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ZDZ engine reliabllity

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Steve Snyder

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Oct 5, 2000, 10:58:50 PM10/5/00
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For my next project I'm thinking about building an 30% Extra 300 and would
like a gas twin to put in it. I'm thinking about the twin 80. Does anyone
have any experience with the ZDZ engines? Are they reliable? All Comments
welcome.

Thank
Steve


aerogra...@my-deja.com

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Oct 5, 2000, 11:54:48 PM10/5/00
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Steve,
I'm presently bench running my Boxer 80 ZDZ and it is a super runner
and very reliable. I Choke the engine 7 or 8 times, open choke,
throttle to idle, ignition on and it starts with the first flip.
My friend has been flying his ZDZ 40 for a few months and he says it
is absolutely fantastic.
Roger
http://www.aerografixs.com

In article <KdbD5.4993$RP.11...@news1.rdc1.md.home.com>,


Sent via Deja.com http://www.deja.com/
Before you buy.

webspuds

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Oct 6, 2000, 3:00:00 AM10/6/00
to
If you're thinking about building something "that" nice, and big,
don't spare any expenses - go with the Brison 4.8 twin (or bigger).
You will be very glad with your decision to go with Brison.

http://www.brisonaircraft.com

In article <KdbD5.4993$RP.11...@news1.rdc1.md.home.com>,
"Steve Snyder" <snyde...@home.com> wrote:

--
We B. Spuds
AKA "webspuds"
webs...@hotmail.com

Michael Block

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Oct 6, 2000, 3:00:00 AM10/6/00
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Steve, check the measurements on the ZDZ twin, I don't think u can stuff
it in the cowl of a 30% extra without the the plugs and wires coming out
of the cowl sides which to me looks absolutely terrible. I would
probably go with the Zdz 80 single for this reason.

Mike

Cliff Griffin

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Oct 6, 2000, 3:00:00 AM10/6/00
to
In the IMAC circles, the ZDZ's are getting a reputation for being
"nicer" than Brisons. Besides the one that I swapped out for my BME,
I've only seen one other Brison (a 3.2) at the contests that I've gone
to this summer. They were great engines several years ago, but they are
quickly losing ground. The new engines are lighter and stronger. Heck,
the ZDZ 2.4 is about the same weight as the BME 2.7, and almost as
strong, too. The little Brison has nothing over the BME, except for
smoothness, which I'm told the ZDZ has also.

With the larger engines, the smoothness isn't as much of an issue, since
they are all twins. Personally, I don't know why anyone would spend that
much money and get a weaker, heavier engine. Brison needs to put their
engines on a diet, or their only market will be the old timers who had
one eons ago, and want to stick with them. ZDZ's aren't cheap shortcuts,
they are modern solutions. Plus, the service you get from RCShowcase
can't possibly be beat. Matched, maybe, but there's no beating it.

webspuds wrote:
>
> If you're thinking about building something "that" nice, and big,
> don't spare any expenses - go with the Brison 4.8 twin (or bigger).
> You will be very glad with your decision to go with Brison.
>
> http://www.brisonaircraft.com
>
> In article <KdbD5.4993$RP.11...@news1.rdc1.md.home.com>,
> "Steve Snyder" <snyde...@home.com> wrote:

Mike Wizynajtys

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Oct 6, 2000, 3:00:00 AM10/6/00
to
I know, I said this same thing in another thread above, but I think it's
worth repeating in this thread.


Brison makes a fine product, very dependable and quite powerful too,
but like everything they have short comings. For instance, they aren't
the lightest motors for their power output and the throttle response is
not particularly linear. So, while I like my Brison I do realize that
they are not only brand of engines available.

ZDZ and BME provide engines that are strong in the departments where
the Brison falls short. This has occurred because those other engine
manufactures saw where the current crop of gas burners fell short and
they addressed those issues. In my opinion, it would be wise of Brison
not to let the grass get too long under their feet and begin updating
their already outstanding line of products.

Wiz


"webspuds" <webs...@hotmail.com> wrote in message
news:8rjv6p$n5l$1...@nnrp1.deja.com...


> If you're thinking about building something "that" nice, and big,
> don't spare any expenses - go with the Brison 4.8 twin (or bigger).
> You will be very glad with your decision to go with Brison.
>
> http://www.brisonaircraft.com
>
>
>
> In article <KdbD5.4993$RP.11...@news1.rdc1.md.home.com>,
> "Steve Snyder" <snyde...@home.com> wrote:

aerogra...@my-deja.com

unread,
Oct 6, 2000, 10:29:47 PM10/6/00
to
Mike if I may add,
BME, Brison and most others are made by using components of other
commercial engines, the BME comes to mind with ECHO and Brison, Fox,
and a few others use the Sach dolmar products. ZDZ on the other hand
fabricate the complete engine specifically for models. They have been
made for 10 years and are very popular in Europe. If you want good
prices, look at Top Model in France. http://www.topmodel.fr/
Look at the price and remove 19.6%
Roger
http://www.aerografixs.com

In article <39de3cf1$0$35010$2c3e...@news.voyager.net>,

Mike Wizynajtys

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Oct 6, 2000, 11:15:39 PM10/6/00
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Hi Roger,

There was a time when I felt that having purpose built model engines
was an advantage, but who are we kidding here. Do our plane engines
really work harder than chainsaws or in a more hostile environment? I
don't think so. Guys like Keith Baker take these very tough time proven
designs and message them into very dependable and powerful aircraft
engines.

I'm not trying to slam ZDZ here, but I wonder how well one of their
engines would hold up in a chainsaw? Maybe very well, but not likely
any better than the Echo or Sachs engines do.

So is a purpose built engine better? Probably, when comparing some of
the less well thought out conversions, but certainly BME has done their
homework. I don't think that BME gives anything away to ZDZ in the
suitability to task department. I will say, the lack of availability of
a quiet after market exhaust system for the BME is more than a little
irritating.

ZDZ does offer a very attractive price. I just wish their 80cc twin
wasn't quite so wide. I also wish Desert Aircraft would get their 100
into production. I'm getting very close to needing to buy something and
I'd like another choice to make my decision even harder. :-)

Wiz

In article <8rm1qn$b2t$1...@nnrp1.deja.com>,

saro...@my-deja.com

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Oct 7, 2000, 12:37:37 AM10/7/00
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Roger,

I've never ordered anything from overseas. Can you actually order from
Top Model in US dollars?

I'm building a Midwest Cap 232 and I'm interested in the BME 2.7 or the
ZDZ 2.4. If I were to go with the ZDZ what muffler would should I
install?

TIA

In article <8rm1qn$b2t$1...@nnrp1.deja.com>,
aerogra...@my-deja.com wrote:

webspuds

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Oct 7, 2000, 1:09:46 AM10/7/00
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Hey Cliff - 'Sup ?

Well I dunno... I am "certainly" no expert, expecially in IMAC
stuff - it's out of my league. However, and based on my findings
with a friend at the air field with an RCS 1.4, I'm not impressed.
Granted, the ZDZ's "are" different, and it's not fair for me to
compare something I've never seen or touched, it's just that whole
RCS 1.4 thing. I'm a real stickler for chrome/nickel liners,
and/or plating, and when I see ST's, and the RCS 1.4 cylinders
are made of plain old "steel", I get "real" turned off "real" fast.
My friends RCS 1.4 kept spewing thick black pasty goo out of it
and hold a swatch of that goo up to the sun light on your finger
tips, and you can see the glitter of metal. If it's all strickly
a matter of "weight", and "power" (which no offence, but seems
to be your goals), then yea, undoubtly, you are probably correct.
But for me, (for whatever reason), there is more to it. Smoothness,
reliability, "chrome/nickel" liners (for heat/friction/wear/power),
amoung other things hold high priority for me with engines.
"Homey" don't do steel liners. Not glow, not gas. Heck, even
the Ryobi 31 CC has a chrome plated cylinder for gosh sakes.

