RC India
Welcome Guest, please login or register.
 
Pages: 1 [2]  All   Go Down
0 Members and 1 Guest are viewing this topic. Topic Tools Topic Tools 
Read
« Reply #25 on: November 18, 2010, 09:40:04 AM »
saurabhhsrivastavaa
Default
Plane Lover
Forum Hero

*****

Reputation Power: 14 
saurabhhsrivastavaa has no influence.
Offline Offline

City: Mumbai
State: Maharashtra
RC Skills: Intermediate
Posts: 1156
Join Date: Aug, 2009



In my experience,

1.) ASP engines need very less opening of the throttle at idling (as compared to OS)
2.) My ASP60 is perfectly tuned to deliver max performance at high speed tuned at 0.70 - 0.75 turns. (Whereas OS has a sweetspot at 1.25 approx) Very rightly pointed by Anwar.
3.) As I was reading through Anwar's post, I could visualize the situation and could immediately make out that the engine might be running too rich rather than lean. ASP engines may not sputter if they are running too rich (Instant pumping will cause a sudden gush of fuel (may not be noticable) into the chamber causing it to die almost instantly. Also, at times the sputter is so small that it is hardly noticable/detectable.
4.) The reason for dying after a few seconds at idling is also very common when the engine is running rich, as the excess fuel keeps building in the chamber and the crankcase which eventually causes the engine to die.
Logged

Cheers !!!
Saurabh
+91 7977382130
 

Read
« Reply #26 on: November 18, 2010, 09:47:20 AM »
saurabhhsrivastavaa
Default
Plane Lover
Forum Hero

*****

Reputation Power: 14 
saurabhhsrivastavaa has no influence.
Offline Offline

City: Mumbai
State: Maharashtra
RC Skills: Intermediate
Posts: 1156
Join Date: Aug, 2009



In such situations, where it becomes difficult to assertain the reason for unreliable idling/performance, it is best to close the high end completely and start from scratch. It is best to open the needle by just 1 turn and then start making adjustments from there. Incase of OS, it will be quite apparent that the engine would be struggling at full throttle at this tuning, hence suggesting to open the needle a bit more.
On ASP, it will become apparent by looking at the exhaust fumes (excess smoke) indicating that the engine is running rich.

Only once the high end is tuned for optimum performance, should you adjust the low end for a smoother idling and acceleration.
Logged

Cheers !!!
Saurabh
+91 7977382130
 

Read
« Reply #27 on: November 18, 2010, 10:28:52 AM »
Mike
Plane Lover
Active Member
**

Reputation Power: 1 
Mike has no influence.
Offline Offline

City: UK
State: OUTSIDE INDIA
RC Skills: Intermediate
Posts: 40
Join Date: May, 2009



Glad you got it sorted!

Does this mean we can raise ASP status to

Always Settup Properly!!

I will look out the procedure to obtain the inital settings on low needle set up by blowing through the fuel pipe, which is what I tried to do at the field but as you say, you really have to close it down completely and work your way up.

From what I have read everyone is on the right track but the "sweet spot" can be hard to find, if you remember we had the same issues on my Moki 135 earlier this year.

 
Logged
 

Read
« Reply #28 on: November 18, 2010, 11:04:30 AM »
flatspin_king
Plane Lover
Senior Member

***

Reputation Power: 3 
flatspin_king has no influence.
Offline Offline

City: New Delhi
State: Delhi
RC Skills: Intermediate
Posts: 175
Join Date: Feb, 2010




Anwar,
As others have said these are classic symptoms of the low end being rich. Fuel builds up while idleing and eventually the engine will quit as the plug loses heat or it will quit the moment you try and increase throttle (with the extra fuel which puts the fire out as it were). 
An easy test for checking if the low end is rich is to pinch the fuel line at idle  -the engine should just speed up - if you have to really pinch down on the fuel line before the rpm changes - its too rich. (And of-course if the engine quits its too lean)

I own a ASP 52 and its a great engine - been running it for the past 6-7 yrs in many diff airplanes - very powerful for its size and will swing a 12x6 prop with authority. I also had the initial tuning problems when running it in. 
« Last Edit: November 18, 2010, 12:00:58 PM by anwar » Logged
 

Read
« Reply #29 on: November 18, 2010, 12:00:08 PM »
anwar
Administrator
Forum Hero

*****

Reputation Power: 141 
anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!
Offline Offline

City: Doha (Qatar) & Thrissur
State: Kerala
RC Skills: Advanced
Posts: 11619
Join Date: Mar, 2009

RC India - Flying and racing with open minds !



I forgot to mention the pinch test.  Everything indicated that we are too rich.  Mike did his "blow test" also, to confirm that the low end is rich.  But what we were surprised about, and why I posted this here is to get confirmation that with ASP engines, the low needle needs very little opening (at least in some cases), and the high can be as low as 0.7 turns !  These would be considered very bad settings for other engines.  Saurabh's post provided the confirmation I was looking for. 

