Re-ring Alusils?

[Wayne 962]

Originally posted by 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

There's a whole section in the Engine Rebuild Book...

-Wayne

[H.G.P.]

So, when the time comes, should I do the red scotchbrite thing on my 1969 E Biral cylinders also. Or are they honed differently?

Thanks

[snowman]

I would suggest the grape style ball hones as they are designed for the application. Thats right I'm backkk. I am now going to do a Northstar 4.6L engine for my next project, so I will not be saying to much about it on this board, but the honing and hard maching operations are certain to be very similar and if comparable I will put my 3 cents worth in.

Could GM be thinking of catching up, say in the next 5 years? I hear they have now just invented vanos and will intoduce it next year, a little late, but better late than never.

[red-beard]

Originally posted by Wayne at Pelican Parts
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

A "certain" 1982 SC has more than 10,000 since rebuild. No problems, no smoke on startup (now that the oil leaks are mostly fixed ).

[safe]

Originally posted by red-beard
A "certain" 1982 SC has more than 10,000 since rebuild. No problems, no smoke on startup (now that the oil leaks are mostly fixed ).

I would consider a re-ringing if I needed one, but I dont think 10000 miles is not enough to say that it has been succesfull, or is it?

[snowman]

I think its getting pretty close. If it dosen't do anything bad at 10Kmiles it is highly unlikely it will start doing something bad in the near future.

[red-beard]

Jack - This is Wayne's old car, the 1982 SC he used as the model while he wrote the 101 Projects book. One of the projects was an engine rebuild. The Alusil cylinders were re-used.

[William Miller]

Wayne must have done an extraordinary job!
Was the intent of the rebuild project to extend the engine's life within a budget or make it like new with an unlimited budget?
Two very different goals and constraints.
Good to hear it's still going strong!

Make sure that whoever buy's the car knows there are many intrested in it's conditon long term!

[red-beard]

Wayne, to my understanding, did not rebuild this engine.

[krazyman]

As a data point when protechnik.com rebuilt my engine he had a guy that does top fuel engines do the silicon lapping. I believe he also used the Goertz rings. At 500 miles car has no oil use and no smoke on start up. Runs great.
Jeff

[snowman]

Replating with Nikasil and then rehoning seems like a safe bet, but how much does it cost vs new cylinders? You are talking about two outside shop jobs, the first plating, the second, honing vs just buying a $50 DIY silicone ball hone.
This does not include the probability of a bad plating job, which is reasonably high.

[William Miller]

Wasn't there a post about the problems BMW has with Nikasil?
What did they determine was the cause?
I heard they replaced a lot of engines!

[mike95125]

Jack,
not to sound disrespectful, but howcome you never grape honed a test cylinder for analysis by the electron microscope? That would support your position and serve as an invaluable resource for the rest of us. I believe in the paste method because of the empirical data presented in this thread. I think it would be awsome if grape honing had the same type of support.
Mike

[snowman]

No one ever sent me a cylinder to hone.

Thats what came off the top of my head. I think someone was going to send me one. I have been busy putting house back togather after major fire last year so I have dropped some things because of overwhelming stuff to do. I will have to look at messages but I think I sent someone my home address so they could send me one. I have flowed one head for someone since moving back into home.

If someone has a cylinder send me private message and a cylinder.

[mike95125]

Jack,
Thats totaly understandable. I wasn't trying to give you any crap, just trying to see if we all could continue with the investigation. Hopefully those that were directly involved can reconnect and continue with this.

Sorry to hear about your fire problems, that definetly takes priority. I hope all is going well for you with that.

[Rondinone]

Originally posted by snowman
No one ever sent me a cylinder to hone.

Thats what came off the top of my head. I think someone was going to send me one. I have been busy putting house back togather after major fire last year so I have dropped some things because of overwhelming stuff to do. I will have to look at messages but I think I sent someone my home address so they could send me one. I have flowed one head for someone since moving back into home.

If someone has a cylinder send me private message and a cylinder.

A house fire? You have my condolences. I was wondering why you hadn't posted in a while.

[Rondinone]

Originally posted by mike95125
Jack,
not to sound disrespectful, but howcome you never grape honed a test cylinder for analysis by the electron microscope? That would support your position and serve as an invaluable resource for the rest of us. I believe in the paste method because of the empirical data presented in this thread. I think it would be awsome if grape honing had the same type of support.
Mike

Also, the experts at Sunnen and KS both said that the paste method works.


On another note, in the last few pages there's been griping about "sometimes it doesn't work". Let's remember some common sense here: a worn-out-part is a worn-out-part. The cylinder prep is about making an otherwise servicable cylinder suitable for breaking in new rings. It's not about bringing an ovalled or out-of-spec cylinder back into spec. This is not voodoo, nor is it quantum physics. This is basic, simple materials science.


The BMW nikasil problem was related to sulfur in gasoline reacting with the nickel. I don't know why it was a problem with BMW and not with Porsche. BMW uses only alusil or lokasil nowadays AFAIK.

[snowman]

I strongly suspect that since these grape style hones are actually silicone embedded in some kind of encapsulant, that they may be exactly the same thing as the paste, without all the mess.

[anh911]

Most of this has been covered but I would like to echo Rondinone. The stories of failed attempts can most likely be traced to 1. trying to save out of spec parts and 2 using unproven methods or tools. 3. inexperience

The grape hone, while it may be impregnated with silicon, is a rigid cutting device, designed primarily for use on cast iron. The silicon paste and felt tipped "brushes" are pliant and only used for final finishing, not resizing. I suggest that the difference between the two is delivery method or technique. Anbother way of looking at the difference is the grape hone cuts a series of grooves into cast iron whereas the silicon paste and felt remove aluminum from between silicon particles.

My feeling is that the grape hone with it's silicon embedded into a rigid medium, will result in silicon to silicon abrasive action which is not desirable.

[snowman]

Grape style hones are NOT used for resizing. They are also very flexible as opposed to a stone hone which isn't. All the mentioned techniques abrade. As to what they are designed to hone see the companies web site, almost everything that can be honed is honed with these things.