258 pistons in a 290

[Wrebelmachine]

Anyone ever tried using 258 pistons in a 290? or even trying it with a 304 crank?

[tufcj]

I've heard the 258 pistons are the same as 304. The problem is finding someone willing to break a set to get you the 2 extras. Time and cost considered, you might as well just get a custom set of 290 pistons. The 304 crank gives you .16" more stroke (3.44 vs 3.28 ), so the pistons may be above the deck. You'd have to do calculations based on crank, rod, and piston compression height you're using.

Bob
tufcj

[Giovanni20]

I've heard the 258 pistons are the same as 304. The problem is finding someone willing to break a set to get you the 2 extras. Time and cost considered, you might as well just get a custom set of 290 pistons. The 304 crank gives you .16" more stroke (3.44 vs 3.28 ), so the pistons may be above the deck. You'd have to do calculations based on crank, rod, and piston compression height you're using.

Bob
tufcj

Piston compression height matters most.