ross001

Hi,

I have a Caliber 30 with O.S 32.

I am using 15%cool power fuel and after each flight there seems to be black watery stuff on my engine.
I think its burnt oil and I think I'm running too lean as I can't touch the engine after the flight cause it is too hot.

I have not had one problem with this engine, no dead sticks and am wondering whether its worth it to richen it.

Will anything happen to my engine having it running hot, and will anything bad happen if I do richen it??

The engine also seems to be very noisy in the hover, is this do to with it being lean?

Thanks,
Ross

BarracudaHockey

My Feedback: (11)

Sounds like the bearings are shot.

http://www.rc-bearings.com replace them with a set of ceramics.

Running hot will damage the piston and liner.

Running a bit rich wont hurt anything.

ross001

Thanks Barracuda, will have a look tonight.

Ross

Capt Jim

My Feedback: (168)

The black stuff is not good, and is most likely aluminum particles, which will appear as black goo in with the unburnt fuel oil. This can occur where two aluminum parts are not fastened tightly, and as a result, they vibrate and severely rub against each other and actually grind away some material. Check all your engine bolts, especially your muffler bolts, carb' bolts to be sure they have not become loose. It could also be coming from metal wearing away inside of the motor, but after break-in, this should not be happening inside the motor.
And also, as was mentioned in the above post, running it a bit richer wont hurt anything, and will not only lengthen the life of your motor, but in the extreme, it can save it from being totally destroyed from running too lean. It is not unusual to be unable to touch the motor right after a run...the head temp' will get to around 200 degrees or more, but if it is crackling, or smoking, then you are wayyyyyy too lean. As a general rule, peak the high end needle valve for maximum RPM and then back off 1/4 turn. When the motor unloads in flight, the RPMs will increase, so you haven't lost any performancewith this tuning procedure.

ross001

Thanks Captain Jim,

I will check all the bolts now and will tell you what I found later.

Ross

jez33

as barracuda says it will damage the piston and liner but also it doesnt do any good to thew bearings so its probably a reason or factor why your bearings are making noise..its normally a better thing to run richer then run week of cause so dont panic if its a tad rich...
as mentioned above check exhaust fit and look at all the silicone piping in the tank and to and from tank ect...

ross001

I've checked over the whole engine/fuel setup and everything is fine,
I'm going flying tomorrow so will richen it and see what difference it makes.

Thanks for all the help,

Ross

Capt Jim

My Feedback: (168)

Ross, quite interestingly, I have found this sort of black deposit on the surface of motors where merely a cowl of fiberglass or plastic has been rubbing. It does not take much to produce the effect. The rubbed contact area will show some degree of "polishing".

JPKII

How long would you consider break-in? Gallon or more?

Capt Jim

My Feedback: (168)

That's like asking three weather men what will happen tomorrow....you'll get three different answers. My take on this subject...from what I have been able to glean from the manufacturers...and from the threads here on RCU, break in goes something like this.
On a non-ringed motor, the so called break-in is a more of temperature cycling process. You run the motor up to temperature in a minute or two, then shut it down to cool. Then do it again, and again, etc, You do not run it sloppy rich because you are not trying to scuff the piston and cylinder liner to fit, as you would in a ringed motor...they are at their optimum fit when manufactured. Scuffing them in a sloppy rich mode would only take away from the built in performance by destroying the very close manufacturing tolerances. You temperature cycle them to relieve the stress that the manufacturing processes introduced to the metal as it was being machined. It doesn't take much time before it is recommended to fly it for the remainder of the break in.
On a ringed motor, the process is decidedly different. Here you should run it very rich, allowing plenty of fuel oil to lubricate the ring and cylinder as they wear thmselves into a more perfect fit. You interupt the sloppy rich running with a short period of leaning the high needle to get best RPM, and then back to sloppy rich again.
In any case, I would consider a gallon to be plenty for a break in, and I personally would be flying the motor through much of it.
Just my spin on it....good luck.

ross001

This probably seems a bit weird but after I richened it the amount of black stuff decreased enormously!!
I richened it 4 clicks and the engine still feels very hot, I am getting a lot of smoke. Should I richen it more??

Thanks again,
Ross

Capt Jim

My Feedback: (168)

HI Ross. Well since the black stuff has decreased.....that is good. As for the smoke trail in the air while flying...that usually means it is nicely rich...not neccessarily too rich, but rich enough to keep the motor happy. Remember, the oil in the fuel is not just a lubricant, but it is also a coolant, to help control temperatures.
HOT, is a relative word. The motor will surely be too hot to touch, and that is perfectly normal while running and also for some time following a run. If you have access to an infrared remote thermometer you could get an accurate reading, but typically it'd be somewhere in the 200 to 275 degree farenheight. Thats a broad range, but a lot depends upon the fuel mix, type of oil, percentage of nitro, ambient temp' and humdity, prop loading...etc. If the motor is performing well, I would just enjoy flying it and not worry unneccessarily about it.

ross001

Thanks captain Jim,
I think I will take your advice and leave it now.

Ross