IMAC Double Build, Carden Pro 124" Extra 300 40%

[Snoopy1]

This is the way I did my baffling. It tool quite some time to do, and now, here are the results. SO what I did is the following. Which was a labor of love . I extended the front lip of the bottom cowl to the front of the cylinders, first using balsa sheeting 1/16th", then layers of 3/4 ounce fiberglass tape and West System Epoxy resin. Then, laid a single layer of carbon fiber cloth with resin. to strengthen this, The front lip then had to be filled with bondo / filler, then sanded down to make it smooth. Once this was done. I then glued on rails on both sides, about 1/2" wide, extending them back, so that I can then install the baffle plates, one on each side. In the back, I glued on(using Aeropoxy) plywood, that is fixed to the firewall, and fills that rear gap. All that is left to do is drill holes thru the whole thing, and fix with 4-40 screws and blind nuts. The Shroud is on as well.

Sorry but I have to ask every time I look at a quad installed and baffled the cylinder head fins a running in the wrong direction. I would want to turn the heads 90 degrees so that air hit the full head and not just the top half and directs the air down , or am I missing something.




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[orthobird]

Well, it is a done deal, as they say, the Fat Lady has sung. Now these airplanes are on ARF mode. Once they are completely assembled, then time to clean the shop up, and then start on the JTEC MX2.

These stripes were all done with Klass Kote Paint.

 

[orthobird]

That looks nice and clean well done. See your location it is possible to fly it as soon as it's completely built. Enjoy the plane.

Yes, temp wise it is Ok, but looks like rain for the next week or so.

 

[orthobird]

Hello Snoopy, At first, I did not see your question, but then I found it. I will post again here for everyone to see it.:


Snoopy asked:

"Sorry but I have to ask every time I look at a quad installed and baffled the cylinder head fins a running in the wrong direction. I would want to turn the heads 90 degrees so that air hit the full head and not just the top half and directs the air down , or am I missing something."



Yes, I believe I understand what you are saying. The top of the cylinder head, the fins should be directed perpendicular to the way they are currently engineered and manufactured. That way, air can cool the top of the cylinder head.

I am not qualified or know much to answer your questions, or to determine if your suggestion would be better.

I do not know if the designers of these motors have performed testing of this. Would be interesting to know.

I do know, that the higher on the cylinder you go, closer to the spark plug, the temps get higher. I assume temp is highest right next to the spark plug on the head.

I have done testing using telemetry, and using this baffling set up, on a hot day (100 degrees F), the rear cylinders will run cooler, and the hottest cylinder temp measured, lets say, during a long upline, will be in 280 to 305 F range.

I have another airplane that the highest temp never gets over 290 F.


Yes, if those fins were directed differently, wonder what temps would be?

This is a good question / comment for discussion.

 

[Snoopy1]

The reason I asked is that I sometimes I help a friend on his full size Lancair plane and looking at the baffling on that plane the fins on the heads run down in the direction of the air. Like the it is pressurized on the top and then forced down through the cylinders and heads and then out the bottom of the cowl.

 

[orthobird]

Spent a good 6 hours on this one today. Tiding the wiring on inside, still not done, until I install the wing servos. but otherwise, I am using rocket tubes as conduit, to help protect the wiring from front to back. I also installed all the telemetry sensors, cylinder head temp for each cylinder, RPM sensor as well.

The front cowl is totally installed, everything is tightened, and prop and spinner is on as well.

 

[orthobird]

Just installed the Landing gear cuffs.

Additionally, I have some Great news! My JR NXB 8921 servos, has the slow start feature, without requiring any special programming. I am using a Jeti Radio system. I was informed, when I purchased the servos, that, they will not have the slow start feature, unless someone with a JR radio programs the servos for me.

Well, turns out, this is not the case, and is not required!! Yippie!

I have to install the vent tube and bottom fuselage fitting, tighten the LG and tW bolts, and then install the servos into the wings, and she will be 100% complete.

 

[Rusty 73]

How's the balance on two of them , will you use the 5.5oz or 1.5 oz pilot in the blue and red bird .
Like how you fastened the baffle and shroud down , doubt the bolts will loosen .

I have to order a few Mcfuelers as well they just look sharp on the cowl . Just assembled the the canopy to the turtle deck using Goop . Had to mount the pilot in first as well as the dash board . I hope it stays tight , will find out tomorrow when I remove as the painters tape.

The fast pace you've worked on your projects , this gives me a lot more motivation in getting mine completed .
Thanks Cam

 

[Rusty 73]

Are you using Tygon tubing in any of the fuel lines , it quite expensive but has great charteristics that the yellow fuel line doesn't.
So the either Jr programmed those servos or the Jeti programming figure out the slow start feature of those Jr's.
Good to heard that no futher programming is required. What made you switch to the 8912 servos , just curious?

 

[Alky6]

They both look beautiful Cam! Enjoy them!!