<br><font size=2 face="sans-serif">Thanks Brett and Vince,</font>
<br>
<br><font size=2 face="sans-serif">I've had a number of off-line emails from folks expressing their interest in a gas engine. Heres my take on it what I'll get to find out through experimentation. What does a 4C glow have over a 2C glow? It is basically noted as having better downline breaking, no pipe issues, more consistent throttle settings for a given throttle stick position wether you are acceleratingor decellerating the engine. What does the electric setup have over a glow setup? The most significant difference on the geared setups is the ability to swing a 20+" prop. Of course there are other factors which I'm not going to get into, but to me, the most significant difference is the large diameter prop and the overall speed profile/presentation you get with it. </font>
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<br><font size=2 face="sans-serif">What does the ZDZ gas engine give us? computer chip controlled timing, larger prop blade profiles than the electrics, comprable vibration to the glow setups, 2-cycle simplicity, no need to tune a pipe, seems to be close to the battery/weight tradeoffs for the electric setups in terms of the heavier gas engine. Concerned about cost of glow fuel? </font>
<br>
<br><font size=2 face="sans-serif">My main goal is to determine (since I have very little gas experience) if the chip-controlled auto-advance timing combined with the huge prop blade profile offers a throttle control and flight profile advantage to flying FAI. Thus far, the larger the prop I put on the Webra 160 and the slower I can fly the FAI pattern, the easier it is to do consistently. </font>
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<br><font size=2 face="sans-serif">Regarding the noise, I've been running in the opening of my garage so it seems loud as hell at full throttle. I've waled a few meters away and at idle, the windmilling of the prop and mechanical sounds of the motor are more prevelant than the popping of combustion. </font>
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<br><font size=2 face="sans-serif">Thanks and keep passing on the experience.</font>
<br><font size=2 face="sans-serif">Jim<br>
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<td><font size=1 face="sans-serif"><b>brett terry <brett.terry@gmail.com></b></font>
<br><font size=1 face="sans-serif">Sent by: discussion-request@nsrca.org</font>
<p><font size=1 face="sans-serif">11/30/2004 12:55 PM</font>
<br><font size=1 face="sans-serif">Please respond to brett terry</font>
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<br><font size=1 face="sans-serif"> To: discussion@nsrca.org</font>
<br><font size=1 face="sans-serif"> cc: </font>
<br><font size=1 face="sans-serif"> Subject: Re: ZDZ 40 RE, 60 plus oz of fuel now</font></table>
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<br><font size=2 face="Courier New">Dick Hanson taught me how to run these engines. They really start to<br>
wake up after two or three gallons. I used the Bambula and MAS<br>
Scimitar 20x10 prop on it, so yours must really scream. The 13# IMAC<br>
plane had far-beyond-unlimited vertical penetration but could not<br>
really cruise at "pattern speed". Perhaps the APC 18x14 2-blade would<br>
work in pattern.<br>
<br>
One other note: the pump in the carb only works at low throttle. If<br>
you try to choke it at WOT the fuel draw depends only upon the suction<br>
from the engine. My starting procedure is like this - after fueling<br>
flip the prop two or three times, close the choke turn on the ignition<br>
and set the throttle to high idle plus a couple of clicks, flip it<br>
until it pops (3-8 flips), open choke, flip it once and it runs. The<br>
idle is super-slow and full throttle doesn't really sag on uplines. <br>
This is the sign it is broken-in.<br>
<br>
After you get a few gallons through it switch to Redline 2-stroke<br>
racing oil at about 50:1 and enjoy! The best part is the cleanup<br>
after flying. They are almost as clean as electric planes, no more<br>
30% fuel, and no more DZ broken cranks. The con rod has roller<br>
bearings at both ends, and your local lawnmower shop carries parts to<br>
fix the carb.<br>
<br>
I have enjoyed your updates on this engine. There are a few new 2M<br>
planes designed around these gas engines and I am axcited to see what<br>
they can do.<br>
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Thanks!<br>
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Brett<br>
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On Mon, 29 Nov 2004 17:55:44 -0500, Bill Glaze <billglaze@triad.rr.com> wrote:<br>
> Jim:<br>
> Next time, could you be a little more detailed about what you're doing?<BG><br>
> Great job of giving us an idea of what's happening on the engine.<br>
> A couple of years ago, Dick Hanson was doing a lot of work with the ZDZ 40<br>
> Side Exhaust. He had a lot of figures on performance, etc. that would<br>
> possibly be relevant to the work you're doing now. He was very enthusiastic<br>
> about the engine. Gerry Dale also did a lot of work on putting a gasser in<br>
> a pattern plane of his own design; you possibly saw the article in RCM a<br>
> couple of years ago; the airplane was called "L'Essence" (not sure about the<br>
> French spelling) but I've seen him fly it in Masters and it did all the<br>
> maneuvers. It was marginal as far as weight went, and was sitting right at<br>
> 11 lbs, Gerry said.<br>
> <br>
> Bill Glaze<br>
> <br>
><br>
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