Will the 3.0 KS Alusil Ring Master please come forward?

[SCadaddle]

Wow. I'm rebuilding the top end of my 82 SC due to a single head bolt stud failure (amongst other minor issues such as finding a valve keeper collet in the bottom of the engine next to the pick-up screen) and find I have the KS Alusil pistons and cylinders.

I have read, thoroughly, the 29 page thread on re-ringing Alusils.

I found a vendor that claimed to have the "correct" ring set being 930 103 985 00. I bought them. UPS just delivered them. They are the Goetze 930-103-986-00/42, Goetze part number 08-320900-10 Piston Ring Set 20812A10.

My 911 engine Guru just confirmed "BRRZZZZZTTTT....wrong answer, those are for the Mahle pistons and cylinders." In the 29 page thread mentioned above I find one fellow that claims to work for Goetze stating this is the correct part number for the 80+ SC and will work with either Mahle Nikasil or KS Alusil.

Would somebody (else) in the know whose business model includes 911 engines that do not smoke from here to eternity please confirm? I've no more hair to lose over this matter however my sleep could be improved. Thanks!

[SCadaddle]

[timmy2]

I installed the ones pelican sent me on my '78. No problems, no smoke at all from my alusils after 3K miles.
Looks like you have the same part number that pelican lists for your car.
Not an expert by any means, but they worked for me. (yes I realize they are different for different years, just saying pelican had the right ones)

[lindy 911]

Why not reuse the rings that were already installed? Do they measure at the gap and on the piston lands? If they do, I would use them.

[TibetanT]

+1 with what Lindy911 said above. Use the ones you have with the pistons if they are within specifications.
Be aware that the 1978/79 KS oil ring is slightly bigger (4.0mm) than the 80-83 specifications.
but hopefully an expert will chime in to set us all straight.

[SCadaddle]

Re: using the old rings.....

As is what I would consider the correct approach on rebuilding an engine, everything was numbered, bagged and tagged as to where it was upon teardown. Cylinders numbered. Heads numbered. Rocker arms numbered. Valves and springs 1 assembly per baggie with note on intake/exhaust/cylinder number.

The rings, considered dispensable by my builder, wound up in a pile on the table. I would agree they are a dispensable part......until the point where I find so much information and/or mis-information on what is correct and what is the correct procedure for a successful build.

The pistons and wrist pins were soaked in lacquer thinner in individual tin cans for a few days. The carbon on tops of the pistons and the skirts removed easily with a red scotchbrite pad continuously dunked in the thinner. The ring lands were cleaned rather meticulously with a dull box cutter blade and the thinner followed by a toothbrush and the thinner. The wrist pins and the wrist pin bores were cleaned with the thinner and green scotchbrite pads. All was returned to soak in the cans for a few more days.

I have no idea if I ruined the iron/tin coating on the piston skirts, and for what it's worth we'll check the ring end gap/land clearance. I haven't looked at the rings closely but apparently at least one of them was worn to the point of having no part number/info on it.

I've been a happy 912 owner for 22 years, but after about a single month of being a 911 owner I'm beginning to re-think this whole Porsche thing.....

[TibetanT]

I feel your pain. But, hey, don't be so hard on yourself, we all make mistakes and it is what we do after the fact that really counts. If we learn from it, then IMHO it was worth it.

Now, if you have bagged everything properly and know where everything goes then I think you are ahead of the game. Worse case, you look for a good set of 95mm Mahles or buy a new set, since everything else can still be used.

Keep the faith, and if you decide some parts cannot be used that have been purchased new, there is always someone here that can use them and will buy them from you for a fair price. For example, three years ago I saw an Ad for a new set of piston rings for $100.00 shipped. I bought them and am now using them in a build. I helped someone with the purchase and they helped me save a few bucks, so it all worked out.

[arbita1]

I know the Mahle and schmidt rings are definitely different. I have the little tech book for the sc that shows the difference.

[lindy 911]

Pick up the phone and call Henry Schmidt at Supertec. He will set you straight. And the 912 thing; it was a great car but nothing like a 911, wait and see...

[SCadaddle]

Thanks for the tip on Henry; I'll see if I can give him a call tomorrow.

As for the 912, it's been just a fantastic "balanced" car. I've got a good set of "twistys" nearby here in central Mississippi (imagine that!) that's probably about 15 miles long that includes the best "corkscrew" this side of Laguna Seca. The 912 more or less "dances" through it, the 92 Miata is blistering through it, and the 911, well, let's say requires a lot more "work" but by far commands the most respect of which is going to be a (safe) learning process to say the least.