But as I said, I suspose that there is also merit to making
decisions just on "power, weight, and cost" too, so who knows.
Admitidly, a lot of this comes down to plain ole "personal
preference", even if it's just baseless things like looks,
or some design factor that warms your heart.

Thanks for the insight.

In article <39DE02E5...@griffinlab.com>,


Cliff Griffin <cl...@griffinlab.com> wrote:
> In the IMAC circles, the ZDZ's are getting a reputation for being
> "nicer" than Brisons. Besides the one that I swapped out for my BME,
> I've only seen one other Brison (a 3.2) at the contests that I've gone
> to this summer. They were great engines several years ago, but they
are
> quickly losing ground. The new engines are lighter and stronger. Heck,
> the ZDZ 2.4 is about the same weight as the BME 2.7, and almost as
> strong, too. The little Brison has nothing over the BME, except for
> smoothness, which I'm told the ZDZ has also.
>
> With the larger engines, the smoothness isn't as much of an issue,
since
> they are all twins. Personally, I don't know why anyone would spend
that
> much money and get a weaker, heavier engine. Brison needs to put
their
> engines on a diet, or their only market will be the old timers who had
> one eons ago, and want to stick with them. ZDZ's aren't cheap
shortcuts,
> they are modern solutions. Plus, the service you get from RCShowcase
> can't possibly be beat. Matched, maybe, but there's no beating it.
>
> webspuds wrote:
> >

> > If you're thinking about building something "that" nice, and big,
> > don't spare any expenses - go with the Brison 4.8 twin (or bigger).
> > You will be very glad with your decision to go with Brison.
> >
> > http://www.brisonaircraft.com
> >
> > In article <KdbD5.4993$RP.11...@news1.rdc1.md.home.com>,
> > "Steve Snyder" <snyde...@home.com> wrote:

Mike Wizynajtys

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Oct 7, 2000, 1:12:12 AM10/7/00
to
If I'm not mistaken, Roger is in Canada. I wonder if us guys in the
States would get as good of a deal as he did. I also wonder how well
you can get the thing serviced. If it were me, I'd stick with R/C
Showcase in Florida.

As for exhaust, KS makes some nice quiet systems that fit ZDZ engines.
I know Desert Aircraft is a KS dealer, maybe R/C Showcase and Topline
are too.

Wiz

In article <8rm9ah$git$1...@nnrp1.deja.com>,

aerogra...@my-deja.com

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Oct 7, 2000, 3:00:00 AM10/7/00
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TIA,
This is the age of the Internet, and buying overseas is the same as
buying from your corner store. Mind you I was buying overseas before
the Internet. When you use your credit card anywhere in the world your
US dollars are simply converted to the particular currency. All this to
say yes you can. The ZDZ 40 would probably cost you in France about
half the BME 2.7. You can also compare the same engine price between
Top Model and RC Showcase. I saved $400.00 CDN on my 80 Boxer and When
I purchase the ZDZ 160 the savings will be $1000.00 CDN between Top
Model and RC Showcase. Something to think about.
Roger
http://www.aerografixs.com


In article <8rm9ah$git$1...@nnrp1.deja.com>,

aerogra...@my-deja.com

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Oct 7, 2000, 3:00:00 AM10/7/00
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Mike the deal is the same for everybody even better for you guys in the
states because of your stong dollar. The mail service is very quick
overseas. Wehn I ordered my BME 2.7 It took about 5 weeks to get here
and when I ordered my ZDZ 80 boxer from France, it took a week. Service
is by mail wether it is in Forida or France. The globe has shrunk quite
a bit with the advent Jet flight and Internet. <G>
Roger
http://www.aerografixs.com

In article <8rmbba$ht3$1...@nnrp1.deja.com>,

Brian D. Felice

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Oct 7, 2000, 3:00:00 AM10/7/00
to
Roger,

True, they're cheap from Top Model. They're even cheaper from Amelung in
Germany though. Remove 16% VAT and convert the D-Marks.... a ZDZ 80 twin (boxer)
is about $60 US cheaper from Amelung than from Top Model at this time. They also
have some very good deals on ZDZ's complete with exhausts. The link is:

http://www.zdz-motor.de/

Brian

"You can always tell an Engineer....

But you can't tell him much."

Brian D. Felice

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Oct 7, 2000, 3:00:00 AM10/7/00
to
Wiz,

True, a BME seems to be a good, powerful engine. The advantage a
purpose-built aircraft engine has is Schnurle porting and independently timed
induction. To the best of my knowledge, the only multi-ported engines available
at this time are the ZDZ and Mokis. Also, all the industrial powerplants use
either piston ported timing (like the BME 44) or reed valve induction; both work
but cannot achieve the ultimate power than an independently timed induction can,
as both ZDZ and Moki use.

Brian

"You can always tell an Engineer....

But you can't tell him much."

Mike Wizynajtys wrote:

> Hi Roger,

<snip>

> So is a purpose built engine better? Probably, when comparing some of
> the less well thought out conversions, but certainly BME has done their
> homework. I don't think that BME gives anything away to ZDZ in the
> suitability to task department. I will say, the lack of availability of
> a quiet after market exhaust system for the BME is more than a little
> irritating.

<snip>

> Wiz


Brian D. Felice

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Oct 7, 2000, 3:00:00 AM10/7/00
to
Wiz,

RC Showcase is in Maryland. The US dealer (RC Showcase) should service an
engine under warranty no matter where it was purchased. This may not apply to
engines purchased outside the country though. ???? At any rate, the postal
charges to Europe seem to be pretty reasonable, and the phone calls for help
will be the same or close to the same in cost as they are across US state lines
anyway. And I bet the majority of Amelung techs. speak English pretty well.....
not as well as Pé but no doubt well enough :-)

Brian

"You can always tell an Engineer....

But you can't tell him much."

Cliff Griffin

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Oct 7, 2000, 3:00:00 AM10/7/00
to
Seeing how the ZDZ is made made by a totally different company in Czech,
and the RCS is made in the UK, I guess I don't understand your logic
here. (And by the way, the ZDZ cylinders are Nikasil plated.) Your logic
is like saying I'll never buy a Ford because my Ford dealer also sells
Mitsubishi's, and I don't like Mitsubishi's.

Moving on...I've looked at my oil residue from my RCS, and there are
positively no visible metal particles in it, even with a magnifying
glass, and I won't have a full gallon through mine until later today.
The only difference between that RCS residue on my plane and the
Homelite (with chromed cyl.) residue is that it's a little wetter...I'm
running the engine a tad richer since it's breaking in. Same oil, same
gas, residue looks almost identical--I even left some Homey residue on
my plane so I could compare it after the switch. Like I said before, if
you've got metal particles in your exhaust that are visible with the
naked eye, then you've probably got other problems with your engine.
With the metal that visible, it would only take a few ounces of fuel to
break the engine in, and a very few gallons to totally wear it out.
Maybe you should suggest that your friend contact RCS and discuss the
issue.

