Didn't wait to find out what the 170 deck height is. This spreadsheet thinks mostly in metric so as to allow feeding in the size of the pistons in metric, since it's aimed at finding out what pistons from the world of import racing could give acceptable results in a slant. However, head gasket thicknesses and milling are still entered in inches. It's already churned out what could be a useful formula for turbo builds with a 225 block:

225 block
198 rods with bushings to use 22 mm piston pins
0.020" thick head gasket
Mill 0.100" off a 54 cc head (or decking the block)
Toyota 3SGTE pistons (Wiseco forgings)

This combination would result in an 8.07:1 compression ratio. Since the pistons are forgings designed for turbo applications, this longblock might work well for turbo buildups, but the compression is all wrong for a naturally aspirated buildup. Decking the block 0.100" in addition to milling the head that much would give a 9.5:1 compression ratio, but I don't know how much you can mill off the deck. It'll be interesting to see what sort of combinations could be put together with the low deck block.

If you want a copy of the spreadsheet, let me know. It's in Correl Quatro Pro format and I haven't managed to get it to save the formulae for Excel correctly.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

Hey Matt,

Can we get some specs on those pistons: Weight, cost, bore sizes available, ring sizes, comp height?

Thanks,

Lou

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Home of Slant6-powered fun machines since 1988

I copied my specs straight from the Wiseco web site. The pistons have a 86.5 mm bore, 13 cc dish, 35.3 mm compression height, and use a 22 mm pin. I plan now to go on with evaluating the possibility of combining alternate connecting rods. For example, a 170 could use Mitsubishi 4G63 rods and pistons with an offset ground crank and get close to 8.0:1 compression with 0.100" milled off the heads. I can probably find some even better combinations - one promising possibility is a 170 running aftermarket 6" SBC connecting rods.

_________________
"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair