running in asp 70 four stroke.

[nigel newby]

I have read several threads on running my engine in, so no problems there. Will follow Lazer John's advice. Just a couple of questions though. I do not have a 12 inch prop, will a 11x7 be ok. Can I use 3 in 1 oil to lube the rockers etc, before starting engine, or does it need to be after run oil.

I don't have a test stand, so can I run the engine in in-situ, I.E. whilst in the fuselage.

Is it advisable to get a rev counter, or can I just use my ears.

Nigel

[Denis Watkins]

Like yours my test stand is in the model, and goes into the air ASAP

3 in 1 oil is Acidic, so don't use it on any motor but it is good on rusty bolts

After run works as it burns away when we fly

Good synthetic motor oil is designed for Aluminium and Steel, so use a few drops of that if northing else

Your ear is quite good at tuning, but a tacho gives you the facts

Don't let the lack of a tacho hold you up though

If The right prop is 12 x 6, then 11 x 7 is ok

[Former Member]

[This posting has been removed]

[nigel newby]

Thanks on the 3 in 1 tip. I was going to put a 13x6 prop on for flying. So a 12 inch prop might be surplus to requirements after running in. Don't want to damage the plane before flying it. So perhaps a few good tent pegs through the undercarriage should do the trick.

There are several on here who do not think following the instructions is the best way to run an engine in.

It does not get upto a reasonable temp, to have any real effect on bedding in the engine. There's not too much difference between the two.

Nigel

[Paul Marsh]

A 12x8 will be ideal. i use them on all .70 four strokes, slightly better than a 13x6 but not much difference.

Edited By Paul Marsh on 11/12/2018 20:17:47

[Jon H]

11x7 will be fine as will 13x5 if you have one. You just want something that is a light load and will allow the engine to rev up nicely. Given the cost of a prop, its probably worth buying one. Even if you only ever use it for running in its better to have it than not. You could also fly with it in a pinch and you can use it as a baseline to check engine performance later on.

As the others have suggested a tacho is not needed but can offer useful information so having one in the box is a good idea. Again though, use it for information only and not a tuning tool.

I also agree 3in1 is not the ideal lubricant. I use the same ML70 as is in my fuel when lubing engines. If not available some 2 stroke oil will work fine. You may want inject some into the crankcase as well.

As previously discussed i recommend you run in as follows:

Start at rich (2.5 turns on main needle) setting and run at approx 3000rpm for a minute or so.

Open up to about 5000rpm or half throttle. Again with the rich mix

After 2-3 minutes wind it up to full power and very quickly tune it for about 90% of peak rpm. It should not take more than 5-10 seconds at full power to do this as you are not looking for the perfect tune. All you want to do is get it hot and get the revs up.

Throttle back to half again, and then just play with it for the next few minutes. Check the temperature (too hot to hold, not too hot to touch. 80-100'c is not a problem) with short 5-10 second bursts at full power and plenty of use through the whole rpm range. Give it a few bursts of acceleration from idle to full power as well. You can get a base setting for the slow run as well. usually they need to go leaner. an idle RPM of under 3000 is what you should aim for.

Once you have about 5-10 minutes time on it pinch the fuel off to stop it and let it cool down. It should have half decent compression and is ready to fly. I have been meaning to do a video of me running one of these in but always forget when the time comes.

Depending on the model you want to fly there are plenty of props that are likely to do the job. If you can let us know what model you have for the engine we can recommend props a little better. Its possible you could use the 13x6 from the get go.

Percy, i agree that in general its a good idea to recommend people follow the instructions that came with their piece of kit. Certainly i will be begging on my knees for people to follow the instructions for my petrol engines so i do understand where you are coming from. In this case however i dont agree with the recommendations in the instruction sheet as they are out of date and do not give the best method for running in the engine. They are simply a clone of 30 year old OS instructions which are no longer valid. Were i merely a club 'expert' stood at the back of the field proclaiming one thing or another then your word of caution is well founded. however, i would hope that i have a little more credibility than that and can assure you this is a better way to go

Edited By Jon - Laser Engines on 11/12/2018 20:13:09

[Don Fry]

Nigel, your last post makes no sense. Percy gave you good advice. Just Engines have a reputation for knowledge of Engines. Follow their instructions. If some fool says otherwise, you can follow that siren, or not.

