Author Topic: MECOA .46 C/L (Read 5924 times)

Christopher Root · « **on:** July 01, 2019, 11:49:47 AM »

Has anyone tried this new engine yet?

C R

M Spencer · « **Reply #1 on:** July 01, 2019, 11:31:13 PM »

Looks Like a Rework of the previous F S OS Clone . ?

see ' royal 46 ' thread .

Vunder Vhatzer Timing iss .

FLOYD CARTER · « **Reply #2 on:** July 02, 2019, 01:43:26 PM »

I don't that engine on the MECOA site. In fact, they don't have any C/L engines.

Reptoid · « **Reply #3 on:** July 02, 2019, 01:52:56 PM »

Quote from: FLOYD CARTER on July 02, 2019, 01:43:26 PM

I don't that engine on the MECOA site. In fact, they don't have any C/L engines.

What are you talking about?

https://www.mecoa.biz/shopexd.asp?id=4985

Fred Quedenfeld jr · « **Reply #4 on:** July 02, 2019, 06:39:46 PM »

Got this info in email from MECOA
For $100 it may be worth a try
3.7 oz muffler
10.3 oz engine
Mild timing
.290 venturi throat
.156 spraybar
shim part number 29-m4611
no info on prop size at this time

Carl Cisneros · « **Reply #5 on:** July 03, 2019, 12:02:24 AM »

bench ran mine this last Saturday. (got 2 of them)

fired up on first flip after choking and flipping a few times to get the fuel thru the motor.
ran 10%N, 22% oil (50-50 mix)
used a Xoar 11x5 prop for breaking in.
plug used was BOTH the supplied K&B 1L as well as one of my O'Donnell Red sport hot plugs.
ran 6 each 2 once tanks with complete cool down between tanks.
motor ran at a just a bit richish 2 stroke to get the heat in the motor so the piston/sleeve fit would settle in.

very nice motor. super smooth bearings.
very docile
muffler is pretty quiet really.

think it will be a very nice motor.

only thing I did was to back off the back plate screws a bit (they were NOT tight) then torqued them in place. I do check for all screws to be tight when I first get a motor.

after running, used my air tool oil/ ATF after run oil.

Carl C

Peter in Fairfax, VA · « **Reply #6 on:** July 03, 2019, 04:21:12 AM »

Carl,

I'm curious as to the mount spacing. I have a plane it might fit, Scott Richlen's Silver Lancer. That plane was set up for an O.S. SF 46. Let me know if you have a chance to measure.

thanks,

Peter

Carl Cisneros · « **Reply #7 on:** July 03, 2019, 07:30:49 AM »

Peter;
Here you go:

case width under mounting lugs: 36mm

engine length (measured from back plate screw heads to front of prop driver): 87.6mm

engine height (measured from bottom of mounting lugs to top of cylinder head fins): 69mm

mounting lug screw hole pattern spacing: 16.1mm

conversion to inches: divide mm by 25.4

Carl

Peter in Fairfax, VA · « **Reply #8 on:** July 03, 2019, 08:11:25 PM »

case width under mounting lugs: 36mm (1.42)
engine length (measured from back plate screw heads to front of prop driver): 87.6mm
engine height (measured from bottom of mounting lugs to top of cylinder head fins): 69mm
mounting lug screw hole pattern spacing: 16.1mm (0.634)

O.S. SF46
case width under mtd lugs 1.381
mtd lug screw hole spacing 0.688 fore and aft
mtd lug screw hole spacing 1.717 right and left

M Spencer · « **Reply #9 on:** July 03, 2019, 09:31:10 PM »

' We ' find , if you overdrill the bolt holes to 4 mm / - 5/32 inch ,

Then fit the bolts & angle them out ( or whatever ) & fore & aft , as its only 1/32 inch odd , we can perhaps avoid the pictured implement .

The ' Pre setting ' means the theads will engage without binding , raising burrs , so lessens thread & bolt stripping problems.
Im using 1/8 unf machine screws & nuts soldered to plates .
Continual forceing has the solder come free & twirly nuts .

resulting in big holes and charred edges when you resolder em .
Did I mention damp rags .

With the 4-40 bolts and threads youd likely have no bother , as the tolerances are way outside what were at , but still drill oversize so theyre free to accomodate & pre align so nut & bolt are co - axial .

Peter in Fairfax, VA · « **Reply #10 on:** July 04, 2019, 02:14:23 AM »

While drilling works, another technique is to use a small diameter rat-tail file and elongate holes. If recall serves, this was how some combat Super Tigre and Fox engines were made interchangeable.

