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overheating TIger

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GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Thu Jan 22, 2009 12:58 pm Post subject: overheating TIger

I have a customer with a 2005 Tiger.  I put a power Flow on it about a month ago.  To the best of my knowledge, he was instructed to take-off and climb, every time, at 80 knots to practice in case he needed to climb over a 50 foot obstacle.   

 

  Here is his posting to me.  Please give me some feedback as to what the general consensus is.

  

 

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   	  Quote: 	
		   	  Quote: 	
		  Hi Gary.  I need some feedback.   Today was the second time that I have taken 

off and climbed out at 80 knots, and by the time I am at 1500 to 2000 feet I have a cylinder head temp of 500 degrees and a climb rate of 1400 to 1500 feet/min.  The outside air temp was 21 C on both days.   This was with full throttle and full rich.  I was just beginning to 

start a cruise climb both times when I noticed it.  I was looking for it today, 

but I got cutoff in the downwind turn by two planes coming in and obviously did 

not hear my takeoff call out.  By the time I dodged both those guys the temp was 

already at 500.   I think the Tach was around 2400.  As soon as I saw it I 

lowered the nose20and the increase in speed cooled it back to 375 or 385 after 

what seemed like a minute or two.  I was too busy worrying about it to time the 

temp drop.  I definitely do not remember seeing those temps when I took it home 

or the next couple of flights.  The oil is 61/4 qts.



Does this mean that I need to climb out at a 100 or more because even at those 

speeds I have at least  500'/min climb rate or more, or do I have to not use 

full throttle on take off?  Is this related to the baffling and/or the open 

hole, or have I just mucked it up somehow.  What cylinder is the probe on and 

could this be related to heat from the Powerflow near the probe and cylinder 

head?



If I am getting this kind of response at these temps, I am definitely concerned 

about when it really gets hot outside, and what if I really need that Vx climb 

rate?



Any suggestions.



As an aside, the first refueling showed a fuel flow of 7.3 gal/hr and today 

after refueling it was 9.3.   I assume that it is somewhat artificially low due 

to runnup and taxi etc time.   This is just feedback.

 

Thanks 	
	


  

 

  

 

  A Good Credit Score is 700 or Above.  See yours in just 2 easy steps! 

  [quote][b]

_________________
Gary
AuCountry Aviation
Home of Team Grumman

jbowman90

Joined: 30 May 2008
Posts: 3
Location: Bellbrook, OH

Posted: Fri Jan 23, 2009 2:42 am Post subject: overheating Tiger

There was a guy here in Ohio with a similar problem.  After a lot of exploration, it finally took testing the differential pressure across the cylinders to determine that there was a baffling problem somewhere.  



Not that I'm an expert, but I'm told that the baffling on Grummans can look Ok but not be - there can be some less than obvious gaps.  Might there be something on Bondline about checking the baffling for Grumman-specific problems?  If it's not the baffling, at least you have some peace of mind and did some preventative maintenance, which is never bad!



Jason

lmassaro(at)tac-eng.com
Guest

Posted: Fri Jan 23, 2009 9:17 am Post subject: overheating TIger

No answers, but some additional info to digest...



I have just "upgraded" to a short stack from the standard DD 

powerflow and have noticed the following:

1)  Increased climb rate (Id estimate 20% better based on various 

weight configs)

2)  Higher CHTs (about 30 deg) on climbout. I also climb at 80kts 

rule of thumb.



Perhaps the short stack is better matched than my previous Classic PF 

or whatever, but higher climb rates to me translate tell me Im 

generating more HP, which translates into more heat?  No?   I haven't 

noticed any significant differences at cruise power settings.

My standard departure profile is to climb out at 80 until 1000AGL 

(~1000 ft/min), then reduce pitch for a 500-750 ft/min climb which 

increases my a/s and keeps things cool.

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Fri Jan 23, 2009 1:14 pm Post subject: overheating TIger

Vy at sea level is 90 knots.  I typically climb out at 105 to 110 knots.  THere really isn't anything to be gained by power climbing.  All you are doing is lifting weight and wasting fuel.   

 

  With the new cowling, #1 will run hottest during a climb.

  

 

  Maybe none of you know this, but, the climb cooling certification portion of the flight testing is NOT done from the take off roll.  Climb cooling is done from stabilized flight at 1000 feet at 75% power with the CHTs stabilized for 5 minutes.  Then climb at Vy is established.  

  

 

  If you want to climb at high angles of attack, get a Maule.

 

 

 --

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Gary
AuCountry Aviation
Home of Team Grumman

JHOSLER(at)epri.com
Guest

Posted: Fri Jan 23, 2009 1:55 pm Post subject: overheating TIger

Is the high CHT the result of the new cowling or the power  flow exhaust?

  

 Does the new cowling require installation of the power flow  exhaust?

  

 80 knots till you clear the trees is pretty normal, then  90-110.



