Tom M'Guinn

You got that right. Sadly, those kinds of shops are everywhere it seeems...

User 41221

FWIW, I'd recommend Timeserts, not Helicoils. They are stronger and work better, imo. ALso, I second the advice to stay away from extractors for the same reasons everyone else has mentioned. I have MUCH better luck just drilling. If done right, once you step up teh size to something close to teh original bolt size, the last of the original material comes out on its own with tehy drill bit, and then you just chase it with a tap and you are back in business. If not, then you just timesert it and you've got a stronger than original hole.

It does take patience. lol Also, I wound up buying a right angle adapter for my drill that makes it possible to drill out water pump studs with the engine in the car.

Regards,

Dare

So here's a question: When drilling the hole for a helicoil or timesert, what do people do to keep the drill in line with axis of the original hole? Obviously a drill press is the right answer here, but I haven't got one of those and sometime its just not practical. Do you all just eyeball it?

User 41221

I have eyeball'd it with good results. I haven't had one go in noticibly crooked yet (alho I am guessing that the very next one will! lol), the trick is to take your time and stop after you get the pilot hole started and make sure its straight. If you get the pilot hole straight, you have to be trying to get the others crooked.

Tom M'Guinn

If you are drilling into an exiting hole with botched threads, the original hole will generally keep the bit centered and straight.

ramius665

Well, after a little research Time Serts seem the only way to go. Now, I have to debate whether to spend the $75 on an M6 kit or just haul the block to the machinist. I wouldn't mind spending the money on the kit, except it's only good for M6 threaded holes, so if I break another stud/strip a hole then I'm out $75 again. BUT, I'm glad I asked the question here, because I'm about a 1000% smarter on stripped threads than I was 48 hours ago. Thanks guys, I'll let you know how the repair goes.

Tom M'Guinn

Timeserts are stronger, no doubt. However, for that stud, a helicoil is plenty strong enough in my experience. I'd venture to say a helicoil is stronger than the original aluminum threads.

ramius665

Well, I'm going to go chat with my machinist tomorrow morning and see if he can/will drill the old studs out and install time serts. If he'll do it for me, then I'll go ahead and let him. He did a perfect job removing two broken exhaust manifold studs on my head. Besides, he's actually excited to see a Porsche owner that's willing to tackle an engine rebuild with minimal help (I didn't tell him about all the help I've received from RL) and has offered more than a few bits of experience that have come in handy.

951Saga

In my experience extractors are better left alone when dealing with rusted or thread locked, (Loctite adhesive), threads.

Center punch the damaged stud, if possible grinding the exposed stud flat makes this more accurate.
Reverse drill bits are best, preferably new Cobalt or HSS.
Begin with a small bit and end with a bit which removes the exposed stud without or slightly contacting the block’s threads.
Use a tapered tap to clean out what’s left of the bolt. It’s best to have a few threads in the block available to start the tap.
Use cutting oil or motor oil on your drill bits and tap.

Throughout the process be patient, do not force the bits or tap and keep them strait.
If you see the original threads are not 100%, use the helicoil or timeserts.

carreracoupe997

+1

Dare

I'm obsessive about contamination, especially when working on a partially assembled block. So before I start drilling I cover the whole thing with a plastic garbage bag. Then I cut a hole in the bag a little larger than the bolt hole, cover it with a piece of painter's tape and stick the tape over the hole in the block. Then I just cut around the hole with a knife leaving the tape stuck to the surrounding metal. With only the hole to be drilled exposed there's no way for a chip of metal to fly into an oil passage and ruin all your hard work.

ramius665

Dare, thanks for the tip, I wound up using it today actually...

URG8RB8

You will need a M6 X 1.00 mm tap (preferrably a bottom tap), not M6 X 1.25, the only threads on the engine that have a 1.25 mm pitch are M8. Plus remember that one of the four water pump studs is shorter than the rest. See my recent post on WP studs for more pictures and detailed length measurements. I will post one of a new stud that I just took below. Also, if you are interested, I am creating a complete engine fastener kit from polished SS. I should be getting the first kit delivered this week for test fitting. I will see if the vendor is willing to break up the kit and just sell the studs or other individual components. I am getting nothing out of this except a 40% discount on the first kit for my efforts on sizes, locations, pictures, etc... The final product will be available at his website shortly, MMS & Accessories in Georgia.

ramius665

Well, after speaking with my regular mechanic and also my machinist, they both said, "Take your extractors straight to the trash, drill them out yourself unless you get in trouble, then bring the block in." So, I'll be drilling them out myself here in a couple of hours.

URG8RB8, please let me know what a full kit will cost, I already have replacement studs on-hand, but would be interested in a whole new set of fasteners.

URG8RB8

As soon as I find out, I will let you know. I will post a link to the kit when he gets it up on his site. He makes nice stuff. I have a kit for an older Z car of mine at it is very nice and complete. He has smaller kits for the 944 available, such as polished SS oil pan studs and nuts to replace the factory bolts and polished SS cam housing plugs. I purchased those from him and then called and asked if he would be interested in making a complete hardware kit for the entire engine. He told me ok, as long as I documented every fastener. I have a pretty nice spreadsheet with pictures of every fastener on the engine I made up. It was a big PITA, but handy none the less.