Originally Posted by A.Delaney

15 gals to break in? I just bought a red head 275. Sounds like I better run it on the rich side for a while. What’s a good temp for break in and after? Anybody know?

A Delaney: Break In & Temp.
The only accurate Temp info is on 3W Germany website, go there and download a manual. You will have to convert from Celcius. Also they only provide these reference temp’s taken by a CHT thermocouple mounted under the Spark Plugs. No Radio manuf. that I know of provide this type thermocouple with their telemetry, So then you have to guess what is the diff. in temps taken under spark plug vs. where your radio manuf. thermocouple is mounted?? I am using Jeti and they have a cylinder temp thermocouple that comes with 2 sensors, they are a “Lanyard” / “Choker” style and the thermocouple makes contact with the Cylinder wall at the top most last groove before the Head fins. To improve Heat transfer / accuracy you can use a thermal compound to “bed” the thermocouple in. I used this:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I have done a lot of research on this topic and WHAT IS VERY FRUSTRATING ON HERE is that people will answer your question but they don’t tell you where the recommended temps are being measured.
So after looking at full scale Lycoming & Continental information, they recommend cruise temps not to exceed 400ºF CHT.
3W Germany, state not to run cooler than 356ºF CHT or you get Carbon build up and you can “for a certain time” at full throttle run 482ºF.

Most of us are aware that one cylinder on a boxer twin will get a richer fuel mix from the Crankcase and therefore runs cooler. SO what I have done with my Baffling is customize the baffling for each cylinder to “TRY” to equalize the temps and thus achieve a more optimized carb mixture setting. The baffling on the Rich cylinder is much tighter to the cylinder reducing the VOLUME of air on that side and a little looser on the Hot side providing more VOLUME of air, this has proven to be effective based on my telemetry data, i.e. Not Opinion, but factual.

So after all this effort and extensive break-in gallons both on the bench then in the air my Hot side telemetry, USING THE THERMAL PASTE, in 90º F ambient temps is running 370-380ºF after sustained Full Throttle flight.

After Extensive Bench break in, the initial Flight Hot side temps reached as high as 430º, and again these were not taken under the Spark plug but at the upper most cylinder groove.

I ran Redline from the beginning, and the engine never ever bogged down in flight. Also during the early stages of flight break-in I would fly full throttle till I hit the 400º’s and then throttle back, let temp’s come down, and then go to full throttle again, and repeat this for entire flight. This was one of the great blessings of accurate REAL TIME flight telemetry.

The engine in question is a 3W 170 Competition Twin Spark.
After many many gallons of fuel, it is now really coming alive !!!

I will close with saying the manuals on AI’s Site for download have temps that are way off, not correct.
Also I have seen on here during my research people say don’t exceed 350ºF, that is not correct for a 3W and not consistent with 3W Germany’s manuals. Perhaps it would be true for other brands?
I did not keep records, but I would estimate I ran 5-6 gallons on the bench before putting engine in the airframe.
I never ran the engine with a LEAN carb setting, but the 3W recommended setting i.e. 200-300 rpm lower than peak rpm.
I was very cautious with initial flight break-in this summer.
My JETI has voice option which was calling out the cylinder temps every 5 seconds.
Hope this info was helpful to someone,
Kind Regards, Ken

Here is a copy of the 3W Germany manual page on Engine Operating Temp’s

Again, the recommended Temp’s in the manuals on Aircraft International’s website (AT THE TIME OF THIS POSTING) are NOT correct.

Thinking to much into this.
I have been flying for 3W since 1998. Just use a good oil such as Redline and duct the cowl and you will be fine.

Tune the carb so the engine has good transition and top end power and fly the heck out of it. The engine will gain power the more fuel you run through it. I have some 3W engines with hundreds of gallons through them and they just keep going. No rebuilds.

I’m sure the on board temps work but they are not needed. We use to land as fast as we could and use a laser temp gun and check for temps below 250. This was before on board temps were available. So that is why you are seeing different numbers.


