Big_Bird

My Feedback: (1)

I gotcha Anthony.

WacoNut

I finished up securing the firewall tonight, no one can say it will come loose
I have 1/2" tri-stock reinforceing the joint front and back and (3) 1/4 dowels 1" long pinning each edge of the firewall. Overall it looks clean and should hold up to all 18 hp.
Anthony

Big_Bird

My Feedback: (1)

Sure looks good Anthony. If you have never started an engine that big, you are in for a thrill. No kickback, just easy starting.

WacoNut

No I haven't even flown a Gas powered plane yet just glow,
I do have a pair of leather welding gloves I will wear while pulling that big prop thru. Will almost be as intimidating as when I propped a full scale J-3 a few times. I just can't see myself going back to small planes except maybe a little electric job just to throw in the truck to fly when the urge strikes. After building this plane even my 1/4 scale Cub looks small.
Anthony

All Day Dan

My Feedback: (5)

I got dropped from this great build even though I am still subscribed to it. Keep up the good work. I'll catch up with the missed posts. Dan.

WacoNut

Hi Dan,
I have had that happen to me from time to time on builds that I am subscribed to, don't hear anything for a while then go check and there are 4 pages to catch up on[]
I am glad you enjoy the thread, once I get a few more things accomplished and start covering and detailing it will get interesting.
Anthony

Big_Bird

My Feedback: (1)

Anthony, never just pull the prop through with the ignition on. When you get the engine ready to start make sure the prop comes up on compression at 11 o'clock. Then, in a downward fast motion so your hand exits the prop arc, swing it through like you mean business. No time to be timid.

WacoNut

I snuck out of work after 5 hrs today
I took the engine box into work and weighed it to see how much weight was saved by the lightening holes and it came in at 11.4 ounces so that is a 1.9 ounce savings.
I mounted the engine to the engine box and found the proper location on the firewall to put the prop shaft in the center of the cowling. I then mounted the engine box to the firewall. I will have tocut a clearance hole for the carb venturi and clearance for the muffler pipes. It feels good to have the engine mounted.
Later!!
Anthony

germrb

My Feedback: (3)

Anthony,

Looks very clean. Good offset and the blocks at the base of the box will give you excellent support. Nice job. Only one thing caught my eye and that is the lower box bolt on the port side. It may be tough to get to with the port muffler installed. But, maybe not. Its always nice to be able to remove the engine without having to remove the mufflers.

Enjoy,

Richard Scale Rocks

Hey WacoNut! I'm looking to purchase the kit very soon. a rep was into our Hobby shop here in Orleans Ontario, Canada, not far from Ottawa. We talked and I'm just getting some cash together. Can you tell me what version this is? I would like t9o get specs on it including pictures from Bob's and perhaps books and specs. What is the model type? Can it be made into a double cockpit?

Great build my friend. I'm just about 3/4 way finishing my Ryan Sta 1/5 scale.

Richard

WacoNut

Richard it can be made into a double cockpit and mine will be.
My kit is the latest version and it is a nice build. The wing span is 120" fuse length is 90". This is a BIG PLANE!!!

Bob,
I can't remove the engine box bolts without removeing the muffler, I can get the engine bolts out without an issue. If I want to remove the engine box I will have to remove the engine 1st. It's only 4 bolts so not an issue as far as I am concerned.
Later!!
Anthony

skylarkmk1

Richard,

Check out the AMR - Aircraft Modelers Research (formerly Genesis) site http://www.amr-rc.com/ for more info on the kit. The kit that Anthony is building is their 33% WACO YMF. It has some updates to make it easier to build and more improvements are on the way.

You may want to take a look at the WACO YMF thread in Vintage and Antique as well. It is primarily about the 1/5th Pica YMF kit but all Waco are welcome. Lots of info is in this large thread (330+ pages, 8250+ entries) including photos of full size Wacos, detail shots, suggested improvements for strength, engines, scale outline and detail to the Pica kit and others including the biggest bugaboo - the wing tips.

lrayj

I installed the landing lights today and tried them out. I think they look pretty good. Here is a picture of the lights. The picture does not do them justice.

WacoNut

Looking good Lonnie!!

