break in

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RevoMatic said:

Hi i just purchased a new OS 21TM that i'm fitting to my Revo 5309 and was wondering what you guys think would be the best break in procedure. Everyone seems to have a different idea & i just wanna get the most out of this engine. Is there anywhere i can find some kind of guide to the running in process, any help would be greatly appreciated. Thanks.

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Hi RevoMatic,
Welcome to the forum.
I'm not familiar with your model, but I have had great luck, watching Savage X engine break-in videos on Youtube.
Just type in your make or model there and see what comes up.

Best wishes, enjoy your models.

Chas

Do what OS says or use the traxxas method. If it's below 60°f outside you should wrap the cooling head with something so it will warm up properly.

I'm just about to do this myself, just have to put the rear end back together on my revo & fit the 21tm into it. I'm going to use the heat cycle method that is on one of the forums, might be the R/C Tech forum I think. Seems a lot of people have used this method & have had better performance & longer life out of their engines, that sounds good to me. Its actually similar to the Traxxas method with slight difference.

RevoMatic, what fuel & nitro/oil percentage are you using, I'm going to use the same fuel I used in the 3.3, Redback sport 20%, it has 12% oil content, although in the book that came with the 21tm engine, O.S say to use fuel with 18-20% oil, bit much I think.

I was going to post up squirrel's tuning guide vids as thats the way I've been doing my break ins but it would seem he has a whole new video series out on breakins that I havent seen myself yet but plan on it. Heres the playlist link if you anyone is interested. This guys own hundreds of RC kits. Some of his how to vids are tops IMO.

http://www.youtube.com/playlist?list=PLFA589778F07E3713&feature=view_all

Pre-heat the engine to 200+F, start the engine and let it idle for 4-5 minutes. Then put it on the ground and drive it around keeping the rpm low for the first half gallon. Drive it as much as you can without shutting it off and letting it cool down, you can re-fuel while it is running and keep it going until the receiver pack dies, then put in a new one and repeat. The heat cycle method does nothing more then wear the starting components while everything is still very tight causing a lot of stress.

Once the "mechanical" pinch has loosened up so when you turn the engine over with no glow plug, and there is only a little bit of resistance at TDC, then you can start tuning for performance and there is a guide in the link below.

I recommend 30% nitro with 8-10% oil content. I also recommend using an MC #59 (hot) glow plug for break-in. Don't be afraid to twist the needles and lean the engine slightly so it will stay above 200F and if needs be then cover the cooling head with a sock or whatever to help contain the heat. Once break-in is done then I suggest going to a MC #8 (medium) plug for the performance tuning.

https://www.rcnitrotalk.com/forum/showthread.php?t=76808

^^^ There's your break-in guide right there. Keep it simple, with everything covered, no nonsense and wasted time.

The heat cycle method is nothing more than a classic case of people over-thinking something simple.
Cold starts are the worst thing for your engine, and you want as few as possible within the first couple tanks.

Not trying to discredit anyone here but in my experiences with OS, I've always used their method with great success. Run the 5 tanks or so and then just ease into tuning from there.

So heat cycle with cool downs, then heating back up with heat gun is not proffered anymore? I thought the cool downs were necessary on a molecular level to expand/shrink (temper) the new parts.

I've always done heat cycle with heat gun warm ups...

Heat gun warm ups are fine for heat cycling, but the idea is to avoid as much "tight running" as possible. The metal will do whatever it does naturally as time progresses.

To even begin to change the molecular structure of an aluminum piston you need a minimum temperature of 700+F. This is not even a possibility to achieve when performance tuned let alone running rich for break-in. The manufacturer will suggest this method because it almost guarantees aftermarket sales for the starting mechanism and parts due to the excessive wear and tear.

So, fire it up and burn half a gallon while adjusting the tune to keep it running without stopping the engine... You have done this personally on many engines I take it? Many engines you keep and know how long they last and how they were maintained?

