2-stroke vs. 4-stroke revisited

2-stroke vs. 4-stroke revisited

Post by Frank Cost » Fri, 29 Mar 2002 05:52:18



Here is my question. If you have an average 5-6 lb. 40-size sport type
plane, say an Advance 40 or a Goldberg Tiger 2, what would be the difference
performance-wise between a hot .50 size motor (Webra, Jett, etc.) and a .70
sized 4-stroke (Saito 72, OS 70)? I am assuming that the 2-stoke would pull
the plane faster, but what other differences would there be? Would the
4-stoke give much better vertical? I am stepping up from my TT pro 46, and
cannot figure out which route to take. Thanks.
 
 
 

2-stroke vs. 4-stroke revisited

Post by Dave&Chri » Fri, 29 Mar 2002 06:03:15


I'm about 3/4 done with my tiger 2 and I plan to put a saito .56 in it. That
engine pulled my heritage stuka aroung fine and my 7lb cub. So I'm just
guessing but it should be great in my Golberg tiger 2.


Quote:
> Here is my question. If you have an average 5-6 lb. 40-size sport type
> plane, say an Advance 40 or a Goldberg Tiger 2, what would be the
difference
> performance-wise between a hot .50 size motor (Webra, Jett, etc.) and a
.70
> sized 4-stroke (Saito 72, OS 70)? I am assuming that the 2-stoke would
pull
> the plane faster, but what other differences would there be? Would the
> 4-stoke give much better vertical? I am stepping up from my TT pro 46, and
> cannot figure out which route to take. Thanks.


 
 
 

2-stroke vs. 4-stroke revisited

Post by Lyman Slac » Fri, 29 Mar 2002 07:15:38


Frank --

        Your .70 FS will pull it faster and with better vertical than most
.50 sized engines. However, why would anyone opt for a high performance Jett
engine or similar in a sport trainer model?

        If you are new to four strokes, I have an article on "The Care &
feeding of Four Strokes" at my Web Site that you might find informative.

Cheers --  \__________Lyman Slack_______/
                    \______AMA6430 IMAA1564___/
                     \____Flying Gators R/C_______/
                      \__Gainesville FL __________/
   Visit my Web Site at: http://personal.bellsouth.net/lig/l/y/lyslack/


Quote:
> Here is my question. If you have an average 5-6 lb. 40-size sport type
> plane, say an Advance 40 or a Goldberg Tiger 2, what would be the
difference
> performance-wise between a hot .50 size motor (Webra, Jett, etc.) and a
.70
> sized 4-stroke (Saito 72, OS 70)? I am assuming that the 2-stoke would
pull
> the plane faster, but what other differences would there be? Would the
> 4-stoke give much better vertical? I am stepping up from my TT pro 46, and
> cannot figure out which route to take. Thanks.

 
 
 

2-stroke vs. 4-stroke revisited

Post by Frank Cost » Fri, 29 Mar 2002 07:50:34


. However, why would anyone opt for a high performance Jett

Quote:
> engine or similar in a sport trainer model?

I was wondering about this. Does a performance 2-stroke have to be put into
a racing type plane (e.g., pylon) to realize it's potenetial? Are these
engines only geared towards extreme RPM's and not torque? I am not talking
about the enormously expensive throw away engines that Jett and Nelson
offers, but their sport models.
 
 
 

2-stroke vs. 4-stroke revisited

Post by Paul McIntos » Fri, 29 Mar 2002 07:49:00


The Webra is much more powerful than most .46-.50 engines.  It is more like
a good .61.  In that respect, it will pull most planes around better than
most .70 four strokes.  On top of that, it is also much lighter than the
four strokes in that size range.  The OS .70 or Saito .72 would be more than
enough for those planes.

