nuch_ss396
07-19-2006, 08:32 PM
I have a question for the group concerning GM's ( Chevy )
use of 4-bolt main blocks on SHP engines vs. 2-bolt main
blocks on STD. & HP engines during the later 1960's & early
1970's.
I was just looking at a thread in another category here
concerning hemi blocks and noticed that these blocks use
4-bolt main caps in the 3 center positions, but only
2-bolt main caps in the front & rear cap positions. I
hope my description is accurate.
Then, I started thinking about the 396, 427 & 454 blocks
and the use of 4-bolt mains front to back on SHP engines.
It has been stated many times to me that you don't really
need to be into 4-bolt main territory unless you are pushing
600+ HP. Is that accurate? If so, why did Chevy put 4-bolt
mains in engines with just 375hp? Is this just a case of
practical, real world knowledge that came about with the
passage of time and engine life analysis vs. what the
engineers of the day thought? http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif
Or, did the use of 4-bolt mains on the BBC factor in
issues like overall engine design ( main bearing support strength )? http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif
Steve
use of 4-bolt main blocks on SHP engines vs. 2-bolt main
blocks on STD. & HP engines during the later 1960's & early
1970's.
I was just looking at a thread in another category here
concerning hemi blocks and noticed that these blocks use
4-bolt main caps in the 3 center positions, but only
2-bolt main caps in the front & rear cap positions. I
hope my description is accurate.
Then, I started thinking about the 396, 427 & 454 blocks
and the use of 4-bolt mains front to back on SHP engines.
It has been stated many times to me that you don't really
need to be into 4-bolt main territory unless you are pushing
600+ HP. Is that accurate? If so, why did Chevy put 4-bolt
mains in engines with just 375hp? Is this just a case of
practical, real world knowledge that came about with the
passage of time and engine life analysis vs. what the
engineers of the day thought? http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif
Or, did the use of 4-bolt mains on the BBC factor in
issues like overall engine design ( main bearing support strength )? http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif
Steve