I'm not doubting really, just curious as that sounds a heck of a lot less annoying that heat/start/stop/cool and repeat 5+ times, which I have been doing for the past 10+ engines I've owned. Every one of them ending with blistered/bleeding fingers by the time I was done for the day... I love pullstarts... except for break-in.

It has been a very long time since I've had an engine "wear out". If I had to guess, I'd say the 3 I currently have are all about 3-4 gallons into their lives (2 LRP28S3 1 TRX2.5R), except for the 3.3 I put in my revo for the winter. It's probably at 1-1.5 gallons.

The last engine I had long enough to lose it's pinch was an OS21RG, it started flaming out around gallon 10/11. I had it pinched and ran about another 5 through it, then started trying out other engines in the power hunt.

I just can't get over the amount of stress that's being put on an engine using the heat cycle method. I have repeatedly used a method similar to the traxxas method and my engines usually last well beyond 5 gallons with no issues......when I don't have air filters falling off .
I actually ran one engine from first startup to tank 8 last summer, then tuned it for max performance after a glow plug change. It's still going strong after 2 years, it has about 4-5 gallons on it. I'll know next year if any of my engines have made it to the 7 or 8 gallon mark, but there's 6 of them and it's hard to keep track with any kind of accuracy.....I count tanks.
I honestly don't think anyone can truly determine if any one method is better than any other, with the exception of knowing that cold starts and cold running are tough on a mill.

Doesn't the traxxas method have you shut off the truck between tanks? So it was basically a truncated heat cycle method... or I thought it was.

olds97_lss said:

So, fire it up and burn half a gallon while adjusting the tune to keep it running without stopping the engine... You have done this personally on many engines I take it? Many engines you keep and know how long they last and how they were maintained?

I'm not doubting really, just curious as that sounds a heck of a lot less annoying that heat/start/stop/cool and repeat 5+ times, which I have been doing for the past 10+ engines I've owned. Every one of them ending with blistered/bleeding fingers by the time I was done for the day... I love pullstarts... except for break-in.

It has been a very long time since I've had an engine "wear out". If I had to guess, I'd say the 3 I currently have are all about 3-4 gallons into their lives (2 LRP28S3 1 TRX2.5R), except for the 3.3 I put in my revo for the winter. It's probably at 1-1.5 gallons.

The last engine I had long enough to lose it's pinch was an OS21RG, it started flaming out around gallon 10/11. I had it pinched and ran about another 5 through it, then started trying out other engines in the power hunt.

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I have been using this method for years as well as all my customers who get engines from me. To date there has been no issues with any of my engines, or anyone who has taken my advice with stock engines in terms of break-in procedure. The guy with the 60mph savage followed my advice and continued to beat and abuse his engine for 6+ gallons before it stopped gaining power and started the slow decent, which he can still get another 4+ gallons of bashing no problem.

I'm not the type of guy to just run my mouth unless I can back what I say with years of R&D and hours of testing. I'm an electrical instructor by trade with 17 years in the field and this is a second job for me. But rest assured, I would never tell anyone to do something if it could potentially cause damage, it's bad for business

I know this doesn't follow the norm of the rc run in procedure, but I have used it on all of my nitro engines. I have built plenty of full size engines and this has always given me the best results. I try to find a nice parking lot or field to do this. I start up and let the engine warm up. While letting it run a little rich, run from one end of the parking lot to the other going from near idle to almost top rpm. Don't hold the rpm's up, just run low to hi under full throttle for about 5 tanks of fuel. Then start to tune in. My friend used the traxxas break in method on his 2.5 rustler and I can run away from him with the exact same truck. I have 3 gallons of fuel through mine and it runs like brand new.

That's not a good idea at all. If your truck is faster than your buddy's truck it's gotta be a slight difference in the chassis, or else he did his break-in even worse than you did.

Olds, I use a method "similar" to traxxas, but I don't shut down every tankful unless it quits. Shutting down doesn't really matter much if you pre-heat before startup.