ic Engine Type

[Martyn Johnston]

Another newbie here.
Thinking of buying my first powered plane.
The kit recommends an Evolution Power Trainer 2 stroke engine.
Am I right in thinking that the 2 strokes are the loud whining screaming engines? Do the 4 stroke engines sound more like proper engines.
Martyn

[Alistair Taylor]

Slightly - but nothing like a Merlin :)

For the purposes of a trainer I would recommend you get a two-stroke. Particularly if it's your first engine.

My reasons for suggesting this are;

1 - Two-strokes are easier to set up - no need for electronic tachometers - no valves to adjust - if you get the needle valve settings wrong (too rich/too lean), you can hear it and, if you're using castor-based glow fuel, they will conk out before any damage is caused.

2 - Two-strokes are cheaper. You will crash if you're a novice, why risk damaging or destroying a £100+ engine into the bargain?

3 - Two strokes need very little servicing. All the bits that whizz around are constantly coated in oil. With four strokes some of the rotating/reciprocating parts are isolated from oil sources, and need regular lubrication. Both need after-run oil to prevent corrosion occurring after flying sessions.

Most modern two-strokes are usually very well silenced. They will scream if you put a small, high pitch prop on them. This is not what you need for a trainer.

If you do buy an engine, read the manufacturers advice on prop sizes, and go for one with larger diameter and lower pitch, which will have the positive side effects of giving your plane better initial acceleration, and thus shorter takeoffs, as well as offering greater propeller braking, and thus slower landings.


AlistairT

[mfin]

All sound advice I reckon, you don't have to stick with the recommended engine though.

It appears that the Evolution Power Trainer 2 is a 0.45 cubic inch 2 stroke...
This means there are plenty of alternative but similar sized 2 strokes you can pick from.

It would appear that the Evolution comes with a prop and spinner?

These are relatively low cost bits and bobs so if you are interested in other engine choices and learning as you shop around then go ahead.

Typically for instance you would be looking for a decent .45/.46/.47 engine to be spinning something like a 12 x 6 APC prop (or maybe a 12.5 x 6 Bolly Clubman prop) and it should perform really well (giving healthy fast, suitable maximum revs) and, importantly for club use, be quiet enough to pass most standard noise tests.

Personally I'd avoid cheap non-ballraced engines (which there are less and less of about anyway as engines get cheaper) and not bother going for the most expensive ones by the big manufacturers either, chances are you'll not get to appreciate the difference much.

For engines, the most helpful people you'll find are the people at Just Engines, look them up at www.justengines.co.uk or give them a ring on 01228 712800.

[Martyn Johnston]

Good, friendly advice.
Thanks all.
Just been given a cheap, 2nd hand, OS 46.
From what you've been saying it sounds like a good first engine.
I'll save my money until I know what I'm doing.
Martyn