I have 1 (one) stud w/Heli coil that is .150/.200 from square @ the top of the stud. The location is one of the blind hole three top studs (closest to the intake location).
It has been suggested to replace the Heli Coil with a
Time-Sert which I have no previous experence with or
drimmel out the cylinder hole and screw in the stud after the head is installed.
I DO NOT want to hack up a set of BMS heads but I'm not also interested in screwing up a S2 block.
Anyone crossed this bridge before?
you are talking about head studs right? I would either put it in a drill press/mill square and redrill or make a guide the could bolt to the deck to square the drill bit/ plate with a tube. Just an idea
I would recommend repairing the problem with a Timesert. I have a lot of experience with timeserts. They are far superior to any helicoil type thread repair. GM has extensively tested Timeserts for aluminum engine repair and are validated for head bolt and main cap useage on many GM engines.
The repair process starts by drilling out the existing damaged threads. You would need to somehow extract the offending helicoil without damaging the block. You would also need a drill jig to be sure you drill and tap the new hole square to the deck. The insert threads into the oversized hole and restores the hole to the correct size.
Timeserts aren't exactly cheap. They'll run you 3-4 times the cost of a helicoil kit...but they beat the crap out of helicoil for strength and durability.
Don's right....you need the new hole straight and square. I would use my deckplate as a drill guide or have a competent machinist make a drill jig that you could bolt to the deck.
