[NSRCA-discussion] Prop for 1.40 DZ??

Michael Cohen precisionaero at comcast.net
Tue Mar 13 17:44:28 AKST 2007


FYI, I run a 17X10N at 5500 feet on the 140 DZ.   RPM is somewhere in the 
mid to high 8000s and I have plenty of power with no noise issues, but 
remember, I am at 5500 ft.

----- Original Message ----- 
From: "Troy A. Newman" <troy_newman at msn.com>
To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
Sent: Monday, March 12, 2007 12:33 PM
Subject: Re: [NSRCA-discussion] Prop for 1.40 DZ??


> Mike,
>
> Yes the 18.1's are great I have been running them since we discussed it 
> back
> in 2005. On the 140DZ I still feel this is too much load. The RPMS will be
> under 8000 and this is about the same load as a 17-12 std or maybe the
> 17-12W
>
> The 140DZ will be finicky at this rpm and not make the best power. Run it 
> at
> 8200-8300 with a 16.5-12W and it will be a beast and also quieter on the
> sound meter.
>
> Just for info, most of the Japanese fliers run the 16.5-13W on the 170DZ 
> on
> 20% nitro. I by the way am running a 18.1 that has been modified on my 
> 170DZ
> and its very quiet and tons of pull and brakes. The motor is detuned a bit
> and really likes the setup.
>
> I personally feel the RPMS should be kept higher than some folks run them.
> If you have trouble with noise then after its setup and running at the
> 8400rpm then travel volume it back to about 8100 and you'll never know it
> was dialed back. It will be smooth, tons of pull and make noise without
> issue.
>
>
> Georgie, on the 140FZ or Sport and even the 140L and 30% nitro a 16-11 is
> pretty good also the 15-12W is a good prop.
>
>
> Troy
>
>
>
> ----- Original Message ----- 
> From: "Adam Glatt" <adam.g at sasktel.net>
> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
> Sent: Monday, March 12, 2007 10:39 AM
> Subject: Re: [NSRCA-discussion] Prop for 1.40 DZ??
>
>
>>I went through the phase of running big props on the 140DZ.  I then
>> switched to smaller props and liked them more.  Try a 15.5x12W and let
>> it rev (8600-8900).  No, it won't make noise, but I don't think a 140DZ
>> has ever made noise without cheating or limiting throttle travel.
>> -Adam
>>
>> Troy A. Newman wrote:
>>> Matt,
>>>
>>> the 17-12W is way too much prop for a 140DZ
>>>
>>> Run the engine between 8200-8500 and you will get the best performance
>>> from it. On the 140DZ's Insane power is 16-12. The 16.5-12W is also
>>> good if you are getting a little too loud. The 17-10 standard might be
>>> good, but a bit loud. I would look at the 16inch props.  The 17-12's
>>> will pull the RPMS down too low and below 8000rpm. this loads the
>>> engine too much its designed to run at higher rpm over 8000...you want
>>> to be over 8200 for sure.
>>>
>>> I know guys run the bigger props and don't have trouble but usually
>>> they complain it doesn't have the power they want. Then they stick a
>>> good prop on it and it goes like stink.
>>>
>>> Depending on the fuel you have chosen to run the  prop will vary. If
>>> you are running 30% Heli then you might get away with a 17-12 regular.
>>> the 17-12W is a bit more load and I only have used this on the 160dz.
>>> If you are trying to run some 20% nitro you need to really back off on
>>> the prop. Follow the rule of RPM above and keep the engine happy in
>>> the 8200-8600 range and it will not only run better with more
>>> performance but it will live longer too.
>>>
>>> The 18-10s are the same way. These are a bit too much load on the
>>> 140DZ to get the good power. The engine is setup to run at a certain
>>> RPM. If you run it there it will be equal power to the 2 stroke 140's
>>> and in most cases more. If you try to load it down to 7700 like guys
>>> do to the 2 strokes you will not keep up. As far as power pulling the
>>> model in the air the DZ will have more if you run it at the right RPM.
>>> 4 stoke vs 2 stroke is a different gear in the car. Run the engine at
>>> the right RPM and it will make more than you need even for a heavier
>>> model.
>>>
>>> troy Newman
>>>
>>>     ----- Original Message -----
>>>     *From:* Matthew Frederick <mailto:mjfrederick at cox.net>
>>>     *To:* nsrca-discussion at lists.nsrca.org
>>>     <mailto:nsrca-discussion at lists.nsrca.org>
>>>     *Sent:* Monday, March 12, 2007 7:49 AM
>>>     *Subject:* [NSRCA-discussion] Prop for 1.40 DZ??
>>>
>>>     I'm currently running a 17x12W on my 1.40DZ but I'm not getting
>>>     the vertical performance I would like. I was wondering what prop
>>>     size I should try? I've considered an 18x10. Any thoughts?
>>>
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>>
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