If you've got problems with steel liners in general, then you'd better
check out your car...chances are it'll be giving you the same troubles.
Heck, even if you got the same reliability of an older car that only
gave you 100,000 miles on it before needing new rings, well, that's the
equivalent of about 4,000 flights at least. Even worse case at your 4
flights a day, 4 days a week, that's still five years of life. I've
never heard of anybody keeping a plane for five years when they fly that
often. If that's not enough flights for you for just one $10 ring, then
maybe you should stay away from a steel liner. But, by then you'd
probably be replacing the bearings anyway, and those cost more than
rings do.

As for the Ryobi...well, those weedwackers are made using the cheapest
technology available. They don't chrome plate them because chrome is
better, they do it because it's cheaper. They really don't care if your
$50 weedie lasts you only a season or two. If you don't like steel
liners, then don't buy them. There's nothing wrong with them, though.

Brian D. Felice

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Oct 7, 2000, 3:00:00 AM10/7/00
to
Cliff,

Er, I believe you're referring to the 1.40 and 1.80 cu. in. engines when you
say "RCS". There is no "RCS" company other than RC Showcase and they don't make
engines. The 1.40 / 1.80 that RC Showcase sells are Mokis, made in Hungary, and
also sold by Mackay engines in the UK. In fact, all of Mackay's engines are
Mokis but he doesn't use the name "Moki" due to a dispute with another "Moki"
(the glow engine) dealer, also in the UK. RC Showcase sells both Moki and ZDZ
engines. The ZDZs are made Czech engines and have no connection in any way with
Moki.

Confusing, isn't it? It took me a while to whittle through that too :-)

Brian

"You can always tell an Engineer....

But you can't tell him much."

Cliff Griffin wrote:

> Seeing how the ZDZ is made made by a totally different company in Czech,
> and the RCS is made in the UK, I guess I don't understand your logic
> here. (And by the way, the ZDZ cylinders are Nikasil plated.) Your logic
> is like saying I'll never buy a Ford because my Ford dealer also sells
> Mitsubishi's, and I don't like Mitsubishi's.

<snip>


aerogra...@my-deja.com

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Oct 7, 2000, 3:00:00 AM10/7/00
to
Cliff,
The RCS is not produced in the UK but in the Czeck Republic, the
same as the ZDZ. The RCS is the trade name of RC Showcase and they are
Gas Mokis. In the UK they call them Mockays or something like that.
Roger
http://www.aerografixs.com

In article <39DF46DF...@griffinlab.com>,

aerogra...@my-deja.com

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Oct 7, 2000, 3:00:00 AM10/7/00
to
Good point Brian,
I knew by getting up this morning, I would learn something.
Thanks
Roger
http://www.aerografixs.com

In article <39DF355C...@flash.net>,


"Brian D. Felice" <bdfe...@flash.net> wrote:
> Roger,
>
> True, they're cheap from Top Model. They're even cheaper from
Amelung in
> Germany though. Remove 16% VAT and convert the D-Marks.... a ZDZ 80
twin (boxer)
> is about $60 US cheaper from Amelung than from Top Model at this
time. They also
> have some very good deals on ZDZ's complete with exhausts. The link
is:
>
> http://www.zdz-motor.de/
>

> Brian
>
> "You can always tell an Engineer....
>
> But you can't tell him much."
>

> aerogra...@my-deja.com wrote:
>
> > Mike if I may add,
> > BME, Brison and most others are made by using components of other
> > commercial engines, the BME comes to mind with ECHO and Brison, Fox,
> > and a few others use the Sach dolmar products. ZDZ on the other hand
> > fabricate the complete engine specifically for models. They have
been
> > made for 10 years and are very popular in Europe. If you want good
> > prices, look at Top Model in France. http://www.topmodel.fr/
> > Look at the price and remove 19.6%
> > Roger
> > http://www.aerografixs.com
>
>

Cliff Griffin

unread,
Oct 7, 2000, 3:00:00 AM10/7/00
to
I know they aren't MADE by RCS, but they aren't made by the same company
that makes ZDZ either. That was my point.

Jonny Bekkum

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Oct 7, 2000, 3:00:00 AM10/7/00
to
RCS or Moki Modell engines are made in Hungary, not the Czech republic.

Go read here:
http://www.moki.co.uk/moki.htm

Jonny Bekkum
Norwegian ZDZ and ZM dealer

<aerogra...@my-deja.com> wrote in message
news:8rnil7$cnd$1...@nnrp1.deja.com...

aerogra...@my-deja.com

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Oct 7, 2000, 3:00:00 AM10/7/00
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Your right Jonny, I stand corrected.
Roger
http://www.aerografixs.com

In article <ZvLD5.376$W31....@news1.online.no>,

Funflyer

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Oct 7, 2000, 3:00:00 AM10/7/00
to

Could somebody please explain the deal about import duty tax? If we
buy something from one of these foreign dealers, do we have to pay
duty? thanks, Larry

On Sat, 07 Oct 2000 16:26:59 GMT, aerogra...@my-deja.com wrote:

>Good point Brian,
> I knew by getting up this morning, I would learn something.
> Thanks

> Roger

> http://www.aerografixs.com
>
>
>


>In article <39DF355C...@flash.net>,
> "Brian D. Felice" <bdfe...@flash.net> wrote:
>> Roger,
>>
>> True, they're cheap from Top Model. They're even cheaper from


>Amelung in
>> Germany though. Remove 16% VAT and convert the D-Marks.... a ZDZ 80
>twin (boxer)
>> is about $60 US cheaper from Amelung than from Top Model at this
>time. They also
>> have some very good deals on ZDZ's complete with exhausts. The link
>is:
>>
>> http://www.zdz-motor.de/
>>
>> Brian
>>
>> "You can always tell an Engineer....
>>
>> But you can't tell him much."
>>
>> aerogra...@my-deja.com wrote:
>>

>> > Mike if I may add,
>> > BME, Brison and most others are made by using components of other
>> > commercial engines, the BME comes to mind with ECHO and Brison, Fox,
>> > and a few others use the Sach dolmar products. ZDZ on the other hand
>> > fabricate the complete engine specifically for models. They have
>been
>> > made for 10 years and are very popular in Europe. If you want good
>> > prices, look at Top Model in France. http://www.topmodel.fr/
>> > Look at the price and remove 19.6%
>> > Roger
>> > http://www.aerografixs.com
>>
>>
>
>

Scorpionjack

unread,
Oct 7, 2000, 5:58:22 PM10/7/00
to
Cliff;
Have you received the new break-in for our 1.4's?

