OS Engine break-in help needed

[HeartBreak]

I have two engines that I'm in the process of breaking in. I've ran one tank through each (at idle on the box), running the engines for about 2 mins, then letting cool, running again for 2 mins, etc.. The instructions aren't very clear on how many tanks to do this step for. I'm guessing two, but I might be wrong....?

Sorry if this has been asked before; I searched and came up empty handed.

 

[MyJeep]

Have you try the "SEARCH"?

You will get instant answer if you do.

 

[HeartBreak]

LOL, yes. I must not have used the right terms. Is there a howto on the site? I don't wanna mess these engines up (TZ.12 and VZRII) after all the money and boloney I went thru to get 'em.

edit; I'm still not too clear after reading thru the 40 pages of results. I'm guessing one tank on the starter box (short two minute runs and cooling), keeping temps around 200F (did that), then on the ground, idling around, etc... OS's instructions are just not very clear.

After plunking down $230 for the TZ and $300 for the VZR (not to mention, getting a defective one and having to send it back), I just don't want to mess up an engine.

 

[MyJeep]

Well,

How about this? Took me less then 5 sec to dig it up.

Heat Cycle Method: - Prefered by most people.

https://www.rcnitrotalk.com/forum/showthread.php?t=14996&highlight=steve

http://www.wildhobbies.com/news/default.asp?cmd=view&articleid=1054

http://cefx.net/tips/nitro/break-in/index.php

http://www.rcuniverse.com/magazine/article_display.cfm?article_id=397

WOT Method:

https://www.rcnitrotalk.com/forum/showthread.php?t=32063&page=1&pp=15&highlight=wot+method

 

[Diver6127]

Just to help, here is the direct link to the WOT method, as described by Josh Cyrul
CLICK HERE

The WOT method is a radical way of doing it that is frowned upon by most r/c modelers because it does go against the grain of what we have been taught through the years. You will see the doubt and opposition to it when reading the link to the thread above.

I can personally say that I have used this method, so has sl0eg1n. We use this for our racing engines and have great success with it. I have also seen it being used more often at track side by other racers. I will personally say that if I feel that the engine can handle it, I will do it. Not all engines can handle this kind of stress so you have to use your better judgement. Definitely, do not do it if you have any doubts or shortcomings in your engine break-in abilities.

 

[HeartBreak]

I've read those links, and pretty much they make my brain itch. Seems break in methods vary by person...

Anywho, from what I can tell, WOT sounds a little too, ummmm, insane for my tastes. Granted, Cyrul uses it, but I don't have the bankroll of someone like him. These two engines (much less the Mugen MBX5ps) cost me literally a years savings.

RCU's article amounts to almost the same thing. It's a method I don't care to try, because I don't want an engine to be at high throttle one second, and shrapnel the next.

The article on Wildhobbies I didn't see on my initial search, but that one helped the most. It clarified one part of OS's instructions that are deeply lacking. Apparently, the second (gradual leaning of the needles) is the method that OS recommends (or a close varient of). The key difference is that wildhobbies actually specifies the number of tanks you idle on the starterbox (that was the initial question of mine).

However, I think I'm going to stick to OSs instructions. They seem to be the most 'sane' to me. Thank you for helping clear up that confusion. Granted, I did search, but I didn't come up with all of those links.

 

[Diver6127]

As I said, the WOT method is not for everyone. I was a bit skeptical at first but it's all I will do for my racing engines. No thick bank roll here ... lol. Especially at over $300/engine, it can be a bit nerve racking at first.

Do what feels more comfortable for your needs. I have done the idle, heat cycle and rolling break in method. All work well and have been used by many. Just remember that when cyrul says 16 hrs of race time, that's about 4 gallons. This is the avg life expectancy of a racing engine since when racing, higher temps are reached than the average joe will see or about a season of racing.

I got this avg by figuring that when racing, the avg touring car will pit about once every 5 minutes and if they get a full tank every time that's 75cc.This will equate to 12 tanks/hour which will equal about 900cc. Multiply that by 16 (Cyruls claims to life expectancy of an engine. 4hrs is runing straight aka enduros). 16 hrs of racing will be about 14400 cc's. To convert this to gallons, multiply 14400 x .0002642 which will bring you to 3.80448 gallons (approx 4 gallons).

If you factor in the element that most of us panic when we see any temp above 250, the consumption of fuel will increase accordingly and engine life will be increased. The average racer in Cyruls circle will run at about 260 degrees mid tank and close to 280 when almost dry. We, the avg racer/basher usually run about 220-240. If you're CorradoPSI, you'll temp over 400 degrees on your savage. LOL (sorry Chris, just had to say it).

 

[HeartBreak]

Thanks for the input, Diver. I definately appriciate the help. It's just too bad OS's instructions on break-in are a little unclear. Seems 4 gallons is about average life expectancy for an engine, or am I wrong?

 

[Diver6127]

Four gallons is pretty avg but I have gone higher before losing compression and needing a rebuild. More like 6 gallons on my OS 12CV-rx

 

[vbgagnon]

Get your engine running and get the temps to about 200-220 no more no less deg run it like that for the tank, then let it cool to room temp, do this for 5-8 tanks then start to tune. You will get plenty of life through the engine.

 

[olds97_lss]

Just an FYI, I haven't gotten less than 10-12 gallons through an engine before it needed re-pinched.

OS 21 RG - 12 gallons, re-pinched, now on gallon 4 after pinch.
Omega 21 Comp - 9 gallons and still running strong.
OS 15 cv-r(x) - 12 gallons, then traded, new owner got a couple more through it.
Orion wasp 18 - 11 gallons then gave up on t-maxx's.

Of course, there are a couple of "exception" engines...
Mach 15 - first engine I had in the hobby, 5 gallons because I didn't know you had to break in.
OS 15 cv-r(x) - 4 gallons, tried my hand at porting... didn't go so well.

I bash only. No racing. I try to keep the temps between 210 and 250 at all times. I run trinity MHP 20% fuel.

4-6 gallons may be the average for a racer though... 11 is my average. All of my engines are obviously not your $200-$500 racing engines. Just run of the mill mid-grade engines.

I use the heat cycle method. Run for 3 minutes or so at 200-210, and let cool with piston at BDC. I rev the engine after the first cycle by driving around moderatly. I don't hit WOT until tank 7-9. I don't "run" the engine until about tank 12. But, I tune accordingly through all tanks to keep the temps around 210.