M Spencer · « **Reply #11 on:** July 04, 2019, 11:46:08 PM »

Yea , I should have said " if you overdrill the ENGINE BEARER bolt holes to 4 mm / - 5/32 inch ," sorry folks .

Filing engine lugs for slotted holes is not recomended , at 2 A.M .
as you might go fwd. instead of aft. on the aft. instead of fwd. holes ,
& have to likewise slot the fwd. ones fwd. as youd intended in the first place .
At least it wont be any heavier when youve finished .

Er , shaving the fin sides flat and whittling a bit off the bypass got about 15 grammes off a late FP 35 so weight matches early FP 40 .

Allen Eshleman · « **Reply #12 on:** July 05, 2019, 06:08:55 PM »

Please give a report of performance once you have used it in the air.

Carl Cisneros · « **Reply #13 on:** July 05, 2019, 08:10:31 PM »

Allen;

Still have to build a plane for it.

Don't want to mess/hack up one of my good profiles to mount the motor.

Hopefully start building on the plane by weeks end next week.

Carl

Peter in Fairfax, VA · « **Reply #14 on:** July 06, 2019, 11:54:46 AM »

Carl,

Good choice to use a profile as the test bed. Easy to unmount the engine for checking, easy to adjust the tank, etc. Curious, what profile are you planning?

Thanks for looking into this engine. Folks are curious as to your findings. Let me know if you need any assistance/parts for the build, or any assistance at the flying field.

Peter

Carl Cisneros · « **Reply #15 on:** July 07, 2019, 02:25:35 PM »

Peter;

thanks much for the volunteering of help.
will probably take you up on it.

As far as the plane is concerned, it is a one off I am putting together.
just a test bed is all, nothing fancy.

Carl

Carl Cisneros · « **Reply #16 on:** July 14, 2019, 11:10:18 AM »

plane is already under way of being built.
tail feathers and fuse all done and almost ready to cover. (use iron on covering only)
Wing gets started this week.
So, hopefully, by end of the month the test bed should be ready to do and get the Mecoa motor airborne for testing.

will startout with my normal Zoar 12x4 and 10% fuel.

Carl

Carl Cisneros · « **Reply #17 on:** July 23, 2019, 08:09:28 AM »

just an update

all tail feathers covered and hinged.

been too dang hot in the garage to work.

hopefully this weekend I can start the wing assembly. all ribs done

MAYBE get done with the plane by the 1st or 2nd week of Aug

Carl

frank mccune · « **Reply #18 on:** July 24, 2019, 08:53:02 AM »

Looks good. Will the nva. and venturi work well for control line use?

Dave Hull · « **Reply #19 on:** July 24, 2019, 04:18:59 PM »

I had one of the factory test engines in my hands this past Saturday. According to Randy at MECOA, this engine design is about 20 years old. It supposedly has more of a low rpm run characteristic. The fits seemed ok, and the compression was fine. Based on what I saw and was told, I ordered one. I can tell you that the muffler (added cost) is nearly identical to the OS 873, except the rear casting is longer. The manifold aperture is slightly different, but the hole pattern looks the same. I didn't check the threads. There might be a metric/English difference there. It is a ball bearing engine with a pretty beefy looking case, so I would expect it to weigh a bit more than an OS .46LA-S.

The needle valve assembly and venturi are designed for control line use. The real question is whether the engine run is what a user would want. The only proof of that is to see it flying successfully.

We should have some test run info before too long.

Dave

Jim Svitko · « **Reply #20 on:** July 24, 2019, 10:45:10 PM »

One of my flying buddies has been flying a Humongous (his engine test bed) with the MECOA 46. I did not witness all flights but managed to see a few flights today. Yesterday, he flew it and he told me that there was a stumble during some maneuvers. He figured it was fuel starvation and made a smaller venturi. I do not know the factory venturi size. I think the new venturi size is about 0.280. Today, I did not notice any such stumble with the smaller venturi.

The factory head shim was measured to be 0.016 thick. Today, I noticed that the engine would run OK for the first part of the pattern then run rich about halfway thru. It went too rich to do any maneuvers. The factory supplied shim was replaced with a thinner one. I am not sure how thick. I think he used a shim from a Stalker 51 since that shim is what he had with him today. Not an exact fit but close enough to continue test flights. I will find out the shim thickness and pass it on.

With the thinner shim, the engine ran pretty much a constant speed thru the entire pattern. This engine does not have a 4-2-4 stunt run.

Several props were tried. All props, as far as I know, were wood props, most likely stock BY & O or modified BY & O. An 11.5 X 5 proved to be too much load for this engine. It ran best with an 11 X 5.

The muffler was Randy's tongue muffler for the ST 51.

