Porting an ABL/ABC Engine
07-19-2011 | 06:49 AM
#76
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From: Kuala Lumpur| Malaysia, MALAYSIA
RE: Porting an ABL/ABC Engine
Heh.. you guys haven't even gotten into the "percent by weight vs. percent by volume" argument yet. SIG measures by volume, a lot of the RC fuel suppliers measure by weight. When you consider that the specific gravity of nitromethane is 1.14 and the s.g. of methanol is 0.8, it really DOES make a lot of difference. 15% nitro Byron or Cool Power fuel would be the equivalent of, say, 11% SIG fuel. When they say 18% oil it'd only be 14% by volume.
Last time I bought castor oil - 17 liter can (looks like the ones at the Chinese takeout restaurant), about $60.
I used to like to carve up cheap chinese engines, too - I flew Brat .28s and the like in Fast Combat. Finally did a Magnum .36 - it lasted three rounds at the Nats, and ended up breaking a crank - after I scored the kill, thank goodness. For RC sport flying, one would use maybe a 10x6 on that engine - I'd run a Scimitar 8x6. On the .28s I ran Taipan 7x6s. Amazing how much more power you get by just grinding on the crank - I was opening them up to 35 degrees ABDC to 57 or 65 degrees ATDC. Of course, you couldn't compete with the Nelsons - the Nelson had a 17mm crankshaft, the Magnum 12.5mm.
Iskandar
Last time I bought castor oil - 17 liter can (looks like the ones at the Chinese takeout restaurant), about $60.
I used to like to carve up cheap chinese engines, too - I flew Brat .28s and the like in Fast Combat. Finally did a Magnum .36 - it lasted three rounds at the Nats, and ended up breaking a crank - after I scored the kill, thank goodness. For RC sport flying, one would use maybe a 10x6 on that engine - I'd run a Scimitar 8x6. On the .28s I ran Taipan 7x6s. Amazing how much more power you get by just grinding on the crank - I was opening them up to 35 degrees ABDC to 57 or 65 degrees ATDC. Of course, you couldn't compete with the Nelsons - the Nelson had a 17mm crankshaft, the Magnum 12.5mm.
Iskandar
07-19-2011 | 06:57 AM
#77
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From: Kuala Lumpur| Malaysia, MALAYSIA
RE: Porting an ABL/ABC Engine
ORIGINAL: iskandar taib
Heh.. you guys haven't even gotten into the ''percent by weight vs. percent by volume'' argument yet. SIG measures by volume, a lot of the RC fuel suppliers measure by weight. When you consider that the specific gravity of nitromethane is 1.14 and the s.g. of methanol is 0.8, it really DOES make a lot of difference. 15% nitro Byron or Cool Power fuel would be the equivalent of, say, 11% SIG fuel. When they say 18% oil it'd only be 14% by volume.
Last time I bought castor oil - 17 liter can (looks like the ones at the Chinese takeout restaurant), about $60.
I used to like to carve up cheap chinese engines, too - I flew Brat .28s and the like in Fast Combat. Finally did a Magnum .36 - it lasted three rounds at the Nats, and ended up breaking a crank - after I scored the kill, thank goodness. For RC sport flying, one would use maybe a 10x6 on that engine - I'd run a Scimitar 8x6. On the .28s I ran Taipan 7x6s. Amazing how much more power you get by just grinding on the crank - I was opening them up to 35 degrees ABDC to 57 or 65 degrees ATDC. Of course, you couldn't compete with the Nelsons - the Nelson had a 17mm crankshaft, the Magnum 12.5mm.
Iskandar
Heh.. you guys haven't even gotten into the ''percent by weight vs. percent by volume'' argument yet. SIG measures by volume, a lot of the RC fuel suppliers measure by weight. When you consider that the specific gravity of nitromethane is 1.14 and the s.g. of methanol is 0.8, it really DOES make a lot of difference. 15% nitro Byron or Cool Power fuel would be the equivalent of, say, 11% SIG fuel. When they say 18% oil it'd only be 14% by volume.
Last time I bought castor oil - 17 liter can (looks like the ones at the Chinese takeout restaurant), about $60.
