Re-ring Alusils?

[mike95125]

Thanks, Nathan. I forgot about that. You have to admit, it is a long thread and it is hard to remember every detail. By the time I get to the end I have forgotten so much.

Are the Goetze rings the same ones used in the nikasil, though? I would imagine.

[Nathan M]

Originally posted by mike95125

Are the Goetze rings the same ones used in the nikasil, though? I would imagine.

Yes they are

[mike95125]

Thanks again, Nathan.

[1fastredsc]

Originally posted by 1fastredsc
I know i haven't posted in this discussion in awhile. But i've got about 150 miles (6 heat cycles) now on my reringed ausil cylinders that i sent out to have the the walls re glazed. Well now when i start it, it gives a very brief huff of smoke and then runs normally. Doesn't burn any oil, just a quick blow on cold start up. Anyhow, runs great, couldn't ask for more. When i start racking up some serious mileage, i'll check back in and post the average oil consumption.

This was my mistake, turned out i had over filled the oil sump just slightly. I figured it out because two cold starts after that it stopped puffing slightly on cold startup. So i checked the oil and it was right at the full mark. Now it doesn't puff anything on cold startup, oops. And since the very first outing with the car, i've been using the accelerate/decelerate method to break in the rings, which i had used successfully on my 944 rebuild as well. I accelerate WOT to ~5k rpm, the let off the throttle and let the motor decelerate the car to 3krpm then pull up to 5k again and so on.

[starlifter1]

thanks everyone!!! I just finished reading the thread and have decided to rering my alusils especially since I have broken one of the original oil rings. The engine has about 80K and the cylinders look clean and fairly dull I think I will clean them and scuff them with a scotch brite pad wrapped around a hone or buy the AN-30 paste have not figured that one out yet. Is everyone that rebuilt their engine still happy with the results they have and if not what would you do differently

[smestas]

I'm really happy with my results. My motor runs like a top and hasn't even gone thru 1qt of oil in 1200 miles. It used to go thru like 1qt every 300 miles. I did however also do a full head rebuild.

The way I prepared my cylinders is I had them washed in a parts washer (took of the glaze) and finished them with a few rounds of scotch brite. They looked good as new when finished with fine hone marks from the pads. I also used new Goetze rings ordered here from Pelican. The last thing I can say I did was that I went the aggresive break in technique. Once she first fired up I drove her like I stole her. Do a search and there is alot of debate on this topic.

I have ZERO regrets with my re-ringed alusils.

[Wayne 962]

It's been widely documented that you can re-ring Alusils. There's also been incidences where it doesn't work too well. Longevity is also an issue - the new rings tend to wear down the cylinders quicker over time. So, you may have a fine running engine after 500 or 1000 miles, but later on down the line, the cylinder linings have disappeared?

Jury is still out - I recommend replating with Nikasil. Anyone have any *long term* mileage on 911s with re-ringed Alusils? (longer than 10,000 miles).

-Wayne

[starlifter1]

so you can replate alusils with Nikasil and use the same pistons? where can you get it done at?

[William Miller]

Wayne, as soon as I get done with my restoration, (Spent a lot of money here!) you will have your answer. I used the scotchbrite method on my rebuild about 5,000 miles. My concept was that I'm doing it for myself and see rebuilding the engine as a long term maintance project.
With 258,000+ miles on the car it's been rebuilt before and I will hopefully have the car for a long time and do it again. I might not get another 100,000 miles on these rings or P&C sets, but hopefully will save the 3K for a while. Again that's me. And as Wayne said the Jury is still out. I will probably buy a P&C set or replate at some point. Just decided to spend that money elsewhere for now.

There was also some bad news for BMW owners with Nikasil cylinders.
Is that still going on or has it been resolved.
There were several others on this board that re-ringed any updates?

[1fastredsc]

500 miles, no oil consumption yet, torque seemed to steadily increase until it's peak of "pull" which i got around 300 miles or so. I'm dropping the motor out to check torques, valves adjust, and fix some leaks in the tranny. So far so good.

[William Miller]

That picture get's me everytime. I have to remember to look closely.
How about doing a compression test and leakdown while your at it.
Might be good data for later as this thread ages.

[Rondinone]

I've broken 5k since the rebuild. No problems so far!

I have half a can of Sunnen AN-30 if anyone wants to buy it.

[starlifter1]

I would spend the money on re doing the cylinders but these are suposed to be damb good cylinders and knowing they could be i would hate to throw money into an experimeent but i need to get at least 50,000 miles out of them I spent a lot of time in germany an if this stuf was cheaper over there i would start to import cylinders but i think it will take me awhile because i rarely see a porsche

[Wayne 962]

Here's a story about a fellow with re-ringed Alusils that are beginning to wear out after 9,000 miles:

http://forums.pelicanparts.com/911-engine-rebuilding-forum/195483-mileage-re-ringed-alusils.html#post1653676

-Wayne

[starlifter1]

so what is the alternitave Nikasil? I just broke an oil ring would it be better If I only replaced the broken oil ring ?do you know of where I can get info on Nikasil

[mike95125]

Not an expert, but smoking can also be due to valve guides. Not sure of the quantity of oil burned. Also, Wayne re reinged the 3.0l 82SC that was used in the 101 projects book and then sold to Red-beard so under some circumstances it must be acceptable. It is in this thread. You can re ring T-390 alloy (alusill's other name). There are many factors to consider such as condition of your "cores". Also, it is western culture to complain when things do not go well. Such a tendency causes polarization of opinion and necessitatiets that you do as much research on this subject as possible (which you are doing so good for you). I had mine re ringed by a man that I greatly respect, and was advised by another of the same caliber. That with all of the hard work and research done on this board made up my mind. You could always start saving a little money every month for a potential rebuild in 10-50K miles. That way if it never happens you will have a chunck of change to use else ware.
Just my $.02

[starlifter1]

well I think After reading all this that I would rering and feel good about it BUT If you only had to replace an oil ring (which I broke)or rering the whole engine what would you do I did seperate the pistons and cylinders Due to the wrist pin being so tight

[Porsche_monkey]

Once you take the piston out to change the oil ring, I believe it is too late.

[mike95125]

Ya, I have heard the same. Once the rings have been separated from the cylinder you are supposed to re ring/hone. There are engine builders here that will let you know for sure, though.

[1fastredsc]

Ok, 500 miles on the motor, and it's been out of my car for 2 weeks and obviously is stone cold. Unfortunately, the type of leak tester i have is kind of cheap, and hard to actually get the end of it to seat in the spark plug hole (cannot tighten with a tool). So this means that i could hear a slighty leak coming from the spark thread around the leak tester. I also heard some slightly coming out of the breather meaning it going past the rings (extremely faint). All in all, these are my numbers.
C1: 5-7%
C2: 9-11%
C3: 4-6%
C4: 5-7%
C5: 6-8%
C6: 8-10%