So I need the help and I can't find the answer. I am cleaning up the 170 block and one of my cylinders has some corrosion I cant remove with a ball hone. I already have pistons and the cylinders r already bored .40 over. Now what is the tolerance from cylinder to piston so I can do a honing on the cylinder to clean it up before I have to go up a size in bore?

Thanks

My '62 FSM says .0005 to .0015" (for stock pistons one woudl presurme). Can't say if that changed at all in later years.

You will need to consult the piston manufacturer on that spec since they are aftermarket, the FSM specs only apply to factory installed components and don't apply to any aftermarket parts.

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There's no such thing as too much cam....only not enough engine!

If you have visible rust pitting that a ball hone won't remove you would have to hone the cylinder way beyond the proper clearance spec to get rid of it. If you want it to be right you need to go up another size on the pistons and bore it bigger.

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Or you could bore and sleeve that one cyl, back to .040, and use the same piston. Might be less expensive then boring all larger, and getting new pistons.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
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A ball hone won't remove any material...it's for deglazing only. As for the corrosion, It really depends on where the corrosion is and what you are trying to build. I would get the bore in question honed with a proper setup. You can take a reasonable amount out of a daily driver and be OK. My last re ring for a daily driver (not a slant) took around .002 out of the bore and it still had a few low spots in the top of the cylinders..Zero oil burning or piston slap, and this was in a small displacement OHC high revving engine. I feel confident it will be fine for at least 100000KM. Sure,if you want a as new build then a rebore is required,but for a limited use resto/stock build I'd look at running it.If the corrosion is in the lower part of the bore I'd feel pretty comfortable as long as there is no major pitting. Hope this helps