Here are a couple of new sites for 3W info as well. Take the space out between face and book as Flying Giants does not allow that word.
https://m.face book.com/3wmodellmotoren/?ref=page_internal&mt_nav=0

https://3wprofessionalline.com/

[QUOTE=torquen;2904949]Thinking to much into this.
I have been flying for 3W since 1998. Just use a good oil such as Redline and duct the cowl and you will be fine.

Tune the carb so the engine has good transition and top end power and fly the heck out of it. The engine will gain power the more fuel you run through it. I have some 3W engines with hundreds of gallons through them and they just keep going. No rebuilds.

I’m sure the on board temps work but they are not needed. We use to land as fast as we could and use a laser temp gun and check for temps below 250. This was before on board temps were available. So that is why you are seeing different numbers.

NOT wanting to start a argument here, but a buddy of mine had the identical NEW motor as mine and we both used Red Line and bench ran, and totally thorough Baffling and he burned up his hot side cylinder. He thought he had it tuned correctly. I was with him when it bogged in the air. Why this happened, not sure, but if he had telemetry telling him his engine was getting too hot at this early stage of break in he could have avoided the repair. I will agree if you want to be on the safe side during the early phases, then run just a hair on the rich side.If you have on board telemetry then you can tune more aggressively as you are basically tuning based on temperature.

I had never heard of 3W till about 6 months ago when i got a 35% Edge with a 3w 106 twin red head(comp) its a very strong running motor and besides having to stick a new carb on it its always ran great. even after sitting for 10-12 years. even with the temp change here (90s-100) to 50s-60s it still running w/o changing the needles.

Originally Posted by closetguy

I like the way they sound,you can always pick out the 3W when flying.

Yes you can. Mine quietly purrs on canisters. I love doing an easy knife edge down the runway just letting the engine torque do it's thing on low rpms.

[QUOTE=SMOKINMAC;2905013]

Originally Posted by torquen

Thinking to much into this.
I have been flying for 3W since 1998. Just use a good oil such as Redline and duct the cowl and you will be fine.

Tune the carb so the engine has good transition and top end power and fly the heck out of it. The engine will gain power the more fuel you run through it. I have some 3W engines with hundreds of gallons through them and they just keep going. No rebuilds.

I’m sure the on board temps work but they are not needed. We use to land as fast as we could and use a laser temp gun and check for temps below 250. This was before on board temps were available. So that is why you are seeing different numbers.

NOT wanting to start a argument here, but a buddy of mine had the identical NEW motor as mine and we both used Red Line and bench ran, and totally thorough Baffling and he burned up his hot side cylinder. He thought he had it tuned correctly. I was with him when it bogged in the air. Why this happened, not sure, but if he had telemetry telling him his engine was getting too hot at this early stage of break in he could have avoided the repair. I will agree if you want to be on the safe side during the early phases, then run just a hair on the rich side.If you have on board telemetry then you can tune more aggressively as you are basically tuning based on temperature.

Again old school,,, Tune for flight and not on the ground,,, Ground RPM's mean absolutely NADA and Never be in a Hurry to properly break in a 3W engine.

Bench running is the Worst thing to do on a new engine.


BV

I just checked out the 3W Professional site......I like the 'on engine' servo mounts they have for throttle and choke. Wonder if they'll make them available as an accessory for non-professional versions?

Originally Posted by Bill Vargas

Bench running is the Worst thing to do on a new engine.


BV

Hey BILL, It would be helpful if you stated WHY bench running is bad.
And Why does 3W’s manual suggest bench running for initial break in?
I bench ran my new engine extensively, and as I stated in my post above, after completing Break In in the Air, my engine is running great !!
Kind Regards, Ken

Sounds like I’ll be setting up telemetry on my plane.

Bill: I am curious to hear your thoughts on why bench running a new engine is bad? Does this go for any engine or mainly 3W?

