RV-10 Running Hot

Hey out there I need some ideas. I bought a used 0540 260hp. I did nothing to the engine but install it. It started and ran fine and the tempatures were ok. The trouble was the left mag was dropping off about 250 rpm and I was not getting ful power. I put the timing up to normal 25 before TDC and the temps went up out of limits. I could only fly at 12 inches of MAP and nurse it back home. The lower baffling under the cylinders was missing when I bought the engine so I bought some and installed it. Now I can fly at 15.5 MAP to keep it with in limits. Remember with out the lower baffling and the timing retarded it would stay in limits and around 375 cyl head temp in cruise. Now with the timing set right and the new baffling installed it is out of limits three minutes after take off. The number one cyl is very unmanageable. I used a baffling kit from VANS and no air is escaping around it. Has anyone else had these problems with the RV10.
Thanks

How many baffles or louvers do you have on the bottom of the cowel?

How can an O-540 run at 250 RPM? Min is around 500.

Hot engine

During my first and second flights I had hot number 1, 2 and 6 cylinders...in that order. Not nearly as hot as yours, I could run 75% in level flight, just had to be careful in climb. If you check the matronics archive you will see some discussion on the issue. Here is what I did.

Cut the fence down in front of cylinder's number 1 and 2. Based on the operating temps, I cut number 1 down a half inch and number 2 down one quarter inch. I reworked my baffle material in the back, I had some spots that could leak, and around the prop governor. This really helped. If I really work at it I can get number 1 to 425, but I have to get down to 85 knots for several 1000 feet of climb. I am sure this will be different in the summer, but I have a few more things to tighten up and seal up to improve total airflow.

Yukon said:

Larry,

He's taking about mag drop.

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Oh, (my face is turning red) I knew that!

A little harsh don't you think He came looking for help and might have felt flamed. If he went away never to return and attempted to sort it out alone, then...

Ok hsdexo, your post comes across as if you are trying to trouble shoot gross power plant installation issues by trail and error. There are many who can help you on this forum and many who can help you locally. Most of what you will find here might be considered "fine tuning". The way your post comes across you need to get some local help; That is eyes on your installation by other builders in the area and or a local A/P. More eyes the better, and you don't really need a RV-10 guy because it sounds as if your problems are engine related not airframe.

Calling any gear heads near Humboldt Tn who can make a hanger call....

HSDEXO,
Please give me a call 256-443-1915, I'm located in Muscle Shaols, AL. up in the Northwest corner of the state. I've put together a few planes and also an A&P. I can fly up and get you going if you give me your airport and a time.
Steve Raddatz

Probe calibration????

We thought the Monarch was literally burning up on short test runs...The calibration of the probes was way off from Blue Mountain's recommended settings. My Rec., is to heat some synthetic oil to about 300 deg with a torch and confirm temp.with a good "Fluke" type multimeter with temp capability. ( Mine is Fieldpiece brand with a K thermocouple)
I am sorry, but I refuse to believe an engine runs that hot at that low a power setting with even the loosest fitting bafflesl!!! Also, the Monarch takes quite a while to cool down from higher CHT's with moderate power settings..... What are your EGT's @ takeoff power? Lyc. says about 1390 deg for a lower comp. motor @ properly leaned setting and approx 25 GPH. Lower EGT for a higher comp motor and vise versa. Maybe you are running horribly lean ????
Also, we spilt the plenum into 2 sides on the Monarch with baffles (idea from an article in Kit planes, this is to prevent forward flow of air as it hits the back baffles) and lowered CHT's 20-40 deg, and we now can run @ WOT all day long!!!!!!!! WOT on the Monarch @ 2000' gives the highest cyl, #6, 400-420 deg., depending on OAT. I don't know many RV-10's that can do that! (and BTW 220 ++ TAS!)......................... Glen

Still Hot

Geico266 said:

How many baffles or louvers do you have on the bottom of the cowel?

How can an O-540 run at 250 RPM? Min is around 500.

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No offense taken.
I have seen baffling on airplanes that are ragged as a cedar tree and they did not run hot. This has really got me perplexed.
I started having the problem when I changed the timing to 25 degrees before TDC as the data plate calls for.
I will admit that I have not checked the cylinder temps with infrared to see if the DYNON 100 is correct but, the oil temp is red hot and the oil pressure has dropped to indicate hot too.
I placed the pieces on the bottom of the cylinders and put RTV on the back of the baffling around the engine mounts. Now I can run it in level flight at 15 inches of MAP at 1000 ft MSL. Can't get any higher because it is too hot to climb further.

Are you sure the flywheel is on correctly so the timing marks are correct? Did you verify the #1 piston was at TDC when the flywheel mark indicates TDC? Don

hsdexo said:

I started having the problem when I changed the timing to 25 degrees before TDC as the data plate calls for.

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As long as you didnt make any other changes at the same time, I am pretty sure you have defined the problem.

If the ignition timing is correct at the flywheel, the only other issue that comes to mind------and you wont like it-------is that the cam is not timed correctly.

One of the earlier posters (Steve R) offered to come up and take a look, sounds like a good idea.

Good luck, and let us know the end solution.

