Ok...
If you ever find a tight wrist pin, heat the piston crown with a heat gun, or propane torch. The piston will expand enough to allow the pin to side out with only finger pressure.

I'm not sure if re-using the same rings is a good idea. If you want to do this, I'd make sure the end gap is within spec. The usual way to check this, is by placing a ring in the cylinder, pushing it down square to the bore about an inch, then measure the gap with feeler guages. The gap spec is listed in the shop manuals.

The other critical point if you wish to re-use the pistons (and rings), is the condition of the ring lands (grooves). The must not have more width than spec, or the rings may rock in the groove, and eventually break.
The side clearance spec is also in the Porsche spec book and Bentley.

Finally, Jim 'Superman' Christensen has posted how John Walker treated his Alusils for a re-ring. Find those posts, and consider how a pro did it. Jim's car runs like a scalded cat!

The method that snowman speaks of sounds familiar (same thing i'm having done). Except the shop told me that it technically wasn't honing, since it doesn't widen the bore at all, just reintroduces the cross scratches that force break-in during initial run. They called it laping, and they said that reringing is gamble since your not guarenteed that it'll properly break-in. They said in some cases reringing alone will cause the motor to take like 10k miles just to break in, while this process will force the rings to break-in to the cylinders within the normal break-in period. And of course his real recommendation was to replace them with a new set of Nikasil's, but sometimes financial status forces you to take what's behind door #2.

Doug, while you have them out, you might as well measure the P&C's, ring groves etc. I have the tools you can barrow. I did mine and found them to be w/in the wear limits. I re-ringed them. I cleaned the cylinder walls with scotch brite pads sandwitched between the cylinder wall and a off the shelf 3 arm stone hone connected to my cordless drill. About 25-30 seconds each 10-15 strokes up and down and there was a very minor cros hatched pattern on the walls. This worked well for me I've got about 2,000 miles since the rebuild and they sealed just fine.

If you want PM me on the NO Va site and you can barrow all the tools.
The tools take a little getting used to but it's a good piece of mind knowing what you have in your engine. I've spent some money on the tools so I wish they would get used more than once. Charlie used them
ask him about it.

William - thanks for the offer and maybe one day I'll take you up on it.

I spoke to Walt (at CE) today and he was of the opinion that at only 97k miles my engine was just about getting broken in :) He said to visually check for any broken rings but other then that he didn't see a problem with just compressing the rings and sliding them back in. Right now my intent is to do just that but if I were to come across a set of cheap Nikasil's that idea just might change :)

Walt is da man! So do what he suggests.
I got a lot of good info from him, JW, and my local pro.
My motor is flawless, thanks to their generous advice.

Although I could have re-used my P & C's (they were well within spec at 80k), I got a good deal on a new Mahle (Nikasil) set. Glad I went with it, as the motor runs stronger than ever.

The issue of re-ringing Alusils comes up periodically. My distillation of the "facts" leads me to conclude:

1) Nikasils - re-ringing and honing are ok.

2) Alusils - re-ringing is ok, honing is not.

I've done (2) and the engine has been just fine.

Yes, but your only one dude. That is what bothers me about people posting here sometimes. They put up "hey, this worked for me fine..." and then everyone assumes that it will work in all cases.

If you put a single bullet in a gun, spin the barrell, and then pull the trigger, and it doesn't fire, then can you assume that you're safe 100% of the time - NO. You can say that you 'dodged a bullet.'

This is why I repeatedly echo comments made by people who have done these things thousands of times, like Walt Watson of Competition Engineering. In writing the book, I took his knowledge (along with many, many other people's knowledge), and filtered out fact from fiction.

The bottomline? Re-ringing Alusil is a crapshoot - it may or may not work. Walt's suggestion is what he has learned from past experience...

-Wayne

Wayne,

You're right. A statistic of one, or two, isn't much to go on, (although it is a lot better than a statistic of zero, which is the basis for the majority of advice proferred on this and other boards).

and then everyone assumes that it will work in all cases

They shouldn't. It's only one point on the curve. However, one of the beauties of a board like this is that it can collect a lot of information from a wide variety of sources, and often it's enough to comprise a meaningful statistic. If fifty guys pop up and say, "Hey, it worked for me." that would be useful to know, I think.


I take your point, though, which is a good one. Don't offer advice or experience unless you've had a professional's equivalent of experience, or unless you are quoting one, or unless you quantify your experience level, which you will note I was careful to do.

Bob

I beleive this is what we refer to as anectdotal evidence. Provided it is offered as 'it worked for me' as opposed to 'this will always work' it is useful information.