And you will need a couple of props, to compare and contrast prop performance

But, if that thing bites you, when you are on your knees, wondering if you can get up, to get to the car, to get to casualty............

You are now asking stupid questions, take some care you don't hurt yourself.

[nigel newby]

Hi Don, Part of the problem was, which set of running in instructions do I follow. There are two sets in the box that came with the engine, both have different methods. That is why I read about half a dozen former post on here about running in engines. One set of instructions tells me about 2 1/2 turns for needle valve, the other say 5 turns. One does not say what throttle setting for the first tank, the other says full throttle and about 8000 rpm. All very confusing.

I don't see where I might hurt myself with the post I made. Percy said don't trust the tail plane glue because the engine will win. So I said that I would secure the plane with a few tent pegs hammered into the ground. trust me if I secure the plane to the ground, then Houdini would not escape if it was him and not the plane.

Jon The plane is the old Bi-Fly 40 I have been finishing off. The engine bay was made for a 70 four stroke, so that is what I have fitted. I have a 11x6 and a 13x6 prop. Will pick up a 12x8 as suggested by several on here.

[Paul C.]

Hi Nigel , I have a number of ASP FS engines 52, 61, 91 and 120 have found them all to good reliable engines. The instructions are not the best in the word for sure, I prefer to fly them a little rich for the first few flights after running half a tank through on the ground again rich and not loading the engine excessively. I did find on the 91 that the valve clearance from the factory was a mile out so I check all new engines just to be sure.

Sure you will be fine,

Paul.

[Martin Harris - Moderator]

I hope I've read some of these comments incorrectly. Are some people saying that the person currently responsible for developing and manufacturing a range of engines almost universally accepted as the first choice for "serious" scale competition models is a fool and not to follow his advice? I've just dug out the instructions from SC (identical engines bar the badge and made in the same factory as ASP) and the JE instructions which I assume were written by the very knowledgeable Paul Landels. They differ in several areas so it seems that advice to follow the instructions from the supplier is not too clear cut. For a start JE state that you must use fuel with at least 2% castor - something that has been largely accepted as unnecessary by many experts and manufacturers now that synthetic oils have been developed so far.

For what it's worth (and as simply an enthusiastic amateur, admittedly it isn't much) my own running in procedure for ringed engines would be very similar to Jon's and has never resulted in any problems with a new engine. You're welcome to call me a fool for adopting a method that works for me as I don't have years of top level professional expertise behind me - perhaps I'll be proved to be one next time I run in a new engine?

I must be doing something very wrong though as for the best part of 20 years I've been over-engineering my models so that the tailplane is strong enough to resist any of my engines pulling them off when running at full power. In fact, if I had one that I felt would come away under engine thrust, I wouldn't trust it in the air anyway! The important thing is never to stand anywhere in front of or directly in the propeller's rotational plane with any meaningful power applied - get behind it as soon as safely possible (and ensure there's no-one in the danger area) before opening the throttle after starting the engine.

Edited By Martin Harris on 11/12/2018 21:49:32

[Jon H]

well then...

Don, thank you for the PM. we are all good.

Regarding model restraints a great deal depends on the construction of the model and how the run is performed. A brief run up retrained by the tail is not going to be a problem to any model built to an airworthy standard. That said, i suspect Percy's comments relate to a prolonged ground run at high power and in that instance some additional tethering is not a bad idea. With my own models i retrain and power check most by the tail, but anything over about 180 size gets some help from me. In the case of my La7, Sea Fury and P39 i more or less hang on for dear life when doing a power check!

Nigel your Bi-fly will be pretty rapid with the 70. I recommend you fly with the 13x6 as you intended and perhaps try a 14x6 to keep the engine from unloading too much in flight. GIve it an hour or so in the air on the 13x6 first though. For run in if you are buying a prop 12x8 or 12x7 will be just fine. I recommend 12x7 for our 70's and they do about 10k on the ground which beds them in nicely. For optimum performance and engine life i recommend you use a prop which gives you between about 8500 and 9500rpm on the ground at full power. Over 10k and its really starting to scream, below 8000 and you are loading it up a bit too much. Once you get into larger engines those RPM drop. A 180 for example would run at 7000-8500, that sort of thing.

a friend has an SC 70 and reports good performance from jxf 13x7 props as well. Might be worth a look. Just make sure you have nice low idle if you are using more than 6'' pitch or you will never slow the thing down enough to land.