40-1 break-in 20 hr's not 6 hr's

50-1 synthetic
Got this information from Dany @ Genesis
Have fun
Jack

"Cliff Griffin" <cl...@griffinlab.com> wrote in message
news:39DF46DF...@griffinlab.com...

aerogra...@my-deja.com

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Oct 7, 2000, 10:34:06 PM10/7/00
to
Here in Canada, there is no import duty on any model stuff, but in the
states I don't the rules. Here people always get weery of duty were it
is the smallest part of the bill, its our federal and provincial taxes
that are the pits.
Roger
http://www.aerografixs.com

In article <fkdvtss482mtabm9k...@4ax.com>,


Funflyer <lk...@mindspring.com> wrote:
>
>
> Could somebody please explain the deal about import duty tax? If we
> buy something from one of these foreign dealers, do we have to pay
> duty? thanks, Larry
>
> On Sat, 07 Oct 2000 16:26:59 GMT, aerogra...@my-deja.com wrote:
>
> >Good point Brian,
> > I knew by getting up this morning, I would learn something.
> > Thanks

> > Roger
>
> > http://www.aerografixs.com
> >
> >
> >


> >In article <39DF355C...@flash.net>,
> > "Brian D. Felice" <bdfe...@flash.net> wrote:
> >> Roger,
> >>
> >> True, they're cheap from Top Model. They're even cheaper from
>
> >Amelung in
> >> Germany though. Remove 16% VAT and convert the D-Marks.... a ZDZ 80
> >twin (boxer)
> >> is about $60 US cheaper from Amelung than from Top Model at this
> >time. They also
> >> have some very good deals on ZDZ's complete with exhausts. The link
> >is:
> >>
> >> http://www.zdz-motor.de/
> >>
> >> Brian
> >>
> >> "You can always tell an Engineer....
> >>
> >> But you can't tell him much."
> >>
> >> aerogra...@my-deja.com wrote:
> >>

> >> > Mike if I may add,
> >> > BME, Brison and most others are made by using components of
other
> >> > commercial engines, the BME comes to mind with ECHO and Brison,
Fox,
> >> > and a few others use the Sach dolmar products. ZDZ on the other
hand
> >> > fabricate the complete engine specifically for models. They have
> >been
> >> > made for 10 years and are very popular in Europe. If you want
good
> >> > prices, look at Top Model in France. http://www.topmodel.fr/
> >> > Look at the price and remove 19.6%
> >> > Roger
> >> > http://www.aerografixs.com
> >>
> >>
> >
> >

Pé Reivers

unread,
Oct 8, 2000, 3:00:00 AM10/8/00
to
This question has been answered in the group before. USA has no import
duties on model stuff.
--
Pé, from Arcen, south-east Netherlands
http://home.planet.nl/~preivers
Remove the obvious to reply my messages


Funflyer <lk...@mindspring.com> schreef in berichtnieuws
fkdvtss482mtabm9k...@4ax.com...


>
>
>
>
> Could somebody please explain the deal about import duty tax? If we
> buy something from one of these foreign dealers, do we have to pay
> duty? thanks, Larry
>
>
>
>
>
> On Sat, 07 Oct 2000 16:26:59 GMT, aerogra...@my-deja.com wrote:
>
>
>
>
>
>
>
>
>
> >Good point Brian,
> > I knew by getting up this morning, I would learn something.
> > Thanks

> > Roger
>
> > http://www.aerografixs.com
> >
> >
> >


> >In article <39DF355C...@flash.net>,
> > "Brian D. Felice" <bdfe...@flash.net> wrote:
> >> Roger,
> >>
> >> True, they're cheap from Top Model. They're even cheaper from
>
>
>
>
> >Amelung in
> >> Germany though. Remove 16% VAT and convert the D-Marks.... a ZDZ 80
> >twin (boxer)
> >> is about $60 US cheaper from Amelung than from Top Model at this
> >time. They also
> >> have some very good deals on ZDZ's complete with exhausts. The link
> >is:
> >>
> >> http://www.zdz-motor.de/
> >>
> >> Brian
> >>
> >> "You can always tell an Engineer....
> >>
> >> But you can't tell him much."
> >>
> >> aerogra...@my-deja.com wrote:
> >>

> >> > Mike if I may add,
> >> > BME, Brison and most others are made by using components of other
> >> > commercial engines, the BME comes to mind with ECHO and Brison, Fox,
> >> > and a few others use the Sach dolmar products. ZDZ on the other hand
> >> > fabricate the complete engine specifically for models. They have
> >been
> >> > made for 10 years and are very popular in Europe. If you want good
> >> > prices, look at Top Model in France. http://www.topmodel.fr/
> >> > Look at the price and remove 19.6%
> >> > Roger
> >> > http://www.aerografixs.com
> >>
> >>
> >
> >

Mike Wizynajtys

unread,
Oct 8, 2000, 3:00:00 AM10/8/00
to
I suppose that's true, but we don't see the ZDZ or Moki engines (Moki
2.10 and ZDZ 40) outperforming the BME 44. So where is the real world
advantage?

Wiz

In article <39DF3576...@flash.net>,


"Brian D. Felice" <bdfe...@flash.net> wrote:

> Wiz,
>
> True, a BME seems to be a good, powerful engine. The advantage a
> purpose-built aircraft engine has is Schnurle porting and
independently timed
> induction. To the best of my knowledge, the only multi-ported engines
available
> at this time are the ZDZ and Mokis. Also, all the industrial
powerplants use
> either piston ported timing (like the BME 44) or reed valve
induction; both work
> but cannot achieve the ultimate power than an independently timed
induction can,
> as both ZDZ and Moki use.
>

> Brian
>
> "You can always tell an Engineer....
>
> But you can't tell him much."
>

> Mike Wizynajtys wrote:
>
> > Hi Roger,
>
> <snip>
>

> > So is a purpose built engine better? Probably, when comparing some
of
> > the less well thought out conversions, but certainly BME has done
their
> > homework. I don't think that BME gives anything away to ZDZ in the
> > suitability to task department. I will say, the lack of
availability of
> > a quiet after market exhaust system for the BME is more than a
little
> > irritating.
>

> <snip>
>
> > Wiz

aerogra...@my-deja.com

unread,
Oct 8, 2000, 3:00:00 AM10/8/00
to
Wiz,
The BME 2.7 and the ZDZ 40 are on par as far as performance is
concerned. The advantage then is the price, if purchased at the proper
place, the ZDZ is nearly half price. It also vibrates less. I have the
BME 2.7 and compared with the ZDZ 40 of a friend.
Roger
http://www.aerografixs.com

In article <8rqq3b$l5t$1...@nnrp1.deja.com>,

> > > So is a purpose built engine better? Probably, when comparing some
> of
> > > the less well thought out conversions, but certainly BME has done
> their
> > > homework. I don't think that BME gives anything away to ZDZ in the
> > > suitability to task department. I will say, the lack of
> availability of
> > > a quiet after market exhaust system for the BME is more than a
> little
> > > irritating.
> >

> > <snip>
> >
> > > Wiz

Ed Johnson

unread,
Oct 8, 2000, 3:00:00 AM10/8/00
to
Roger - or anyone: Is there much difference in weight between the two?
(Including ignition modules)
....Ed....

aerogra...@my-deja.com wrote:
>
> Wiz,
> The BME 2.7 and the ZDZ 40 are on par as far as performance is
> concerned. The advantage then is the price, if purchased at the proper
> place, the ZDZ is nearly half price. It also vibrates less. I have the
> BME 2.7 and compared with the ZDZ 40 of a friend.
> Roger
> http://www.aerografixs.com
>

om/
> Before you buy.

Ed Johnson

unread,
Oct 8, 2000, 3:00:00 AM10/8/00
to
Import duty? Taxes? Not on any model stuff I've ever ordered from Europe. (Or
Hong Kong, Japan, or Singapore either, for that matter.) We don't pay the Euro
V.A.T., so we get quite a break there too.

BTW, I'm curious as to what you are doing in Galena. Is there still an Air Force
base there?

I lived in Fairbanks for over 30 years, and have visited Galena many times. Do
you happen to know Harold Esmelka of Ruby?

