retroman

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Posted 11 April 2018 - 08:54 AM

 

The honing pattern looks odd....

 

It does look very 'flat' but doesn't always photograph too well.

 

I wouldn't be mucking about with it. Bore and new Pistons.

 

It looks more like its been cleaned up with wet and dry.

 

It needs at least honing and new rings, and preferably a bore and new pistons.

 

Remember too that the rings have also had the same corrosion as they were part of that rusted area.



#14 ace01

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Posted 11 April 2018 - 12:04 PM

I had a similar issue with an A plus block.  I had had it bored and then when refreshed a year or so later after it started smoking these marks appeared.  I was told this was a casting issue prevalent in this type of block (MG Metro).  Fortunately a rebore +40 thou got rid of it.  



#15 country clubman

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Posted 11 April 2018 - 10:29 PM

Was at machine shop today, it does need boring and honing and crank needs grinding! But one of the bores has had a piston liner in at some point so this will make it more complicated to bore, thus making it really expensive to sort. So been in touch with ebay seller hopefully we can sort something out, but as he sold it me saying all bores good condition when I asked if any issues, I don't think I will have much luck.

 

Ebay eh love hate thing, sometimes you just get caught out! sometimes you get a great deal.


Edited by country clubman, 12 April 2018 - 11:53 PM.





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