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Engine Strip Down, Are These Pistons Useable


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#1 booton

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Posted 17 March 2012 - 05:57 PM

ok after taking the pistons out of my block. there are some wear on the skirts of the pistons.
no damage to any parts around the rings but where it was burning through the piston rings it has left some marks.

the strange thing is there are no marks on the bore.

have a look and please let me know what you think. always good to have a second opinion.

piston 1

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Piston 3

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Piston 4 Has damage on both sides.

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please let me know what you think.

thanks

#2 Cooperman

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Posted 17 March 2012 - 06:00 PM

I think you had better have a re-bore and fit new pistons. Those have scored very badly and it really is not worth considering using them again.

#3 hazpalmer14

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Posted 17 March 2012 - 06:01 PM

yeh i agree with cooperman, what are the bores like inside the block?

#4 Pauly

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Posted 17 March 2012 - 06:03 PM

Thats some deep scoring :ohno: Well...I would think twice before re fitting them. I wouldn't re use them but thats just me.

Was they tight in the bores at all? Is it a previously re build engine? Its either picked up some foreign debris, or bore tollerences where to tight?

Strange there isn't any marking in the bore. Any marks at the bottom of the bore?

Edited by Pauly, 17 March 2012 - 06:04 PM.


#5 oltonlad

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Posted 17 March 2012 - 06:06 PM

the best place for those pistons is the bin............... :ohno:

#6 booton

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Posted 17 March 2012 - 06:15 PM

The bores are in good condition.
Was a tight fitwhen fitted.
When I measured the bores it was under the standard size by 0.020"

#7 Pauly

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Posted 17 March 2012 - 06:20 PM

If its been rebored the size will be 0.020" over standard. If it is 0.020" under standard, im suprised they even fitted.

#8 booton

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Posted 17 March 2012 - 06:21 PM

Will double check the measurements.
But its a shame as they looked really good before i took them out.

#9 03jkirk

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Posted 17 March 2012 - 06:24 PM

there was an article in either mini mag or mini world about oils and it showed a pic of pistons like that and they said it was caused by thin oils in the early years of the engine when they used to be run 10w40 oils rather than the now standard 20w50 oils

#10 booton

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Posted 18 March 2012 - 05:37 PM

ok second engine strip down.
this is a A+ engine i took out of my mini that ran good for two years.
looks like the engine has had some work done to it in the past due to the gaskets and new bolts etc.

the top of the cylinders don't look 100% but may clean up with a home hone.

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the cam shaft look to be a standard 998 A+ cam shaft
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the pistons look really good.
but i don't recognise them,
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the crank has these id numbers on them, is there anything special about that.

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ok and my last question will be would there be a problem putting a A+ crank pistons, cam etc on to a pre 72 A series block.
as all the interals are exellent on my A+
but the block is much better on the old A series.

thanks steve

Edited by booton, 18 March 2012 - 05:40 PM.


#11 bmcecosse

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Posted 18 March 2012 - 06:40 PM

The pistons look like they have overheated/seized in the bore - did the engine get a roasting, or run short of oil?? Yes you can fit the A+ parts into an A block.....but you need to decide what bore size it is!!

#12 booton

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Posted 18 March 2012 - 06:51 PM

the engine ran sweet for two years.

i've not cleaned them up at all and they came out easily enough were not seized.

would there be a problem with these pistons once they have been cleaned up.
it is a std bore on both pistons and bores.

#13 booton

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Posted 18 March 2012 - 07:51 PM

al these pistons usable then if they have overheated,
are these standard pistons std ones. as all the pistons i have seen have circlips to hold the pin in the piston.

does anyone know where i could find out what the number on the crank means.

thanks

#14 booton

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Posted 19 March 2012 - 07:55 AM

bump

#15 booton

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Posted 19 March 2012 - 06:29 PM

can anyone confirm i can use these second lot of pistons.
thanks steve




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