IRBB,

Start by looking at the relative weights:

OS FS40S is 12.5 oz.
OS FS30 is 9.56 oz.
OS FS26S is 9.45 oz,
OS FS20 I don't have the weight
Veco .19 BB is 6.2 oz.
Veco .19 is 5.6 oz.
Cox .15 Medallion is 4.24 oz.


The Peacemaker is not a very large airplane. If I recall correctly, George wanted something to fly on a .15 diesel. The front end is not very long, and will not take a large tank. So no thirsty engines, else expect a bit shorter runs. The four strokes have an advantage there, but....

Don't look at the heavier engines as "just adding a few more ounces that I can take back out of the airframe."  The heavier engines you are considering just about double the weight of the engine. The only way to balance properly is to add weight to the tail. So for another 5 oz. in the nose, plan on adding 1.25 oz. to the tail. So your weight went up 6.25 oz. If the plane weighs 28 oz. normally, then you just increased the weight, and the wing loading by over 20%. You are not going to "get that back out" of the airframe. Quite the opposite, the larger, heavier, more powerful engines may require more structure up front to keep them attached.

Not sure which Veco .19 is shown on your plans, but the .19BB (ball bearing) has plenty of horses and to spare to fly the Peacemaker. Anything more and you are just screwing around, which can be fun, but it isn't going to match the airframe and perform well, in my opinion.

I can't imagine a 40 of any type in the Peacemaker unless you just want to go fast and level--and with a ton of tailweight. Which entirely defeats your notion of building one light. The 40 will make short work of a significantly lightened airframe. And, you will undoubtedly have to widen the whole thing just to try to get it in.

So you have to decide what you want to do with it. And, in general, sticking closer to the way the original was built and fitted carries less uncertainty. Yes, engines have improved very significantly. But you may not need/want the extra power, and you have to find a way to manage it. Control line stunt and sport flying is very different from R/C. We never run the engines balls to the wall. Only the control line racing and speed guys do that. And we don't do it with Peacemakers.

Weight has not changed over the years. Too heavy is still too heavy.

Have fun, whatever you decide.

Divot McSlow

PS--I have a Super Combat Streak, which is not much different than a Peacemaker. I flys fine on an old-school OS 30S for power. It just burbles along rich. I also was gifted--and rebuilt--a Jr. Flight Streak. It was equipped with a wire hook to tie on a streamer. With big lead weights attached. And the nose was cut out for a 40. I cut off the hook and rebuilt the nose for a McCoy .19. It flies fine for what it is. Biggest problem is again the limited space for a fuel tank.

IRBB(F?),

When you consider engines, a few of the first considerations should include:

1. Is it a Schnuerle ported engine, which will likely run at higher rpm, or is it cross-flow ported?

2. How heavy is it?

3. What do I have to do to it, if anything, to make it run well in a control line plane?

4. How much and what kind of fuel will it need? Will the tank fit? Can I buy that kind of fuel, or do I need to make/doctor my own?

5. If I am flying over pavement, and learning/relearning, is the engine too precious/expensive/nostalgic to risk losing in a crash?

6. Do I need a muffler where I plan to fly? Do I want to damage my hearing without the muffler when you "forget" your ear plugs?

There are others, but these may help you decide what you should start with.


If your K&B .19 is a green head, or pre-green head, they are light, and pretty powerful. If it is not worn out, it should haul a Peacemaker built to a reasonable weight. No muffler.

The Enya is on the small side, but depending on condition, it would haul it around for mild maneuvering.

The O&R is an antique. If you enjoy antiques, you might run it on something smaller/older. Anyone running antiques should be prepared to do repairs, parts hunting, and enjoy that more than actually flying. It would probably haul your Peacemaker around doing the straight and level thing. If in really good shape, it might do a bit more--for a while. Then you are back to the parts thing.

If you want to know about small 4-strokes used in control line, ask Dane "Vegas" Martin. I believe he actually flies them, so his experience is worth ten times my opinions.


Divot McSlow

C.T.S.

Good info on the Peacemaker. That is a very respectable weight. What did you cover/paint yours with?

The Brodak .25 has a ton of power potential, if you need to tap it. In fact, we race Super Slow Rats with them.... For stunt, I imagine you really need a small venturi. Their website claims it is .300 ID, but I doubt that. It weighs 5.4 oz. without muffler, so comparing it to IRBB's choices, it comes in both very light and with a ton of power potential. But it may take more fuel if you try to run it rich.

For my Super Combat Streak, knowing I wanted to run an old-school engine in 4-2-4, I cut a tank so that it would just squeeze between the bulkheads. I'd have to check, but I'm guessing it is just under 3 flowing ozzies.

Let us know how yours flies. More info is good, and good info is even better!

Divot McSlow

The Peacemaker has been on my list for some time......and I finally bought the Brodak kit!  This is pretty much George's original concept, kinda far removed from the TopFlite version.  I've seen the TF one flown with a Fox 36X up front....made a very attractive slow combat airplane, but that wasn't the original intent.

My plan is/was to use an original Oliver Tiger, but the 3.5 Major instead of the 'regular' OT 2.5 Mk III.  It only weighs about 1/2 oz more than the basic (6.9 oz), so it's lighter than most of the alternatives, has buckets of torque and will work on a bit more than 1 oz of fuel...yeah, I know what they sell for on eBay, but they're still a model engine, intended to be flown!

The primary problem with the PM is that the 'numbers' are dated.  The balance point is much too forward for a flapped airplane and consequently may give sluggish performance.  After all, it's still just a big Flite Streak, and would probably fly as well, properly trimmed, without the flaps.

Just my two-bits' worth.....or whatever a shilling is worth these days!

Dave G.

I had an original TF Peacemaker with unmuffed Fox 35. It was a long time ago but I remember the Fox had plenty of power with a 9/6 wood prop.

I missed this subject! The peacemaker is indeed a small plane. Having built several 4 stroke powered models in this size, I'd say os .20, if you can find one. Next choice, os 26, then possible last ditch effort use an os or magnum 30.
 Like Divot says, going larger on engine isn't just additional weight, but it also needs a taller prop to make power. The 20, 26 and 30 are all very happy on a 9x5 or 9x6.

Also consider the saito 30. Very very potent little engine.

I've seen a Ringmaster flown very nicely on an OS 26FS.  I suspect the Peacemaker would fly nicely on that as well.

I've got one of those engines in a 48" wingspan Ugly Stik RC plane, with some really old really heavy servos in it.  The engine pulls that plane with authority -- or at least it did, before I lost interest in RC.  As far as I'm concerned, that's more indication that your Peacemaker will do just fine.