Notices
Glow Engines Discuss RC glow engines

SK ENGINES

Old 09-06-2006, 01:32 PM
  #51  
Oldbob
 
Join Date: Jun 2005
Location: georgetown, TX
Posts: 637
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

Overworked, Me too

oldbob
Old 09-06-2006, 03:50 PM
  #52  
NM2K
Senior Member
My Feedback: (14)
 
Join Date: Jan 2002
Location: Ringgold, GA
Posts: 11,488
Likes: 0
Received 2 Likes on 2 Posts
Default RE: SK ENGINES


ORIGINAL: OVER WORKED

Ok, I’ve been avoiding this thread but I think a couple of things should be set straight. So this is the one and only time I will reply to it. If you choose to believe me, that’s fine, if not that’s fine too... We sell over 150 engines a month, And I have been dong the tech support on them for 6 years. About 3% are returned with real problems, the rest of the customers just need a little help getting them dialed in.
1} Yes we have had a problem with sticking carbs, the clearance between the body and the barrel is too tight, and occasionally a deformation producing an edge at the venturi opening. The problem occurs in about 1 in every 75 motors. The new carb design is in testing now.
2} even though the engines are ringed we still run cylinder taper, so we need heat to expand the top for correct break-in. Four-stroking is bad in all our engines.
3} We did make the 75-90’s in both ring and ABC, the ABC has been discontinued, seems we cant get people out of the old habit of four stroking them during break-in and they were scoring the cylinder/piston and eating crank pins.
4} Artisian’s post#43 is wrong. Several things happen when the engine runs out of port timing that are sometimes difficult to understand. It’s not the same as closing the throttle and restricting the air. Some of the symptoms are fuel leakage from the back plate gasket or the front bearing, the engine will go lean, and you will see excessive cyl. head temp. The reason for this is the crankcase takes a full charge but it can’t get it up through the ports to the top end. As the piston comes down crankcase pressure becomes excessive and it has to go somewhere. On occasion you will notice fuel that actually spits out the carb, or some of the other symptoms of reversion.
5} our engine are ported for a max RPM between 11,000 and 12,500 depending on the displacement. Short port timing allows the engine to produce more torque, but restricts RPM. They like larger diameter props.
6} We use a very hard chrome on the liner that takes longer to break in than most other engines, most don’t develop full power for several gallons of fuel, again depending on the displacement and SPFC.
8} there have been enormous strides made in engine development and design in just the last couple years alone, partly do to metallurgy and a better understanding of flow dynamics. They are getting lighter, more powerful and more user friendly. What was standard just a few years ago no longer applies to some designs.
9} be careful what advice you take from the threads on the net, here or elsewhere. I can’t tell you how many times I have heard someone tell me “I’ve been doing it that way for 30 years, it’s always worked and I ‘m not about to stop nowâ€. People with that attitude are idiots, avoid them. If it was true we would all be using AM transmitters and building our airplanes with Ambroid and carpenters glue.
10} Kangke has not changed owners, the man who started it still owens it, Peter Ma.
11} I was not trying to sell Artisian a Brison engine for his Cap 232-120, here is the exact wording of my e-mail to him, you decide for yourself.
“Ed,
I don't know too much about the Brillelli engines, I can tell you that a Brison 2.4 {40cc} is all the engine the airframe can handle.
Also the firewall was not designed to carry an engine weight greater that 3 lbs 5 oz.â€


As I said I will not respond again to this post.

--------------------


How did you know that I still use Ambroid and carpenters glue? <G>

Thanks for taking the time to come on RCU to state your opinion. Since you said you will not come back to post to this thread, I guess I won't ask you why you design your ringed engines with a tapered bore. Seems kind of odd.

You presented yourself well and your arguement concerning running past the port timing is a new one to me. I'll have to think that over. Thanks for the education. Glad you are the same people.

You have to admit that a person that is as suspicious and paranoid as I am could easily have misread your reply to my query about the Brillelli 46cc engine. I will accept your explanation as fact.

