Help with gas engine

[shrek]

I am curently installing a dle 20 in my p-47. Can i mount the ignition batterie on the engine mount with zip ties or should i keep it in the fuselage. I have no room on the fire wall. Also it will help eliminate 1/2 pound of weight i had in the nose. Cowling for balancing. http://img.tapatalk.com/d/12/09/20/y4y2y6yr.jpghttp://img.tapatalk.com/d/12/09/20/yqe7aqaz.jpg

[Sempai-mj]

Where is the ignition box?
Keep it away from your RX

[Kevin Rochon]

Gas engines makes a lot of vibration so everything need to be well attached and with foam to save your part, otherwise it WILL come loose.

I wouldn't mount your Battery? on the engine mount like I think I see there, can't you put it on the top of the firewall?

I see a nylon mount on the engine is that what they recommend?? I'd go with metal (alum.)

[shrek]

Micheal the ignition box is on the fire wall behinde the exaust. Kevin i have no room on the fire wall for the ignition batterieand yes they are plastric lock nuts but i have taped the engine mount right thrus and have tread lock everywhere.Here are more pics

[shrek]

http://img.tapatalk.com/d/12/09/20/te7e3yse.jpghttp://img.tapatalk.com/d/12/09/20/aragezy9.jpghttp://img.tapatalk.com/d/12/09/20/6y9amyba.jpghttp://img.tapatalk.com/d/12/09/20/eqera5us.jpghttp://img.tapatalk.com/d/12/09/20/arunaqe3.jpghttp://img.tapatalk.com/d/12/09/20/qavepaqu.jpg

[David Janashvili]

Hi Stephane,

I totally agree with Kevin. Nylon engine mount for gas engine is not recommended because there's alot of vibration and it will break where the screws hold the engine in place. Cracks will appear quickly and then the engine will come out especially at lower speeds.

For the ignition battery installation you can install the battery on the engine mount but before you tiewrap, put two-sided tape between the battery and engine mount. Then tiewrap so that it doesnt move anymore.
If you need any help Call me 514 889 0043 David

[briankizner]

nice looking setup. I agree with David. My ignition battery for 55cc is mounted to the side of the engine box with tie-wraps. There is foam tape (two layers ) between the battery and the wood. The only problem in 2 years has been that the ties loosened up by biting into the wood. This was easily corrected by hardening the wood with a soaking of thin CA. Rightly or wrongly , the servo battery is mounted the same way on the other side of the engine box. I do worry about vibration but so far it seems that the foam is doing its job. One other small and very inexpensive measure I took against vibration consists of eight rubber washers(look in the plumbing department of any hardware store)- four between the engine box and the metal standoffs and four between standoffs and engine.
I would hate to add unnecessary weight when there is a heavy battery not placed as far forward as possible .

[briankizner]

oops. Never mind what I just wrote about standoffs. I was not looking at your photos while writing . You are using a mount like a glow engine. I think the other fellows are right. A metal mount is more durable .

[Sunfly]

On the same line of thought as Brian::
An other suggestion to cut vibrations:
Reno Depot sells those things called "well nuts" it is in the hardware department near the nylon screws.
You would then need to drill your firewall holes up to 3/8".
You will then tighten your motor mount on these.
It worked well for me with a Saito 100 for years.

[Kevin Rochon]

Most if not all manufacturer of Gas engine recommend not using soft mount, that it would void the warranty.

[Ronald Longtin]

Les Wellnut ou des rondelles de caoutchouc isolent bien la structure mais ne sont pas des <soft mounts>. Le moteur demeure solidement monté.

Les <soft mounts> permettent au moteur de bouger, ce qui n'est pas recommandé pour la plupart des moteurs.

