Engine opinions...

techguy

I am going to build a Spa3d from
http://www.spadtothebone.com/SPAD/SPA3D/index.html

I am considering putting on an SC .46 or .53 what are your experiences with SC engines,are they reliable?
I also have an OS .46LA available to put on the plane. If I was to put this engien on would it have enough power for hovering and 3d etc.
BTW this plane is rated for a .46 engine but will the LA engine be a weak 46?

Hakko

Fobia

hakko1872003 wrote:

what are your experiences with SC engines,are they reliable?

I've used several, and the answer to your question is no, they're not. But they're damn cheap so unless you're planning on entering world championships they're good enough .

The OS should do you for now, once you feel it's underpowered buy a more powerful engine but no point in wasting money (engine's get cheaper, and they have a lifespan, so waiting until you really need them is often the best idea money-wise).

coolwings

OS LA weaker ... but also lighter, very smooth, not fussy tuning wise, expensive, bushings
OS FX solves all problems of LA, stronger, more expensive, ballraced
Irvine ... strong, smooth, heavier, medium expensive, bushings
SC looks like OS FX, performs like Irvine, doesnt last as long as either, medium-cheap
MDS ... 2 in every 20 are horrible, 15 in 20 are OK, cheap
Webra high compression, expensive, high power, tune it right and it will beat all the above
MVVS .... high compression, similar to Webra on power, distributes direct into Ireland so costs less, ballraced, very hard steel takes 10+ tanks to run in
West ... a modified Webra, also very strong, very good, high compression, expensive.

Low compression engines popular in US, and with beginners. High compression engines popular in Europe and with competition fliers. The high compression engines give more power, a good comparison is that they on 5% nitro are the same as others on 10% nitro, or the others with a tuned pipe.

My view, if you have trouble tuning engines get OS, if you want power get MVVS/West/Webra. The others Enya etc are in the middle.

An interesting fact is that the budget (far east/russian?) engines have been designed to provide 15 hours of lifetime. That is also why experienced modellers should ignore all the claptrap about how good budget engines are. They generally last us 2-4 year then lose compression/get loose bearings/crankshaft/exhaust manifold treads fail. That is the end of the typical average modellers "lifespan" worldwide, and the big distribution companies know it, and do not design in extra (expensive) engine lifespan.

A regular flier has plans to get 1000+ hours from an engine which is substantially more than cheapies are designed to do.

This is just my own personal view. Others will have their own different views of course.

techguy

I will put in the .46LA and and add a bigger engine if I need it.
I want power,but no complicated high compression engines. The engine must also be around the hundred mark and I will be looking for around a .53
I might go for the irvine they seem to fairly popular..but at around €150!

Have you any experience with the Spa3d Coolwings?
Hakko

EDIT: What about Thunder Tiger and Super Tigre engines just looking at a site now and they seem around the hundred mark.

coolwings

hakko1872003 wrote:

...I want power,but no complicated high compression engines...

Then U must use the next bigger size of engine !

hakko1872003 wrote:

...The engine must also be around the hundred mark and I will be looking for around a .53 I might go for the irvine they seem to fairly popular..but at around €150!

But an MVVS 50 is EUR109.50 and is ballraced where the Irvine has bushings.

hakko1872003 wrote:

Have you any experience with the Spa3d Coolwings?

Not me, I don't try to reinvent the wheel .... I do mainly kits.

hakko1872003 wrote:

What about Thunder Tiger and Super Tigre engines just looking at a site now and they seem around the hundred mark.

there have been Thinder Tiger 42s in The Green Hobby sale for EUR70 for the last 6 months

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LATER EDIT Just to correct a mistake ... the Thunder Tiger 42s are EUR52.50 in the Green Hobby sale, (EUR70 was the old price).

The Spad idea works for modellers I know, but I never tried it. I don't know which design is the favoured one. I would probably look at a flat profile delta design if I was going to do one. A flat wing goes well on a delta. I have seen several of these fly. They are very fast.

techguy

If I get the cash I might go for the MVVS .50 , would this be two powerful for the spa3d which is rated for a powerful .46 what are the consequences with overpowering your plane? if it is then I will just stick it on my wot 4 and put the .46LA into the spa3d.
Also i'm not at all to sharp at tuning engines,so does this mean I will make crap of the MVVS?
Is running in the engine just just running the engine from low revs to high revs and leaving high for a sec then back down to low and repeat again for 10 tanks of fuel.If not how?

Hakko

coolwings

hakko1872003 wrote:

If I get the cash I might go for the MVVS .50 , would this be two powerful for the spa3d which is rated for a powerful .46 what are the consequences with overpowering your plane?

Something about 1350mm-1450mm wingspan is about right, other parts of plane in proportion. Think in terms of Wildcard, Diablo dimensions, etc.

hakko1872003 wrote:

...then I will just stick it on my wot 4 and put the .46LA into the spa3d.

I'm not knocking the OS46LA, it is just a "softer" engine, use with slightly lighter airframe for best results, that's all. (It is the ultimate "easy to run" engine)
For 3D, with the 46LA, a 11x4 prop is good using 5% fuel, or with 10%+ nitro a 12 3/4 x 3 3/4. The MVVS 46 uses the 12 3/4 x 3 3/4, and the MVVS 50 use a 13 x 4 on 5% or Straight..

hakko1872003 wrote:

i'm not at all to sharp at tuning engines,so does this mean I will make crap of the MVVS?

Nope. Just leave it on "makers setting per manual" & don't bother tweaking, "about right" will be more than good enough.

hakko1872003 wrote:

...Is running in the engine just just running the engine from low revs to high revs and leaving high for a sec then back down to low and repeat again for 10 tanks of fuel.If not how?

SUGGESTIONS ON RUNNING_IN MODEL ENGINES (2-stroke)
1 Run rich
2 Stop after 1st 4 mins, let cool
3 Restart run rich for 2 tanks/20 mins
4 Run fast, lean out a bit, if engine slows after a short time, richen a bit again.
5 Run and lean out progressively until normal settings are achieved without cutting out.
6 Retune and run at normal setting until engine begins to idle smoothly.
7 Fly
Time taken for above....3 -6 tanks "soft" engines, or "1/2-2 hours running for "hard" engines.

Alternative "fast run in " procedure, run rich, lean, monitor temp richen to keep running, then lean again, sooner or later the engine is run in. It takes 1/5th the time of above. But I don't do it that way, since I feel it is harsh on piston, liner & conrods. I suspect it shortens the life of those parts some, and so I run them in the methodical way.

Always be prepared to replace a glowplug or two when a high power engine is new. The element gets pushed in a bit with the forces.

It is the smooth idle that tells you when an engine is run in, before that point, any engine will only idle when tuned "richer than normal" but later it idles stronger and smoother on a "lean-normal" setting because it needs less lubricant oil to revolve freely.