And that "anectdotal evidence" is what makes this board tick.

It worked for me!

I tried it knowing the risks and accepting them. This is on my car and I am the only one to blame if I have to pull it apart again at some point.
I chose to invest the 2K+ money in other parts of my car. I also like most people on this board have a limited budget for my toy and I want to get the most bang for my buck. I don't count my time because working on my car is a hobby, not a business. It's something I love to do. If my risk went south I would say goodie, I can tear it apart again and rat's because now I have to spend the money on the P&C's.

If it was my business and my reputation there is only one way to do it. Do it right the first time or it will come back to haunt you and cost you later. The pro's on this board are speaking from this point of view and they are correct in their recomendations. If you want to do it right the first time, do everything you can to eliminate the risk. Any pro that doesn't do it this way is an idiot (There is a certain rebuilder that consistantly get's bashed on this board because of this.)
That's why it costs so much to get a porsche engine rebuilt by a respectable pro or to buy all the parts and machining to do it yourself.

Everyone has to make their own choices and again I chose to take the risk. Why? My car now has 255,000 miles on it. My plan is to drive it daily as I have for the 2 years I have owned it. (Except the few months while I was rebuilding the engine.) I do my own work because I have seen what wrenches can do to screw up a car. I rebuilt the engine because it had a broken ring and I wanted to extend it's life. I followed Waynes book pretty much to the letter except this one issue. For me it was worth taking the risk. I'll let you know in a few years or sooner if it fails.
My car will never be worth much because of the miles. It has great value for me because I drive it daily and relative to anything new it's pretty cheap transportation.

I bet many people who frequent this board are in simular situations and would take simular risks knowing the consequences. I don't think the board is intended for pro's but for enthusiasts. These are people willing to take some risks. There is a right way for pro's to do things and for those that are racing and others that want perfection. What's right for one guy may not be right for another. I know what's right for me and that might not be right for others. So again:

It worked for me! (Maybe I should qulify that) It worked for me so far!

Well stated William, especially d-i-y vs professional choices.

In answer to someone's question, yes, I did a compression check. Again, the engine did no smoking and still does no smoking. The rings seem to have seated just fine. I don't have the compression test results here in front of me, but there were no particularly weak cylinders.

Doug is right on the money, as usual. Ring lands, and cylinders must be in spec. Mine were, but I would not try this without measuring first.

I'd agree this is probably a crap shoot. It worked for me. I certainly needed no honing tool to clean up the cylinder walls, since my cylinders made a trip through John's BFPW (large parts washer) and were clean as a whistle. As I've posted previously, I think this was key. The washer changed the color and appearance of the cylinder walls. Those cylinders were measured (rebuild was at 183K miles) and the most wear we found on any cylinder was .0015". One and a half thousanths. In other words, those cylinders were about as straight and parallel as could be. If they were tapered, this probably would not have worked.

And finally, Doug is also correct about wrist pin removal techniques. Don't pound on them! Heat the piston, and the wrist pin will nearly fall out.

FWIW, I did not replace my wrist pin bushings, and if I were in there again, I'd do that. Mine was one of those Neanderthal/Kamikaze rebuilds. Hey, it's a motor, okay.....?

"Life not worth living without taking some risks."
Besides, worst thing that happens is that it doesn't work and the rings don't seat properly. Now your out of a few gaskets and an oil change, and back to square one with needing new P&C's.

During my rebuild I sent my pistons and cylinders to EBS. Told them 'do what you think is best'. They measured everything and used new rings, properly gapped, and send it all back to me. The motor has performed flawlessly.
Good luck,

Does anyone have a "this DIDN'T work for me" story in relation to re-ringing their Alusils?

Can those of you who have re-rung alusils comment on the type of rings used? Im going to be rolling the dice as Im in the process of re-assembling a motor with alusils. I purchased a set of GOETZE rings (930.103.963.00) from our host for the job and have been hesitant since I have found a previous posts that is saying there is another specific factory part ID for alusil rings (930.198.967.00).

Here is a link its the last post in the thread.
http://forums.pelicanparts.com/porsche-911-technical-forum/87658-what-price-my-3-0-p-cs.html

Could these be the same rings with different part#'s? Should I be concerned or run with the set I have?

Simon, call the guys at EBS (http://www.ebsracing.com) and ask them. They are extremely helpful and I am sure they would tell you what they use. As I said, in my case I would have bought new P&C's if they had said the word, but their assurance was that the new rings would work - and they have.
Good luck,

Mine were the Goetze rings. Don't know/have the part number with me.

William - after looking at the documentation, mine were Goetze as well.