Where is a good place online to order aluminum from?

[Charles Perdue]

I have been making head inserts for various engines since the 1970's from 2011 aluminum. The reason for this is this alloy contains a larger percentage of copper than other aluminum alloys, allowing the inserts to expand more. This helps the insert to seal better to the cylinder ( especially for inserts that recess into the cylinder ). For those of you who like to squeeze the head clearance to the bare minimum the 2024 alloy seems to take the "blasting" better than the 2011 alloy. Both materials machine very nicely, with the 2024 being the tougher of the two. Keep in mind, all of the machined edges that are exposed in the cylinder area need to be sharpe and crisp. Buff the money side of the insert with some extra fine 3M pad, but don't over do it. I've been getting my material for turn fins, etc. from onlinemetals. I seem to get better deals when I talk to the boss, Steve Pierce.

Dick Tyndall

Hello Dick, in the past I made head buttons from 2011 and 2024. These were OK as long as we ran fairly cool engine temps, but as we restricted the water and built more temp in the engine, to better burn the fuel, the 2011 and 2024 would expand faster than the sleeve and push the sleeve away from the piston, loosing the fit and loosing power.

Jack O'Donnell told me about the 4032 aluminum. It is a high silicon aluminum with almost the same expansion rate as the sleeve. The button-to-sleeve fit that you start with when the engine is cold, is the fit that the engines run with at full temp, this is allowing us to keep more heat in the engine without the power dropping off.

Maybe Jack will come on here and explain this better than I can.

Hi Charles,

Everything you are saying here makes perfect sense but I don't believe that I ever experienced this happening with any engines of mine. Even when going from controline airplanes to boats ( air cooled versus water cooled engines ) I don't recall this happening. I made a lot of different combustion chamber shapes for many different engines, so I guess it is possible that what you are saying occured to me. It is possible to pick up a 200-300 RPM loss with a tach running an engine on a test stand but not so running a boat checking RPM with an audio tach ( at least not mine! ). Of course, the radar gun doesn't lie...................

Dick Tyndall

Charles

Hello Dick, maybe I did not express myself correctly, and for this I appologize. I wasn't trying to contradict you or your opinions, I have the upmost respect for you. I was just trying to pass along information that was given to me, and has helped me, so possibly this information could help someone else also.

I try constantly to learn everything I can about this obsession called Model Boating and to be better at it.

Charles

 

[El Zorro]

I have been making head inserts for various engines since the 1970's from 2011 aluminum. The reason for this is this alloy contains a larger percentage of copper than other aluminum alloys, allowing the inserts to expand more. This helps the insert to seal better to the cylinder ( especially for inserts that recess into the cylinder ). For those of you who like to squeeze the head clearance to the bare minimum the 2024 alloy seems to take the "blasting" better than the 2011 alloy. Both materials machine very nicely, with the 2024 being the tougher of the two. Keep in mind, all of the machined edges that are exposed in the cylinder area need to be sharpe and crisp. Buff the money side of the insert with some extra fine 3M pad, but don't over do it. I've been getting my material for turn fins, etc. from onlinemetals. I seem to get better deals when I talk to the boss, Steve Pierce.

Dick Tyndall

Hello Dick, in the past I made head buttons from 2011 and 2024. These were OK as long as we ran fairly cool engine temps, but as we restricted the water and built more temp in the engine, to better burn the fuel, the 2011 and 2024 would expand faster than the sleeve and push the sleeve away from the piston, loosing the fit and loosing power.

Jack O'Donnell told me about the 4032 aluminum. It is a high silicon aluminum with almost the same expansion rate as the sleeve. The button-to-sleeve fit that you start with when the engine is cold, is the fit that the engines run with at full temp, this is allowing us to keep more heat in the engine without the power dropping off.

Maybe Jack will come on here and explain this better than I can.

