Author Topic: Blackhead McCoy .40, series 21 (Read 3063 times)

DanielGelinas · « **on:** November 03, 2013, 02:47:09 PM »

Guys,

I'm wanting to break in a new series 21 .40 ringed engine.
This will be for the Brodak Viking I am building.
I'm using 5-29 fuel all castor.
The instructions say that once the engine is running, to let it run in a rich setting for over 15 minutes to set the ring.
Would this be a non-stop 15 minute run??
Or should I do the regular 2 minute runs until I have run it for 15 minutes?
I have no experience with ringed engines.

Thanks,

-Dan

Jim Thomerson · « **Reply #1 on:** November 03, 2013, 04:08:16 PM »

I think the series of 2 minute runs will be fine. I tried three different McCoy series 21 40's on my Viking and replaced them with a K&B 4011. I was not pleased with any of the McCoys. Hopefully you have a good one.

Bill Hummel · « **Reply #2 on:** November 03, 2013, 04:20:29 PM »

Dan, short runs, 2-3 minutes, cool down, run again. It's the heat cycling we are seeking. A 15 minute run gets you "one run". Also, suggest you do not use
all castor. Up to 50/50 synthetic will keep things cleaner and keep ring from sticking. Read over Randy Smith's engine recommendations, great info!

DanielGelinas · « **Reply #3 on:** November 03, 2013, 05:57:01 PM »

Yeah, I heard a lot of bad things about the engine. The one I had in 1973-74 was a great engine in a full sized magician at the time. But I ran it into the ground (blacktop) after a wire broke pulling out of a wingover.

Thought I would try another one just for kicks. If it's a bad engine, I'll probably go for a very good enya .35.

I was under the impression you needed to run it for a long time to seat the ring.

Thanks guys!

-d

Brett Buck · « **Reply #4 on:** November 03, 2013, 06:09:12 PM »

Quote from: DanielGelinas on November 03, 2013, 05:57:01 PM

Yeah, I heard a lot of bad things about the engine. The one I had in 1973-74 was a great engine in a full sized magician at the time. But I ran it into the ground (blacktop) after a wire broke pulling out of a wingover.

Thought I would try another one just for kicks. If it's a bad engine, I'll probably go for a very good enya .35.

I was under the impression you needed to run it for a long time to seat the ring.

Thanks guys!

-d

You don't need to run it a long time just to seat the ring, and as mentioned straight castor not be your best bet.

The bad things you hear about are mostly true. The unit-to-unit variation seemed to be astonishingly large and overall the engines looked very crude. However, get a good one, and it could run very nicely. I never had one, but everybody I ever flew with back in the 70's did. One individual engine was just remarkable, quite powerful, incredibly good run characteristics for the time, and lasted a long time. Most of the others were absolutely worthless.

Brett

DanielGelinas · « **Reply #5 on:** November 03, 2013, 06:22:36 PM »

I got my fingers crossed

I'll switch to half synthetic, half castor 28% as soon as this quart is empty...
-D

Brett Buck · « **Reply #6 on:** November 03, 2013, 06:30:27 PM »

Quote from: DanielGelinas on November 03, 2013, 06:22:36 PM

I got my fingers crossed
I'll switch to half synthetic, half castor 28% as soon as this quart is empty...

One more thing, very important! I am no fan of the hoary old "disassemble/clean/lube" routine, but in this case I would make an exception and at least the backplate off, put in some sort of solvent (like fuel), and clean the inside of the engine out before running it. Oil with something if you didn't use fuel. You can't assume it will be clean inside.

If you have already run it, then, just go ahead.

Brett

YakNine · « **Reply #7 on:** November 04, 2013, 06:09:15 PM »

I have a few of these and I have been running one of them that was a nos engine the ring was stuck to the piston with dried out assembly lube I couldn't get enough compression to start it until I pulled it apart and worked the ring back and forth with penetrating oil. It is a real pussycat now and is probably going to end up on a twister after I adapt a tongue muffler to it. T.J.

YakNine · « **Reply #8 on:** November 04, 2013, 06:11:26 PM »

My engine seems to like the 5% GMA power master fuel. I do add a little extra castor to my fuel usually about 4 oz per gallon for the older ones. T.J.

afml · « **Reply #9 on:** November 04, 2013, 08:15:20 PM »

Bob Baron took 4th at the 71' Nats with one!

"Tight Lines!"

Wes

DanielGelinas · « **Reply #10 on:** November 05, 2013, 09:05:58 AM »

Quote from: afml on November 04, 2013, 08:15:20 PM

Bob Baron took 4th at the 71' Nats with one!

