A WHOLE TEN BUCKS!!!:eek:

Crap!!! Adam, I want my cylinder back!!!:D

If anyone wants one or all of the remaining cylinders, you pay shipping...you know where to find me.SmileWavy

edited to make sense....

Bill, great work getting KS onboard. I tried and got no response. It's just a guess but I think he meant, "why would we produce and sell oversize pistons if you couldn't bore them?" or roughly that. Interesting that he did not directly talk about 911 P&Cs. Call me paranoid but I can hear a caveat coming a mile away.

Rondinone - great new sig. sounds like the revolution has a motto!!http://www.pelicanparts.com/support/smileys/2ar15.gif
VIVA Alusil!

Hey, this might be a stupid question but do 3.6s have alusil or the soon to be discontinued ;) niks?

Yes, I am up to it. Send me a cylinder. I will pay return postage too.

An excellent plan.

Rondinone:
I pretty much came to the same conclusion. The "comparitor" machine is what he initially offered to me for measurement of the cylinders and pistons to see hao much they have worn. It seems like a lot of people are experiencing little wear or at least within Porsche specifications.
What do you think of this machine for this purpose?
I believe they use it for quality control.
Anyway, I have nothing for him to measure at the moment. I didn't really know the complete history of my cylinders because they were from a rebuilt engine that the PO installed in the car. Who knows how many miles are on them.

The reply from KS probably took 3-4 weeks on e-mail. I asked them also to send me the document, but I suspect it is what we have seen here. I'll update when I get it. That might take a long time.
Does MSI / KS have a us office?
How would the distribute parts? I've never herd of someone buying replacement KS pistons and/or cylinders.
Maybe I'll check a dealer.

I've seen the listing for the KS USA office, think it's somewhere in PA or DE. It's on their website, sorry I don't recall exactly where, I'll look later this afternoon.
The oversize pistons are probably a dealer special order item but I doubt you find anyone who has ever done it. Besides the oversize they are talking about are just that, 95.05 over etc. nothing close to 3 or 4mms over, not intended for displacement increase but replacement for out of spec cylinders that are refinished.

Anthony

Anthony. I was thinking the same thing about the Oversized pistons.
If sold at a reasonable price they would be a great option for those that have cylinders worn beyond specifications as that is what they would be intended for. Even within the specificaions for standard there is a range of acceptable tollerance for "new" pistons and cylinders.

I just pulled my little spec. book. It shows the ranges for standard size "0" and 3 larger sizes. If I am interpreting this properly they are either oversized "sets" or specifications for boring oversize with the oversized pistons. Would they sell oversized cylinders since you can bore them out?
I don't think they are tollerance groups (Like weight groups.)

Based on my measurements my pistons fall into the largest #3 group.
I kept my sheet with my measurements but at the time I don't think I paid too much attention to the #3 size although I circled it in my spec. book.
I was more concerned with the clearance between the piston and cylinder which turned out to be fine.

So, I am the owner of an oversized set or oversized pistons with the cylinders bored out.

Some fine work all of you have done here. Outstanding job finding the truths to the Alusil debate. http://www.pelicanparts.com/support/smileys/clap.gif

You guys rock. http://www.pelicanparts.com/support/smileys/pray.gif Rock on!

Well, today I've had my old Alusils in to work. There we have a "Surtronic Talisurf" (as our Goetze technical man described it), otherwise known as a surface finish testor. We tested the surface finish of all 6 bores in varying positions. My engine has covered approx 80000 miles.

Depending on position within the bore, my cylinders measured between 0.49 & 0.60 mu.m RA. The area outside the ring reversal point ie below the bottom of the ring running area, measured a consistent 0.80mu.m RA, suggesting this is the factory standard RA.

My technical colleague, who I should point out is Federal Mogul Europe (Goetze) Aftermarket cylinder products technical boffin, conducted the test and pointed out the industry standard is 0.5-1.2 mu.m RA for newly finished cylinders. On this basis he says there would be absolutely no problem using Goetze phosphated cast iron rings, certainly on my bores. He pointed out chrome plated rings would *never* seal on such a surface, but Goetze have never offered these as 911 replacement parts. He also pointed out no harm in removing the chemical glaze which builds up on the bores, as a by-product of the combustion process, providing the cleaning agent used was not likely to harm the cylinders (parts washer?!!).

