Super Custom .46 Break in help ...

[shanemarsh28 11]

I have been wondering, how would you guys break in a SC ABC engine??

 

In the past with model cars I've always been quite particular about breaking in engines, running several tanks, no full throttle until the 2nd-3rd tank, let the engine run and cool in cycles up to maybe 5-6 tanks then finally, lots of fuel later change the glow plug then use it as I wished.

 

The reason why I'm asking is because this ritual seems now a little bit excessive and the details I can find seem very vague and about I'm wondering if it may be better (and cheaper!) to break in a couple of tanks instead, run it ritch, make sure its not overheating, ensure it idles OK then get it in the air! Is that advisable?

[Bravedan 106]

The better car engines nowadays have huge amounts of taper on the bore so have very particular requirements, usually you have to heat them up to turn them over at all, even with the plug out !!

 

In any event over rich for too long means too cool to bed, as bad as over hot, usually its short bursts of high throttle at a just two stroke/4 stroke break point

 

You know what I'm going to say............

 

SC Engine Manual Page 4 "Running in 2 Strokes".

 

I suggest you follow it and don't short cut, OK?

[shanemarsh28 11]

The better car engines nowadays have huge amounts of taper on the bore so have very particular requirements, usually you have to heat them up to turn them over at all, even with the plug out !!

 

In any event over rich for too long means too cool to bed, as bad as over hot, usually its short bursts of high throttle at a just two stroke/4 stroke break point

 

You know what I'm going to say............

 

SC Engine Manual Page 4 "Running in 2 Strokes".

 

I suggest you follow it and don't short cut, OK?

 

I knew exactly what you were going to say, and I have read the manual several times and It's just as confusing to me after the first time I read it Hence this thread.

 

On page 4-5 it explains in a lot of detail on how to properly break in a 4 stroke ringed engine, I was in a way hoping for the same level of detail for the 2-stroke engine. As you say with the 2 stroke variety, you run the engine in short bursts of high throttle around the 2-4 stroke break point until a reliable high speed and idle can be obtained without overheating. That's all it really says.

 

I think what's confusing to me is: It's a 2 stroke engine, how can it have a 4 stroke idle and what is the 2-4 stroke break point?

[Bravedan 106]

As a 2 stroke engine is very slowly richened with it running, it will reach a point where there is so much fuel slopping around it that it cannot fire every time it should as there is not enough air in the ratio to do so, and the exhaust note will change down pitch (and of course lose power if power was being asked for). THAT is the so called four stroking. The transition is an uneven beat as the engine hunts between clean 2 stroke running and not.

 

Here is a good sound video of a motorbike :-

 

http://www.youtube.com/watch?v=0wzph3hL6EE

 

Still applies, just because of the bigger cc and bigger silencer its a bit deeper all round.

[Gerard 10]

ABC engines require a different "break-in" routine than ringed engines.

 

There are many web pages on how to break one in. The following is as good as any:

 

http://www.mecoa.com/faq/breakin/breakin_abc.htm

[hotrod 0]

Hi Shane

The best thing is to bring the plane with engine installed to the field and we would be happy to show you.

When you have it running you will soon get it. If the weather is ok perhaps tomorrow

Rod

[Bravedan 106]

Rightly or wrongly I have always considered that the manufacturer knows best with regard their own product.

 

There are quite differing types of engine construction/setup even just in ringless ABC type. Their own advice should be best, surely?

 

Differing generic or information intended for a differing engine/setup, even just in terms of bore taper, will quite likely affect the running in process, possibly adversely.

 

Maybe its just an engineer thing..................

 

No, I'm definitely not anal about looking after an engine after run in, never used "after run oil" in my life, but I do try and follow the specific manufacturers running in process, which if nothing else gets out of one possible issue if a warranty matter ensues.

[shanemarsh28 11]

Thank's everyone for your help .. really appreciated! BraveDan your Youtube video and explanation was just what I was looking for .. If anything I feel a little silly now that I didn't look that up my myself.

 

It's been a very long time since I last broke in an ABC engine, they were a lot smaller .(12 & .15) and not built to the same tolerances these aero engine are today. I do remember the engines making that 4 stroking sound while breaking in, I guess never understood what it was for and why that was important. I will as Rod suggests bring it up to the field before I go any further with it, the engine is already in, assembled and ready to go - hopefully tomorrow if the weather is reasonable.

 

Thanks again everyone for all your help ...

 

Shane

[shanemarsh28 11]

I think you knocked the nail on the head there .. I personally believe that following the manufacture instructions for more or less everything, not just the engine is usually the best place to start .. I'm saying that as a newbee .. but everyone has their own method that works, usually with just as much great success. Everyone does it differently ..