Hmmmm

Great suggestion Mike!!!! I had not thought of that about the cam timing. I actually had that problem due to an incompetant mechanic..long story, dont ask. But I will say that I did not have temp. problems, just lack of power. Any way, I can talk you through the easy way to tell if the cam is timed wrong..Takes 10 min. after the cowling is off to check.....561 670 6095. Glen

Running Hot

OK guys, good suggestions. Steve is coming up on Saturday and see if he can help me figure this out. I will let you know what we found out. I wish I did not work out of town where I could work on it today but only on the weekends. I have to keep working to support this habit of flying.

RV10 Running Hot

OK folks out there. I had a two fold problem. First one I hate to admit. I pulled the left mag off to check the marks on the gears at TDC. Well at TDC according to the marks on the flywheel the marks on the mag drive gear inside the case were not where they were suppose to be. I moved the prop until the marks inside the case were in place and the flywheel timing marks were off one bolt hole. At that point I got the screw driver out and brought #1 to real TDC and put me some new marks on the flywheel with a marker. I wanted to fly it first to see it that was the problem. I will change the flywheel now after flying the airplane. Second issue, I did not buy thr FWF kit from VANS so I did not get FWF installation instructions. My used engine had a new air box from Aircraft Spruce. There is a 6.5 inch distance from the front of the cowl inlet to the installed airbox. This allowed the air coming through the inlet to pressurize the lower cowling and not allow the air coming in the top to flow down. I closed off the intake and flew the airplane with the new timing and cowl improvement and climbed to 9.500 hottest cylinder got up to 400 #1. The rest stayed at 385. I am building the VAN intake to attach directly to the cowling inlet. It looked like I lost about an inch or inch and a half manifold by closing the inlet. I still was cruising at 188 mph WOT 2400 turns. I still do not have the wheel pants on or painted either. Think I will be real close to the 200 mph barrier with the addition of these items.
Thanks for the help everyone. Sometimes the least thing can put you to thinking.
R/Harry

hsdexo said:

OK folks out there. I had a two fold problem. First one I hate to admit. I pulled the left mag off to check the marks on the gears at TDC. Well at TDC according to the marks on the flywheel the marks on the mag drive gear inside the case were not where they were suppose to be. I moved the prop until the marks inside the case were in place and the flywheel timing marks were off one bolt hole. At that point I got the screw driver out and brought #1 to real TDC and put me some new marks on the flywheel with a marker.

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Be sure you check your ring gear support and the drive lugs on the crank shaft for damage.
One of the drive lugs has a small shoulder on it that is meant to be positioned on a specific hole in the ring gear support. This hole is usually marked with a capital O stamped nearby but it can be hard to see. This is the indexing key for keeping the timing marks on the ring gear properly positioned relative to the engine timing.
If your ring gear support has been forced on (by bolting up the prop.) in the wrong position, then you have possibly damaged the shouldered drive lug and one of the holes in the ring gear support.

Can I ask you what you changed the timing from when you changed it to 25 deg?, and was it running cooler there?

rvbuilder2002 said:

Be sure you check your ring gear support and the drive lugs on the crank shaft for damage.
One of the drive lugs has a small shoulder on it that is meant to be positioned on a specific hole in the ring gear support. This hole is usually marked with a capital O stamped nearby but it can be hard to see. This is the indexing key for keeping the timing marks on the ring gear properly positioned relative to the engine timing.
If your ring gear support has been forced on (by bolting up the prop.) in the wrong position, then you have possibly damaged the shouldered drive lug and one of the holes in the ring gear support.

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You are correct and that was the reason I thought I had it on correctly. I am still not sure that this flywheel was not stamped wrong in relation to the timing marks when it was made. I changed the flywheels because the one I received with the engine was cracked all the way around the bolt hole pattern.

Rivethead said:

Can I ask you what you changed the timing from when you changed it to 25 deg?, and was it running cooler there?

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I was using the timing marks on the flywheel and they were standard marks 20,23,25 BTDC. I set the timing at 25 BTDC and the engine was running extremely hot with in minutes after take off. When I discovered the flywheel marks were incorrect or I had it on the engine incorrectly I put my own timing marks on the flywheel with the engine up on #1 TDC. I then removed both mags and timed them at 25 BTDC with the new marks. Engine started and ran great at the right tempatures. Covering the intake helped also to allow air flow in the right direction and pressure.
Harry

hsdexo said:

I was using the timing marks on the flywheel and they were standard marks 20,23,25 BTDC. I set the timing at 25 BTDC and the engine was running extremely hot with in minutes after take off. When I discovered the flywheel marks were incorrect or I had it on the engine incorrectly I put my own timing marks on the flywheel with the engine up on #1 TDC. I then removed both mags and timed them at 25 BTDC with the new marks. Engine started and ran great at the right tempatures. Covering the intake helped also to allow air flow in the right direction and pressure.
Harry

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The flywheel should be indexed to fit on the crank only one way.

This is done with one of the bushings that are in the flange-----it is larger than all the rest.

As was suggested above, check that you have an indexing bushing, and that both it and the flywheel are undamaged-------if you mistakenly put the flywheel on wrong, and then cranked down on the bolts, the bushing---if there--- or the flywheel could be damaged.

I think for starters I'd take a plug out of number one and check top dead center against what the flywheel says. If all is as it should be I'd start looking other places starting with the timming of the mags and then moving on to the accessory case. My guess is (and it is exactly that, a guess) that the mags themselves need adjusted.

Something I found out was the indexing marks on the flywheel are in different places on the front and on the back. On the back side, TDC is straight up. On the front side, its around the 4 o'clock position, and appears to line up with a hole/mark on the starter.