One of the times when I was R/C club president, I had to put up with an older fellow that used to "red ass" the club officers. I just realized that I have become that older fellow and that I have been red assing the vendors in our business. I will attempt to desist. But you have to admit that we probably would never have gotten such a good explanation on the forum if I hadn't been a PITA. <G>

Take care and thanks for popping in.
Old 09-06-2006, 06:54 PM
  #53  
RC-Bearings
My Feedback: (1)
 
Join Date: Oct 2003
Location: Castle Rock, CO
Posts: 384
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

Mostly you who doesn't know what you are talking about When engines are run past their optimum port RPMS, they will lean out and get hotter. Extreme examples of this are trying to get the last bit of RPM from a hot engine when a tuned pipe is cut slightly too short. The symptoms will be blown and mangled glow plugs and a hot engine. Putting a slightly larger prop on that engine will keep it running, although not at its peak.

Larger engines are designed mainly for lower RPM ranges to take advantage of the efficiency gained by larger props. Another factor is noise. If you turn these larger props too fast, you gat a LOT of noise which is becoming frowned upon at many sites. A 15X6 is no where near too much prop for a .91 two stroke. Even .91 four strokes handle that size easily. The YS .91AC is famous for handling 14X10 and 15X8 props.

I would trust the manufacturer rep for an engine.

ORIGINAL: Artisan


ORIGINAL: mitchmcf

I too have a SK 90 and it runs so nice but did have one problem it would slowly lean out when in the air. No mater what we did it still would lean out and heat up but never dead-stick so I called the Tech. support and asked them and this is what they said. The first thing he asked was what prop I had on it and I told him it was a 14x8 mas and was told that it was to small to go to a 15x6 or 15x8 . what was happing was that in the air it would unload and get over 11000 rpm and it is not ported for RPM over 11500 so it would lean out once I put on the bigger prop no more lean condition and runs like a champ.

------------------


What a crock!

Overloading an engine heats it up too much and advances the timing too far. The symptoms of having the timing advanced too far is an apparent leaning out of the engine and overheating. The correction to retard the timing can be accomplished in several ways. One can reduce the prop load, one can reduce the compression, one can drop to a cooler heat range glow plug, or one can reduce the nitro content in the fuel. All of this is prefaced upon the engine having adequate cooling air.

A 13x8 or a 14x6 is more appropriate for a .91 two-stroke. Also, being a ringed engine, it is going to need some break-in time running rich to seat the ring and to keep it cooled off during break-in.

If an engine runs past its porting/timing, nothing is harmed unless it is ridiculously high. Breaking-in ringed engines is done with a smaller prop than the normal flying prop, not a larger prop.

There have been no changes in technology that would warrant this advice. Someone doesn't know what they are talking about.
Old 09-06-2006, 10:25 PM
  #54  
mitchmcf
Senior Member
 
mitchmcf's Avatar
 
Join Date: Feb 2004
Location: West Elelizabeth, PA
Posts: 157
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

It is so nice to see that some company's still have knowledgeable Tech ppl who do not have to read out of a book . I for one will be getting more Sk Engines very good price good power and good support GOOD combination.
Old 09-06-2006, 10:58 PM
  #55  
NM2K
Senior Member
My Feedback: (14)
 
Join Date: Jan 2002
Location: Ringgold, GA
Posts: 11,488
Likes: 0
Received 2 Likes on 2 Posts
Default RE: SK ENGINES


[quote]ORIGINAL: RC-Bearings

Mostly you who doesn't know what you are talking about When engines are run past their optimum port RPMS, they will lean out and get hotter. Extreme examples of this are trying to get the last bit of RPM from a hot engine when a tuned pipe is cut slightly too short. The symptoms will be blown and mangled glow plugs and a hot engine. Putting a slightly larger prop on that engine will keep it running, although not at its peak.

Larger engines are designed mainly for lower RPM ranges to take advantage of the efficiency gained by larger props. Another factor is noise. If you turn these larger props too fast, you gat a LOT of noise which is becoming frowned upon at many sites. A 15X6 is no where near too much prop for a .91 two stroke. Even .91 four strokes handle that size easily. The YS .91AC is famous for handling 14X10 and 15X8 props.

I would trust the manufacturer rep for an engine.

