notorious_benny
IMAC wannabe!
Registered: December 2005
Location: Griffith, NSW, Australia
Posts: 3186
|
|
Review Date: Wed April 11, 2007
|
Would you recommend the product? Yes |
Price you paid?: $2,650.00
| Rating: 8
|
|
Pros:
|
Excellent power, smooth idle, ignitions run on a straight Li-ion, twin-spark CS version looks mean!
|
|
Cons:
|
The carb block leaks a little, a little more difficult to mount than a DA, the 170 has just been released for the same weight!
|
|
I have a 3W 157 CS TS which I have run in since new. This is my first "150 class" motor, my previous large motor experience has been a DA 100.
This particular motor is running in a comp-arf super xtra, so far I am very happy with its performance for IMAC flying which is my main focus.
I followed the instructions for break in and ran it for four hours on the ground making sure it didnt get hot (ie low rpms), then I put another 15 litres through it in the air on the mineral break in oil (I flew it gently for this period with no hovering or long extended uplines)
The motor now runs on the 3W oil at 50:1
Since the initial break in the motor is performing more and more strongly, it has about 40 litres of fuel through it now, I am spinning a 32-10 PT models carbon prop, it turns up about 5900-6000 rpms on the ground, but in the air this prop unloads quite hard (it will rip at half power while in level flight), I will be trialling a Fuchs 32-12 very soon in an attempt to keep the model quiet.
Starting this motor is just as simple as my DA 100 was to start, flip it with the choke on till it pops, then it takes between 2 and 3 flips to start after that.
At first I had a fair amount of fuel seeping from the side of the black carb block, I gently lossened the four bolts which hold the block onto the crankcase, then slowly nipped them up in a criss cross pattern, now the carb block barely leaks at all, though after a full days flying there is evidence that a little fuel has seeped between the block and the crankcase.
Mounting the motor is not quite as straight forward as the DA's, the cast crankcases apparently do not like any torsion forces on them, which resulted in a solid plywood mounting 'plate' needing to be fabricated to keep the motor 'happy'.
See pictures in my build thread here to see what I mean... http://www.flyinggiants.com/forums/f...ba-scheme.html
In summary, this motor has so far proved to be totally reliable, it is starting to make some pretty good power, though I believe you need to be patient with it, it started to 'come alive' after about 30 litres of fuel, and from what I have been told will take a lot more fuel before its really broken in well.
I havnt started to lean the motor yet, I am sure there is a lot of potential power there to be tapped.
It is a little more finicky than my old DA 100 in that it requires a bit more care to run in and mount it to the airframe, also the small leaks between the carb block and the crankcase are something to keep an eye on.
Probably the biggest killer for this motor is the fact that 3W have released a 170 that is the exact same weight and external dimensions, in a way that almost makes the 157 redundant before it ever caught on.
------------------------------
Stay tuned for the new IMAC model in '09!!!
|
|
FlyingGiants Forums