Personally and this is my belief(3W), engines that are ran for extended periods on a stand(bench run) will over heat and or run hotter than normal and that's where the damage begins. Damages I have seen and have had happen to me,,, a Learning curve if you will. If allowed to run too hot the heat will damage the front bearing rubber seals and the next thing you see is the black grease getting spewed out between the hub and the crankcase. Over Heating will also loosen up the cylinder screws and the next thing you will see is the gasket getting pushed out. If ya blow that out its an instant Lean condition for that cylinder and you'll end up with an even bigger parts/repair invoice. If ya catch that one before it happens consider yourself lucky



Controlling the cooling air flow around the cylinders is important so as to prevent excess/excessive heat build up and as with most cowlings with all the different types of baffling, that works, the heat is carried away like it should be with The constant controlled airflow as the plane flies thru the sky. That is why I say, bolt it up to the plane, start it up and set the needles accordingly and go fly

I'll add to that, when you bench run a engine your not letting that engine run at it's full potential for extended periods.Sort of babying it if you will and that engine will always run like it was broke in.Prop your engine so your in the max rpm range for your engine from day one,and not over loading it with a large prop.

Originally Posted by SMOKINMAC

Hey BILL, It would be helpful if you stated WHY bench running is bad.
And Why does 3W’s manual suggest bench running for initial break in?
I bench ran my new engine extensively, and as I stated in my post above, after completing Break In in the Air, my engine is running great !!
Kind Regards, Ken

3W engines are meant to be flown to break them in , the varying loads of flight help immensely , and always use correct baffling
Not had any real prob's with my 3W's over the last 20 yrs
They all run great on pro-flow pipes up to the 210csts
The tillotson carb is more finicky than the walbro

Thanks Bill and ClosetGuy for the additional information.

I have had no issues as stated before on 3 diff. 3W’s with doing the 3W recommended “INITIAL” break-in on the bench. If you follow their instructions the engine doesn’t overheat on the bench. I also use a temperature sensor to monitor both cylinders during this process. After a period of time you can, while monitoring temperatures, periodically advance the throttle and back off again, alternating the RPM during this Bench run process.

I believe it is true that the 3W engines are produced with TIGHTER/CLOSER tolerances and therefore the additional care during the early stages of Break-In are warranted, i.e. Use a smaller prop for initial bench break-in, don’t exceed recommended RPM’s, at first, Gradually increase RPM’s on bench as temperatures allow. This bench phase for me has been valuable.

My experiences with these motors would support following 3W’s recommendations of initial Bench Break-In.

Everyone has their preferences and I respect that.

Originally Posted by Bunky F. Knuckle

3Ws got a real bad rap a long time ago, with ignitions failing. I have had 2 fail in 19 years running them.

You mean they are as reliable as the coil packs on German automobiles

Gotta love that "German Engineering"

Originally Posted by ghoffman

In 10 years, I have never seen one in person.

Elie Hughes flies (or used to?) 3W in his big 50% planes... Back when I was more active going to New England area fly ins I saw his Hemple Edge fly with a 3W275 quad red head a couple of times in Mass. Hauled it around pretty good.....

Originally Posted by epoweredrc

I had never heard of 3W till about 6 months ago when i got a 35% Edge with a 3w 106 twin red head(comp) its a very strong running motor and besides having to stick a new carb on it its always ran great. even after sitting for 10-12 years. even with the temp change here (90s-100) to 50s-60s it still running w/o changing the needles.

3W is one of the oldest vendors in the business... When they got started I think the most popular RC gas engines where still Quadras and Zenoahs. Dave Johnson of DA was a 3W importer/service center before he decided to start building his own motors... the rest is history...

Originally Posted by SMOKINMAC

I believe it is true that the 3W engines are produced with TIGHTER/CLOSER tolerances and therefore the additional care during the early stages of Break-In are warranted, i.e. Use a smaller prop for initial bench break-in, don’t exceed recommended RPM’s, at first, Gradually increase RPM’s on bench as temperatures allow. This bench phase for me has been valuable.

The main purpose of break in is to seat the ring. How is a tighter crank run out tolerance going to make the ring seat slower?

Lots of debate but most of what I have read online from professional two stroke builders seems to favor breaking in at real operating temps and speeds and varying the loads to heat cycle the engine. One of the most respected writers on the subject - Gordon Jennings - promoted high RPM/low load break in. Get it up to speed/temp fast to seat the ring but dont bog it. Translated to aircraft that favors an in the air break in, using a small prop to start, varying the throttle a lot but avoiding hovers and other 3D moves that load the engine at low airspeeds...

BTW, can you lay off the SHOUTING ?