I'm still waiting for my Euro pistons/Nikasil barrels to arrive, which have supposedly covered similar mileage, so I'll do the same test when I get these.

Nathan....
Very informative post. Thank you!
And it looks like another nod in the direction of the BFPW (ala: JW).

Good post Nathan. Outside of ring mfgs, who would have such equipment ? I'd love to get more data for higher mileage etc. Maybe we could come up with some general rules of thumb for X miles then expect Y wear. (given no extreme circumstances)

William, I think the piston oversizes in the tech specs are both the standard for oversize and tolerance groups. We need someone with access to Porsche factory parts fiche to look up what is/was avail. for pistons.
I find it strange that Mahle makes so many combinations and KS only std. bore...

I think the surface finish tester was one of the machines my neighbor's
guy mentioned along with the "Comparitor" I tried that link but it didn't work. I would think the electron microscope would certainly see the variation, will it measure it?

anh911: Your last statement, can you expand?

All good machine shops should have surface finish testers. Certainly most of our big engine rebuilding customers in the UK do.

Sure William. I just meant that it seems strange that KS would only supply standard replacement sizes and not offer oversize. I can understand if they don't offer overbore "kits" if they aren't in that business but still. I guess we are lucky that Mahle makes the big kits. It would be nice if there were more options - prices might be a little less astronomical with some competition.

Adam (Rondinone) should have the cylinder...FedEx delivered it yesterday.

I sure do. It's much shinier than all six of mine (115k), indicating that it's pretty worn. Of course that just makes it a better test subject. Buffing an in-spec cylinder would get us nowhere. I'll get started on it this weekend.

I also have a surface tester, but we call it a profilometer. This one's accurate to a few angstoms in Z, and about 1 micron in X,Y. I'll run several important areas of Jerry's cylinder through it as soon as possible. As for the electron microscope, it's very accurate, with the added benefit of distinguishing ring material from cylinder material. The unfortunate aspect of the EM is that we can't look at an intact cylinder, which is why Jerry's our hero for providing the test subject.

I'm glad to read that information about the average surface roughness and industry standard. That's just the kind of information we need. Basically your expert is saying that with 60% roughness remaining, the new rings will seat fine. I really like the idea of defining a standard for cylinder re-use.

In the interest of cost, expediency, and availability, I've decided to finish hone, or buff, or whatever we should call it, using a quarz-based polish rather than getting the Sunnen AN-30. Although I can get the AN-30, it may take a while and the winter won't last forever (It took Sunnen almost a day just to get me a price quote). 3M makes a paint cutting polish with about 40% quartz powder in oil (The AN-30 is 50% silicon powder in oil.). Quartz has a hardness very close to silicon (Mohs 7). I can get the 3M product locally at Pep Boys. If the 3M product fails then I'll go ahead and get the AN-30. I'll do the physical polishing with an engine hone and some felt pads.

Since this is a group project, I'll leave this discussion open for the night, and if you guys object to the 3M switcharoo then I'll get the AN-30, with the understanding that it may be a few weeks before we have some meaningful results.

Rondinone,

Are you also going to test a cylinder that has been washed in a over the counter degreaser or parts washer?

see next msg

For the record, that cylinder is about 222K miles old.

http://forums.pelicanparts.com/uploa...1074218886.jpg

Note on the before flex hone operation the very sharp peaks on the graph. THese are the ones that the rings have to wear down during break in.

The second graph, after flex honing shows the shorp peaks removed and all remaining are closer to the same level or plateau.

A worn cylinder should have close to the same thing as the flex honed one if it broke in properly and materials used are good quality (leaves out most english stuff) Quality rings are all pre lapped now days so they should seat without any diffilculty to a worn cylinder iif sufficient cross hatch is present. The grit in a flex hone or silicone paste or whatever is used to re establish the surface is all that should be needed to do this if the cylinder is worn past the cross hatch. On the other hand a GOOD cylinder will always have cross hatch remaining, so the honing operation is just to clean things up a bit and add a few extra grooves for holding oil. If the cross hatch dissapeared I think it means the material is poor and or the engine never broke in properly and consequently no oil retaining grooves remained, allowing for significant wear to take place.