I do not have any fuel consumption data or what type of fuel was used. I do not know the all-up weight of the Humongous with this engine.

At the end of today's flying session the engine seemed to settle in. With the changes I mentioned above, the engine ran well enough. Is it equal to or better than something like the LA 46? I do not think so but you will have to decide for yourself if this engine is suitable for your purposes.

More test flights are in store but probably not until Sunday at the earliest.

Dave Hull · « **Reply #21 on:** July 24, 2019, 11:52:31 PM »

Great info, Jim! Thanks!

Jim Svitko · « **Reply #22 on:** July 26, 2019, 07:24:25 PM »

For those of you who have the MECOA 46, I have some verified information.

The engine weighs about 11.5 ounces with no muffler.

The factory head shim of 0.016 thickness was replaced with a shim of 0.005 thickness. Four ounces of fuel was needed to do the pattern. I think the fuel was 5/22. Best prop, as I mentioned in an earlier post, was BY & O 11X 5.

The Humongous, with the MECOA 46, weighs 50 ounces.

My flying buddy measured the port timing. He said it was 130 intake, 150 exhaust. This is not 4-2-4 stunt engine. It will run at near constant speed, in a wet 2 cycle, maybe hitting a 4 cycle at times. More flights with this engine might not be in the works since tonight he told me he feels he got all he could from it and will most likely put the Stalker back on the Humongous.

So, you can try it for yourself and see how it performs for your needs. You might like it but I will take the LA 46.

Carl Cisneros · « **Reply #23 on:** August 27, 2019, 06:59:33 AM »

Well, the new plane is ready to fly with the Mecoa 46 in the nose.
Hopefully this Friday or Saturday will be test day.

Set up will be using a Xoar 12x4 prop using 10% 22% (50-50 mix) oil fuel.
The Xoar 12x4 is the prop I always use on my LA46 motors.
Plug is McCoy Red Hot plug. Again, the same plug I always use on the OS motors.

Will see how she runs.

Carl

Carl Cisneros · « **Reply #24 on:** August 28, 2019, 08:08:36 AM »

thats why I want to see how it performs and what might be needed to be done.

Carl Cisneros · « **Reply #25 on:** August 30, 2019, 04:27:52 PM »

Well, Scott and I went to the filed today and had a very nice time.
Great weather conditions.

Put the test bed up using 10% fuel and the motor was a bit finicky.
NExt flight up we tried 5% fuel and it really like it alot.

might need just a bit more head clearance.
My motors are set at .0167" of head clearance.
I am goinng to bring the head clearance up to .020 ".
I checked the bowl volume and it is a bit on the small side more a-kin to using no or very low nitro.
My CMB 21 racing marine motors have a bigger bowl volume. LOL
I had the cc'd info written down but now I can not find it. Go figure.
More than likely an age thing I guess.

ordering a new tank for the plane as all I had was an older standard vert one and it gave up the ghost.

So, this weekend will make a head shim and wait for the new tank to arrive.

The motor really loved the Xoar 12x4 prop.

Later for now.
will update when I get the new tank installed and the model flow again.

Carl

Carl Cisneros · « **Reply #26 on:** September 16, 2019, 08:42:32 PM »

New uniflo tank installed on the plane.

Took it out to the field this past Saturday morning with other club members in attendance.

first flight with a short filled tank, I FORGOT it was short filled and it quit at the top of the inside square loop and I landed it nice and soft on its' back.
No damage at all.

2nd flight, full tank this time and it ran a treat. Nice semi quick 2 stroke with a bit of rpm increase in the manouvres.

ran the complete tank out with out a hitch and ran perfect thru-out the flight.

3rd flight same thing. perfect semi quick 2 stroke (not full chat) and again a bit of rpm gain when doing the manouvres.

ran complete tank out again with out a hitch.

prop: XOAR 12x4
fuel: 5% Nitro 20% oil (50-50) mix
Tank: Brodak uniflo 4 oz.
plug: O'Donnell Sport Hot Red plug

need to take a couple pics of the test aircraft but will wait until I get the vinyl lettering for the plane from my daughters friend
in the Arts/Graphics section at JMU this week.

Carl C

phil c · « **Reply #27 on:** October 05, 2019, 11:27:22 AM »

Quote from: Dave Hull on July 24, 2019, 04:18:59 PM

..... I can tell you that the muffler (added cost) is nearly identical to the OS 873, except the rear casting is longer. The real question is whether the engine run is what a user would want. The only proof of that is to see it flying successfully.
Dave

Yay! OS made the 863 and similar mufflers too short. Presumably that made them quieter, but they also ran a lot hotter than a stunt engine should.