Stalker Engines---General Information
Stalker engines are manufactured in Ukraine. All are ABC, baffle piston control line stunt engines, which operate in a classic 4-2-4 run style. They are moderate in weight. All are equipped with ratchet type needle valves which are quite insensitive, allowing very accurate settings. Virtually no break-in is needed to ready them for flight. They are not high RPM pipe engines-they're designed to operate in 8 to 9 thousand RPM range, with appropriate propellers, of 5to 6 inch pitch.
Unfortunately, Stalker engines are not a direct bolt-in replacement for other brands. The bolt pattern is similar, but crankshaft length is a bit longer than others.
Fuel consumption is quite moderate, often less than other engines of similar size.
It is assumed that the purchaser of a Stalker engines has some previous experience with control line aerobatics engines, therefore only limited information is given below:
Fuel: All synthetic oil fuel is recommended, in nitro content consistent with power needs for various conditions. Oil content should be 18 to 20%. Sig Four-Stroke fuel is recommended. Other similar brands may be satisfactory. Do not use fuels with all castor content.
Glow Plug: The Sig R/C glow plug is recommended. Others may be OK, but if in doubt use the Sig plug.
Propellers: wood props in appropriate size are recommended---.40's should run 10" to 11" diameter--- .46 to .51, 11" to 12"---.60 to .66, 12" to 13"----.76 & .82 13" to 15" diameter---There is no one perfect prop, you'll have to experiment for the best in your application.
Fuel tanks: Plastic or metal tanks are OK. Mount C/L of tank in line with C/L of needle assembly. On profile models, side exhaust engines should mount the C/L of tank about 1/4" above C/L of engine. On rear exhaust engines side mounted, tank should be mounted centered on the C/L of the engine.
Mufflers: Supplied mufflers are multi-chambered for efficient sound suppression. Tongue mufflers can be used on side exhaust engines, but are not manufactured by Stalker. Rear exhaust mufflers should be supported with a tuned pipe type mount in the fuselage. Allow air to exit cowl via a hole roughly the size of the muffler on rear exhaust engines.
Head shims: The engines are supplied with three .007" head shims installed. Extras also come with the engine. In many cases you'll find the engine to operate best with 5 or more shims if running 10% nitro (or more) or in cold weather.
Repairs: It is recommended you return the engine for any needed repairs. Repair cost will be the cost of parts plus return shipping-no labor charge.
Enjoy your Stalker engine, and always operate it in a safe, common sense manner, consistent with AMA safety code.
Controline Sales L.L.C.
315 Santa Anita Ave
Woodstock, Ga. 30189
Stalker Stunt Engines
All Stalker engines are ABC, baffle piston, ball bearing designs built specifically for control line precision aerobatics. The rear exhaust (RE) engines allow the furnished muffler to be hidden in the fuselage. Side exhaust (SE) engines have traditional bolt-on lightweight tube-type mufflers. Stalker engines sold by me are equipped with Sig R/C glow plugs and SAE size prop nut. All Stalker engines have 1/4" x 28 threads on crankshaft. Available engines are listed below. I may not have all in stock at a given point, as I must "bundle" orders from Ukraine for efficient shipping and payment purposes, but delivery is very prompt.
|Stalker 40 SE
|Stalker 40 RE
|Stalker 46 SE
|Stalker 51 RE
|Stalker 61 RE LT
|Stalker 61 RE longstroke
|Stalker 66 RE
|Stalker 76 RE
|Stalker 76 SE
|Stalker 81 RE
Prices are subject to change due to currency fluctuations and varying shipping costs to get the engines to USA. Exact price verified at time of your order.
Modifications Of Your
I am still providing
re-work services on OS-FP and LA engines supplies by customers. (Some
other engines can also be re-worked.) My modifications allow the
engine to run in a traditional 4-2-4 manner at lower RPM, allowing use
of 5" or 6" pitch propellers. Most people find this type of run to
be more pleasant, more "traditional", and there is no need for special
carbon fiber low-pitch propellers. Most wood propellers on the
market will work just fine.
The FP-LA re-work consists of:
Double Star needle valve
SIG R/C glow plug
Double Star tongue
Return shipping in the
U.S. and Canada
Total Price $80.00
Send the engine, Priority
Controline Sales L.L.C.
315 Santa Anita Ave
Woodstock, Ga. 30189
Payment can be made by
cash, check or money order.