ORIGINAL: Artisan


ORIGINAL: mitchmcf

I too have a SK 90 and it runs so nice but did have one problem it would slowly lean out when in the air. No mater what we did it still would lean out and heat up but never dead-stick so I called the Tech. support and asked them and this is what they said. The first thing he asked was what prop I had on it and I told him it was a 14x8 mas and was told that it was to small to go to a 15x6 or 15x8 . what was happing was that in the air it would unload and get over 11000 rpm and it is not ported for RPM over 11500 so it would lean out once I put on the bigger prop no more lean condition and runs like a champ.

------------------


What a crock!

Overloading an engine heats it up too much and advances the timing too far. The symptoms of having the timing advanced too far is an apparent leaning out of the engine and overheating. The correction to retard the timing can be accomplished in several ways. One can reduce the prop load, one can reduce the compression, one can drop to a cooler heat range glow plug, or one can reduce the nitro content in the fuel. All of this is prefaced upon the engine having adequate cooling air.

A 13x8 or a 14x6 is more appropriate for a .91 two-stroke. Also, being a ringed engine, it is going to need some break-in time running rich to seat the ring and to keep it cooled off during break-in.

If an engine runs past its porting/timing, nothing is harmed unless it is ridiculously high. Breaking-in ringed engines is done with a smaller prop than the normal flying prop, not a larger prop.

There have been no changes in technology that would warrant this advice. Someone doesn't know what they are talking about.

---------------------


Nice to run into you again, Paul.

We're not talking about a piped engine. I am very familiar with the principle of which you are speaking. I probably ran piped engines while you were still in school. Even then, the engine doesn't blow backplate gaskets when ran higher than its timing. If it did, it could not pull fuel at all and it would just quit, not run lean. Ditto an unpiped .91.

Being a vendor (hobbyshop owner or engine reseller) does not automatically make one an expert, which means ones own pet theories (Kangke) will be taken to task upon occasion.

Ed Cregger

Old 09-06-2006, 11:02 PM
  #56  
RC-Bearings
My Feedback: (1)
 
Join Date: Oct 2003
Location: Castle Rock, CO
Posts: 384
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

Glad to see you are still among the living! You an't THAT much older than me! BTW, I ran piped engines in the 6th grade!
Old 09-07-2006, 12:03 AM
  #57  
XJet
Banned
 
Join Date: Mar 2003
Location: Tokoroa, , NEW ZEALAND
Posts: 3,848
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

I've noticed that quite a few of the new generation 90/91 and 50/52 engines have quite significant transfer-port restriction. This seems to be produced mainly because they're being made in 60 and 40-sized crankcases respectively.

As you make the bore wider, the ports have to become shallower -- there's only so much space between the liner and the outside of the engine after all.

I definitely noticed this with the TigerShark 56R engine that I bought a while back.
Old 09-07-2006, 12:31 AM
  #58  
RC-Bearings
My Feedback: (1)
 
Join Date: Oct 2003
Location: Castle Rock, CO
Posts: 384
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

ORIGINAL: XJet

I've noticed that quite a few of the new generation 90/91 and 50/52 engines have quite significant transfer-port restriction. This seems to be produced mainly because they're being made in 60 and 40-sized crankcases respectively.

As you make the bore wider, the ports have to become shallower -- there's only so much space between the liner and the outside of the engine after all.

I definitely noticed this with the TigerShark 56R engine that I bought a while back.
One of the main limiting factors in 60-90 engines is that most engine designers use rear bearings only slightly larger in diameter than most 40 size engines. That is why the 40-50 size sport engines develop so much power while the 60-90 class seems anemic by comparison.
Old 09-07-2006, 12:33 AM
  #59  
NM2K
Senior Member
My Feedback: (14)
 
Join Date: Jan 2002
Location: Ringgold, GA
Posts: 11,488
Likes: 0
Received 2 Likes on 2 Posts
Default RE: SK ENGINES


ORIGINAL: RC-Bearings

Glad to see you are still among the living! You an't THAT much older than me! BTW, I ran piped engines in the 6th grade!

