Hair line crack in SBC block
04-06-2010, 04:55 AM
#1
Senior Member
DYNO OPERATOR
Thread Starter
Join Date: May 2003
Location: Moscow Mills, Mo.
Posts: 533
Hair line crack in SBC block
Anybody have any suggestions on repairing a hair line crack in a block when it's in the car. Looks like the crack is on the passenger side 1 inch to the right and left of the 1/8 pipe thread drain plug on the passenger side on a SBC motor.
I drained the block, blew air in the radiator to help dry the area and get all the anti freeze and water out, brake kleened the area, peened on both sides of the crack to help stop it from cracking more, wire wheeled the crack then ground the crack to help when I put JB weld on it. I'm letting it dry with a drop light on it for 15 hrs.
Anybody have a different way or do you think this will work? Oh, I also will fill it with water and aluma seal then run a 5# radiator cap.
Thanks for your help.
I drained the block, blew air in the radiator to help dry the area and get all the anti freeze and water out, brake kleened the area, peened on both sides of the crack to help stop it from cracking more, wire wheeled the crack then ground the crack to help when I put JB weld on it. I'm letting it dry with a drop light on it for 15 hrs.
Anybody have a different way or do you think this will work? Oh, I also will fill it with water and aluma seal then run a 5# radiator cap.
Thanks for your help.
04-06-2010, 10:59 AM
#2
Senior Member
RACING JUNKIE
Join Date: Jan 2006
Location: La.
Posts: 2,890
Vince if you reach it easy you can weld it with NI-ROD, just V it out preheat it with a torch and weld about 1/2" at a time, if it's just a tempary fix i'd run the block sealer.
The 400 blk 377", that i have in my Malibu has a 4" crack 3/4" below the deck on the passeneger side. It wasn't caught during the build, the blk wasn't decked. I v'ed it out and Tig welded it without pulling the heads. I'd weld about 1/2" and pean it too relieve the stress then weld another 1/2" with NI-ROD. It has over 200 passes on it and running a 16# cap. Course when i pull it apart next time ill change the blk. out. This was done as quick fix and it's been running for about 5 yrs.
Zip.
The 400 blk 377", that i have in my Malibu has a 4" crack 3/4" below the deck on the passeneger side. It wasn't caught during the build, the blk wasn't decked. I v'ed it out and Tig welded it without pulling the heads. I'd weld about 1/2" and pean it too relieve the stress then weld another 1/2" with NI-ROD. It has over 200 passes on it and running a 16# cap. Course when i pull it apart next time ill change the blk. out. This was done as quick fix and it's been running for about 5 yrs.
Zip.