   From:  owner-teamgrumman-list-server(at)matronics.com  [mailto:owner-teamgrumman-list-server(at)matronics.com] On Behalf Of  teamgrumman(at)aol.com

Sent: Friday, January 23, 2009 4:11  PM

To: teamgrumman-list(at)matronics.com

Subject: Re:  overheating TIger

 

Vy at sea level is 90 knots.  I typically climb out at 105 to  110 knots.  THere really isn't anything to be gained by power climbing.   All you are doing is lifting weight and wasting fuel.    



 With the new cowling, #1 will run hottest during a climb.

 



 Maybe none of you know this, but, the climb cooling certification portion  of the flight testing is NOT done from the take off roll.  Climb cooling is  done from stabilized flight at 1000 feet at 75% power with the CHTs stabilized  for 5 minutes.  Then climb at Vy is established.  

 



 If you want to climb at high angles of attack, get a  Maule.

--

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Fri Jan 23, 2009 2:13 pm Post subject: overheating TIger

and if there are no trees? 

 

  this was a stock 2005 Tiger onto which In installed a Power Flow.

  

 

  Yes, my cowling requires the Power Flow.

 

 

 --

_________________
Gary
AuCountry Aviation
Home of Team Grumman

flyv35b(at)minetfiber.com
Guest

Posted: Fri Jan 23, 2009 3:37 pm Post subject: overheating TIger

Sounds like the biggest problem is the PROLONGED climb  to 1500-2000 ft at 80 kts.  There is no reason to climb at that slow a  speed for more than a couple hundred feet.  Climbing at 100 kts will  provide just about the same ROC as at 90 kts because of the higher engine RPM  and horsepower and the cooling is better.

  

 I've heard the factory CHT instrument on the AG-5B is  not all that accurate and I'm not sure what cylinder it is located on, but  AG-5Bs had a reputation of the #2 cyl running hot at Embry-Riddle in Prescott,  AZ.  And the baffling below #1 is very restrictive because of the  alternator mounting and different baffle design from the AA-5B.  Bill Scott  modifies the stock baffling to provide more air flow on  #1.

  

 Allowing the CHT to reach 500F will shorten the life  of the exhaust valves, guides and result in cracks in the exhaust port  probably.  The PF exhaust probably aggravates the problem as it puts more  heat into the cylinder.  Don't climb at partial throttle as the carburetor  has an enrichment valve that will result in a leaner mixture than if you  reduce the throttle even a half inch.

  

 Cliff

  

 [quote]   ---

Discover

Joined: 26 Feb 2007
Posts: 429

Posted: Fri Jan 23, 2009 4:41 pm Post subject: overheating TIger

Hi Gary's Customer,

  

 Just back from being stranded in Cowboy country. The Starter  went out in my '02 Tiger. Les Staples overnighted a new one and it works great!  I'd like to respond to this query as I had overheating problems with my '02  Tiger and found severall things to help it cool better. I always climb at 80kts  and never have cooling issues but...when I first had my Tiger it would  overheat.

  

 First, I'd confirm measurement instrumentation

 Second, I'd look at look at ways to make the engine cool  better.

  

 I'm guessing this plane has JPI and not EI engine scanner? As  the chief GGG (that's Grumman Guru Gary) has said the JPI  indicates....70deg hgher than the EI and Lycoming Factory instrumentation  indicates....So your 500 was really only 430....

  

 Yep, GGG's cowl will make the cylinders run really cold, under  Lyc's recommendations and I can't wait to get that cowl on mine..my  EI 325deg heads may be in the high 200's then:)

  

 Ways to make it run cooler....lots of secrets there that lots  of mechanics did not want to let me know about...took long time to find out some  of them.... dinner bell just rang.... so here is just a short list of  some:

  

 1) Whatever hole you are talking about patch it up. In fact go  out at night and put a light in the cowl and find all the holes and patch them  up with silicone

 2) Ensure that the baffles are open "enough" ...that is on the  bottom of the cylinders. The distance between the rear wrap around baffle and  the intercylinder baffle is often too small especially on the 2000 vintage  AG5B's

 3) Look for cylinder cast flashing between the spark plugs  blocking cooling air near the exhaust valve.

 4) Make sure all the silicone baffles lay flat against the  cowling. Pay attention to the front baffle cowl because my '02 silicone was too  short and did not even reach the cowl.

  

 I'll try and get more details later gota run but GGG knows all  this so just take her back to him and have him get it done...

  

 ned

 [quote]   ---

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Sat Jan 24, 2009 1:27 am Post subject: overheating TIger

the 2005 Tiger only has one CHT and it came with the plane

 

 

 --

_________________
Gary
AuCountry Aviation
Home of Team Grumman

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Sat Jan 24, 2009 1:34 am Post subject: overheating TIger

and it's on #4

 

 

 --

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Gary
AuCountry Aviation
Home of Team Grumman

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