27-08-24, 10:34 AM
Well finally had a go at this when my son badgered me into it!
Tried a mig welder, welding nuts onto the thread, it worked for one stud that came out fairly easy. other 5 no joy, the block being a giant heat sink especially on cylinder 2 and 3 struggled to get heat into the stud without melting the nut, moved up to a bigger M8 nut that got one more out, All the rest the weld either sheared off due to lack of penetration or others the welds took but the stud sheared further inside the block.
Tried building up the weld still would not budge.
Resorted to drilling them out. Took the radiator off to get better access, ( lower retaining bolt sheared- solid with corrosion was able to drill out and retap the captive nut)still not great, the drill chuck fouled by the frame so had to get long drills could only get black HSS drills, they just bounced off it even with a good centre dab. Put a 5mm Cobalt drill the smallest diameter that was long enough not to foul, that sliced through it. Drilled it out not 100% centred but good enough, fitted a helicoil and that seems to be solid with new stainless stud.
Ran out of time and need to get some smaller Cobalt drills can only presume the numerous attempts at welding have case hardened the studs, I can think of no other reason why new 3mm HSS drill bits will not bite but just bounce off the surface.
On plus side 3 to go 2 are horrendous access do the frame, oil scavenge pipe and cam chain casting, other 1 looks ok just need to find the time
He also decided to investigate the loose front indicator, result the fairing is off and down to the inner frame he likes to give me work!
Tried a mig welder, welding nuts onto the thread, it worked for one stud that came out fairly easy. other 5 no joy, the block being a giant heat sink especially on cylinder 2 and 3 struggled to get heat into the stud without melting the nut, moved up to a bigger M8 nut that got one more out, All the rest the weld either sheared off due to lack of penetration or others the welds took but the stud sheared further inside the block.
Tried building up the weld still would not budge.
Resorted to drilling them out. Took the radiator off to get better access, ( lower retaining bolt sheared- solid with corrosion was able to drill out and retap the captive nut)still not great, the drill chuck fouled by the frame so had to get long drills could only get black HSS drills, they just bounced off it even with a good centre dab. Put a 5mm Cobalt drill the smallest diameter that was long enough not to foul, that sliced through it. Drilled it out not 100% centred but good enough, fitted a helicoil and that seems to be solid with new stainless stud.
Ran out of time and need to get some smaller Cobalt drills can only presume the numerous attempts at welding have case hardened the studs, I can think of no other reason why new 3mm HSS drill bits will not bite but just bounce off the surface.
On plus side 3 to go 2 are horrendous access do the frame, oil scavenge pipe and cam chain casting, other 1 looks ok just need to find the time
He also decided to investigate the loose front indicator, result the fairing is off and down to the inner frame he likes to give me work!