Building a ´71 SCJ now - take two
4 posters
Page 1 of 1
Building a ´71 SCJ now - take two
Hi to all who responded to my initial posting on this engine.
We chose the Pertronix distributor, I went with the Clevites and we bought a Powermaster starter. The plan then is to install an MSD box with a built in retard, rev control; the works. This engine has obviously seen its share of battles in the past. It was originally installed in a dark green ´71 Mach with a 3.91 trac lock gear.
But, now we have a more serious issue to discuss.
Upon beginning the short block assembly it is clear that the rods have been balanced in the past. The pads on the rod clamps have been ground down to a differing degree, some almost ground off completely.
Additionally, the lower halfs (clamps) have been renumbered. The machine shop has thus altered the location of all of the rods except nr. 8.
I bought a clean 4U 429 crank since the original was damaged. Then I replaced the original L2366 pistons with a set of the same, except .030 over.
The question I have is this: Which numbering sequence do I use; the original or the custom one? (considering the original pistons and crank are gone)
G:
We chose the Pertronix distributor, I went with the Clevites and we bought a Powermaster starter. The plan then is to install an MSD box with a built in retard, rev control; the works. This engine has obviously seen its share of battles in the past. It was originally installed in a dark green ´71 Mach with a 3.91 trac lock gear.
But, now we have a more serious issue to discuss.
Upon beginning the short block assembly it is clear that the rods have been balanced in the past. The pads on the rod clamps have been ground down to a differing degree, some almost ground off completely.
Additionally, the lower halfs (clamps) have been renumbered. The machine shop has thus altered the location of all of the rods except nr. 8.
I bought a clean 4U 429 crank since the original was damaged. Then I replaced the original L2366 pistons with a set of the same, except .030 over.
The question I have is this: Which numbering sequence do I use; the original or the custom one? (considering the original pistons and crank are gone)
G:
gcj- Posts : 56
Join date : 2012-03-11
Location : Europe
Re: Building a ´71 SCJ now - take two
You need to go get the balance checked, of crank, rods, pistons, dampener, and flywheel
rods might of been moved around for other reasons, take it somewhere and get it checked
rods might of been moved around for other reasons, take it somewhere and get it checked
BOSS 429- Posts : 2372
Join date : 2009-08-10
Location : Ill
Re: Building a ´71 SCJ now - take two
Have it rebalanced
dfree383- BBF CONTRIBUTOR
- Posts : 14853
Join date : 2009-07-09
Location : Home Wif Da Wife.....
BOSS 429 likes this post
Re: Building a ´71 SCJ now - take two
The position of the rods should not matter if they were balanced and rebuilt previously. But the pistons will be a different weight, and the crank is not balanced to the parts you now have. As was stated, you need to have the assembly balanced (again).
pmrphil- Posts : 171
Join date : 2016-10-29
Similar topics
» building a sc 460
» Building a c-4 for a 408
» Building a ´71 SCJ now.
» Building A Mean 460...?
» Building headers?
» Building a c-4 for a 408
» Building a ´71 SCJ now.
» Building A Mean 460...?
» Building headers?
Page 1 of 1
Permissions in this forum:
You cannot reply to topics in this forum