ed_crouch
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| posted on 7/11/05 at 06:11 PM |
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Pinto piston fit - opinions please
Chaps/chapesses,
Just honed out the bores of my Pinto lump (just a gentle hone to break the glaze).
I trial fitted the pistons in afterwards, without rings, and found that they are not exactly a dead tight fit in the bores. There is a small fraction
of a millimeter gap: just enough that you can see them move around.
Is this normal??
The pistons still have the machining marks around them, and the bores still had cross hatching on, so I cant beleive that its worn out. Confused...
Any opnions would be appreciated.
Ed.
I-iii-iii-iii-ts ME!
Hurrah.
www.wings-and-wheels.net
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Jon Ison
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| posted on 7/11/05 at 06:22 PM |
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yup sounds ok too me, its the rings that do the contact not the pistons, all they do really is carry the rings up and down the bore, oh and fill the
hole in the middle.
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ed_crouch
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 posted on 7/11/05 at 06:25 PM |
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Thanks, Jon.
Ed.
I-iii-iii-iii-ts ME!
Hurrah.
www.wings-and-wheels.net
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mookaloid
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| posted on 7/11/05 at 06:28 PM |
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Agree totally with Jon. Also there needs to be a bit of play as the pistons will expand when hot and take up some of the slack.
Cheers
Mark
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romer
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| posted on 7/11/05 at 07:38 PM |
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If you want to be absolutely sure about bore wear, you should pop one of the piston rings into the bore (without the piston) maybe 1/4 to 1/2 an inch
down so that it sits in the area that the rings would normally slide on when running. Make sure the ring is sitting square in the bore ie parrallel
with the top block surface and there will be a gap where both of the ring ends don't quite touch to complete the full circle. You then need to
measure this gap using feeler gauges and check it against what the manual says is the correct gap. Too big a gap and the bore is worn 
Make sure though that you're using new rings, because if the rings are old (and worn) then that will also make the gap wider.
Hope that helps
Romer
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