35% Jtec Radiowave Extra 330

[JayB]

Oh yeah, this motor is a 3-W 100i B2. does anyone know what the length is of the DA 100? My motor from back to the spinner backing plate is 7 3/4 inches

[Yakster]

YIKES! Only way to fix that Jay is to cut the motor box cheeks back, and re-install the firewall. A PITA, but atleast it will be right. The DA 100 is shorter than the 3W... but not by 2"! Is that a rear-carb or a side carb... I cant remember on the older 100s. Personally, I would measure how much you need to move it back, add 1/4" to 1/2" (so that you have to use a spacer). Then mark those measurements from the front of the firewall, measuring back onto the cheeks, so that you maintain built in thrust angles. Take a circular saw, and zip the motor box cheeks on the lines you have marked, effectively shortening it within your needs. Youll have to use a small standoff to get your motor to exit the cowl... but atleast you wont be too long again. Once instance where if you cut too much off, its not as much of a PITA as if you have to much.

[SleepyC]

JayB, where di dyou get the Volt meters?
And.. I have the same power expander for my 33% extra.. where do you plug in the meters?

[ShortBus]

http://www.cactusaviation.com/Produc...s/i4c/i4c.html



^^^^^^Voltmeter^^^^^^

[JayB]

Hey Sleepy, SB's got the link for the volt meters. and their on a y harness right to the voltage regulator after the switch.

[JayB]

Alright after some thought, research, and phone calls with yakmanI decided that I'm going to cut off the front of my motor box. I found that my 3-W 100 sticks out 2 and 1/4 inches too far. With that kind of space between the engine backplate and cowling it will look a little ugly. The 3-W 100 is 7.5 inches from back to front. And the DA 100 is 6.5 inches from back to front, so if I did go with a DA 100 it would still stick out 1 1/4 inches. still a bit much.

I plan on cutting 2.25 inches off the front, another problem is that there are 3 lightening holes that I cut on the sides of the motor box. If I cut the 2.25 inches off I'm going to be right in the middle of the front hole on the side of the box. So I'm also going to have to reinforce the sidewalls on the motor box. I'll keep you posted on the mods after I go the the LHS and buy the wood. Shouldn't be too difficult.

[ShortBus]

Just cut it off right behind the lightening hole and use stand offs....

[JayB]

OK, So heres how the process went. Very simple actually, I marked the motor box 2.5 inches all the way around. In hind sight I should have maybe cut only 2.25 or 2 inches off. to leave room for washers for up, down, and right thrust setups. It looks like I may need to add 2 more washers to each mounting bolt to get the correct distance I need.

After the motorbox was marked I took my jig saw and just fallowed the line. After that I cleaned up the firewall block and stuffed it back in there to check the fit. I tacked it in with CA and remounted the motor. Check to see how the spinner lines up and take it back apart. I'm going to have to wait till I get some wood to really tie the motor box back together but all in all it worked out fine. Only really took about a half hour, I figure another 45 mins to tie everything back togeather. Minor setback.Heres some pics.

[Rob B]

Looking good Jay, coming together nicely.

[rodman]

Damm nice job!!
Keep up the good work on that bad boy its almost flying
season!!

[aviti]

I'm curious if the 3W and the DA are both too long for the cowl, what engine did Jtec design the cowl to fit?

[GremlinX]

Yeah, what motor did they design it to fit?