Mailing List lml@lancaironline.net Message #53097
From: Dan Reagan <dreagan@fuse.net>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] High #2 CHT on a IVP
Date: Tue, 06 Oct 2009 13:23:12 -0400
To: <lml@lancaironline.net>
I checked the fuel flow at 31.5" and 2500 rpm.  It was 29.8 g/h.  Would the difference between the suggested 32 g/h and my 29.8 make enough difference to cause my problem?
 
Dan Reagan
----- Original Message -----
From: Dan Reagan
Sent: Sunday, October 04, 2009 10:28 PM
Subject: Re: [LML] High #2 CHT on a IVP

I am getting the 43.5 at wide open throttle at 38.5 inches.  I will check the 32 gallons at 31.5" and 2500.
 
I have the standard TCM injectors which are all the same size.
 
After testing today I found that #2, #4, and #6 all peak about the same time.  Number 1, 3, and 5 seem to peak at about the same time.  The fuel flow difference from first to peak and last to peak looks to be about .6 gallons per hour. (this is at 23" and 2500 rpm) It seems strange that all on the left side peak first but then I don't know a lot about the workings of this engine.
 
The air flowing around #2 is well managed.  It flows properly around the back and is directed well around the bottom.
 
I don't know the answer to the "degrees the  hottest egt is  below peak when at full rich".
 
I think I am about to the point of investigating the setting lean of peak that will give good tit's and good cht's.  I sure can't get any speed while running rich of peak and I know the heat is not good for the engine.
 
I really really appreciate the input to this problem. 
 
Dan Reagan
----- Original Message -----
Sent: Sunday, October 04, 2009 5:07 AM
Subject: Re: [LML] High #2 CHT on a IVP

Dan,
There's no reason you can't get a non-fadec engine to have reasonable cooling.  I think you got some other change along with this engine.
- I agree with Craig on fuel flow.  Do you get the 43.5 wide open?  If not, I would fix that first.  Then are you getting the 32 at 31.5?
- 375 for the other cylinders is also high which is another reason to suspect FF is too low.
- you really don't want #2 to be first to peak so you want more flow on that injector.   Do you have gami jectors?
- You didn't mention the gami spread between #2 and the others. (gph fuel flow between when #2 peaks and the others).
- re: the oil cooler, is the air actually flowing through the fins on #2 or escaping around the back.  you also want flow guides
under the back of #2 to force the air to flow through the bottom fins
- 400 in cruise is extreme.  how many degrees is your hottest egt below peak when you are full rich?  you should be able to get 150-200 dF rich of peak if you want it.    When you lean it, tit will go past 1700 dF near peak.   you have to go to the other side of peak. to get it to come back down.  it would be worth knowing if there is a mixture setting on the lean side that will get your tit down and your cht's e.g. in the < 350 range.
 
Colyn
 
 
----- Original Message -----
Sent: Saturday, October 03, 2009 8:36 PM
Subject: [LML] High #2 CHT on a IVP

Dan, my engine is doing the same thing.  One thing to try is putting your "last" to peak injector in #2 cylinder.  #2 is the hardest cylinder to cool in my plane as well.  This may cause you to fly quite lean if you cruise "lean of peak. Two, check your fuel rate at 2500 rpm and 31.5 inHg. I think at full rich it should be approx 32 gph and mine is way below that.  I have 43.5 gph at 2700 rpm and 38.4 inHg.  It appears I may need to pull the fuel pump and check the calibration.  I'm trying to find fuel flow rate data for the TSIO550 right now.
Craig Berland
IV-P N7VG
The current engine I have is brand new with approximately 20 hours on it.  It has a standard mixture control and replaced the previous FADEC controlled engine.
 
I can not seem to correct my number 2 CHT problem.  The previous engine did not seem to have the problem to this extent.  The mod of building a recess in the oil cooler plenum was done long ago.
 
I cannot climb with 31.5" MP, full rich without #2 hitting 400F at about 11,000 feet.  Climb speed is 165 knots.  Today's ground temp was 70F.  I have made a clear path for the air by relocating hoses, spark plug leads, brackets and anything that might disturb the cooling air.  The only thing left to move is the air conditioning hoses which are right in the way of the air as it enters the cowling.
 
All the baffling is very tight and everything is the same as was on the other engine.
 
Has any one had to use a larger injector to keep number 2 cool.  Number 2 EGT is the first to peak.  All the other 5 CHT's run within 3 degrees of each other with number 2 being about 25 degrees higher.  EGT's are running in the 1450 range with #2 being the hottest.
 
Straight and level at 17,000 feet indicating over 200 knots the #2 CHT will stay just under 400 degrees  31.5" and full rich.  When I try to lean it out the TIT's start above 1650.
 
Has anyone got any suggestions?
 
I will be looking at the injectors tomorrow.
 
I wonder what the trade in value of a slightly used red knob control cable is?
 
Dan Reagan
IVP 670 hours and wishing I had my FADEC back
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