Alusil or Nikasil ? % of how many?

[Gunter]

What is the % of Alusil vs. Nikasil? It is my understanding that most of the 2.7 Liter are Kolbenschmidt (KS) which means Alusil Pistons & Cylinders and that most of the 3.0 Liters are Mahle Nikasil P & C.
Has anyone seen KS (Alusil) in a 3.0 Liter? It is my understanding that you don't know until you open the engine. I was fortunate to have Mahle but a friend had KS which was a nasty surprise because the Alusil P&C cannot be re-ringed. So, is it a crap-shoot when you buy a 3.0 Liter which could have either Mahle or Kolbenschmidt?

[emcon5]

KS from an 82 3.0 Litre.



I don't know the percentage (or if anyone does) but many 3.0L engines came standard with KS pistons. Off the top of my head, me, Superman, Doug Zilke, and Chris Striet all have had KS pistons from the factory.

Tom

[Gunter]

O.K. What did you end up doing regarding re-ring? New P & C ??
It sounds like Porsche took whatever they had on the shelves that day when they build the SC's.
Can there be world domination with Kolbenschmidt Alusil P & C ?

[emcon5]

I haven't decided yet. Most likely get my jugs reconditioned and put JE pistons in. Doug and Chris both bought new Mahle sets, Superman reringed his KS's and is running fine.

Tom

[Wayne 962]

I don't think anyone has any figures on it - it varied year to year...

-Wayne

[Hetmann]

My 78 has the nikacil.

[911nut]

There was a big discussion about this over on Rennlist a few weeks ago. The conclusion was that Alusil cylinders have 10 cooling fins and Nikasil has 11. So you could get under your car and figure out what you have.
I've got Nikasil

[Bill Verburg]

Tom, I strongly urge you to bite the bullit and get a set of Mahles, especially if your car is a keeper). We've been very disappointed w/ the reliability of the JEs in quite a few of the local track cars(I am sure that there will be a bunch of JE advocates jumping in here but I am just honestly reporting the feedback from half a dozen local shoes from this past summer, former JE advocates are no longer in the fold). For not much more the 98mm are an attractive option

[TimT]

JE's dont seem to work well with Alusil cylinders. They work fine with Nikasils.

Ive used 10.5:1 JE's in my 2.2 (with Mahle nikasil cylinders) for 4 years now with no problems.

A friend of mine tried JE's in his 2.7 (Alusil) rebuild, and the pistons were ruined. Seems like to much scuffing, and the rings never sealed, the pistonskirts were ruined.

We have talked to people in the "know", and they dont seem to know why the JE's dont work with the Alusils..

[speeder]

My '82 SC has Alusil, (KS), it is my understanding that all of the U.S. 3.0s w/ 9.3 CR are KS, that would be 1980-83. The ROW cars of this era, (9.8 CR), are Mahle. It is B.S. that Alusil cannot be re-ringed, provided that P/Cs spec-out properly. At least according to the most respected Porsche machine shop in the U.S., and the experience of fellow board members.

[emcon5]

Originally posted by Bill Verburg
Tom, I strongly urge you to bite the bullit and get a set of Mahles, especially if your car is a keeper). We've been very disappointed w/ the reliability of the JEs in quite a few of the local track cars

Bill, very interesting, thanks for the heads up. Can you elaborate a bit on the reliablilty problems?

On an unrelated note, you mentioned someone coming out with a brake kit a while back, I searched, but can't find the thread. Did you have any more news?

Thanks,

Tom

[J P Stein]

KE pistons don't work with Alusil cyls nor will any other pistons besides KS. The KS pistons for these cyls have a coating on them.....iron based....ferrocoat (had to go look that up). To the best of my knowledge, the KS pistons are the only ones available with this coating.

Without the coating, pistons gall in Alusil cyls. This is pretty basic stuff but apparently it's worth repeating....it's all in Anderson's book. pg 68.

While you're there, you may want to do a "fin count"....assuming he has the pics correctly labeled.

[juan ruiz]

I had KS on my 88,still have them 4 sale pistons and cylinders 2 cylinders are with scuffing, I let them go Real cheap if some one is interested

[diy83sc]

I had mine reringed when the top end was rebuilt. Did not have the extra bucks for mahles, but am running fine. Every once in a while, I get a puff of smoke on startup, but oil consumption is low. What are other side effects of KS and why go the extra $3K for Mahle?

[911nut]

Originally posted by speeder
My '82 SC has Alusil, (KS), it is my understanding that all of the U.S. 3.0s w/ 9.3 CR are KS, that would be 1980-83. The ROW cars of this era, (9.8 CR), are Mahle.

Denis, some were Alusil, some were Nikasil. Count the cooling fins.

[Doug Zielke]

I think Supermans SC engine may prove fears about re-ringing KS pistons and cylinders are groundless. I drove his car shortly after the rebuild, and it ran strong, with absolutely no smoke.
Jim's P & C's measured well within spec, so the re-ring made good economic sense.

The original KS set (85K miles) I took out of the 'Bomber, was also in near new shape. I opted for a new Mahle set mostly because I had budgeted for it (not wanting to open the motor up again for another 100K miles).

IMO, the "You can't re-ring Alusil P &C's" camp is trying to create a new P-myth.

Edit: There *are* Porsche part #'s for a KS Alusil ring sets.
(3.0 '78-'79) 930 198 967 00
(3.0 '80-'83) 930 198 985 00

[Gunter]

Page 68 of Anderson's book shows both Alusil and Nikasil cylinders. I counted the fins and they both have 11? Did Bruce use the same cylinder for the pic.? Are there any other pics to see the difference in the number of fins?
My 1980 SC is US with Nikasil P&C which started life in Hawaii. When I answered an "SC For Sale"-Ad, and I saw the vehicle, my eyes almost popped out. It turned out that one of the PO had converted the SC into a Carrera with Carrera front valance, 930-tie rods, valve covers, tensioner upgrade, rear wiper, 16" rims, full leather, 3-spoke steering wheel, Euro lights, etc. Except for the engine, it is a Carrera and the fellow who sold it to me had no idea about these expensive up-dates. Strange things can happen. But back to the fin count: Any other way that one can tell KS or Mahle without tearing the engine down?

[Bobboloo]

As JP Stein pointed out the Alusil cylinders need ferricoat pistons. They also need the proper rings to go with them. I seem to recall that the factory manual stated them as using a plated ring. (chrome?) I think the idea is that the cylinder breaks in to the ring as opposed to the other way around. However, this is from memory so, I'm not sure about this.

Bobby

[911nut]

Originally posted by Gunter
Page 68 of Anderson's book shows both Alusil and Nikasil cylinders. I counted the fins and they both have 11? Did Bruce use the same cylinder for the pic.? Are there any other pics to see the difference in the number of fins?

But back to the fin count: Any other way that one can tell KS or Mahle without tearing the engine down?

Gunter,
Yeah I saw that picture too. I can only refer you to the thread over at Rennlist. In it there was e-mail correspondance from both Mahle and Kobenschmidt stating that the Mahle cylinder has 11 fins and the Kobenschmidt has 10.
If you lay under your engine you will be able to see enough of a cylinder to count them.