Hi Charles,

Everything you are saying here makes perfect sense but I don't believe that I ever experienced this happening with any engines of mine. Even when going from controline airplanes to boats ( air cooled versus water cooled engines ) I don't recall this happening. I made a lot of different combustion chamber shapes for many different engines, so I guess it is possible that what you are saying occured to me. It is possible to pick up a 200-300 RPM loss with a tach running an engine on a test stand but not so running a boat checking RPM with an audio tach ( at least not mine! ). Of course, the radar gun doesn't lie...................

Dick Tyndall

Charles

Hello Dick, maybe I did not express myself correctly, and for this I appologize. I wasn't trying to contradict you or your opinions, I have the upmost respect for you. I was just trying to pass along information that was given to me, and has helped me, so possibly this information could help someone else also.

I try constantly to learn everything I can about this obsession called Model Boating and to be better at it.

Charles

No need to appologize, Charles..................you did nor said anything to offend anyone! I appreciate information such as yours because we all learn from other's experiences, good and sometimes not so good. Now I'm going to have to find some 4032 alloy next time I make some head inserts!. I follow a lot of the different posts on here and see your name pop up quite a bit. You seem to be one of a handfull of people who have knowledge and experience with this hobby and don't mind sharing it with others on this website. I thank you for that.

Dick Tyndall

 

[Charles Perdue]

I have been making head inserts for various engines since the 1970's from 2011 aluminum. The reason for this is this alloy contains a larger percentage of copper than other aluminum alloys, allowing the inserts to expand more. This helps the insert to seal better to the cylinder ( especially for inserts that recess into the cylinder ). For those of you who like to squeeze the head clearance to the bare minimum the 2024 alloy seems to take the "blasting" better than the 2011 alloy. Both materials machine very nicely, with the 2024 being the tougher of the two. Keep in mind, all of the machined edges that are exposed in the cylinder area need to be sharpe and crisp. Buff the money side of the insert with some extra fine 3M pad, but don't over do it. I've been getting my material for turn fins, etc. from onlinemetals. I seem to get better deals when I talk to the boss, Steve Pierce.

Dick Tyndall

Hello Dick, in the past I made head buttons from 2011 and 2024. These were OK as long as we ran fairly cool engine temps, but as we restricted the water and built more temp in the engine, to better burn the fuel, the 2011 and 2024 would expand faster than the sleeve and push the sleeve away from the piston, loosing the fit and loosing power.

Jack O'Donnell told me about the 4032 aluminum. It is a high silicon aluminum with almost the same expansion rate as the sleeve. The button-to-sleeve fit that you start with when the engine is cold, is the fit that the engines run with at full temp, this is allowing us to keep more heat in the engine without the power dropping off.

Maybe Jack will come on here and explain this better than I can.

Hi Charles,

Everything you are saying here makes perfect sense but I don't believe that I ever experienced this happening with any engines of mine. Even when going from controline airplanes to boats ( air cooled versus water cooled engines ) I don't recall this happening. I made a lot of different combustion chamber shapes for many different engines, so I guess it is possible that what you are saying occured to me. It is possible to pick up a 200-300 RPM loss with a tach running an engine on a test stand but not so running a boat checking RPM with an audio tach ( at least not mine! ). Of course, the radar gun doesn't lie...................

Dick Tyndall

Charles

Hello Dick, maybe I did not express myself correctly, and for this I appologize. I wasn't trying to contradict you or your opinions, I have the upmost respect for you. I was just trying to pass along information that was given to me, and has helped me, so possibly this information could help someone else also.

I try constantly to learn everything I can about this obsession called Model Boating and to be better at it.

Charles

No need to appologize, Charles..................you did nor said anything to offend anyone! I appreciate information such as yours because we all learn from other's experiences, good and sometimes not so good. Now I'm going to have to find some 4032 alloy next time I make some head inserts!. I follow a lot of the different posts on here and see your name pop up quite a bit. You seem to be one of a handfull of people who have knowledge and experience with this hobby and don't mind sharing it with others on this website. I thank you for that.

Dick Tyndall

Thanks, coming from you, that is a real compliment.

Charles Perdue