[nigel newby]

Now I am upset. Laser Jon gets a PM. I get nuffink, hummff.

Have I put the cat in with the pigeons, oppps

Thank you chaps so much valuable info coming this way. Will get a rev counter. It is nice to know parameters, for engine etc.

Percy was right in what he said as he had not seen the model and was giving cautionary advice. Thanks. As Jon said with one model he hangs on for dear life.

Martin, yes I have both those instructions, and was a bit baffled. I would assume that one follows the manufactures instructions, unless of course the both differ, hence the look at the forum. Also I learnt at the age of about 7 not to stand in front of the engine. My Father had bought us a Cox .49 control line plane. As we started the engine I was standing in front of it, and the prop. flew off in my direction. In those I was wearing shorts, and the prop hit me on my shin. I was wearing long socks, so no cuts. But did it hurt, and the bruise was huge.

Thanks Jon on the extra advice on the prop size vs revs etc..

Nigel N looking forward to all his PM's

[Jon H]

Dont be offended Nigel, the PM was not specifically thread related.

One quick bit of info on tacho's.

Dont be tempted to rev chase once you get one. By that i mean dont be too worried about the exact rpm you see and look at the overall picture.

For example, if i tell you an engine should do 8500rpm on a given prop/fuel combo and you see 8450 dont sit there trying to chase the last 50 RPM with a bunch of twiddling. Equally, if you check your engine on a warm summer day and see 8600, then check it again on a freezing cold winter day to see 8400 or even less, dont panic. Engine rpm varies due to atmospheric conditions and colder dense air will usually cause a drop in RPM. It will however give you power power as well as the engine gets a denser charge of air in the cylinder for a bigger bang, and the prop has nice thick air to grab on to. In the summer the air is thinner, engine revs rise, power drops.

The other trap is tuning with the tacho. Staring at the screen for minutes at a time tweaking the needle. Dont do this. When the engine is cold and you run it up to full power you will see a given RPM. After 15-20 seconds the engine begins to warm up and RPM will drop. This could be 100-200rpm on most engines. If you then try to recover this lost RPM by leaning all that will happen is the engine will get hotter and hotter while you fiddle, and will loose more and more RPM as a result leading you to attempt an even leaner mixture. This is not a good idea!

Tune by ear for MAX rpm. Hold that max RPM for 10-15 seconds. If there is no noticeable drop in performance the engine is good to go. Dont bother with a nose up test, its a waste of time. If the engine dies in flight having been tuned this way something else is wrong. Likely tank level or cooling.

When running the 10-15 second power check listen very carefully for any knocking. It will sound like a sharp crack within the overall engine note. Not always easy to spot, but once you know what to listen for its obvious. If you hear any, go 1 or 2 clicks richer on the main needle.

[Engine Doctor]

I had a quick look through the threads ,excuse me if it already been suggested but when running a engine in the plane on the ground make sure you have the wings fitted . The wings absorb/ dampen a lot of the vibration and shocks that can otherwise damage the fuselage and tail plane .

Edited By Engine Doctor on 12/12/2018 09:37:21

[Jon H]

Posted by Engine Doctor on 12/12/2018 09:35:42:

I had a quick look through the threads ,excuse me if it already been suggested but when running a engine in the plane on the ground make sure you have the wings fitted . The wings absorb/ dampen a lot of the vibration and shocks that can otherwise damage the fuselage and tail plane .

Edited By Engine Doctor on 12/12/2018 09:37:21

yes absolutely. I have had many customers complain how much their engine vibrates only to find the model was missing its wings!

[ken anderson.]

Nigel put the motor in your model,fill it up and fly it,take it easy for the first 3-4 flights...i.e.... cruise around in circuits.. no constant full throttle etc..... after a couple of tanks and flights then have a go at doing any fine tuning and that's the job done......

ken anderson...ne...1..my way dept...……..(Frank Sinatra)

[nigel newby]

Thanks for that Jon, and also Doc all noted. Never though about the wings being on.