How to make a engine header
04-04-2009 | 10:57 AM
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From: Victoria,
MN
How to make a engine header
These are not my ideas, I copied them from a webpage.
http://www.sci.fi/~ini/Header/header.html
Incase the webpage stops here are the directions
will post picts later
How to make a custom header to a two-stroke model aircraft engine.
It is possible to join aluminium parts together by hard soldering.
Only simple tools are needed: propane torch and of course alloy aluminium bar and soldering powder. Powder is needed to get rid of the oxide coating that prevents molten alloy aluminium to attach to the base material.
Steps:
1. Make parts to be joined. I have used 20x1 aluminium tube and simply 6 or 8 mm aluminium plate. Make necessary opening for exhaust port, don't try to be too accurate, since it is not possible to attach parts together very accurately. Threaded holes can be done later.
2. Clean parts thoroughly with sand paper and solvent e.g. ethanol.
3. Create a soldering setup. I have used ceramic tiles that I put the parts on. DO NOT fix any Al parts on a vice. It will draw all the heat away from parts and virtually makes soldering impossible. Ceramic tiles are great because they withstand a lot of heat and do not conduct heat that much. Have a bucket of water available. If the parts become too hot just sink them in the bucket. Good for putting down fire as well. BTW soldering is preferably an outdoor job. If you are working inside the space must be well ventilated and fire protected. Definitely do not do it at home inside.
4. PRACTISE on scrap parts. Do not ruin your carefully formed header parts, learn to solder first. You need to have the correct touch. The base material melts at 620 °C and the working temperature is appr. 590 °C. The color of base material does not tell you anything, so it is a delicate job. You just have to practise ! I do it so that I try to warm all of the parts as evenly as possible and the thicker parts (e.g. flange) just a little more more. After the powder becomes a bit yellowish it starts to melt, now you are close. Try to stir the powder a little heating the parts all the time. At certain point the powder starts to melt the oxide and the base material becomes shiny. Soon after that the alloy bar also melts and you are ready to bring in material into the joint. Make it gas tight. You may have to redo the joint if it is not tight.
5. Harden the soldered joint. This is simple: as soon as the aluminium has become solid again sink the the whole thing in the bucket. This may sound weird but it really makes the joint strong. If you omit this the joint will be very week and soft. If you are making a header it doesn't last very long because of vibration. If the material you use contains too much magnesium it does not harden properly: use low magnesium Al alloy.
6. Trim and polish and do what ever you want to in order to get a good finish. This is the method Hatori uses to produce their headers, it is stronger than welding and easier to implement, especially if the wall thickeness differs in joined parts.
I have made several of these and used them with good results. They last as well as Hatori ones if done properly. The pictures show the header I made for OS 1.40 RX to be used with bolly EQ 140N carbon fiber pipe. This header is weighs only 45 g incl. bolts compared to Hatoris 65 g. The header is a bit shorter than Hatori (Bolly pipe is longer) but weight is for Hatori lenght.
I may try this method for a gas engine setup but the heat may be too high? and cause it too fail
http://www.sci.fi/~ini/Header/header.html
Incase the webpage stops here are the directions
will post picts later
How to make a custom header to a two-stroke model aircraft engine.
It is possible to join aluminium parts together by hard soldering.
Only simple tools are needed: propane torch and of course alloy aluminium bar and soldering powder. Powder is needed to get rid of the oxide coating that prevents molten alloy aluminium to attach to the base material.
Steps:
1. Make parts to be joined. I have used 20x1 aluminium tube and simply 6 or 8 mm aluminium plate. Make necessary opening for exhaust port, don't try to be too accurate, since it is not possible to attach parts together very accurately. Threaded holes can be done later.
2. Clean parts thoroughly with sand paper and solvent e.g. ethanol.
3. Create a soldering setup. I have used ceramic tiles that I put the parts on. DO NOT fix any Al parts on a vice. It will draw all the heat away from parts and virtually makes soldering impossible. Ceramic tiles are great because they withstand a lot of heat and do not conduct heat that much. Have a bucket of water available. If the parts become too hot just sink them in the bucket. Good for putting down fire as well. BTW soldering is preferably an outdoor job. If you are working inside the space must be well ventilated and fire protected. Definitely do not do it at home inside.
4. PRACTISE on scrap parts. Do not ruin your carefully formed header parts, learn to solder first. You need to have the correct touch. The base material melts at 620 °C and the working temperature is appr. 590 °C. The color of base material does not tell you anything, so it is a delicate job. You just have to practise ! I do it so that I try to warm all of the parts as evenly as possible and the thicker parts (e.g. flange) just a little more more. After the powder becomes a bit yellowish it starts to melt, now you are close. Try to stir the powder a little heating the parts all the time. At certain point the powder starts to melt the oxide and the base material becomes shiny. Soon after that the alloy bar also melts and you are ready to bring in material into the joint. Make it gas tight. You may have to redo the joint if it is not tight.
5. Harden the soldered joint. This is simple: as soon as the aluminium has become solid again sink the the whole thing in the bucket. This may sound weird but it really makes the joint strong. If you omit this the joint will be very week and soft. If you are making a header it doesn't last very long because of vibration. If the material you use contains too much magnesium it does not harden properly: use low magnesium Al alloy.
6. Trim and polish and do what ever you want to in order to get a good finish. This is the method Hatori uses to produce their headers, it is stronger than welding and easier to implement, especially if the wall thickeness differs in joined parts.
I have made several of these and used them with good results. They last as well as Hatori ones if done properly. The pictures show the header I made for OS 1.40 RX to be used with bolly EQ 140N carbon fiber pipe. This header is weighs only 45 g incl. bolts compared to Hatoris 65 g. The header is a bit shorter than Hatori (Bolly pipe is longer) but weight is for Hatori lenght.
I may try this method for a gas engine setup but the heat may be too high? and cause it too fail