WacoNut

I am working on mounting the boot cowl and the cowling. The boot cowl will be fastened with #2 screws in scale locations, the clowling will be mounted per the plans except I will be making the boot cowl removeable so I need to modify the cowl mounts slightly. I am going to mount the engine switch, battery and charge jack in the boot cowl and I want to be able to have access for maintenance. I will post some pics of the cowl mounting this afternoon, I am waiting for some glue to dry so I can drill holes for the supporting dowel rods.
Later!!
Anthony

WacoNut

I need some advice from you gas guys,
Should I trim the cowling for just enough clearance around the pipes and venturi or should I just remove a rectangle in the bottom of the cowl and allow for extra cooling? I don't want to butcher the cowling too bad but I also do not want to cook this engine either.
Anthony

germrb

My Feedback: (3)

Anthony,

The exhaust only need about 1/4" clearance. I have some planes with slightly less and don't have any temperature problems. What you want to avoid is any contact between the exhaust and the fiberglass due to vibration. Large openings around the exhaust stacks won't do a lot for cooling and its just plain ugly. The carb clearance is much the same, except turbulance can be an issue. With the velocity stack installed, turbulance will not be a problem.

Proper ventilation is big concern. You will need to baffle the cowl to force all the incoming air through the cylinder vains. Cooling a twin in a round cowl is about the most inefficient setup imaginable. You will need to close off everything except the cylinders. Also, make the gap between the cowl and the boot cowl as large as possible without destroying the scale. If you have to cheat the scale a little, this is one place to do it. I'll see if I can find some photos of baffles for you.

By the way, I had to laugh when you said this was your first gas engine. To go from glow to a DA150 is like going from a Yugo to a Farrari. Your in for a big surprise. The 150 is a real brute.

WacoNut

Thanks Bob,
I do have a DL-50 on my 25% Waco but I have not started it yet. I need to wrap a few items up on that plane and get it in the air soon. The 25% will see alot of air time before I fly the 33%.
I will trim the cowl for a nice fit and I can always open it up more, easier to take the material off than to put it back on.
Anthony

germrb

My Feedback: (3)

Anthony,

I couldn't find what I was looking for, but here is some general information.

http://www.cactusaviation.com/Tech/baffling.html

Big_Bird

My Feedback: (1)

Anthony, here is the baffle that I added to the big Super Decathlon. Regardless if it is a round cowl or one like the SD the baffling principal is the same. Force the cooling air to go through the fins. On the second photo you will see that I added vertical pieces near the spark plugs.

WacoNut

Bob and Ken,
Thanks for the pics and the link, I plan on making a baffle out of 1/16" ply, I will have to make standoffs for the ply to mount too. I will use the baffle as a mount for the dummy radial when I get around to that.
Anthony

germrb

My Feedback: (3)

Ken,

Beautiful layout!! I'm going to save your photos for my files. Yours is one of the best I have seen for a big cowl.

I have a RCS250 in my WACO and have yet to find a baffle arrangement that improves engine cooling. If I baffle between the cylinders, the exhaust collector ring really cooks. The big radials are particularly sensitive to heat and require lots of ventilation.

By the way, your SD is coming along very nicely.

WacoNut

I ran into another issue, the cowling will not clear the muffler canisters[:@]
There is about 1/4" of interference, my options here are a bit limited. I can either raise the engine approx 3/8" above center line, find different mufflers with a smaller profile or machine the offending radius of the muffler away and weld a flat piece of metal to allow clearance. The latter would be a real pain in the *****.
Here are a few pics of the issue,
Pic #1 shows the bottom cowl mount and you can see the canister below the mount.
Pic #2 shown the canister againt the fiberglass cowl.
Pic #3 shows the top of the cowl sitting below the top mount with the cowl against the muffler canister.
Pic #4 side view of the engine showing the position relative to center line.

Do you think raising the engine 3/8" for clearance would be a good option? This is definetly the quickest, easiest and cheapest option.

germrb

My Feedback: (3)

Anthony,

First, I would not move the engine! Raising the thrust line will significantly affect the flight dynamics, especially on a biplane.

Second, you can open the bottom of the cowl to accommodate the muffler. Since it is on the bottom, it would be the least offensive.

Third, start searching for a muffler option. If you call Bision Custom Mufflers, they can make anything you can design. They aren't that expensive considering the service.
http://www.bissonmufflers.com/en/index.html

Fourth, have you dry fit the cowl with the ignition attached? My guess is that you are going to have an interference problem on the port side. The spark plug cap may not fit inside the cowl.

This is not a problem, its an opportunity. Yea, right!

Big_Bird

My Feedback: (1)

Bob, thanks for the complements.

Anthony, I would be tempted to carefully saw off the corner, file it flat, and have a flat piece of aluminum welded on. You could also cut a clearance hole in the cowl, and make a fiberglass bump to cover it. I don't think it would be too noticeable.