--
Paul McIntosh
Desert Sky Model Aviation
ARFs, engines, bearings, etc
http://fly.mcintoshcentral.com

Quote:
> Here is my question. If you have an average 5-6 lb. 40-size sport type
> plane, say an Advance 40 or a Goldberg Tiger 2, what would be the
difference
> performance-wise between a hot .50 size motor (Webra, Jett, etc.) and a
.70
> sized 4-stroke (Saito 72, OS 70)? I am assuming that the 2-stoke would
pull
> the plane faster, but what other differences would there be? Would the
> 4-stoke give much better vertical? I am stepping up from my TT pro 46, and
> cannot figure out which route to take. Thanks.

 
 
 

2-stroke vs. 4-stroke revisited

Post by emc.. » Fri, 29 Mar 2002 11:25:12


A friend has a Tiger 2 with a Magnum .52 4 stroke. Its a good flying
combo.

4 strokes vs 2 cycles:

Its as much of an attitude, as it is a performance issue. There is no
other way to explain why someone will pay $175 for a 4 stroke when a
$75 2 cycle will do the same job.

I currently own 3 Saito and love them.

In rc planes, the order of priority is:

1. Is it pretty?
2. Does it sound good?
3. How does it fly?
4. What does it cost?

On Wed, 27 Mar 2002 20:52:18 GMT, "Frank Costa"

Quote:

>Here is my question. If you have an average 5-6 lb. 40-size sport type
>plane, say an Advance 40 or a Goldberg Tiger 2, what would be the difference
>performance-wise between a hot .50 size motor (Webra, Jett, etc.) and a .70
>sized 4-stroke (Saito 72, OS 70)? I am assuming that the 2-stoke would pull
>the plane faster, but what other differences would there be? Would the
>4-stoke give much better vertical? I am stepping up from my TT pro 46, and
>cannot figure out which route to take. Thanks.

 
 
 

2-stroke vs. 4-stroke revisited

Post by John Mille » Fri, 29 Mar 2002 11:40:26


Quote:

> In rc planes, the order of priority is:

> 1. Is it pretty?
> 2. Does it sound good?
> 3. How does it fly?
> 4. What does it cost?

Interesting.  Mine is
3. How does it fly?
4. What does it cost?
1. Is it pretty?
2. Does it sound good?  
--
John "I'm not cheap; I'm thrifty" Miller        
AMA 739245
 
 
 

2-stroke vs. 4-stroke revisited

Post by Georg » Fri, 29 Mar 2002 15:22:45


Performance-wise, you won't see much difference.  You're not going to get a
Tiger to go fast in any case (due to aerodynamics) but will get better
vertical and bigger loops with the 4-stroke because you can swing a bigger
prop.  Vertical assumes you can keep it going straight in the up-line, and
if you can do that consistently you should move up to a fully aerobatic
plane.

Frankly, I'd keep the Pro 46 in the Tiger and get either a Sig Kougar or GP
Tracer for the hot 50, or a CAP 232 or similar for the 70 four-stroke.

Best regards,
George Wagner


Quote:
> Here is my question. If you have an average 5-6 lb. 40-size sport type
> plane, say an Advance 40 or a Goldberg Tiger 2, what would be the
difference
> performance-wise between a hot .50 size motor (Webra, Jett, etc.) and a
.70
> sized 4-stroke (Saito 72, OS 70)? I am assuming that the 2-stoke would
pull
> the plane faster, but what other differences would there be? Would the
> 4-stoke give much better vertical? I am stepping up from my TT pro 46, and
> cannot figure out which route to take. Thanks.

 
 
 

2-stroke vs. 4-stroke revisited

Post by Mathew Kirs » Fri, 29 Mar 2002 22:04:44


Quote:

> I was wondering about this. Does a performance 2-stroke have to be put into
> a racing type plane (e.g., pylon) to realize it's potenetial? Are these
> engines only geared towards extreme RPM's and not torque? I am not talking
> about the enormously expensive throw away engines that Jett and Nelson
> offers, but their sport models.

