Hi Grumpy,
Thanks for this site and taking the time to look at this for me
Am building a 383 at the moment using a gm 2 bolt block that had 4 bolt caps installed by previous owner.
The job they did fitting the caps appears ok and it looks like the tunnels were line bored.
Problem is the crank main bearing clearances are tight and I think maybe the cause is the tunnel sizing is on the small side
and they're not very uniform.
I have found this acl site that specs tunnel tolerances http://www.aclperformance.com.au/us/Che ... ingsus.htm.
Do you think if I have the block line honed it will sort the main bearing clearances out?
What about bearing crush? i guess the crank tunnel size dictates this.
Here are the measurements I have.
Journal Block Main Bearings Crank
No 1 2.639.2" 2.448.8 2.448.3
No 2 2.638.5" 2.448.9 2.448.3
No 3 2.639.4" 2.448.6 2.448.0
No 4 2.639.6" 2.448.8 2.448.2
No 5 2.639.6" 2.449.0 2.447.7
I think this is a good example to everyone why everything needs to be checked
Thanks for this site and taking the time to look at this for me
Am building a 383 at the moment using a gm 2 bolt block that had 4 bolt caps installed by previous owner.
The job they did fitting the caps appears ok and it looks like the tunnels were line bored.
Problem is the crank main bearing clearances are tight and I think maybe the cause is the tunnel sizing is on the small side
and they're not very uniform.
I have found this acl site that specs tunnel tolerances http://www.aclperformance.com.au/us/Che ... ingsus.htm.
Do you think if I have the block line honed it will sort the main bearing clearances out?
What about bearing crush? i guess the crank tunnel size dictates this.
Here are the measurements I have.
Journal Block Main Bearings Crank
No 1 2.639.2" 2.448.8 2.448.3
No 2 2.638.5" 2.448.9 2.448.3
No 3 2.639.4" 2.448.6 2.448.0
No 4 2.639.6" 2.448.8 2.448.2
No 5 2.639.6" 2.449.0 2.447.7
I think this is a good example to everyone why everything needs to be checked