...Ed...

Don Hatten wrote:
>
> Did you use a good currency conversion table with the current rates? Then there's
> import duty, shipping, taxes, etc.
>

Michael Block

unread,
Oct 8, 2000, 9:45:21 PM10/8/00
to
We seem to getting gouged by the US dealers, not only is ZDZ much less
expensive in Europe but so is 3W . I just looked at their website and
there is a difference of $100's of dollars on their engines as well.

Mike

"Brian D. Felice" wrote:
>
> Roger,
>
> True, they're cheap from Top Model. They're even cheaper from Amelung in
> Germany though. Remove 16% VAT and convert the D-Marks.... a ZDZ 80 twin (boxer)
> is about $60 US cheaper from Amelung than from Top Model at this time. They also
> have some very good deals on ZDZ's complete with exhausts. The link is:
>
> http://www.zdz-motor.de/
>

> Brian
>
> "You can always tell an Engineer....
>
> But you can't tell him much."
>

Don Hatten

unread,
Oct 8, 2000, 9:49:23 PM10/8/00
to
Did you use a good currency convertion table?

Michael Block wrote:

--
****************************
Don Hatten AMA SOARDOG
Galena, Alaska KE6TJG
USHGA 17442
http://www.freerepublic.com
****************************
"Guard with jealous attention the public liberty. Suspect everyone who approaches that
jewel. Unfortunately, nothing will preserve it but downright force. Whenever you give
up that force, you are ruined." - Patrick Henry

"Americans are so enamored of equality that they would rather be equal in slavery than
unequal in freedom."
-- Alexis Charles Clerel de Tocqueville - "Democracy in America" (1835)


Don Hatten

unread,
Oct 8, 2000, 9:50:51 PM10/8/00
to
Did you use a good currency conversion table with the current rates? Then there's
import duty, shipping, taxes, etc.

Michael Block wrote:

--

Don Hatten

unread,
Oct 8, 2000, 9:57:05 PM10/8/00
to
On the ZDZ website the ZDZ 80 is $470.75 and with the ignition set it is $559.65 at
Fridays rate. How much are they at Top Model?

Michael Block wrote:

--

aerogra...@my-deja.com

unread,
Oct 8, 2000, 10:28:45 PM10/8/00
to
Ed,
The BME 2.7 weighs 2.7 lbs and the ZDZ 40 weighs 2.75 lbs according
to their respective Web sites. The electronic modules would weigh the
same and then it depends on the mufflers you use.
Roger
http://www.aerografixs.com

In article <39E11A9C...@maine.rr.com>,

aerogra...@my-deja.com

unread,
Oct 8, 2000, 10:48:56 PM10/8/00
to
RC Showcase shows the ZDZ 80 single cylinder at $650.00 USD.
Top Model has the same engine for $357.49 USD after removing the 19.6 %
V.A.T. which is not applicable outside Europe.

Top Model also has my next engine the ZDZ 160 Boxer twin for $730.00 USD
RC Showcase has it for $1475.00 USD for a difference of $744.91 USD.

Roger
http://www.aerografixs.com

In article <39E1258F...@worldnet.att.net>,

Don Hatten

unread,
Oct 8, 2000, 11:26:35 PM10/8/00
to
I am at the old Air Force Base. We keep it in caretaker status just in case.

Ed Johnson wrote:

> Import duty? Taxes? Not on any model stuff I've ever ordered from Europe. (Or
> Hong Kong, Japan, or Singapore either, for that matter.) We don't pay the Euro
> V.A.T., so we get quite a break there too.
>
> BTW, I'm curious as to what you are doing in Galena. Is there still an Air Force
> base there?
>
> I lived in Fairbanks for over 30 years, and have visited Galena many times. Do
> you happen to know Harold Esmelka of Ruby?
>
> ...Ed...
>
> Don Hatten wrote:
> >

> > Did you use a good currency conversion table with the current rates? Then there's
> > import duty, shipping, taxes, etc.
> >

--

Ed Johnson

unread,
Oct 9, 2000, 12:42:31 AM10/9/00
to
Thanks, Don. Pee in the Yukon for me, would ya?

....Ed....

(I know, this has nothing to do with ZDZ engines, but I just had to ask :))

Don Hatten

unread,
Oct 9, 2000, 1:14:10 AM10/9/00
to
Well, it all gets there eventually. :-)

Ed Johnson wrote:

> Thanks, Don. Pee in the Yukon for me, would ya?
>
> ....Ed....
>

--

Jonny Bekkum

unread,
Oct 9, 2000, 1:50:10 AM10/9/00
to
Just a small correction here on the content from Amelung at
http://www.zdz-motor.de :
ZDZ80 single WITH processor control ignition and small parts package is
470.75$
ZDZ80 single (as above) WITH header/coupler/tuned pipe is 559.65

Jonny Bekkum
Norwegian ZDZ and SM dealer

"Don Hatten" <hat...@worldnet.att.net> wrote in message
news:39E1258F...@worldnet.att.net...

webspuds

unread,
Oct 9, 2000, 2:43:40 AM10/9/00
to

> Seeing how the ZDZ is made made by a totally different company in
Czech,
> and the RCS is made in the UK, I guess I don't understand your logic
> here. (And by the way, the ZDZ cylinders are Nikasil plated.)

My appologies - didn't know ZDZ's were Nikasil plated, and/or they
were made by a different manufacture - bad assumption on my part.


Your logic
> is like saying I'll never buy a Ford because my Ford dealer also sells
> Mitsubishi's, and I don't like Mitsubishi's.

Ture, and it is bad logic.

>
> Moving on...I've looked at my oil residue from my RCS, and there are
> positively no visible metal particles in it, even with a magnifying
> glass, and I won't have a full gallon through mine until later today.
> The only difference between that RCS residue on my plane and the
> Homelite (with chromed cyl.) residue is that it's a little
wetter...I'm
> running the engine a tad richer since it's breaking in. Same oil, same
> gas, residue looks almost identical--I even left some Homey residue on
> my plane so I could compare it after the switch. Like I said before,
if
> you've got metal particles in your exhaust that are visible with the
> naked eye, then you've probably got other problems with your engine.
> With the metal that visible, it would only take a few ounces of fuel
to
> break the engine in, and a very few gallons to totally wear it out.
> Maybe you should suggest that your friend contact RCS and discuss the
> issue.

Good point, I may do that. By virtue of you not seeing this,
means that at least, the RCS does have the capibility to be Ok.

>
> If you've got problems with steel liners in general, then you'd better
> check out your car...chances are it'll be giving you the same
troubles.

I knew if would be a matter of time before someone brought this up.
Car engines don't do 10K RPM's, they are low compression, and more
tolerant of wear, blowby etc. Car engines are no high performance.

> Heck, even if you got the same reliability of an older car that only
> gave you 100,000 miles on it before needing new rings, well, that's
the
> equivalent of about 4,000 flights at least. Even worse case at your 4
> flights a day, 4 days a week, that's still five years of life. I've
> never heard of anybody keeping a plane for five years when they fly
that
> often. If that's not enough flights for you for just one $10 ring,
then
> maybe you should stay away from a steel liner. But, by then you'd
> probably be replacing the bearings anyway, and those cost more than
> rings do.