---------------


Dang it! I can't top you no matter what I do...<G>
Old 09-07-2006, 07:00 PM
  #60  
rustypep
My Feedback: (6)
 
Join Date: Sep 2004
Location: Lebanon, OH
Posts: 446
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

Yep, Ray is the one I talked to. Real nice guy. Thanks for the response Ray. Nice to know about the hard chrome in the liners. Like I said in my post, it took a good gallon before my SK 50 was really broken in and it sounds like it still might improve some more over time. I have really enjoyed my SK 50.
Old 09-08-2006, 03:34 AM
  #61  
XJet
Banned
 
Join Date: Mar 2003
Location: Tokoroa, , NEW ZEALAND
Posts: 3,848
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

ORIGINAL: RC-Bearings
One of the main limiting factors in 60-90 engines is that most engine designers use rear bearings only slightly larger in diameter than most 40 size engines. That is why the 40-50 size sport engines develop so much power while the 60-90 class seems anemic by comparison.
Are you saying that the smaller bearings produce far greater frictional losses and thus results in engines that have less power per cubic inch?

I would say that it's more likely that the latest 90-sized engines are not all that much more powerful than the 60's from which they originally came is that the transfer port depth is significantly compromised by the over-boring.

Taking a 40-sized engine out to 50 is an increase of only 25%.

Taking a 60-sized engine out to 90 is a 50% increase. That means you sacrifice a lot of transfer port depth if you're gaining that displacement by any real amount of bore-increase.

That's probably why an engine like the ST90 only has 32% more power than the ST61, despite having 50% more displacement.

I'd be surprised if the bearing size had much to do with it.
Old 09-08-2006, 07:25 AM
  #62  
OVER WORKED
Senior Member
 
Join Date: Feb 2003
Location: Deer Park, NY
Posts: 145
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

I know I said I wasn’t going to reply again to this post, but I think some questions should be answered.
Artisan, cylinder taper is used in most air cooled engines. Even the Lycoming IO-360 in my real Piper has taper. The reason is a temperature difference between the top and bottom of the cylinder. The object is to have enough taper the bore straightens out when the engine is at normal running temp. This prevents excessive ring expansion and contraction allowing for tighter end gap and reduces the wear in the ring land. It also allows for closer piston to wall clearance at top dead center assisting in reducing blow-by. Because the cylinder is steel it does not expand as much as the aluminum piston per BTU absorbed, so the piston to wall clearance actually gets smaller as the engine warms up. A hot piston in a cold cylinder is not a good thing in our engines. Some model engines with rings do not use taper, it is a more complex machining process and thus more expensive to produce with accuracy, but it is a better design. Also here’s some food for thought, RC-Bearings comments about the tuned pipe are not far off. The returning pressure wave to the exhaust port from the short pipe will prevent the evacuation of part of the chamber. This remaining pressure will in turn prevent the full charge in the crankcase from entering the combustion chamber, many of the symptoms are the same. I too have been running pipes since the 60’s although not much lately.
XJet, you are partly correct in that as the bore gets larger the cross section of the transfer port gets smaller, this however could be made up for by increasing the length of the port. Don’t confuse port timing with port flow. Shorter port timing allows the engine to produce more torque at lower RPM, this is becoming more attractive to the fun-fly or 3-D pilot as it allows for a larger diameter propeller, and as we all know in this arena the greater the disc area of the prop the better even though it does increase the P factor. I believe what RC-Bearings was saying is that glow engines with front mounted carbs have there induction through a hole down the center of the crankshaft, The size limit of the bearing to fit a 60 case greatly restricts the cross section allowed for this hole, limiting the available crankcase charge, it’s kind of like the restrictor plates used at some NASCAR tracks to limit horsepower. If the cross section of the hole is increased without a larger bearing ID, the crank sidewall will become thinner and will not be able to handle the torsion loads.
Rustypep, Glad I could be of assistance. Every once in a while my engineering degrees actually help.
Old 09-08-2006, 07:41 AM
  #63  
Super Splatter
Senior Member
 
Super Splatter's Avatar
 
Join Date: Mar 2006
Location: , MN
Posts: 432
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

I'd say he trying to say, smaller bearings, smaller crank.