[briankizner]

to add to Ronald's explanation. I place rubber washers between firewall and motor mount (standoffs or manufactured nylon or metal mount) and between mount and motor. I then tighten the bolts very tight . As such, there is no visible engine movement but I think (without evidence) that the rubber does contribute a bit of shock absorption and noise reduction. Anyone who has used true soft motor mounts (I remember they used to be available from Dave Brown?, Dubro may have made them as well), as I know Ronald has and so have I, can attest that the motor at idle really does shake a lot and the vibrations are not transmitted to the fuselage. The advantage of soft mounting is that the setup will be much quieter as the fuselage will not act as a resonator and the airframe's screws and glue joints should not loosen over many hours of operation. The disadvantage, as Kevin rightly pointed out, is that engine manufacturers prefer a rigid mount- the benefit for the motor being that damaging vibrations are then shared by the motor and the fuselage, not completely borne by the motor.

[George Bozian]

I used a DU-BRO 682 motor mount on my funtana 90 powered by a DLE20 flew all summer no problems and very litle vibration also the dle manual recomends shock mount for breaking in so wy not use them all the time.
Also noticed your ignition on light is inside the cowl should it be outside the plane to be able to see if ignition is on or off at a glance.

[shrek]

If i install ruber washers in between the firewall and the nylon engine mounts would that be enough for the vibration or do i need to use metal mounts. And everyone thanks for your advice.

[briankizner]

sorry about all the digression-the dreaded "thread drift". I like your installation. I think the nylon mount is not as strong as a metal one but should be adequate. If it was mine, I'd place rubber washers between firewall and mount and between mount an engine. As for the batteries, if the engine box is your best place for them, go for it. Just use some foam around them to protect from vibration.
Having said this, this discussion has made me consider my mounting of batteries to the engine box. It has been OK for two years so far but I wonder if I am heading for a catastrophic vibration-related failure.
To digress again, my plane, a PilotRC Extra 300, flies better than any other plane I have ever owned but I find that I cannot perform really impressive spins (a maneuver my old brain and thumbs can execute well, a long departed Sig Kougar was an impressive spinner), nor can I maintain a prop-hanging hover (a maneuver I am not so good at so I should not be blaming the plane), which indicates to me that it is a tad nose-heavy for 3-D. Therefore, I am thinking of moving the batteries farther back to move the CG back and eliminate any vibration concerns.

[Burning Head]

Nilon mount allready absorbe some vib . I use rubber washers on metal mount to wood wall only.

[Kevin Rochon]

My bat. is on the engine box and even the EI but the batt. is wrapped in foam and the EI as foam between it and the ply. so it is ok for the past 5 years. You can notice that Greg used fuel tubing over the tie wraps, clever ideal;)

[Ronald Longtin]

Comme le moteur vibre et qu'il y a beaucoup de fils autour du moteur, assure toi qu'aucune pièce ne s'use avec la vibration. Les ouvertures dans la capot moteur sont particulièrement abrasives. Les fils doivent être bien retenus pour éviter tout frottement.

[briankizner]

Thanks for the reassurance, Kevin. My EI is also on the engine box with foam tape. The airplane's instruction manual shows the EI mounted there but does not mention battery mounting. Using fuel line as an antivibration is an idea I have not yet heard of but it looks like a good solution.

[shrek]

Thanks guys i will secure my wires more and thanks Kevin i will use the fuel tubing for for the tie raps its a great idea.

[shrek]

Ok guys i have an other question. What kind of syntheric oil is best for the dle-20. Some one told me STIHL is pretty good and how should i break in the engine. Any suggestions.

[Sunfly]

I used Castrol 2 stroke in many small engines and it works very well.
It is mentionned on the can "ASHLESS" that means it will really minimize deposits.
It is the only oil I saw with this mention.
Deposits of carbon if they ever build up will only do so on the exhaust port.
It is something easy to remove (if ever).

On normal operation follow the engine manufacturer for the oil if they say 40:1 go for that. I would never go further than 50:1 even if they specify 100:1

For the break in: Here is what I would do:

Phase 1: First 15-30 minute (On the ground)
Double the amount of oil so if they say 40:1 go for with 20:1.
Run the engine with the smallest prop recommended do not exceed 3000 R.P.M.
for this period.

