Editing Forums/Z31P/z31-repairs-forums engine-mechanical/Chasing higher compression numbers.

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|op_user=z31 maniac
|op_date=2017-09-03 15:25:43
|post_count=2
|archive_url=/Z31performance_archive/forum/z31-repairs-forums/engine-mechanical/536817-chasing-higher-compression-numbers.html
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'''z31 maniac:''' <small>(2017-09-03 15:25:43)</small>

I intend to increase the compression of my vg30et by swapping the ET pistons for NA pistons. However, the NA pistons came from a very high mileage NA engine. I can see scaring on the NA pistons. Would it be advisable to make the swap? Would it make things worse than before I started it? Instead of increasing the compression it might inadvertently decrease it. Will new piston rings compensate for the scaring on the NA pistons? Will new piston rings maintain the NA pistons' higher compression ratio? Hope someone can shed some light on this.

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'''mwolvinm:''' <small>(2017-09-10 01:41:13)</small>

Pistons usually aren't wear out items… that said, you can usually get them included in a rebuild kit. I haven't priced or checked availability at rock auto for the vg30, but the vg33 is ~300 including pistons, seals and bearings. Note vg33 pistons wont fit a vg30.