It is not that we did not identify the symptoms, it was the fact that the solution was so extreme that surprised us Shocked

This also shows that when it comes to tuning, there are no hard and fast rules.  Whatever works without overheating the engine, shall be acceptable.
Logged

Hangar : Please see my introduction.
RC India forum and me : About this forum.
 

Read
« Reply #30 on: November 18, 2010, 04:43:11 PM »
flatspin_king
Plane Lover
Senior Member

***

Reputation Power: 3 
flatspin_king has no influence.
Offline Offline

City: New Delhi
State: Delhi
RC Skills: Intermediate
Posts: 175
Join Date: Feb, 2010



Quote
"The reason for this is that making it rich was not helping (not hurting much either), so I went the other way, leaning it out bit by bit."

"And regarding the splutter, it did not ! Death was near instant, we could barely detect a huge gush of fuel/fumes, yet it was later diagnosed to be too rich. This is one reason why we tried going both ways, as it had become difficult to detect the required changes just by observing symptoms alone."       

well, I was just going by the implications of these two statements. The reason I said that these were classic symptoms of a rich low end was your first description of the engine slowing down and dying (as opposed to just quitting) after idling for some time. This tells me that the engine is loading up. (although of course hindsight is 20/20 Smiley )
When I was learning to fly I was always told "clear the throat" of the engine just before takeoff (i.e. run it at mid to full throttle) after a prolonged idle -such as taxiing to the flight line from the pitts. This was even if one had run it at full throttle and done the tilt test in the pitts -of lifting the nose up check if engine is too lean and quits at full throttle).   

« Last Edit: November 18, 2010, 08:56:30 PM by anwar » Logged
 

Read
« Reply #31 on: November 18, 2010, 09:06:59 PM »
anwar
Administrator
Forum Hero

*****

Reputation Power: 141 
anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!anwar is awe-inspiring!
Offline Offline

City: Doha (Qatar) & Thrissur
State: Kerala
RC Skills: Advanced
Posts: 11619
Join Date: Mar, 2009

RC India - Flying and racing with open minds !



True, the classic symptoms were recognized too. But the point is that even by starting at one turn from fully closed on the LSN caused the same symptoms, so we were going richer for the fear of killing the engine (driven more by fear/common knowledge... than just the symptoms). Who would try an engine with the LSN pretty much fully closed ?  And there was virtually no difference in behavior for up to 3 turns (we stopped playing with "rich" settings at that point). Something as sensitive as the low needle should induce some difference in behavior (one would expect!), but NONE !!!  No change in the time required for the engine to die in idle, no change in the way it stopped on sudden high throttle, etc ! 

Looks like ASP just lived up to it name again of being funky at tuning.
Logged

Hangar : Please see my introduction.
RC India forum and me : About this forum.
 

Read
« Reply #32 on: January 14, 2012, 09:37:50 AM »
sanjayrai55
Plane Lover
Forum Hero

*****

Reputation Power: 75 
sanjayrai55 has a powerful will.sanjayrai55 has a powerful will.sanjayrai55 has a powerful will.sanjayrai55 has a powerful will.sanjayrai55 has a powerful will.sanjayrai55 has a powerful will.sanjayrai55 has a powerful will.
Offline Offline

City: Gurgaon
State: Haryana
RC Skills: Intermediate
Posts: 7260
Join Date: Dec, 2011

Don't wake a Tiger until you've factored the teeth



sorry if that doesnot help as am into electric (less noise less pollution Grin Grin Grin) (and of course less global warming  Grin Grin) (glow gas or nitro lovers please take it lightly  Roll Eyes Roll Eyes Roll Eyes Roll Eyes)

Dear pikle, Why take lightly? Everyone who pollutes this planet is responsible. there should be a complete ban on glow/gas engine or atleast some emission control.  we should not allow anymore pollution just because its cheaper.

Look at the the total picture:

You use electricity to charge your battery. Electricity production/generation causes pollution & warming

You use LiPo or NiMh, their production causes the same, and their disposal is a major pollution hazard

Best to train a bird!
Logged

Sanjay - Gravity is my enemy
 

Pages: 1 [2]  All   Go Up
Jump to:  

Related Topics
Subject Started by Replies Views Last post
Engines, Engines and more Engines...!!! « 1 2 ... 15 16 »
Fuel and Engines
flyingboxcar 393 170719 Last post December 30, 2018, 12:28:50 AM
by ssk320
Wanted: Engines.
Wanted
sumit joshi 4 1804 Last post November 06, 2014, 12:04:52 PM
by miginstruments
ic engines
Fuel and Engines
anujaggarwal2207 2 4734 Last post February 28, 2014, 08:00:04 PM
by shobhit17
RC Gas Engines
Wanted
crazyhorse21 5 1431 Last post January 27, 2016, 02:19:53 PM
by anileshrai
Pennzoil Mineral oil for Gas engines
For Sale
ravikoth 1 676 Last post September 11, 2017, 12:51:51 PM
by ravikoth