Previously Timeserted block?

[97 STS]

I finally got around to starting the Time Sert procedure. 1st hole seemed to go pretty good, got insert installed. Drilled 2nd hole and while running the tap in I felt a snap and the tap just spins, won't cut anymore. So I back it out and it has threads wound around the cutting teeth, this is odd. I'm trying to figure out how this happened.Where did this metal come from? I clean the tap off and finish the hole. I find more of this thread material in the bottom of the hole while cleaning it out. Now I'm scratching my head. Finally I ask myself is this block already inserted? How to tell? Run a magnet into the other holes? It would stick to the steel inserts. I don't have one that will fit. Finally dawns on me to check the filings. How about that they all stick to the magnet. Aluminum should not stick so I must be cutting steel? Well what to do next? Will a Norms kit work? Any thoughts or advise would be much appreciated.
Thanks, Bob

[zonie77]

Norm's are longer but I'm not sure if they are any larger diameter. You could contact him and find out.

Timesert makes a bigsert that you can use.

Are the inserts bad? Did any come loose or did the HG fail? If so can you tell where the HG failed?

[submariner409]

I wonder......Is this the first time someone has attempted to insert this block.....??? If it apparently is, and there are inserts in some holes, what does this indicate about original assembly ??

IF some holes are inserted already, your only hope is to go to an insert which will screw into complete, newly formed threads and do all 20 holes. Getting the old inserts out, if any, will be pure hell. One hiccup and you'll have a broken drill or tap stuck down in an aluminum block. Not good......

[Ranger]

Perhaps the last repair was done with Helicoils.

[dkozloski]

Before doing any more drilling, sharpen the drill bit as if you were going to be drilling brass or plexiglass to keep it from hogging and getting stuck. Either BigSerts or Norm's serts should work just fine to renew the threads.

[97 STS]

Well testing with a magnetized screwdriver it appears that all 20 holes were inserted. I have drilled out 3. When I pulled it apart all of the headbolts came out without any additional threads attached, which I was kind on suprised to see, since I had figured that I had failed threads, as has been described in several other posts. All of the inserts remained in the block. There was lots of oxidation and other junk around all of them, so I assumed that I was working with a stock block. Some of the bolts did not seem to be tight enough, they didn't snap when I first broke them loose. My leakers appeared to be #'s 1 & 3. I guess I'll contact Norn to see what he has to say.
Thanks, Bob

[submariner409]

Ranger hit it: Helicoils. (........but, some Helicoils (Brand name Helicoils) are stainless steel, no magnetic attraction........)

[97 STS]

Reply from Norm.
If your engine has been repaired in the past with timeserts, the unthreaded portion of the hole above the threads will be around .532 diameter. If it had been repaired with helicoils, the hole may be smaller.
If it had been repaired with bigserts, the hole above the threads will be much larger than .532 diameter, it will be over .615 diameter.
Guess I'm off to look for something to measure the holes with. I don't think my tape measure will be quite accurate enough.

[Ranger]

Get a dial caliper.

[97 STS]

Picked up a digital dial caliper from harbor freight today. Less than $20. Holes heasure about .529. Looks like Norm's kit will work. Off to check ebay.
Thanks for your replys, Bob