Yup - I see your "perspective". My perspecive was simply that
if Chome is available in many glow engines (and gas), why settle
for steel that wears, rusts from moisture/humidity, and has much
more friction when you can get Chrome ? Maybe I don't have this
in its proper perspective, but at $400-$500 an engine, it should
actually be "gold plated".


>
> As for the Ryobi...well, those weedwackers are made using the cheapest
> technology available. They don't chrome plate them because chrome is
> better, they do it because it's cheaper.

But the Ryobi's DO have Chrome plated jugs - that's what I've said !

> They really don't care if your
> $50 weedie lasts you only a season or two.

Point was, with all of the friction/wear/rust/mess of steel liners,
and the true advantages of chome, even Ryobi made a decision to
go to chrome, but yet RCS didn't. Says something in my mind.


> If you don't like steel
> liners, then don't buy them.

I don't - that was my point Cliff.


> There's nothing wrong with them, though.

Compared to chrome, theres "everything" wrong with them.

Michael Block

unread,
Oct 9, 2000, 3:00:00 AM10/9/00
to
Just checked and the ZDZ 80 single is $357 USD at TopModel, $395 USD at
Amelung and $650 USD at RCshowcase. That's a hell of a
difference!Simular differences on 3w at their site.

Mike

Michael Block

unread,
Oct 9, 2000, 3:00:00 AM10/9/00
to
Don, I don't know where you're located but, if u r not in Europe , u can
back out the European Value Added Tax (VAT) . which on the German site
Amelung is -16% and the French site TopModel is -19.4%

Mike
Toronto

Michael Block

unread,
Oct 9, 2000, 3:00:00 AM10/9/00
to
thought I'd check on the 80 twin as well , for those interested,ZDZ 80
twin is $593.97 at Amelung, $652.56 Topmodel, $865 rcshowcase. All
quoted USD

Mike
Toronto

Michael Block wrote:
>
> Just checked and the ZDZ 80 single is $357 USD at TopModel, $395 USD at
> Amelung and $650 USD at RCshowcase. That's a hell of a
> difference!Simular differences on 3w at their site.
>
> Mike
>
> Don Hatten wrote:
> >

Michael Block

unread,
Oct 9, 2000, 3:00:00 AM10/9/00
to
Also the "set price" is the engine\ignition and exhaust system combo.
the standard price is the engine with ignition - no exhaust system

Mike

Michael Block wrote:
>
> Don, I don't know where you're located but, if u r not in Europe , u can
> back out the European Value Added Tax (VAT) . which on the German site
> Amelung is -16% and the French site TopModel is -19.4%
>
> Mike
> Toronto
>
> Don Hatten wrote:
> >

Mike Wizynajtys

unread,
Oct 9, 2000, 3:00:00 AM10/9/00
to
WOW!!! That's a huge savings! For me, that has tipped the scale in favor
of ZDZ. Now, all I need to do is find a 33% plane that is wide enough to
fit the 80cc twin into without cutouts.

Thanks for showing us the light, Roger. ;)

Wiz

<aerogra...@my-deja.com> wrote in message
news:8rrbmn$264$1...@nnrp1.deja.com...

Brian D. Felice

unread,
Oct 9, 2000, 3:00:00 AM10/9/00
to
Mike Wizynajtys wrote:

> I suppose that's true, but we don't see the ZDZ or Moki engines (Moki
> 2.10 and ZDZ 40) outperforming the BME 44. So where is the real world
> advantage?
>
> Wiz

I don't have either engine so I don't can't compare power output myself. But
judging by the performance reports of others, the ZDZ 40 equal's the performance
of the BME 44. If so, then the ZDZ easily outperforms the BME due entirely to
displacement differences- the BME is larger by a full 10%.

The advantage of timed induction are better throttling, higher top end RPMs
and higher power output. The advantage of Schnurle porting is better scavenging
which results in greater efficiency; this is used to increase power, decrease
fuel consumption or both. Both of these techniques are used on glow engines for
the same reasons. The only glow engine series that I'm aware of that does not
make use of these designs are the Cox series, specifically the .010, .020 and
.049s.

The Moki 2.1 is a glow engine so it's of no comparative use. The Moki 45 cc
gasoline engine supposedly out-runs the BME. Again, I don't have either one so
can't offer solid performance data.

I'm not saying that BME engines are inferior or poor engines in their own
right. It's just that they use an older, inferior design when compared with some
of the latest purpose built aircraft engines.

Red Baron

unread,
Oct 9, 2000, 3:00:00 AM10/9/00
to
webs...@hotmail.com (webspuds) wrote in <8rrpes$bjk$1...@nnrp1.deja.com>:

>I knew if would be a matter of time before someone brought this up.
>Car engines don't do 10K RPM's, they are low compression, and more
>tolerant of wear, blowby etc. Car engines are no high performance.

Yes they are!
Take a look at the Honda S2000, which you can buy from any Honda dealer (at
least in Europe).
The car comes equipped with a gem of an engine.
The performance speaks for itself: 2 litre (122 cu.in.) 240 b.h.p. @ 8300
rpm. Redline: 9000 rpm. That's 1.97 bhp/cu.in without a turbo!
There are a several model aircraft engines (gas and methanol) that have
inferior performance.
O.K. I know the redline is below 10k but most model aircraft gas engines
are run below 10k as well.

/Red B.

Rich Sichler

unread,
Oct 9, 2000, 3:00:00 AM10/9/00
to

Michael Block <2mb...@home.com> wrote in message
news:39E1C483...@home.com...


> Don, I don't know where you're located but, if u r not in Europe , u can
> back out the European Value Added Tax (VAT) . which on the German site
> Amelung is -16% and the French site TopModel is -19.4%
>
> Mike
> Toronto

Does anyone having experience with ordering from Germany or France and
shipping to the US? Are there any import fees involved?

Rich Sichler
Cocalico Propbusters


m3/911

unread,
Oct 9, 2000, 3:00:00 AM10/9/00
to
Could you suggest a reliable dealer that sell these engines for a good
price? Dealer does not have to be located in the States.

<aerogra...@my-deja.com> wrote in message
news:8rr1n6$qsm$1...@nnrp1.deja.com...


> Wiz,
> The BME 2.7 and the ZDZ 40 are on par as far as performance is
> concerned. The advantage then is the price, if purchased at the proper
> place, the ZDZ is nearly half price. It also vibrates less. I have the
> BME 2.7 and compared with the ZDZ 40 of a friend.

