Stroking BBC

Old 10-16-2008, 02:58 PM
  #1  
jreiley
Senior Member
MASTER BUILDER
Thread Starter
 
Join Date: Aug 2007
Location: Iowa - USA
Posts: 218
Default Stroking BBC

How big can a bbc be stroked before the block has to be machined. The block is stock gm. Thanks.
jreiley is offline  
Old 11-06-2008, 11:22 AM
  #2  
radicalz
Senior Member
MASTER BUILDER
 
Join Date: Dec 2004
Location: out of my mind in Kalamazoo, MI
Posts: 179
Default Re: Stroking BBC

Originally Posted by jreiley
How big can a bbc be stroked before the block has to be machined. The block is stock gm. Thanks.

I saw this out there and I tought I would try to answer this....the short deck or tall deck depends on the crank and rods you are going to use usually if going to a 4.125 throw crank you will need to clearance the rods on the oil pan rail...now I'm not sure about the tall deck but be aware that at some point you will need to clearance the crank and rod throws depending on how big you are going....I think the new casting for the big inch crate motors that GM is offering already has those considerations in mind hence the big cubic inch numbers...maybe somebody else has an idea
radicalz is offline  
Old 11-07-2008, 02:11 AM
  #3  
cepx111
Senior Member
RACING JUNKIE
 
Join Date: May 2006
Posts: 2,044
Default

I used a stock 454 block and put 4.25 eagle rotating assembly in and everything cleared, even a stock oil pan without notched rails cleared.
Maybe I got lucky who knows but I do know the later 454 blocks i've seen do have a little relief cast into the pan rails which looks like it was meant to accomodate a longer stroke. JMO> Cp
cepx111 is offline  
Old 11-07-2008, 05:59 AM
  #4  
Tod74
Senior Member
RACING JUNKIE
 
Join Date: Sep 2007
Posts: 4,143
Default

I got a 512 casting block that had a 4 1/4 stroke crank in it when I got it...I don't remember seeing any evidence of being clearanced but I wasn't looking for that either.
Tod74 is offline  
Old 11-07-2008, 08:06 AM
  #5  
jreiley
Senior Member
MASTER BUILDER
Thread Starter
 
Join Date: Aug 2007
Location: Iowa - USA
Posts: 218
Default Re: Stroking BBC

Originally Posted by radicalz
Originally Posted by jreiley
How big can a bbc be stroked before the block has to be machined. The block is stock gm. Thanks.

I saw this out there and I tought I would try to answer this....the short deck or tall deck depends on the crank and rods you are going to use usually if going to a 4.125 throw crank you will need to clearance the rods on the oil pan rail...now I'm not sure about the tall deck but be aware that at some point you will need to clearance the crank and rod throws depending on how big you are going....I think the new casting for the big inch crate motors that GM is offering already has those considerations in mind hence the big cubic inch numbers...maybe somebody else has an idea
Thanks for the reply. My thoughts are that I have to replace the rotating assembly anyway and I might as well stroke it. I have very limited access to any good machine shops.
jreiley is offline  
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service