Which way sholud the heads point on a twin
01-23-2004, 12:46 PM
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Which way sholud the heads point on a twin
Hi Guy's:
Does it matter which way the heads point on a twin if you are using single cylinders and they will not be sticking out of the cowl.
Thanks Dave R
Does it matter which way the heads point on a twin if you are using single cylinders and they will not be sticking out of the cowl.
Thanks Dave R
01-23-2004, 07:34 PM
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RE: Which way sholud the heads point on a twin
Dave,
I have built seven twins that I can remember. I don't think it matters. Four of them had cylinders at the 9:00 o'clock position viewed from the front (three with 2-cycles, one with 4-cycles) Two had inverted engines, one of which is still flying for one of my friends after about 15 years. One has heads at 3:00 o'clock. They all seemed to work for me. I have found that propeller balance is absolutely essential however.
Chuck
I have built seven twins that I can remember. I don't think it matters. Four of them had cylinders at the 9:00 o'clock position viewed from the front (three with 2-cycles, one with 4-cycles) Two had inverted engines, one of which is still flying for one of my friends after about 15 years. One has heads at 3:00 o'clock. They all seemed to work for me. I have found that propeller balance is absolutely essential however.
Chuck
01-23-2004, 10:08 PM
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RE: Which way sholud the heads point on a twin
Position them whatever way you like. If you are doing a scale job and use a pitts muffler they'll have to be sideways, but it depends on your application. If you can avoid it don't run them upside dow simply because they have a high change of loading up and quiting on you and one engine out on a twin is not a good thing unless you like building....
01-23-2004, 10:08 PM
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RE: Which way sholud the heads point on a twin
I am not sure of your question but
I think I would point the heads out the cockpit window.
That seems to be the way all the other guys do it.
Greg
I think I would point the heads out the cockpit window.
That seems to be the way all the other guys do it.
Greg
01-24-2004, 10:39 AM
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RE: Which way sholud the heads point on a twin
what are the heads doing in the cockpit (lol), I'll bet you meant pointed at the cockpit window however this can cause some exhaust (muffler) issues with some glow engines, trying to point both heads at the cockpit. If as stated the engines are completely covered by the cowls and assuming that remote glow igniters are used place the engines in a position that they run the most reliable. If you are not using a remote glow, access to the glowplug is a big consideration, it could be difficult to safely remove an igniter from the area between an engine nacel, fuselage, wing and spinning prop.
01-25-2004, 02:45 PM
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RE: Which way sholud the heads point on a twin
I would summarize that gas heads should go down for better scale appeal, and glow heads should point right 'cause glow heads should never point down and for most glow engines a right head gives you exhaust down.
mt
mt