> Roger
> http://www.aerografixs.com
>
>
>
>
>
> In article <8rqq3b$l5t$1...@nnrp1.deja.com>,


> Mike Wizynajtys <mik...@voyager.net> wrote:
> > I suppose that's true, but we don't see the ZDZ or Moki engines (Moki
> > 2.10 and ZDZ 40) outperforming the BME 44. So where is the real world
> > advantage?
> >
> > Wiz
> >

> > In article <39DF3576...@flash.net>,
> > "Brian D. Felice" <bdfe...@flash.net> wrote:
> > > Wiz,
> > >
> > > True, a BME seems to be a good, powerful engine. The advantage a
> > > purpose-built aircraft engine has is Schnurle porting and
> > independently timed
> > > induction. To the best of my knowledge, the only multi-ported
> engines
> > available
> > > at this time are the ZDZ and Mokis. Also, all the industrial
> > powerplants use
> > > either piston ported timing (like the BME 44) or reed valve
> > induction; both work
> > > but cannot achieve the ultimate power than an independently timed
> > induction can,
> > > as both ZDZ and Moki use.
> > >

> > > Brian
> > >
> > > "You can always tell an Engineer....
> > >
> > > But you can't tell him much."
> > >

> > > Mike Wizynajtys wrote:
> > >
> > > > Hi Roger,
> > >
> > > <snip>
> > >
> > > > So is a purpose built engine better? Probably, when comparing some
> > of
> > > > the less well thought out conversions, but certainly BME has done
> > their
> > > > homework. I don't think that BME gives anything away to ZDZ in the
> > > > suitability to task department. I will say, the lack of
> > availability of
> > > > a quiet after market exhaust system for the BME is more than a
> > little
> > > > irritating.
> > >
> > > <snip>
> > >
> > > > Wiz
> > >
> > >
> >

aerogra...@my-deja.com

unread,
Oct 9, 2000, 11:34:47 PM10/9/00
to
Yes you can order from Top Model in France
http://www.topmodel.fr/
or From Amelung in Germany
http://www.zdz-motor.de/

and I believe that Jonny Beckmun (sorry for the spelling)on this list
is also a dealer.

Roger
http://www.aerografixs.com

n article <7lvE5.8587$j%6.13...@wagner.videotron.net>,

Cliff Griffin

unread,
Oct 10, 2000, 3:00:00 AM10/10/00
to
As a reference, my older Acura Integra red-lines at 7k, and I've got
170,000 miles on it. On the freeway, my tach is at 4,000 rpm. If steel
cylinders wore out immediately, then my car would have been parked years
ago.

The RCS has a rev limiter built into the ignition at 9k. They'll bump
that up to 15k if you ask them to, though. Anyway, 2,000 rpm difference
as a standard setting sure isn't a LOT.

Cliff


Red Baron wrote:
>
> webs...@hotmail.com (webspuds) wrote in <8rrpes$bjk$1...@nnrp1.deja.com>:
>

> >I knew if would be a matter of time before someone brought this up.
> >Car engines don't do 10K RPM's, they are low compression, and more
> >tolerant of wear, blowby etc. Car engines are no high performance.
>

Pé Reivers

unread,
Oct 10, 2000, 3:00:00 AM10/10/00
to
Brian.
Respectfully allow me to disagree on some parts.
While tuning 50cc engines for motocross purposes, the same high end power
could be had using both rotary disk engines and piston skirt induction
engines. Only above 16000 rpm, did rotary disk win. Low end torque however
was worse for the rotary disks, because of a problem initiating and
sustaining high speed induction gas flow, which was required to provide ram
gas charging in the suction cycle. By that token, all leading road racing
engines were rotaries with extremely wide carbs and very short induction
tubes, running between 16000 and 20000 rpm (20% usable rpm range) using
six-speed gear boxes, and all potent motocross engines were piston induction
engines using smaller carbs, long induction tubes and four-speed or five
speed gearboxes, running between 11000 and 16000 rpm (31% usable rpm range).
While having more power, them rotaries never stood a chance in the rough.
With many of our fields endangered by noise complaints and law limitations,
sheer top power is not an issue any more. More important is the ability of
an engine to be set up to a more powerful lowish rpm figure. My best guess
here would not be a rotary set up for short intake duration, and well
controlled early closing angle for more power down the rpm curve. This goal
can be just as easily achieved using piston induction porting and less
moving parts.
As an example, I tune my ST2300 for about 7500 ground rpm because of our
80dB(A) noise limit. Top power is at 12600. I think the same, or more usable
power could be generated using piston induction instead of the crankshaft
rotary of the ST, and have the carb in the back closer to the tank as well.
--
Pé, from Arcen, south-east Netherlands
http://home.planet.nl/~preivers
Remove the obvious to reply my messages


Brian D. Felice <bdfe...@flash.net> schreef in berichtnieuws
39E1CDD0...@flash.net...


> Mike Wizynajtys wrote:
>
> > I suppose that's true, but we don't see the ZDZ or Moki engines (Moki
> > 2.10 and ZDZ 40) outperforming the BME 44. So where is the real world
> > advantage?
> >
> > Wiz
>

webspuds

unread,
Oct 10, 2000, 11:32:35 PM10/10/00
to
What is your current compression ratio on that Accura ?
Also, pop the head, and run your finger nail up the cylinder
and let me know how big, and "sharp" that ridge is about a
quarter inch from the top of the cylinder. Also remember that
your little Accura engine is a water cooled 4-cycle with a
pressurized oiling system that spends most of it's life at 2-4K RPM.

should'nt we be comparing this to maybe 2-cycle motorcycles
and snowmobiles and such ? This is much more "comparable"
to what we're talking about here.

The 9K limiter is a problem too. Drove my friend nuts, and
everyone else at the field tring to figure it out. Sounds
"horable" in the air when it starts cutting out which is basically
all the time on a APC 16x8. RCS did tell him about the limiter,
but never mentioned that it was adjustable/defeatable. Instead,
they recommended he go find (an extreamly hard to find) 17x8.

Made me wonder - why have a rev limiter at all ??? Expecially
set to 9K! What, they 'fraid it will "scatter" at 10K ? Hummm.

In article <39E32A45...@griffinlab.com>,


Cliff Griffin <cl...@griffinlab.com> wrote:
> As a reference, my older Acura Integra red-lines at 7k, and I've got
> 170,000 miles on it. On the freeway, my tach is at 4,000 rpm. If steel
> cylinders wore out immediately, then my car would have been parked
years
> ago.
>
> The RCS has a rev limiter built into the ignition at 9k. They'll bump
> that up to 15k if you ask them to, though. Anyway, 2,000 rpm
difference
> as a standard setting sure isn't a LOT.
>
> Cliff
>
> Red Baron wrote:
> >
> > webs...@hotmail.com (webspuds) wrote in
<8rrpes$bjk$1...@nnrp1.deja.com>:
> >

> > >I knew if would be a matter of time before someone brought this up.
> > >Car engines don't do 10K RPM's, they are low compression, and more
> > >tolerant of wear, blowby etc. Car engines are no high performance.
> >

> > Yes they are!
> > Take a look at the Honda S2000, which you can buy from any Honda
dealer (at
> > least in Europe).
> > The car comes equipped with a gem of an engine.
> > The performance speaks for itself: 2 litre (122 cu.in.) 240 b.h.p.
@ 8300
> > rpm. Redline: 9000 rpm. That's 1.97 bhp/cu.in without a turbo!
> > There are a several model aircraft engines (gas and methanol) that
have
> > inferior performance.
> > O.K. I know the redline is below 10k but most model aircraft gas
engines
> > are run below 10k as well.
> >
> > /Red B.
>

--

Mike Wizynajtys

unread,
Oct 11, 2000, 12:29:17 AM10/11/00
to
Brian,

I'm not going to attempt to argue the points with you on a technical
basis because I can't. In the real world, the ZDZ 40 cannot turn a
Mejzlik 20x10 at 7600 rpm. It runs around 7200. The BME however does.
Now that's not quite a 10% difference, but it does show that the
differences in design may not be as significant as you think.

The Moki 45 is not a particularly light weight motor, and so I have no
idea what it's output is. I can't imagine a purpose built gasoline
engine not being optimized for low weight. What were those guys
thinking?

I think ZDZ has a great product and I'll probably buy their 80, but I
don't see much real world advantage to the fact that it's a purpose
built model airplane motor.