Smaller crank, smaller hole through the crank, less air, less fuel, less power
Old 09-08-2006, 07:42 AM
  #64  
Super Splatter
Senior Member
 
Super Splatter's Avatar
 
Join Date: Mar 2006
Location: , MN
Posts: 432
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

Oops, sorry ray I spoke right over ya'

My Dad told me all about taper bores on B-29's in his day...
Old 09-08-2006, 09:04 AM
  #65  
mitchmcf
Senior Member
 
mitchmcf's Avatar
 
Join Date: Feb 2004
Location: West Elelizabeth, PA
Posts: 157
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

Nice post Ray all I can tell you is after I followed your advice my 90 runs like a champ . I will hve no problem with getting more Sk's frome now on.
Old 09-08-2006, 03:46 PM
  #66  
XJet
Banned
 
Join Date: Mar 2003
Location: Tokoroa, , NEW ZEALAND
Posts: 3,848
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

XJet, you are partly correct in that as the bore gets larger the cross section of the transfer port gets smaller, this however could be made up for by increasing the length of the port.
When you say "length", are you referring to the port height (as this definitely does affect timing. The taller the port, the longer the port duration either side of BDC.

If you're talking about the port width -- that also becomes a bit of a problem with ringed engines because if they're too wide you end up with the risk of a ring snaging on the uppoer lip of the port as the piston goes back up. Some ringed engines have bridged ports but they also reduce the efficiency of the port by introducing extra losses associated with the vorticies around those bridges.

I take your point on the crank diameter -- however, a larger crank bore doesn't always equate to more power either.

One of the problems with our crank-shaft induction engines is that the volume of the crankshaft hole contributes to the total crankcase volume and the pumping efficiency of the engine (ie: the ability to move the air/fuel mixture from the crankcase to the cylinder) is a factor of port efficiency *and* crankcase volume.

In an engine with a *large* crankcase volume (for a given displacement), the crankcase pressure will be lower when the ports are exposed and that means less force to drive the crankcase charge into the cylinder -- thus less air/fuel to burn in the next combustion cycle.

It's not uncommon for race-tuners to "stuff" the crankcase of high-performance 2-stroke engines in order to minimze the crankcase volume and thus get higher crankcase pressures and better pumping through the ports.

The other limiting factor is the bore of the carburetor. If this is the same as (or less than) the bore of the crankshaft then further increasing the crank bore won't do a thing -- except lower crankcase pressure and the ability to pump air/fuel into the cylinder.

Of course the other factor is the area of the transfer ports (which is where we started). If the ports are too small then they will choke and a shockwave will be set up that effectively limits the speed at which air/fuel can be transferred through them. Once this happens, nothing else matters because the crankshaft bore, carburetor bore and crankcase volume are all irrelevant. The whole flow path is only as effective as the weakest link.

Now, give that many of these "overbored" engines are flow-limited by their transfer ports, the size of bearing/crankshaft-bore diameter is probably not a factor in their performance.

N'est pa?
Old 09-08-2006, 05:02 PM
  #67  
OVER WORKED
Senior Member
 
Join Date: Feb 2003
Location: Deer Park, NY
Posts: 145
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

XJet you are correct, in my youth racing go-carts we used stuffer plates in the West Bend 820’s and the Mac 91A’s.
Everything in engineering is a collection of compromises and we have touched only a few in engine design, there are many more from rod length to piston weight to counter balance weight and balance percentage, crank pin shear vs. diameter to squish area, chamber volume, etc. etc. etc..
Welcome to the tedious world of engineering.
Old 09-08-2006, 05:21 PM
  #68  
NM2K
Senior Member
My Feedback: (14)
 
Join Date: Jan 2002
Location: Ringgold, GA
Posts: 11,488
Likes: 0
Received 2 Likes on 2 Posts
Default RE: SK ENGINES

Thanks for the follow up, Ray.

Nice to meet you.
Old 09-08-2006, 10:18 PM
  #69  
XJet
Banned
 
Join Date: Mar 2003
Location: Tokoroa, , NEW ZEALAND
Posts: 3,848
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

ORIGINAL: OVER WORKED
Welcome to the tedious world of engineering.
Actually I find it all very fascinating and exciting.

Over the past 7 years I've been working on advanced jet engine designs which has involved an enormous amount of learning in respect to metalurgy, engineering, fluid dynamics and thermodynamics. It's amazing how much of this jet-engine stuff is totally relevant to the humble 2-stroke as well.
Old 09-09-2006, 03:29 AM
  #70  
NM2K
Senior Member
My Feedback: (14)
 
Join Date: Jan 2002
Location: Ringgold, GA
Posts: 11,488
Likes: 0
Received 2 Likes on 2 Posts
Default RE: SK ENGINES


ORIGINAL: XJet

ORIGINAL: OVER WORKED
Welcome to the tedious world of engineering.
Actually I find it all very fascinating and exciting.

