helicoil on an iron head

Dart Vader · Post by **Dart Vader** » Wed Feb 18, 15 11:20 pm

Can this be done?

Got a stripped thread on each end of the heads, last bolt so water corroded.

Any tips?

Cannonball · Post by **Cannonball** » Wed Feb 18, 15 11:28 pm

yes no problem they are 3/8 unc,,,,,,

autofetish · Post by **autofetish** » Thu Feb 19, 15 9:15 am

yep love a heli coil buy as a little set with the correct tap and drill bit and tool

Dart Vader · Post by **Dart Vader** » Thu Feb 19, 15 2:41 pm

cheers, was a bit worried the iron would be too tough.

Blue · Post by **Blue** » Thu Feb 19, 15 4:51 pm

Cast iron isn't that nice to drill, it tends to snatch a bit. Make sure the head is firmly held down, drill on a slow speed with a good firm grip on the drill and take it easy, you should be fine. Don't risk snapping the bit off in the head or you'll be in a world of Bananarama!.....

mopar_mark · Post by **mopar_mark** » Fri Feb 20, 15 12:00 am

As Blues said, drill nice n slow, you shouldnt need to lubricate. But make sure you do when tapping.

Keep backing the tap out, as they tend to clog quickly with cast iron.

bratfink · Post by **bratfink** » Fri Feb 20, 15 1:00 am

If you can setup to use a pillar drill or even better a mill it'll be easier to get a nice cut (if the head is off of course - be a bit tricky if the head is still on the engine)

autofetish · Post by **autofetish** » Fri Feb 20, 15 9:38 am

if this is the same size as a 727 sump pan i have a kit you can borrow