Re: [AMC-list] 258 crankshaft differences

[adh@xxxxxxxxxxxxxxxxx (Sandwich Maker)]

" From: Jim Blair <carnuck@xxxxxxxxxxx>
" 
" []
"    The piston design changed at the same points, but its compression
" ratio more than anything. 
"    I think the combustion chamber size increased at those points too.

chamber size went from 66 cc to 74 cc in '77 iirc.  pistons changed at
the same time but i don't know what the dish sizes were.  they might
actually have gotten smaller.

199s and 232s had seperate pistons, but from '71-9 232s and 258s
shared.  after the 232 was dropped the 258 got a taller slug that
wouldn't fit the smaller sixes.

" I stuck a small chamber head on a motor with flat tops and it smoked
" like crazy but ran like a bat out of hell till the pistons cracked. 

the flat tops would've been late 199 slugs.  '64-7 heads had 56cc
closed chambers and even 199 slugs had small dishes.

i don't know why your slugs would've cracked, unless you were flogging
the whatnot out of it, or the ignition timing was really off for the
compression, or some other defect/problem.
________________________________________________________________________
Andrew Hay                                  the genius nature
internet rambler                            is to see what all have seen
adh@xxxxxxxxxxxxxxxxx                       and think what none thought
_______________________________________________
AMC-list mailing list
AMC-list@xxxxxxxxxxxxxxxxx
http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com