New engine temps question

trib · #1 12-10-2009, 10:04 AM

Getting ready for first flight and I would like to know what to anticipate for initial engine temperatures (CHT's). I performed the engine run-in procedure on ground with temps in the low 80s and had to secure when CHTs reached 350F, splitting the 10 minute total time at 1400 into two periods of 5 min. Initial flight will have temp around 50F so will have some more cooling. I'm hoping to keep CHTs below 400F with plan to land if temps approach 450F. Can a few of you give me feedback on what kind of CHTs you saw for the first flight of a new engine? I'd appreciate it if you recorded the CHT at takeoff (following taxi/run-up), climb and when stabilized at 75% power for engine break-in procedure. I'm not sure what to expect and this will help

Bavafa · #2 12-10-2009, 10:22 AM

Depending on which engine but in general If it is a new (unbroken engine) expect a bit of higher temp then normal and you ought to limit your ground run ups to a minimum. I think temps in the lower 400 (400-410) should not be of any concern while climbing but once you are in cruise, if things are setup right (with baffles, etc) they should run in mid to upper 300s, maybe a bit higher during breaking period.
Your CHT will always be higher on the ground as there isn't much cooling provided while on the ground.

Good luck and enjoy the first flight

noelf · #3 12-10-2009, 10:41 AM

...and how is VaBeach these days??? I grew up there, just outside the traffic pattern for NAS Oceania.

My new Superior O-360 initial runs (North Carolina, 95 outside air temps, no wind condition) brought the CHT's up to 450 and I then shut down the engine. The next runs were to bed-in the brakes, and the CHT's were a bit lower. I put less than 30 min on the engine before the first flight.

First flight was great, CHT's were less than 400, oil temp was 195, all at high power settings, and OAT was 90. I have 8 hours on the engine, need to balance the CHT's at this point. Unfortunately, I am "stuck" in my father-in-laws' house right now...20 miles north of OSH. And, yes, this has been my first blizzard.

Steve Sampson · #4 12-10-2009, 10:49 AM

Here is mine. An RV4 cools well though. Good luck!

Graph

lostpilot28 · #5 12-10-2009, 10:52 AM

Hey Tim,
I spoke to the regional ECI rep last February when I was getting ready for my first flight. He said that you really want to keep it as cool as possible. One or two run-ins (maybe 3 if needed) but all should be really short. I asked him about the 3 minute time limit (up to 4 with the ECI nickle-carbide cylinders) and he said to keep it even shorter, if possible. This guy was very smart...he definitely knew what he was talking about, so I followed his advice. I used the ECI run-in/break-in guide as my maximum guideline.

My CHT's took between 1 and 2 hours to drop...and they didn't appear to drop much. Maybe 25 F, on average. I would recommend you not do any more run-ins and just fly it. The ECI rep said that after starting, take off within 3 minutes and keep the throttle and mixture all the way in. Make sure your climbout isn't too steep so that your engine is being properly cooled.

Best of luck! Let us know what happens!

trib · #6 12-10-2009, 05:29 PM

Sonny,

Run-ins are done- Mahlon gave me a schedule he has used in the past. What I am looking for are the first flight temps you saw. I'll be minimizing taxi, and the next start (hoping for saturday) will be for the initial flight. Reread the initial post for the temps I'm looking for.

Sorry that I didn't mention the engine is an O360, 180 hp.

thanks

yakdriver · #7 12-10-2009, 06:15 PM

I have done four first flights/new engine. The CHTs stayed in the high 300-low 400 range. It is best if you can put an hour on it at full throttle/mix rich for cylinder break in. Your oil temps might get up a bit but I wouldn't worry if they stay under 230-235. The temps will go down after the first couple of hours. Remember above all else FLY THE AIRPLANE! Also have fun, nothing like piloting a brand new airplane on its first flight. Don

db1yg · #8 12-10-2009, 06:21 PM

Hi Tim,

I first flew my Eci 0360/RV9a back in March of 2006. Outside temps were in the high 60s. I flew it like Eci recommended--throttle and mixture to the firewall for the first 30 minutes and I kept the altitude around 5K density to run a high power setting. The highest cht I saw was 418 F. The second and third flights showed decreasing temps. Sorry -- I did not record the cht at take off!

Hope this is of value.

Cheers,

db

trib · #9 12-11-2009, 09:52 AM

Thanks for the feedback guys. Based on your info, I'm expecting low 400's. Since the temp expected for tomorrow morning is a brisk 32F, hopefully it will be a little lower even and won't be a concern.

Plan is for an hour long first flight to get the ECi recommended time of 65-75% power for 45 minutes on first flight to help initially seat the rings.

db1yg · #10 12-11-2009, 06:52 PM

Good luck Tim!

There is NOTHING--I repeat--NOTHING like the first flight of an airplane that you built with your own two hands!! When you line up for take off, push that throttle in, and that airplane literally jumps off the runway you are going to be one very focused but happy guy. There is really no way to put the feeling into words. I was actually "hung over" the following day after my first flight from the adrenalin rush.

Be careful, insure you and the airplane are ready, and enjoy yourself!!!!

Let us know how it goes!

All the Best and as always,

Cheers,

db