The re-worked FPs and LAs
work especially well on profile models.
All OS-FP or LA engines,
from .25 to .46, can be re-worked. (The LA 60 is too heavy to be
Turn-around time is usually
within five days from the time I receive the engine.
ENGINE TUNING STALKER, AND OTHERS - June 2017
Stalker engines, Double Stars and some others were designed for zero, or very low nitro-methane content in the fuel. Most USA fuels have at least 5% nitro, and more commonly 10% nitro.
In control line stunt use, running nitro fuel at stock cylinder head spacing in these engines can result in sensitive needle valve settings,
"run-away", or too hard a 2 cycle break in maneuvers. One solution is to lower the compression ratio via machining material off the squish-band of the cylinder head, usually ten to thirty thousandths of an inch. Easier, and much more adjustable, is to simply raise the head via head
shims/gaskets. For most "no nitro" engines, adding 0.030" in head shims is pretty close. In cold, dense air, more spacing (shims) will likely be needed. The opposite is true for 100 degree weather in Tucson or Phoenix.
Many of the early Brodak .40's were over compressed, and respond well to shimming the head up. This gives a much broader needle, and no real loss in usable power, and starting without "biting" your fingers! Simply use extra head gaskets from Brodak to do this. Add shims until the 2 cycle break power falls off, and then remove 1 or 2 for optimum setting.
Any engine will make more power with more Nitro in the fuel. Often, for stunt engines, lowering the compression makes it very docile and friendly. Adding nitro brings up the power without changing the run characteristics. Extra nitro doesn't turn it into a racing engine - it just makes it a "torqueier" stunt engine. I often vary nitro level as the day gets hotter by adding, say, 1 ounce of 25% nitro fuel to 4 ounces of 5°/o, to yield 5 ounces of 9%. Two ounces of 25% nitro fuel and 3 ounces of 5% yield 5 ounces of 13%. I keep two quart bottles of fuel in my flight box, one 25% nitro and the other whatever base fuel that I'm running for the particular engine of the moment, either 5% or 10% nitro.
By filling the tank with a 5 ounce graduated syringe, it is easy to measure the amounts needed.
As a rule, engines get easier to set the lower the prop load. This is because a larger diameter prop requires a leaner needle to make more power to turn it. A leaner needle means there is less fuel now flowing hrough the engine, and less cooling as a result. I find that running the smallest practical diameter prop that will adequately pull the plane is
always best. This usually means a 10 to 10 1/2 inch diameter for
.35/.40's, 11 inch diameter for .46 to .50's, and 12 inch or so for .60's.
run a 13 x 5 wood on my Stalker . 76 and it is very happy there.
Smaller props also cause less gyroscopic precession (side-way
wiggles) as the plane maneuvers. Lighter (wood) is better than heavier plastic too. If the engine is "happy" but the plane is too fast, reduce the prop pitch at the same diameter and needle setting. If the engine is
happy and the power seems low, go up in pitch one inch. I've seen lots of guys who have great running engines on models falling out of the air - turns out their buddy told them to run a 4 or 5 inch pitch prop when
they really needed a 6! This is especially true on heavy, or draggy
airplanes and hot weather. If your engine is running well, and you are running a 6 inch pitch prop, but the plane won't perform well, then you need a lot more nitro, or a new/or bigger engine!
While electric power is becoming more popular in control line stunt, electric systems cannot completely compensate for temperature (air
density) changes. An electric motor does not lose power as the
temperature rises, since it doesn't use air for it's power. However, it is hard to add power to an electric, on the field, to compensate for lower prop and wing efficiency as the temperature (density altitude) rises. On a glow engine, just add more nitro! Extra power (not speed) will
overcome a lot of efficiency loss of the wing and propeller!
Glow plugs are a crucially important part of an internal combustion stunt power system.
"Hot" plugs are required! My favorite glow plug has, for years, been the Sig RIC (#SIGGP003). The newest Sig RIC plugs are produced by
another manufacturer, but appear to have the same running character ----- Thank goodness! Many people have liked the Thunderbolt line of plugs, but as of this date, they are no longer available. Some of the
Merlin line of plugs may be hot enough to work---I have not tested them. My refrain for a long time, has been, "Put a fresh Sig Plug and good fuel in it, then let's see what else it may need."
This has been an attempt to hit the "high points" of stunt engine
tuning. If you have more questions or problems, feel free to call me at 770-592-3279.