I used to like to carve up cheap chinese engines, too - I flew Brat .28s and the like in Fast Combat. Finally did a Magnum .36 - it lasted three rounds at the Nats, and ended up breaking a crank - after I scored the kill, thank goodness. For RC sport flying, one would use maybe a 10x6 on that engine - I'd run a Scimitar 8x6. On the .28s I ran Taipan 7x6s. Amazing how much more power you get by just grinding on the crank - I was opening them up to 35 degrees ABDC to 57 or 65 degrees ATDC. Of course, you couldn't compete with the Nelsons - the Nelson had a 17mm crankshaft, the Magnum 12.5mm.
Iskandar
07-19-2011 | 06:59 PM
#78
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RE: Porting an ABL/ABC Engine
ORIGINAL: iskandar taib
Heh.. you guys haven't even gotten into the ''percent by weight vs. percent by volume'' argument yet. SIG measures by volume, a lot of the RC fuel suppliers measure by weight. When you consider that the specific gravity of nitromethane is 1.14 and the s.g. of methanol is 0.8, it really DOES make a lot of difference. 15% nitro Byron or Cool Power fuel would be the equivalent of, say, 11% SIG fuel. When they say 18% oil it'd only be 14% by volume.
Iskandar
Heh.. you guys haven't even gotten into the ''percent by weight vs. percent by volume'' argument yet. SIG measures by volume, a lot of the RC fuel suppliers measure by weight. When you consider that the specific gravity of nitromethane is 1.14 and the s.g. of methanol is 0.8, it really DOES make a lot of difference. 15% nitro Byron or Cool Power fuel would be the equivalent of, say, 11% SIG fuel. When they say 18% oil it'd only be 14% by volume.
Iskandar
Not sure what oil or mix you refer to, but the weight that I have found on Castor-oil is 0,956g/ml and that would give:
On 67%Me, 18%Oil, 15%Nitro in weight, would be by volume: 72,6%Me, 16,1%Oil and 11,3%Nitro.
On 72%Me, 18%Oil in weight, would be by volume: 84,6%Me, 15,4%Oil.
But then again, not all fuels are even labeled in more then Nitro %...
07-19-2011 | 07:24 PM
#79
RE: Porting an ABL/ABC Engine
ORIGINAL: Nitrovein
Not sure what oil or mix you refer to, but the weight that I have found on Castor-oil is 0,956g/ml and that would give:
On 67%Me, 18%Oil, 15%Nitro in weight, would be by volume: 72,6%Me, 16,1%Oil and 11,3%Nitro.
On 72%Me, 18%Oil in weight, would be by volume: 84,6%Me, 15,4%Oil.
But then again, not all fuels are even labeled in more then Nitro %...
ORIGINAL: iskandar taib
Heh.. you guys haven't even gotten into the ''percent by weight vs. percent by volume'' argument yet. SIG measures by volume, a lot of the RC fuel suppliers measure by weight. When you consider that the specific gravity of nitromethane is 1.14 and the s.g. of methanol is 0.8, it really DOES make a lot of difference. 15% nitro Byron or Cool Power fuel would be the equivalent of, say, 11% SIG fuel. When they say 18% oil it'd only be 14% by volume.
Iskandar
Heh.. you guys haven't even gotten into the ''percent by weight vs. percent by volume'' argument yet. SIG measures by volume, a lot of the RC fuel suppliers measure by weight. When you consider that the specific gravity of nitromethane is 1.14 and the s.g. of methanol is 0.8, it really DOES make a lot of difference. 15% nitro Byron or Cool Power fuel would be the equivalent of, say, 11% SIG fuel. When they say 18% oil it'd only be 14% by volume.
Iskandar
Not sure what oil or mix you refer to, but the weight that I have found on Castor-oil is 0,956g/ml and that would give:
On 67%Me, 18%Oil, 15%Nitro in weight, would be by volume: 72,6%Me, 16,1%Oil and 11,3%Nitro.
On 72%Me, 18%Oil in weight, would be by volume: 84,6%Me, 15,4%Oil.
But then again, not all fuels are even labeled in more then Nitro %...
07-19-2011 | 09:43 PM
#80
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From: Kuala Lumpur| Malaysia, MALAYSIA
RE: Porting an ABL/ABC Engine
ORIGINAL: 1QwkSport2.5r
So in hindsight, should one homebrew by weight or volume? Most go by volume, but if that throws the ratios off that far..... Then what?
So in hindsight, should one homebrew by weight or volume? Most go by volume, but if that throws the ratios off that far..... Then what?
Iskandar
