Help tap broke off in crank snout
06-23-2009, 06:21 PM
#1
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Help tap broke off in crank snout my machine shop put in a sbc crank instead of my original lt1 crank, my lt1 bolt would not thread into the sbc crank. i went by the shop and picked up a sbc crank bolt, which happened to be the EXACT same as the lt1 crank bolt.
the lt1 bolt is 7/16-20 right?
the bolt he gave me is 7/16-20 also....
i called them back and asked wtf and was told the sbc crank bolt is 7/16-20 and he said to run a tap down the snout because the threads might befubared. well i was running a 7/16-20 tap down the snout and it was going in easy enough and it got to one point and got really hard so i pulled it out and blew out the hole, and went back in, snap, half the damn tap is in the snout, only saving grace is a little bit is sticking out..
as i was going in and out with the tap i could see it was cutting new threads. only reason i kept going is because i figured i could just go ahead and use the new threads i was making..
F M L.
any suggestions?
the lt1 bolt is 7/16-20 right?
the bolt he gave me is 7/16-20 also....
i called them back and asked wtf and was told the sbc crank bolt is 7/16-20 and he said to run a tap down the snout because the threads might befubared. well i was running a 7/16-20 tap down the snout and it was going in easy enough and it got to one point and got really hard so i pulled it out and blew out the hole, and went back in, snap, half the damn tap is in the snout, only saving grace is a little bit is sticking out..
as i was going in and out with the tap i could see it was cutting new threads. only reason i kept going is because i figured i could just go ahead and use the new threads i was making..
F M L.
any suggestions?
06-23-2009, 07:07 PM
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not much to grab with pliers but im gonna try in the am
06-23-2009, 08:53 PM
#7
There are a few things you can do.
1. weld a nut onto the end of the stud and try to remove it with a wrench
2. file down the tap so that you have two flat spots to put a wrench on it or turn it
3. use a tap extractor, the proper way, enco and walton make them.
4. plasma cut it out.
5. take it to a shop to edm it.
Also get some lube, some penetrator, my favorite is actual beeswax, heat up the area and apply the beeswax, I have NEVER seen something stuck that can not be removed by heat + beeswax.
fyi I used beeswax to remove head studs on the main engine of a 950ft long ship. 146mm studs broke off in the threads.
1. weld a nut onto the end of the stud and try to remove it with a wrench
2. file down the tap so that you have two flat spots to put a wrench on it or turn it
3. use a tap extractor, the proper way, enco and walton make them.
4. plasma cut it out.
5. take it to a shop to edm it.
Also get some lube, some penetrator, my favorite is actual beeswax, heat up the area and apply the beeswax, I have NEVER seen something stuck that can not be removed by heat + beeswax.
fyi I used beeswax to remove head studs on the main engine of a 950ft long ship. 146mm studs broke off in the threads.
