Performed an Engine Breakin Today

[JoeMAXX]

I know this has been mentioned many times in the past.

It was 55 degrees outside today and I had just bought a new HPI Trophy 4.6 Truggy. So I wanted to perform the engine breakin so in the spring I can finish the break in process. I carried enough fuel today to get thru the 4th tank of fuel I will perform the 5th tank in the spring. The hottest my engine got today was about 160 degrees.

Below 60 degrees outside you need to keep the engine a bit warmer for proper breakin and seating of the parts.

Wrapping no more then the top half of the fins of the engine with foil will help to reduce effects of cold weather break in and this is my suggested method. It was warm enough today that I did not need to wrap the engine.

Wrapping the bottom half of the fins on the engine might get your engine too hot and may not provide enough cooling to the areas that require it the most.

I have multiple different Engines manuactures installed in my various R/Cs and each seem to have a slightly different break in procedure then some have also changed it over the years. I am old school and have been running nitro engines since 1999 than like the old tried and true method of a 5 tank breakin procedure.

O.S Engines used to post a similar procedure years ago now they suggest you can break in an engine with just 3 tanks. They also suggest using a High Oil Content fuel these days of least 18% or higher during engine break in.

NovaRossi suggests an 8 Tank break in procedure. They also suggest using a High Oil Content fuel during Break in. These are high compression engines so I see why they suggest it.

Picco also suggests using a High Oil Content Fuel during break in to reduce wear on the parts and keep the engine cooler.

Traxxas has always suggested a 5 Tank procedure for their engines. Traxxas top fuel is a high oil content fuel mix. I used the 20% Nitro for my engine break in today.

HPI Racing blew me away with them suggesting running the first tank of fuel with the tires off the ground and only a 3 tank breakin procedure. This is the worst thing you can do to your new engine :whhooo:

So in conclusion if I am ever asked what is the best break in procedure I will suggest a 5 tank gradual procedure leaning the fuel mixture by 1/8 of a turn on each tank of fuel with slow to meduim speeds thru the first 4 tanks and do not sustain full throttle on the 5th tank for long periods of time until you are on your 6 tank of fuel. By the 7th tank your engine is race ready.

 

[lesclaypool]

I would also suggest pre-heating the daylights out of it, and try to keep temps up over 200. If that takes more wraps with tinfoil, so be it. Just don't lean out to get temps up. The last engine I broke in, I ran over a half gallon through it before ever shutting it off. Started it for the first time, then ran it continuously for the half gallon. Super rich and super easy on it leaning only very slightly on the HSN. Then next time out I started it up and ran the remaining half gallon I had. So one gallon through, and I only started it twice lol. Once pinch was relieved(which took a full gallon), then I started performance tuning.

 

[olds97_lss]

I've read many break-in methods with the most recent one being the seemingly most aggressive, but in theory it sounds good and helps relieve excess strain of repeatedly starting the engine.

https://www.rcnitrotalk.com/forum/showpost.php?p=986008&postcount=6

 

[lesclaypool]

That's the exact method I used, with fantastic success. Just remember to go easy, lots of smoke, etc. I used(and use for all my rigs) Byrons 30%/9% lube for break-in and otherwise. It's about the 'best' fuel I can get around here, and I've had good luck with it.

 

[2revo1maxx]

^That's the way to fly right there^. Joe you should've partially covered the head with something. I will run uncovered in 60° weather, but not during a break-in.

 

[JoeMAXX]

I only ran 4 tanks this time out. Yes I agree that I should have let the engine get a little hotter on these first few tanks. They were run very rich with only a few stalls on the first tank of fuel. The rest were medium speed runs without any stalling. I am going to finish the break in procedure of the engine in the spring time when the temps get a lot warmer out.

 

[Racer 1966]

Why wait now? In 4 tanks if it's going to be damaged by the temps it's already done. I'd wrap the head and finish it now but then I wouldn't have started it in those temps. Just my

 

[Greywolf74]

The break-in method I use is pretty similar to Robin's

 

[JoeMAXX]

Why wait now? In 4 tanks if it's going to be damaged by the temps it's already done. I'd wrap the head and finish it now but then I wouldn't have started it in those temps. Just my

The engine can wait till spring to finish breakin and the low temps with lots of oil will never damage the engine.

So we all understand the break in process it is to seat the piston to the sleeve and never run full all out throttle runs until it is achieved. A longer break in process will not hurt the engine as long as there is plenty of lubrication on the engine even in cold weather which is why I chose to run the 5th and 6th tank in the spring.

Now I must ask do any of you park the piston at bottom of the stroke when your done running and put after run oil into the engine. All my engines pistons get parked at the bottom of the stroke.

Since R/C engines do not have pistion rings like real engines than are best to store them when they are at the bottom of the stroke so you do not expand the piston sleeve with the piston sitting somewhere in between. Over time it will reduce the compression of the engine. How many of you guys take the time to turn the engine over so the piston sits at the bottom of the stroke ?

 

[lesclaypool]

Always have, always will

 

[Nitro4910]

I always leave the piston @ BDC when I put them up, it's something I've always done & see no reason not to.

The downside to running an engine too cool during breaking is you never get it warm enough to break it in, & running it too cold during breaking doesn't allow
for the needed expansion of parts & can put extra stress on the engine internals.

If your not going to get the engine up to a proper break in temp then there no reason to waste the fuel.

Too rich is almost as bad as too lean, just my

 

[2revo1maxx]

^This is it, right up here^.

Too cold will stress the conrod and piston/sleeve set, I don't care how rich it runs. I'm sure it'll be fine if you maintained 160°, but that's a bit cool. Also, for the record, you can break-in with 10% oil in your fuel if you wanted to, it's not gonna matter as long it was run rich.

 

[Greywolf74]

I break in my engines with the same fuel I run in them. Odonnell's 30% race blend which only has 8% oil in it. I just make sure I'm running it rich enough to bog (but not die) for the first several tanks then I start tuning it.

 

[frickenjoey]

Now I must ask do any of you park the piston at bottom of the stroke when your done running and put after run oil into the engine. All my engines pistons get parked at the bottom of the stroke.
How many of you guys take the time to turn the engine over so the piston sits at the bottom of the stroke ?

Yeah no big secrets here. I think pretty much everyone does if they know the first thing about nitro.

 

[JoeMAXX]

Well now newbies also know it if they read thru this.

Back to the fact that I have not hurt this engine and it will provide me with years of play time. Rich engine mixes will never hurt an engine and does not put a strain on any parts. this comes from the manufacturers of engines the only that happens during really rich mixtures over time it will build up an oil deposit on the parts. You can call it carbon build up on an engine that has excessive oil leak from worn piston rings. This can happen in Two Stroke engines over a long period of time. Break in is short period of time. Lean settings will fry parts rich settings never hurt anything but will fry a glow plug. My glow plug did not fry from excessive oil content on it.

 

[2revo1maxx]

Too rich means too cold most of the time. If you run too cold your engine runs too tight, which will damage it. You can also ruin plugs by running too rich.