How to machine the alusil block's?
09-17-2013, 12:09 PM
#17
Rennlist Member
It seems to me that the conclusion lies in the answers to the following questions, most of which are raised by what has so far been posted in this thread:
1. Once a freshly bored alusil cylinder has been honed to the finish diameter, as directed by the Sunnen article, why does the aluminum need to be removed to whatever degree it is removed, in the final honing stage, with felt pads and AN-30 silicon compound?
2. In other words, why can the rings and piston NOT ride on both aluminum and Silicon particles?
3. Since there must be a very good reason to remove the aluminum, then the question is, even though the silicon is very hard, it does appear to wear some over time, so how long does it take to wear the silicon down to where the aluminum was left in the final honing stage?
4. Once the silicon is worn down to where the aluminum is, why is there no apparent problem with the piston and rings riding on the aluminum and silicon at that point, which was what was avoided in the original final honing stage?
5. If it takes a very long time to wear the silicon down to where the aluminum was left, what would be wrong with doing the final honing stage again in a rebuild to remove the aluminum back away some more to avoid getting close to or on it during the next several thousand miles of use?
6. If the silicon is worn down to the aluminum by the time of a rebuild why is it not a problem for some users who have posted here with actual experience, to continue to ride new or even the original rings in the bore as worn, which may very well be riding on aluminum and silicon?
7. So, back to the original question--Why remove the aluminum in between the silicon particles in the first place with the final paste hone?
8. And then, again, why does it not seem to be a problem later after much use, to have the rings riding on both Aluminum and Silicon, if in fact that is the case?
So, I think the answer is going to be that either the Silicon does not wear almost at all so the aluminum never comes in contact with the rings, or that after some use and wear it really doesn't matter that the rings are riding on aluminum and silicon, but perhaps only after some use, at least the original break in.
1. Once a freshly bored alusil cylinder has been honed to the finish diameter, as directed by the Sunnen article, why does the aluminum need to be removed to whatever degree it is removed, in the final honing stage, with felt pads and AN-30 silicon compound?
2. In other words, why can the rings and piston NOT ride on both aluminum and Silicon particles?
3. Since there must be a very good reason to remove the aluminum, then the question is, even though the silicon is very hard, it does appear to wear some over time, so how long does it take to wear the silicon down to where the aluminum was left in the final honing stage?
4. Once the silicon is worn down to where the aluminum is, why is there no apparent problem with the piston and rings riding on the aluminum and silicon at that point, which was what was avoided in the original final honing stage?
5. If it takes a very long time to wear the silicon down to where the aluminum was left, what would be wrong with doing the final honing stage again in a rebuild to remove the aluminum back away some more to avoid getting close to or on it during the next several thousand miles of use?
6. If the silicon is worn down to the aluminum by the time of a rebuild why is it not a problem for some users who have posted here with actual experience, to continue to ride new or even the original rings in the bore as worn, which may very well be riding on aluminum and silicon?
7. So, back to the original question--Why remove the aluminum in between the silicon particles in the first place with the final paste hone?
8. And then, again, why does it not seem to be a problem later after much use, to have the rings riding on both Aluminum and Silicon, if in fact that is the case?
So, I think the answer is going to be that either the Silicon does not wear almost at all so the aluminum never comes in contact with the rings, or that after some use and wear it really doesn't matter that the rings are riding on aluminum and silicon, but perhaps only after some use, at least the original break in.
09-17-2013, 12:21 PM
#18
Archive Gatekeeper
Rennlist Member
Rennlist Member
WWGD?
09-17-2013, 12:31 PM
#19
Jerry -
If the piston never saw aluminum, it wouldn't have to be coated with iron. And we would not gaul a bore if we ran straight uncoated aluminum pistons. But we do, and it does. So there is the possibility for aluminum pistons - it seems to me to be a balancing act with minus Si particles.
If the piston never saw aluminum, it wouldn't have to be coated with iron. And we would not gaul a bore if we ran straight uncoated aluminum pistons. But we do, and it does. So there is the possibility for aluminum pistons - it seems to me to be a balancing act with minus Si particles.
09-17-2013, 05:16 PM
#20
Rennlist Member
09-18-2013, 09:15 AM
#21
Nordschleife Master
If I did this the office would need a good cleaning.
One thing you're not including in your calculus is that the Al is wearing away as well as the Si. It's very soft compared to the Si. Dirt and carbon bits move the back tiny amounts so the Si is still proud of the Al surface.
One thing you're not including in your calculus is that the Al is wearing away as well as the Si. It's very soft compared to the Si. Dirt and carbon bits move the back tiny amounts so the Si is still proud of the Al surface.
09-18-2013, 03:01 PM
#22
If I did this the office would need a good cleaning.
One thing you're not including in your calculus is that the Al is wearing away as well as the Si. It's very soft compared to the Si. Dirt and carbon bits move the back tiny amounts so the Si is still proud of the Al surface.
One thing you're not including in your calculus is that the Al is wearing away as well as the Si. It's very soft compared to the Si. Dirt and carbon bits move the back tiny amounts so the Si is still proud of the Al surface.
10-23-2013, 09:53 AM
#26
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New Honing Options for Hypereutectic Aluminum Cylinder Bores
Mechanical version of honing. Download the pdf from bottom of the page for more information.
http://www.aera.org/engine-professio...ylinder-bores/
Nikasil - Alusil, also some interesting information about piston/ring coatings. Again, check the pdf at bottom of the page for more information.
http://www.aera.org/engine-professio...ae-and-alusil/
New coatings are being used, why not for our pistons?
Just a question, what kind of piston ring is barrel shaped ring?
http://www.aera.org/engine-professio...ylinder-bores/
Nikasil - Alusil, also some interesting information about piston/ring coatings. Again, check the pdf at bottom of the page for more information.
http://www.aera.org/engine-professio...ae-and-alusil/
New coatings are being used, why not for our pistons?
Just a question, what kind of piston ring is barrel shaped ring?
10-23-2013, 02:45 PM
#27
Addict
Rennlist Member
Rennlist Member
5. If it takes a very long time to wear the silicon down to where the aluminum was left, what would be wrong with doing the final honing stage again in a rebuild to remove the aluminum back away some more to avoid getting close to or on it during the next several thousand miles of use?
