High CHT's Too Lean or Timing? - Page 3

PaulR · #21 08-27-2012, 03:22 PM

I just wanted to update this thread a little with some positive results over the weekend. I have been in contact with DanH and he convinced me to look over the baffles one more time and gave me some clues as to what to look for.
Well, I did that on Saturday and he was certainly correct. There were several places, mostly behind 3 and 4 that needed more attention that I had given it when installing them originally.

Also, where the baffles wrap around the fins on the bottoms, it's amazing how well they DON'T fit right out the of the box. Hind sight being 20/20, had I paid as much attention to them as I did the rest of the build, it would have been easier to close up the small gaps.

At any rate, I still have a little issue with CHT's when climbing, but I did cool off the cruise CHT's by at least 10 degrees and I believe actually more than that but won't know for sure till I download the data this evening.

For now, I'm going to fly it some more to ensure it's broken in (only 16.5 hours) and when I'm convinced they aren't going to drop any more, I may address it further.

I would suggest to all of you who are in the baffling process to take EXTRA care to seal up any openings however small and make sure that the "wraps" are tight to the fins.

THANKS DANH

flyingriki · #22 07-19-2014, 07:14 PM

Paul,
Am going through the same things right now with almost the same setup. Did disconnecting the MP hose to the P-Mag do any good early on? You never followed up on that. What else did you do to get temps down? Did you re-jet?
How long before temps settled down?
Thanks!

N941WR · #23 07-19-2014, 08:11 PM

That single P-mag, with the jumper installed, will bring the timing down to 26* BTC. Removing the MAP line does keep it from advancing but, and this is important, the P-mag will only advance when MAP drops off, such as at altitude or partial throttle.

I suggest you download the ECAD program from Emag's site and "tune" the P-mag by reducing the timing. This "tuning" is done to the "B" Curve so you will want to run without the jumper.

The other option is to buy one of our EICommanders and tune it with that. Then when you buy your second P-mag, you are all set.

With the EICommander, you can play with the timing in flight, unlike the ECAD program, which requires the engine to be stopped.

PerfTech · #24 07-19-2014, 09:48 PM

... If you guys haven't seen our new EZ Cool cowl flaps go to our website and have a look at the video. Thanks, Allan...

PaulR · #25 07-21-2014, 07:28 AM

Flyingriki,
Sorry about not updating this post, actually I had forgotten about it. I was still battling high CHT's on climb out at anything under about 115 knots so I did a "lean test" at altitude as some have described here. I figured out that I was too lean at full rich and opened up the jet in the carb.

At this point, around 200 hrs., on a hot summer day (90 plus) the CHT's can still get too hot at a slower (85 knot) climb. I have a couple more things I want to do baffling wise, before adding Perf-Tech's cowl flap. I just don't see a down side to the cowl flap.

I think that most of the planes I see, mine included, seem to be hard to seal around the nose bowl. If the inlet ramps aren't in just the right place it makes it really tough to seal there.

flyingriki · #26 07-21-2014, 07:47 AM

Paul, could you quote some numbers for me please. What was your jet before, what did you open it up to, what are the temps now vs. before and what is too hot in your mind, which cylinders.
Thank you!

MauiLvrs · #27 07-21-2014, 11:49 PM

Quote:

Originally Posted by flyingriki

Paul, could you quote some numbers for me please. What was your jet before, what did you open it up to, what are the temps now vs. before and what is too hot in your mind, which cylinders.
Thank you!

We drilled ours from #42 to #40 and it dripped 20-25 deg. Still toying with going to #39.
We also opened the exit 5/8" and that made a 30+ deg. drop.

PaulR · #28 07-22-2014, 12:24 PM

I went to #40 also. Like Dave, I also opened the lower cowl area 5/8 or 3/4" forward.

flyingriki · #29 06-08-2015, 03:04 PM

I understand the success folks are having with bigger jets. Is this for climb temps or all conditions? I ask because I dont want to try it and find I can't get any economy at cruise any more. Our does leaning at high altitude cruise bring the gph back down without increasing temps?
Thank you!

PaulR · #30 06-09-2015, 06:36 AM

As far as my plane goes, enlarging the jet has nothing to do with economy at cruise. That's what the red knob is for. You can still lean it back to be very efficient, it just helped me when we determined that I wasn't flowing enough fuel at full throttle down low.