I want to bore my b18c to 2000cc. What would the bore size have to be to get near 2000cc with same length rods and stock crank?

 

i'm guessing somewhere around 85mm ? it's a little different because the GSR stroke is not as long as a b20. someone with more experience will chime in i'm sure

 

84mm x 89mm would yield 1972.87cc which would be rounded to 2.0L. If you went 85mm x 89mm you'd end up at 2020.12cc

 

Any logical reason behind this (class limit), or is it just a whim to hit a certain spec? 81mm can make lots of power and still spool a turbo fast enough for road racing, but >84mm is considered somewhat risky (and less rebuildable). You will also be spending more on custom pistons to hit 2k cc exactly

 

You do plan on resleeving it, don't you? Stock sleeves can only go out to (correct me if I'm wrong) 82mm. Anything past that and you're grinding the block itself.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Schister66 &raquo;</TD></TR><TR><TD CLASS="quote">84mm x 89mm would yield 1972.87cc which would be rounded to 2.0L. If you went 85mm x 89mm you'd end up at 2020.12cc</TD></TR></TABLE>

True, but that's an LS crank.

A B18C... 84 x 87.2 comes out to 1933.16 which can still be rounded up to 2.0

 

True, but if you're spending that much money already, why not toss in an LS crank for the added displacement

 

Good question.

 

Some people still think that rod/stroke ratio is more important than displacement, and do not understand the mechanics of RPM vs Displacement, nor how bore & stroke affect torque. Given the same displacement, a longer stroke will make move overall power, even with less RPM's. I would not like to judge by one (or even all 18) of his posts, but if I was, I'd guess he already has GSR crank & rods, and doesn't want to remove his oil squirters. Or he has dreams of spinning to 11k rpm...

However, when you consider the cost of building a re-sleeved motor, squirter-removal and the cost to change crank & rods (sell the old set!) is chump change. If you're not in a hurry, it won't cost more than a few hours of your time and $200 at the most. Golden Eagle sells polished LS cranks for $100/shipped, and unused rods rarely sell for $50-100 less than new sets. A GSR crank is worth at least $50 to someone.