Wiz

In article <39E1CDD0...@flash.net>


"Brian D. Felice" <bdfe...@flash.net> wrote:

Brian D. Felice

unread,
Oct 11, 2000, 3:00:00 AM10/11/00
to
Wiz,

Perhaps the advantage is more theoretical than practical.

You're right in that it makes no difference what the parts (cylinders,
crankcase) were made for. The BME's specifically are very lightweight engines
all the way to the 100 (102 now) cc twins. In fact, the 102 cc BME twin is the
lightest engine I've found in that size range- only the ZDZ 80 is in the same
weight class and then it's a full 20% less displacement. I don't think any of us
care what the engine's parts were originally made for as long as the product is
competitive.

The advantage should be the timing, and gas passage size of the rear rotary
disk induction system. This was introduced to improve the performance of 2 cycle
engines and has, at least in the past. The other two choices, piston skirt and
reed valve induction, should be inferior. But as Pé has mentioned, perhaps this
advantage isn't great at relatively low speeds and without a tuned exhaust. I
would be most interested in seeing some performance figures for both types when
used with tuned exhausts although that's not likely as few people use them on
gasoline engines. I suspect that a rotary-valved engine would show it's
advantage then.

Brian

"You can always tell an Engineer....

But you can't tell him much."

Brian D. Felice

unread,
Oct 11, 2000, 3:00:00 AM10/11/00
to
Pé,

I don't doubt your experiences but I do wonder about the limitations of a
rotary disk induction compared with piston skirt induction.

The rotary disk can be set up to duplicate the same timing parameters of
piston skirt timing but the reverse is not true. Even at low speed, different
BTDC and ATDC opening / closing points are almost always used on any 2 cycle
able to control this parameter; a piston ported engine cannot and both timing
points must be the same.

To the best of my knowledge, this timing differential possibility is used by
designers to control the induction phase more accurately than would be possible
with either piston timing or reed valve timing. This is why it exists in the
first place because as you correctly point out, rear rotary disk induction is
more expensive and complicated than either of the other two types of induction.

I would think that independent timing control would always be desirable;
piston skirt timing can be duplicated or other timing can be used at will.
Rotary disk should always be as good or better than other types....or am I
missing something? The ZDZ, Moki and BME all turn in the same RPM band- if there
were no advantage to using rotary disk induction, why do ZDZ and Moki use it?
(this is not sarcastic- I really am interested in your thoughts on this)

Brian

"You can always tell an Engineer....

But you can't tell him much."

aerogra...@my-deja.com

unread,
Oct 11, 2000, 3:00:00 AM10/11/00
to
If I may jump in here for a second, and I am not an authority by all
means. ZDZ does mention that there engines operate at a lower RPM then
most with larger props, where as the BME 2.7 will, (acording to Keith
Baker on a personal E-mail,) will turn all day long at 9500 RPM and
will red line at 14000 RPM of course that depends on the load.

Roger
http://www.aerografixs.com

n article <39E453CC...@flash.net>,


"Brian D. Felice" <bdfe...@flash.net> wrote:

Paul Nesbitt

unread,
Oct 11, 2000, 3:00:00 AM10/11/00
to
I have been saying the same thing about 3Ws for years. Very strong,
purpose built engines, but they are terribly heavy. Where the only
choices were the Zenoahs, Sachs style, Quadra and 3W, 3W was the best
because all of the engines were fairly heavy and the 3W was the
powerhouse. But now, how many 3Ws do you see? In the 27-35% airplanes,
BME and ZDZ seem to be taking the lions share, and in the 40% class, the
DA 150 has become the one to beat. I would think 3W and Moki (and some
of the others) would get the message; we want the lightest engine we can
get.

Paul Nesbitt

>
Snip...


>
> The Moki 45 is not a particularly light weight motor, and so I have no
> idea what it's output is. I can't imagine a purpose built gasoline
> engine not being optimized for low weight. What were those guys
> thinking?
>

Snip..

chriss...@my-deja.com

unread,
Oct 11, 2000, 3:00:00 AM10/11/00
to
Will the zdz 40cc do well on a 15-1/2 pound 80" span Edge540?

I noticed a Brison add for the 3.2 that said unlimited vertical to 18
pounds. That makes me wonder if the 2.4 zdz would be marginal.

AT

unread,
Oct 11, 2000, 3:00:00 AM10/11/00
to

chriss...@my-deja.com <8s20nc$cam$1...@nnrp1.deja.com>...

>Will the zdz 40cc do well on a 15-1/2 pound 80" span Edge540?
>
>I noticed a Brison add for the 3.2 that said unlimited vertical to 18
>pounds. That makes me wonder if the 2.4 zdz would be marginal.


According http://www.zdz-motor.de/html/powerdata.html:
20x10 Mejzlik 7400
20x12 Menz 7000
22x12 Mejzlik 6100
22x10 Mejzlik 6900

Which means that static thrust is between 25 - 33 lb, depending on the prop.
These are achieved with tuned pipe.

Personally I do not doubt those revs, cause I have 80cc and measured
readings are equivalent to those on the web page.

AT


Pé Reivers

unread,
Oct 11, 2000, 3:00:00 AM10/11/00
to
Yes Brian, you seem to miss one most important fact, and one less important
one, but still significant in my views of both systems. (forgetting
simplicity of construction for convenience)
1) The piston speed near top is not linear at all. If the porting is such,
that the piston skirt rises above top of port level, a totally unobstructed
gas flow is presented for more than 50% of the induction time, because the
piston "lingers" in, or near top position so long. The rotary disk has near
linear motion, so will never give the same results if timed the same as
piston induction. In other words, they need to be of large induction period
design to be effective.
2) Rotaries have the induction in line with the crank shaft, at right angles
to the crank rotational plane. Gas flow inside the engine has to make a 90°
turn, before it can enter the ports, making it hard to get a bit of flow
symmetry. Long ram tubes were not practical in cycle engines, because no one
wants that carb sticking so far out the side. (does not hold true for model
engines). Furthermore, if the piston has no crown ports for the boost
scavenge port, internal piston cooling is quite marginal, resulting in a
hotter piston bottom. With piston induction, flow remains in symmetry with
the saggital plane. Some of the flow curls upward to scavenge the piston
inside a bit and take care for gas exchange, regardless of the presence of
inner boost porting.
It is my firm belief, that these two differences are the reason, that piston
induction can perform so well, and hold it's own if well designed. (12 hp
from modified 50cc Kreidler moped engines, vs 18 hp from all-out racing
engines with 12-speed gearbox in the Kreidler world speed record attempt)

--
Pé, from Arcen, south-east Netherlands
http://home.planet.nl/~preivers
Remove the obvious to reply my messages

Brian D. Felice <bdfe...@flash.net> schreef in berichtnieuws

39E453CC...@flash.net...

Mike Wizynajtys

unread,
Oct 11, 2000, 3:00:00 AM10/11/00
to
15.5 lbs.....Yeah the 2.4 from Brison or ZDZ will eb marginal. I would
suggest you go up one notch in either of the brands for a plane that
size.

Wiz
In article <8s20nc$cam$1...@nnrp1.deja.com>,


chriss...@my-deja.com wrote:
> Will the zdz 40cc do well on a 15-1/2 pound 80" span Edge540?
>
> I noticed a Brison add for the 3.2 that said unlimited vertical to 18
> pounds. That makes me wonder if the 2.4 zdz would be marginal.
>

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