diference in performance on engines question please.
05-14-2011 | 02:58 PM
#1
Thread Starter
My Feedback: (139)
Joined: Jan 2011
Posts: 169
Likes: 0
Received 0 Likes
on
0 Posts
From: Weston,
FL
diference in performance on engines question please.
i have a few engines and was looking at the tower hobbies magazine the difference in the description on these engines and have a few questions please:
one engine is an OS 61 FX; acording to tower
ractical rpm range:2000-17000
hp@rpm 1.9@16000
the second is av super tigre 90(china version)ractical rpm range: 2500-16000
hp@rpm: 2.5@14800
well the question is: what practical rpm range means? what hp@rpm means?
what is the rule to decide wich one is more powerfull or has more torque?or has more speed?
what is the rule in this cases?
wich one is more powerfull for a cessna 182 gold edition kit from top flite; the 0s 61 fx or super tigre 90?
regards.
one engine is an OS 61 FX; acording to tower
ractical rpm range:2000-17000hp@rpm 1.9@16000
the second is av super tigre 90(china version)
ractical rpm range: 2500-16000hp@rpm: 2.5@14800
well the question is: what practical rpm range means? what hp@rpm means?
what is the rule to decide wich one is more powerfull or has more torque?or has more speed?
what is the rule in this cases?
wich one is more powerfull for a cessna 182 gold edition kit from top flite; the 0s 61 fx or super tigre 90?
regards.
05-14-2011 | 03:23 PM
#2
My Feedback: (47)
Joined: Jan 2002
Posts: 725
Likes: 0
Received 0 Likes
on
0 Posts
From: Benton,
IL
RE: diference in performance on engines question please.
I would take any manufactures claims with a grain of salt. In other words in my opinion they don't mean anything. Go to the tachometer forum and do a search and you will probably find some reading on the engines with different props that will provide some actual useable info. Naturally none of the posters on this site would inflate their rpm claims.
A 90 size is 1/3 larger than a 60 so it should have 1/3 more power. Doesn't work that way all the time as some engines are revvers and some are ported for larger props at a lower rpm.
I do not like anything super tiger so I would go with an OS or Thunder Tiger in a size that would give the plane adequate performance.
Fred
A 90 size is 1/3 larger than a 60 so it should have 1/3 more power. Doesn't work that way all the time as some engines are revvers and some are ported for larger props at a lower rpm.
I do not like anything super tiger so I would go with an OS or Thunder Tiger in a size that would give the plane adequate performance.
Fred
05-14-2011 | 03:42 PM
#3
Senior Member
RE: diference in performance on engines question please.
Unfortunately the manufacturers dont have a way to post idle and transition characteristics. Good Idle and transition makes your engine far more user friendly than raw power .
Trying to deal with a balky engine while trying to fly your nice sport plane is frustrating.
Although Ihave seen Super Tigres that would idle and transition well I would bet on the OS to give better running.
Posted RPM range means almost nothing to us.
Trying to deal with a balky engine while trying to fly your nice sport plane is frustrating.
Although Ihave seen Super Tigres that would idle and transition well I would bet on the OS to give better running.
Posted RPM range means almost nothing to us.
05-14-2011 | 04:31 PM
#4
Senior Member
My Feedback: (494)
Joined: May 2004
Posts: 1,437
Likes: 0
Received 0 Likes
on
0 Posts
From: Palm Bay, FL
RE: diference in performance on engines question please.
ORIGINAL: Turqui
i have a few engines and was looking at the tower hobbies magazine the difference in the description on these engines and have a few questions please:
one engine is an OS 61 FX; acording to towerractical rpm range:2000-17000
hp@rpm 1.9@16000
the second is av super tigre 90(china version)ractical rpm range: 2500-16000
hp@rpm: 2.5@14800
well the question is: what practical rpm range means? what hp@rpm means?
what is the rule to decide wich one is more powerfull or has more torque?or has more speed?
what is the rule in this cases?
wich one is more powerfull for a cessna 182 gold edition kit from top flite; the 0s 61 fx or super tigre 90?
regards.
i have a few engines and was looking at the tower hobbies magazine the difference in the description on these engines and have a few questions please:
one engine is an OS 61 FX; acording to tower
ractical rpm range:2000-17000hp@rpm 1.9@16000
the second is av super tigre 90(china version)
ractical rpm range: 2500-16000hp@rpm: 2.5@14800
well the question is: what practical rpm range means? what hp@rpm means?
what is the rule to decide wich one is more powerfull or has more torque?or has more speed?
what is the rule in this cases?
wich one is more powerfull for a cessna 182 gold edition kit from top flite; the 0s 61 fx or super tigre 90?
regards.
05-14-2011 | 05:18 PM
#5
Senior Member
My Feedback: (264)
RE: diference in performance on engines question please.