It all boils down to using the right engine for the application.
Putting a hot racing engine on an intermediate sport plane is a waste
of time. Hot racing engines are meant for hot racing planes.

If it's a sport engine, it would be appropriate to put it on a sport
plane.

 
 
 

2-stroke vs. 4-stroke revisited

Post by James D Jone » Fri, 29 Mar 2002 23:14:38


The Nelson is a real go getter.  A friend of mine put one on a fun-fly.
No one could touch him on the climb and glide.  Competition fun-fly
aircraft are really helped by such engines.  A 4-stroke would be too
heavy.  But, 4-stokes cause fewer problems with noise irritation, use
less fuel and use more efficient props.

Jim - AMA 501383

Quote:

> . However, why would anyone opt for a high performance Jett

>>engine or similar in a sport trainer model?

> I was wondering about this. Does a performance 2-stroke have to be put into
> a racing type plane (e.g., pylon) to realize it's potenetial? Are these
> engines only geared towards extreme RPM's and not torque? I am not talking
> about the enormously expensive throw away engines that Jett and Nelson
> offers, but their sport models.

 
 
 

2-stroke vs. 4-stroke revisited

Post by Martin X. Moleski, » Sat, 30 Mar 2002 02:31:46


Quote:

>In rc planes, the order of priority is:

>1. Is it pretty?
>2. Does it sound good?
>3. How does it fly?
>4. What does it cost?

I nearly choked when I read this.

The truth hurts.  ;o)

                        Marty

Golden Griffs/Revenuers: TS #20; DJ #88; KH #29; RN #12; MK #17
     & ABGAH!

 
 
 

2-stroke vs. 4-stroke revisited

Post by Dave McDonal » Sat, 30 Mar 2002 10:27:14



Quote:
> In rc planes, the order of priority is:
> 1. Is it pretty?
> 2. Does it sound good?
> 3. How does it fly?
> 4. What does it cost?

This is a fascinating survey because everyone will have a different answer.
Otherwise, we'd all be flying the same planes and the same engines.
Here's my priorities....

1.  Does it fly well?
2.  How much does it cost?
3.  Does it have a high fun/cost ratio?
4.  How quickly can I get it flying?
5.  Is it pretty?
6.  Does it sound good?

cul8r,
Dave McDonald,  Lake of the Ozarks,  Missouri
AMA 40128       Amateur KA?OEI

Visit my webpage at: http://mypage.yhti.net/~dmcdnld/

 
 
 

2-stroke vs. 4-stroke revisited

Post by Dave McDonal » Sat, 30 Mar 2002 10:27:29



Quote:
> 4 strokes vs 2 cycles:
> Its as much of an attitude, as it is a performance issue. There is no

other way to explain why someone will pay $175 for a 4 stroke when a $75 2
cycle will do the same job.

OR......to put it another way.......
http://mypage.yhti.net/~dmcdnld/4cycle.htm

 
 
 

2-stroke vs. 4-stroke revisited

Post by John Mille » Sat, 30 Mar 2002 10:55:17


Quote:

> OR......to put it another way.......
> http://mypage.yhti.net/~dmcdnld/4cycle.htm

Loved it!  

--
John Miller     AMA 739245
N4VU            DoD 1942
"There ought to be a shortage of offense; so much more is taken than
given."  -Noah Little

 
 
 

2-stroke vs. 4-stroke revisited

Post by emc.. » Sat, 30 Mar 2002 23:08:07


Thanks for taking it in the humorous matter it was intended.

Some guys just don't know when to laugh.


Quote:


>>In rc planes, the order of priority is:

>>1. Is it pretty?
>>2. Does it sound good?
>>3. How does it fly?
>>4. What does it cost?

>I nearly choked when I read this.

>The truth hurts.  ;o)

>                    Marty

>Golden Griffs/Revenuers: TS #20; DJ #88; KH #29; RN #12; MK #17
>     & ABGAH!