Phase 2: 1 hour (On the ground)
Still double the amount of oil so if they say 40:1 go for with 20:1.
Stil use the smallest prop recommmended
Keep it rich but mainly run from 3000 R.P.M. push to 6000 R.P.M. for short periods
10 seconds and with the time going do periods of 20 seconds then 40 seconds then 1 full minute.

Phase 3: 10 hours: I would fly it during this phase.
Oil mix as per engine manufacturer with only short excursions at full regime.
Keep it overly rich during that period.

Last note:
Always warm up your engine near idle regime for at least one full minute --- Always ---

Hope that helps;)

Cheers,

[shrek]

thanks Luc i'll try that.
;)

[Kevin Rochon]

Not to contradict Luc but I always heard that you should fly your plane because on the ground it will tend to overheat. A break-in takes at least 2 to 3 gallons and they, lets say DA, recommends a prop that will bring the RPM up to at least 6500RPM. I remember an member, Norman who was a aircraft tech at Air Canada told me that it was good because it would let the ring sit as high as possible in the cylinder. Of course at first you don't run all the time at full speed but in burst of 10 sec then more and more.

Also for the oil, going with more oil is ok but double?? Before I got the Amsoil Saber which is supposed to be used at 100:1, I didn't believe in it, but now I see how much thicker it is then the 50:1 formula or what not, hey when I got the Fuji 50cc it came with a little bottle of 150:1 oil:eek:, never used it but I should check how thick it is:confused:

[Burning Head]

The season is a fact on a ground breaking engines. I mean, During the hot summers days , I dont thing too it's a good idea except to adjust the L/H idel:o But during the fall, with the fresh air...just don't over push the motors

[zorba]

Just fly the darn thing.
I don't mean any 3D stuff just normal flying you have to out some load on the engine. Did you ever had to break-in your chainsaw or weedwacker? Hell no, just pull the cord and way you go.:D:D

[Sunfly]

I would break in the engine no matter what other people say.
My experience with Ski-doos, motor cycles and cars showed me the benefits of a good break-in.
For the overheating on the ground I would do it without a cowling.
The blow of the propeller should be sufficient to prevent over heating specially on the fresh days of fall.
I would avoid doing this on the warmest day of summer though.

And yes doubling the amount of oil is welcome so the engine first wear off is even.
Doubling the oil will not harm anything. I have seen so many people that have that perception of a lot of oil is a bad thing. It could be annoying to fly it with that ratio :
lot of smoke + lack of power but it won't harm the engine.
I have seen for instance a two stroke engine on the bench of a mechanics:
the engine had 6 hours on it ,the cylinders were scratched badly and I was told the owner didn't follow the break-in procedure and then the engine doesn't have enough compression to hold idling properly.
I could feel the depth of the scratches by passing my finger on them.
This might be a rare and extreme case but I saw it.

I saw also my engines having better performance than others of the same brand and size because they where well lubricated and mostly broken in with patience.

For the very low oil ratios at 100:1 and 150:1 is there a contest about who will break the barrier or a mondial record at 200:1 ?
What is the reward at the end ?


Sorry but my experience is preventing me to change my mind on this whole topic.

[zorba]

maybe so, but even the big companies like Vario they say to fly the craft while breaking and not on the ground.
Gas engine on a heli is broken in by flying. Why can't this be done with the plane?
And don't forget the heli engine is always at max RPM not like the plane where the RPM varies. They seem to work very well and last a lont time.
My three cents.