Over the past 7 years I've been working on advanced jet engine designs which has involved an enormous amount of learning in respect to metalurgy, engineering, fluid dynamics and thermodynamics. It's amazing how much of this jet-engine stuff is totally relevant to the humble 2-stroke as well.

---------------


Sadly, the humble two-stroke is on the edge of extinction. []
Old 09-15-2006, 10:02 PM
  #71  
Ed_Moorman
My Feedback: (1)
 
Ed_Moorman's Avatar
 
Join Date: Jan 2002
Location: Shalimar, FL
Posts: 4,059
Likes: 0
Received 1 Like on 1 Post
Default RE: SK ENGINES

After reading all the comments on the SK, I decided to give one a try myself so I ordered a .91. It came in this afternoon in a nice orange box. The engine did not come with a plug so I used an OS #8. I quickly mounted it on my test bench and ran it through the recommended break-in of 1 tank n a rich 2-cycle, 1 tank alternating lean and rich and 1 tank cycling rpm from idle to full power. Then a 4th tank in a flight 2-cycle with the needle 4 clicks or so off the max. Every time it started right up and ran very well. The carb is tight. I am hoping it will wear in. If not I'll check for high spots and use some fine paper.

For some flight time, I pulled the old OS .61SF from my Ultra Stick 60 and installed the SK .91 on the nose. The mounting holes fit exactly. The length of the .91 is a little bit longer so I had to adjust the throttle pushrod length. The muffler, which has a "Tower" look, clears the fuselage easily. I am running large wheels so the 15-6 Zinger prop has ground clearance.

I'll put a couple of flights on it tomorrow and see how it acts in the air. It's bound to have a lot more power than my old OS, but I really don't expect good running until I get a gallon or so through it.
Old 09-16-2006, 10:27 AM
  #72  
Kimhoff
My Feedback: (22)
 
Join Date: Sep 2003
Location: Jefferson, MO
Posts: 655
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

Buy a FOX at the same time you buy the SK, you will need it to learn how to make the SK run?
Old 09-16-2006, 10:39 AM
  #73  
NM2K
Senior Member
My Feedback: (14)
 
Join Date: Jan 2002
Location: Ringgold, GA
Posts: 11,488
Likes: 0
Received 2 Likes on 2 Posts
Default RE: SK ENGINES


ORIGINAL: Kimhoff

Buy a FOX at the same time you buy the SK, you will need it to learn how to make the SK run?



------------


A real model engine man has no trouble making a Fox run.

I have two SK engines, but haven't ran them yet. I wonder if they are timed similarly to the .91? Mine are a .50 and an .80. Should I be swinging humongous props on these engines too? Or are they timed conventionally? Don't want no cotton picking standing waves forming in the intake tract and slowing down me little engines. <G>
Old 09-16-2006, 11:40 AM
  #74  
Kimhoff
My Feedback: (22)
 
Join Date: Sep 2003
Location: Jefferson, MO
Posts: 655
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES





------------


A real model engine man has no trouble making a Fox run.

I have two SK engines, but haven't ran them yet. I wonder if they are timed similarly to the .91? Mine are a .50 and an .80. Should I be swinging humongous props on these engines too? Or are they timed conventionally? Don't want no cotton picking standing waves forming in the intake tract and slowing down me little engines. <G>

[/quote]


Exactly why I said this. You will need to ba a "real model engine man" to make the SK run?
Old 09-16-2006, 12:21 PM
  #75  
Turk1
 
Turk1's Avatar
 
Join Date: Oct 2004
Location: Istanbul, TURKEY
Posts: 1,085
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SK ENGINES

My 1 st SK 50 was my 3rd engine.I could run it very easily without any problem.So you dont really need to be an Engine expert for SK engines.
Ed, once Ray Nano informed me against my mail for SK 50;
:Quote"
Ahmet,

Because you are running no nitro fuel I think you should prop for around 10-11,000 static.
This will allow it to unload to around 12,000 in flight.

Ray Nano
Kangke / Super Kraft / Brison / SK Engines
Tech Support/Design Team"
Quote

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.