ORIGINAL: Turqui
one engine is an OS 61 FX; acording to towerractical rpm range:2000-17000
hp@rpm 1.9@16000
the second is av super tigre 90(china version)ractical rpm range: 2500-16000
hp@rpm: 2.5@14800
well the question is: what practical rpm range means? what hp@rpm means?
what is the rule to decide wich one is more powerfull or has more torque?or has more speed?
what is the rule in this cases?
wich one is more powerfull for a cessna 182 gold edition kit from top flite; the 0s 61 fx or super tigre 90?
regards.
one engine is an OS 61 FX; acording to tower
ractical rpm range:2000-17000hp@rpm 1.9@16000
the second is av super tigre 90(china version)
ractical rpm range: 2500-16000hp@rpm: 2.5@14800
well the question is: what practical rpm range means? what hp@rpm means?
what is the rule to decide wich one is more powerfull or has more torque?or has more speed?
what is the rule in this cases?
wich one is more powerfull for a cessna 182 gold edition kit from top flite; the 0s 61 fx or super tigre 90?
regards.
These figures really don't reveal much about these engines and haw they like to run.
In the real world, the ST G-90 has pretty good grunt and likes to run in the 9500-11000 range at full throttle, it is a strong runner just doesn't like to be spun up real high.
The .61fx is only average in power for a .61 engine and begins to run out of steam above 13000, it will not like to turn the prop sizes of the ST 90. you would go about 2 inches smaller in diameter.
How heavy will the cessna be?
05-14-2011 | 07:50 PM
#6
RE: diference in performance on engines question please.
well now
because I want to change mufflers I just happen to tach my OS 61 FX last weekend, I got 12,200 with an APC 11x8 on 20% nitro, it has the rather restricted SlimLine Pitts Muffler on it,, this Engine has about 6 or 7 galons run threw it,,
I would think (or hope) that the stock OS Side Muffler would give 200 to 400 more RPMs over this restricted SlimLine Pitts
Jim
because I want to change mufflers I just happen to tach my OS 61 FX last weekend, I got 12,200 with an APC 11x8 on 20% nitro, it has the rather restricted SlimLine Pitts Muffler on it,, this Engine has about 6 or 7 galons run threw it,,
I would think (or hope) that the stock OS Side Muffler would give 200 to 400 more RPMs over this restricted SlimLine Pitts
Jim
05-15-2011 | 12:57 AM
#7
My Feedback: (29)
RE: diference in performance on engines question please.
The published HP figures are not far off with an open exhaust. In actual use think of a 90 as around 20% more power than a 60. Supertigre 75-90s are very good "60" sized engines with carbs that many people struggle with. OS have great carbs but the engines are expensive with occasional issues that the mfg wont resolve. Other cheap engines are OS clones that can run every bit as well, or not. I now pull carbs off old OS 61s and put them on new Supertigre 75-90s. This makes for a cheap engine with consistent quality that runs good and lasts forever with good parts support if needed.
05-15-2011 | 01:36 AM
#8
Senior Member
RE: diference in performance on engines question please.
ORIGINAL: Kweasel
The published HP figures are not far off with an open exhaust. In actual use think of a 90 as around 20% more power than a 60.
Supertigre 75-90s are very good ''60'' sized engines with carbs that many people struggle with.
The published HP figures are not far off with an open exhaust. In actual use think of a 90 as around 20% more power than a 60.
Supertigre 75-90s are very good ''60'' sized engines with carbs that many people struggle with.
The published HP claims made by most engine manufacturers, are usually overly optimistic; even if tested in open-exhaust configuration.
If you look, for example, at [link=http://supertigre.com/engines/supg0235-man.html]this review of the ST S.90[/link] by Mike Billinton, it states "Max. b.hp 2.35 @ 14,418rpm (open exhaust/5% nitro)".
The [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFV79&P=ML]product page[/link] on the Tower Hobbies web site, states "Output: 2.5 bhp at 14,800 rpm".
And in this day and age; who would be crazy enough to run his glow engine with an open exhaust?! It needs a muffler to idle...
There must be a standard established, for maximum output claims made by engine manufacturers; which ANY modeler will be able to duplicate, with the engine he/she received, as it comes equipped from the factory.
05-15-2011 | 02:27 AM
#10
Senior Member
RE: diference in performance on engines question please.
The simple rule is: Manufacturers claims are bu.lsh.t and a bigger engine will have more power and torque than the smaller (with a few exeptions)
You will never run any of those engines too the listed top practical rpm because then you had to use a toothpick of a prop and it wouldn`t fly your plane very well.
The ST .90 will have the most power for your Cessna
You will never run any of those engines too the listed top practical rpm because then you had to use a toothpick of a prop and it wouldn`t fly your plane very well.
The ST .90 will have the most power for your Cessna
05-15-2011 | 04:12 AM
#11
Thread Starter
My Feedback: (139)
Joined: Jan 2011
Posts: 169
Likes: 0
Received 0 Likes
on
0 Posts
From: Weston,
FL
RE: diference in performance on engines question please.
Thanks everybody for your comments. Should i use the stock muffled or a pist muffler?
What about prop size?
I just want Enough power to flight smoot and avoid stalls.
Best regards. Thanks,
What about prop size?
I just want Enough power to flight smoot and avoid stalls.
Best regards. Thanks,