"Tight Lines!"
Wes

Thats very interesting. Do you know with what plane?
-d

John Craig · « **Reply #11 on:** November 25, 2013, 12:49:58 PM »

Out of the box, was there an option of a manufacture's venturi restrictor? ?

Two flights this weekend with one, 11-4 MA, 10% 12% 12% . Once the fuel line/filter/ needle were corrected; the engine ran fine, but not exciting. The needle setting was a bit hard to find. I ended up in a wet two.

Dave_Trible · « **Reply #12 on:** November 26, 2013, 09:22:57 AM »

Like has been said here, a good one could be a great one but quality control of the assembly process (like older Foxs') could be lacking at times. I remember one really outstanding copy of that engine in a friends Sig Chipmunk. Only thing I'm concerned about the prop choice. That 11/4 tells me you may be trying to run it like a modern engine-low pitch, high rpm- which will wear it out very quickly and isn't really using it in its most effective range. Try a wider blade wood 10/6 if you can find some. Keep the heat down and turn its lower rpm power into thrust. Use plenty of oil and I agree on the synthetic / castor blend. While true older high mileage engines need to stick with 100% castor, if the engine is newer without the castor film buildup on it will last much longer with the blend. I've got a silly number of new-old classic motors broke in with modern fuels and oils that will long fly and outlive me. If we had these oils 'back then' most of those engines would still be around today.

Dave

Brett Buck · « **Reply #13 on:** November 26, 2013, 10:09:41 AM »

Quote from: John Craig on November 25, 2013, 12:49:58 PM

Out of the box, was there an option of a manufacture's venturi restrictor? ?

Two flights this weekend with one, 11-4 MA, 10% 12% 12% . Once the fuel line/filter/ needle were corrected; the engine ran fine, but not exciting. The needle setting was a bit hard to find. I ended up in a wet two.

Try an 11-6 wood. This is not a 40FP. It will spin fast enough to fly with 4" of pitch but will have no overhead left for maneuvering. The 11-6 will be a lot less stressing on the engine and will put it in a better RPM range.

I don't recall if it had a venturi insert. If it seems too twitchy at low revs, make a wedge of 1/8" balsa and stuff it in on one side of the spraybar.

Brett

DanielGelinas · « **Reply #14 on:** November 26, 2013, 03:26:45 PM »

YES, there is a venturi insert installed, out of the box.
-Dan

BillP · « **Reply #15 on:** November 26, 2013, 07:15:49 PM »

Daniel,

How did the Viking cg work out with that 40? Did you have to add weight anywhere to balance it?

bp

DanielGelinas · « **Reply #16 on:** November 26, 2013, 07:51:16 PM »

Bill, still building the viking. I'm what you might call a slooow builder.
The wing is almost done.
I'm still breaking in the blackhead 40.
I'll surely report back when done.
Cheers,
-Dan

BillP · « **Reply #17 on:** November 27, 2013, 09:17:17 AM »

Thanks Dan. I have a Brodak Viking kit and need to figure what engine to use. I currently have and want to use either a McCoy 40 RH or Fox 45...depending on how much trim weight it needs and whether on the nose or tail.

DanielGelinas · « **Reply #18 on:** November 27, 2013, 01:31:42 PM »

Hi Bill, from what I have been reading, most vikings come out tail heavy. That's one reason for using the blackhead 40, as it is over 9 ounces. But if the engine is not a good one, I have an enya 40ss which is also 9 ounces...
-Dan

afml · « **Reply #19 on:** December 09, 2013, 08:45:49 PM »

Quote from: DanielGelinas on November 05, 2013, 09:05:58 AM

Thats very interesting. Do you know with what plane?
-d

Sure do!
71' Humbug
Not the twin boom machine, but a 'normal' looking layout.
"Tight Lines!"

Wes

Kozmo77 · « **Reply #20 on:** December 31, 2013, 08:43:27 AM »

Regarding the Viking: have one in final stages.

Did not use a wing jig( haven't built a plane since 1965) Has serious warp@1/2" down on outbaoard wing. Weighs 39 ozs without motor Afox 35 is ready. Ebay find at $22. Runs awesomely on PM GMA. Hope it has enough to pull the plane. Started working on it in March last year. AM going to fly it someday. Have acquired some BH35s along with Combat Foxes and a ST35 and Torp35 and Enya35. plus my old RH35s and an OS 35S from the 50s and 60s. May try the BH35 in the Viking if the Fox wont quite do it. REALLY enjoy all the info and good will on this and other sites. Will armchair fly with you guys till my lines are hooked up. This may be the easiest and most enjoyable site going . Thanks Admiral Bob.