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3w 120i b 2 f

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Old 09-04-2010, 11:07 PM
  #1
plane jocky
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Default 3w 120i b 2 f

im getting ready to install this engine on a knoxhobbies pitts m12same as a blazing wing pitts m12 any one did this yet ???? and what size prop should i run???? thanks guys
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Old 09-05-2010, 04:15 AM
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Default RE: 3w 120i b 2 f

Dunno that motor, but I am assembling that pitts with a DA-120. Going to use a Mezjlik 28x12.

Are you going to use the stock undercart?
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Old 09-05-2010, 06:20 AM
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Default RE: 3w 120i b 2 f

Hi,

If you use a 28 x 10, you can expect between 6000 and 6500 rpms depending on the condition of the engine.

Hope this helps

Elson
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Old 09-05-2010, 08:50 AM
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plane jocky
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Default RE: 3w 120i b 2 f

this w3 120 is kinda heavy. at around high 8 lb maybe 9lb it puts out about 11.5 hp from what i can find out. do you think i should go with the dle 111 it weight is around 6.5 lb and puts out 11.5 hp .eather way i go im useing stock cans
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Old 09-05-2010, 10:40 AM
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Default RE: 3w 120i b 2 f

I have a friend that has that engine in an Extreme Flight Yak. Yes it is a little heavy but he swares the power and torque it produces is worth the weight.
He runs a 29/10.
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Old 09-05-2010, 08:09 PM
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Default RE: 3w 120i b 2 f

Hi,

I have both 3w-106s and 3w-120s. On paper, they are rated close to the same power but the 120s have significantly more grunt than the 106s. Heavier engines, yes but more torque due to the larger displacement.

Elson
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Old 09-06-2010, 12:09 AM
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Default RE: 3w 120i b 2 f

Yup, that's a stone cold fact..

People like to under rate the heavier 3w's. Don't ever put the competiton's 150 up against a 3w-140. I hate to see grown men cry
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Old 09-06-2010, 11:05 AM
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Default RE: 3w 120i b 2 f

That's nice to know TOM I've just bought a 3W Ultimate with a 140 in it but I'm waiting for a WB25 carb for it
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Old 09-06-2010, 08:32 PM
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Default RE: 3w 120i b 2 f

Hi,

The main problem with the 120 is that it weighs the same as the 140 and 150 (within a couple of oz) so if you are going to run a 120, you might as well find a 140 and fly with throttle management.

Two of the 4 older 140s that I use post better numbers than a lot of people post flying a DA 150. The other two turn similar numbers. These are those old engines with the brown fiber carb block.

Elson
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Old 09-07-2010, 02:23 PM
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Default RE: 3w 120i b 2 f

does the older 3w still use that brown block if it goes bad or has a new better item replaced it?
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Old 09-07-2010, 07:22 PM
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Default RE: 3w 120i b 2 f

Hi,

I still use the brown block. As I recall, DA made a black block which was a preferred replacement. I just use 2 carb gaskets and do not over tighten the carb bolts which warp the brown block. Perhaps the newer 3w poly setup found on the newer 150s would work.

Elson
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Old 09-08-2010, 02:23 AM
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Default RE: 3w 120i b 2 f

3W now list either a black plastic one or an aluminium one on their webpage I believe the alloy one is cheaper
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Old 09-08-2010, 10:23 AM
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rc bugman
 
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Default RE: 3w 120i b 2 f

Coke,

I believe the parts you are talking about are for the new style engine. The old style requires the block. For a few extra bucks, you may be able to convert the old style to the new style. Call Gerhard at AI and ask.

Elson
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Old 09-08-2010, 10:31 AM
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Default RE: 3w 120i b 2 f

I can't remember who is making them, but someone is making the aluminum carb block for the old style 3w engines.
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Old 09-09-2010, 10:09 AM
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Default RE: 3w 120i b 2 f

f back who even is making those blocks is that a replacement for that red/brown block?
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