[briankizner]

I am sure that Luc has forgotten more than I ever knew about gas engines but I have to agree with Zorba and Kevin on this one. Running too long on the ground overheats the motor and stresses bearings. I agree with Luc that the motor needs adequate lubrication but I would use the oil/fuel mixture recommended by the manufacturer, definitely not double. In my own case, I recently started a thread in this forum because my DLE 55 would not run for more than a few seconds after I mistakenly used too high an oil concentration. My motor ran perfectly and I have flown several times since then after I remixed the fuel to the manufacturer's spec of 30:1.
Read some of the hundreds of opinions about breaking in gas engines on Flying Giants. Everyone has different ideas but the ones who seem most knowledgable to me generally recommend to add oil of the type and concentration you intend to use while flying and to use the prop you intend to fly with and go fly. Avoid prolonged running at wide open throttle and vary the throttle often for the first few runs. They also discuss 100:1 Amsoil quite a bit and there is no consensus but, again, the opinions of the fellows who actually know and repair the motors is that there is some risk in minimising the oil content.
Luc, I am also surprised about your problems with snowmobiles. I have owned many over the years, including models from Arctic Cat, SkiDoo, Polaris and other now defunct manufacturers (MotoSki, Mercury). Right now, I have a 2002 Polaris 500cc. Some have had reliability problems but I find that almost any model built within the last twenty years is very reliable and the carburetors practically never need adjustment or repair.

[xed]

Crazyness....

Gas engines do NOT need to be broken in on the ground. The ones you are flying have cylinder heads that are designed to have air flowing over them. You will get some air from the prop wash on the ground but much more by flying it in the air at normal speeds.

For a new engine, good practice is run it uplines, then downlines and some level flight and rince and repeat. This gives it a good workout to let the rings seat and the breaks so that the engine does not overheat. With some engines, for example, DLE's, they use stiffer rings than say DA, and will take a lot longer to settle in so expect to run 8-10 gallons at least.

This whole non-sense about break-in oils and break-in props... a whole lot of hoopla. If your oil manufacturer says to run 40:1 then run 40:1.

There are some very dedicated threads with combined knowledge and experience on the order of years on Flying Giants...

[Sunfly]

By the way the 2 stroke engine I was mentioning was not mine.
In the facts the owner took it brand new and just gunned it using the standard oil ratio
recommended.
I still have difficulty to think that running an engine on the ground would cause it to over heat. I believe it would run a little bit warmer but not at such high temperature so it could be damaging.

Anyway I will experiment when I get a plane with a gasser.
I don't believe in many things but break-in....I can't let it go.

Cheers,

[Ronald Longtin]

Voici un bel exemple de <soft-mount> avec un Saito 56.

http://www.flickr.com/photos/10827061@N00/8031037988/in/photostream

[zorba]

Crazyness....

Gas engines do NOT need to be broken in on the ground. The ones you are flying have cylinder heads that are designed to have air flowing over them. You will get some air from the prop wash on the ground but much more by flying it in the air at normal speeds.

For a new engine, good practice is run it uplines, then downlines and some level flight and rince and repeat. This gives it a good workout to let the rings seat and the breaks so that the engine does not overheat. With some engines, for example, DLE's, they use stiffer rings than say DA, and will take a lot longer to settle in so expect to run 8-10 gallons at least.

This whole non-sense about break-in oils and break-in props... a whole lot of hoopla. If your oil manufacturer says to run 40:1 then run 40:1.

There are some very dedicated threads with combined knowledge and experience on the order of years on Flying Giants...

+1 on that I agree 100% And I was saying that all along...
But some people don't want to listen,,,
Cheers

[Kevin Rochon]

Well in the end anyone can break-in their engines the way they see fit for them, hey it's your engine. I prefer to fly it it's a lot more fun and does not bother anyone with the noise on the ground.

If someone is going to run an engine for a few hours on the ground I suggest doing it during the week(ok bother the retired guys they need a little stress in their lives:D) and in the break-in area we built for that purpose;)

[jim]

You guy's are going to love my break-in process.
Fill engine with gas, oh ahh, oil ratio: hold oil can above gas container and flip rist, hold for 2 secs, flip rist back, your done.
start engine, kick the shit out of it, and fly.
Simple, no problems.
Works great.

[Burning Head]

I think some of the confusion came with all the clip on Youtube show it ground break in a gaser engine. But for the prop, Thunderbolt sell propeller bundle with the specification on each prop size utility, http://www.thunderboltrc.com/index.php?main_page=product_info&cPath=152&products_id=1287 is that a other way to go or just the usual marketing