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Old Mar 01, 2013, 10:26 AM
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www.5bears.com has a couple of nice radial build logs as well as a couple of turbines. nice site with lots of info on the machines and skills needed to pull it off.

another favorite of mine are rotary engines and this is one of the best IMO: http://modelrotaryflyer.tripod.com/gnome160/index.html he has done both a gnome and a leRhone from scratch.
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Old Mar 01, 2013, 11:08 AM
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Originally Posted by earlwb View Post
Darkenor,
For the engine kit. I would suggest getting a tube of Yamabond sealant to use on the engine too.

For machining your own stuff, you only need a lathe and a milling machine. You don't need to get a fancy CNC machine setup either. That would let you make pretty much anything you want to make within the size limits of the equipment. You start out making more simple things and work your way up to more complex things. Sometimes it is just chucking up something in the lathe to machine it down to nothing to see what happens, sort of like whittling on a piece of wood with a knife.

I have done things like make crankshafts and connecting rods along with other things. Some stuff is more mundane such as making hinges for my screen door at home or parts for my motorcycle, et cetera. A lot of machining effort or time is in coming up with jigs and fixtures to hold parts while you machine them. You can sometimes spend hours making a fixture to perform a few minutes of machining on the part.


Reginald,
yeah I think he likely had 2,000 hours just making jigs and fixtures too.
It looks like they are planning to run two of those V12 engines in a DH 98 Mosquito twin engine bomber. But yeah I sure don't remember anyone flying a liquid cooled multi-cylinder engine before. The only single cylinder I know of is the MVVS 55 liquid cooled engine and it has a fairly small radiator on it. I wonder if the extra large radiators on the stationary engines was because they didn't use a fan to blow air through them or not.
This is the MVVS 58 complete with radiator and pipe but it is to go into that big dragster hanging on the wall, another project waiting to get finished... but the Wilga will have to come first.
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Old Mar 01, 2013, 12:22 PM
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Wow! How did you find that place? I can't believe there are two places that make a Merlin motor like that. Now if only I could afford one...

I'm pretty amazed at what the community has been able to come up with. That 18 cylinder engine is (I think) the "biggest" engine I've seen so far.
Actually Siedel before they went out of business used to produce single and double row model radial engines to sell. Siedel had made a deal with UMS in India to manufacture their lower cost radial engines, and when Seidel folded up shop, the Evolution engine company figured out as way to have UMS continue to make the single row radial engines under the Evolution brand. So they were able to keep having the radial engines manufactured. The price is amazingly affordable for the Evo radial engines too.

Actually one doesn't have to use a V12 engine to get the scale sound. Kolm makes a inline three cylinder engine, that when you see and hear it flying in their giant scale planes, it just sounds fantastic. A three cylinder engine sounds like a 12 cylinder engine as it is turning the higher RPMs but with three cylinders it sounds like a 12 cylinder engine at speed. But a V12 model engine will sound more like a full size F1 car engine at speed.
www.kolmengines.com/

Galloping Ghost Kolm Engines Warbirdgrillen 2012 MFC Lungau (5 min 56 sec)
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Old Mar 01, 2013, 12:52 PM
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The Netherlands
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Originally Posted by Reginald View Post
I do have my doubts about flying a model watercooled multi cylinder, you know, the smaller the engine the bigger that radiator has to be, just look at those stationary model V's or 4's they all do have an out of proportion radiator, something to do with the law of quadrates ?? do'nt know how to translate excatly in Enlish language. I have a V-8 Conley but am sure it would be useless in amodel airplane. Having said that..... you never know if someone is already flying a similar engine somewhere.
Nope, you don't really need a big radiator on a small engine, and cylinder count has only little to do with it, Radiator size is all depending on the airflow, and the amount of heat it has to remove. And the amount of heat is completely depending on the amount of power that is demanded from the engine.
A compact engine might make it difficult to remove that heat, but that is the beauty of liquid cooling: you can cool an engine with liquid, where aircooling would not be effective. Only problem could be presented by the pumping system.

A properly constructed radiator can be smaller than the size of a pack of sigarettes for every kW, you need roughly 150~200 square cm for a 1 kW shaft output motor.
My liquid cooled helicopter (10 cc 2-stroke) is designed for "no airflow" radiator, and has approx 450 square cm. I really had to shield that radiator from all flight wind otherwise the engine would be cooled tot he point where it would run very poor, as soon as I would go from hoover into forward flight.
That radiator is more or less same size as two packs of marlboro stacked on top of each other:

Vario Xtreme liquid cooled engine.wmv (7 min 19 sec)


Brgds, Bert
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Old Mar 01, 2013, 01:12 PM
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Originally Posted by Brutus1967 View Post
Nope, you don't really need a big radiator on a small engine, and cylinder count has only little to do with it, Radiator size is all depending on the airflow, and the amount of heat it has to remove. And the amount of heat is completely depending on the amount of power that is demanded from the engine.
A compact engine might make it difficult to remove that heat, but that is the beauty of liquid cooling: you can cool an engine with liquid, where aircooling would not be effective. Only problem could be presented by the pumping system.

A properly constructed radiator can be smaller than the size of a pack of sigarettes for every kW, you need roughly 150~200 square cm for a 1 kW shaft output motor.
My liquid cooled helicopter (10 cc 2-stroke) is designed for "no airflow" radiator, and has approx 450 square cm. I really had to shield that radiator from all flight wind otherwise the engine would be cooled tot he point where it would run very poor, as soon as I would go from hoover into forward flight.
That radiator is more or less same size as two packs of marlboro stacked on top of each other:

http://www.youtube.com/watch?v=MgT4T5juNRc

Brgds, Bert
I was talking about those stationary engines, just try find one with a scale radiator, I do'nt know any.
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Old Mar 01, 2013, 01:31 PM
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I think I've made a mistake. This thread has made me want to learn how to make my own engines from scratch. Check this forum out:

http://www.homemodelenginemachinist....building-8701/
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Old Mar 01, 2013, 01:36 PM
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In that case. www.modelenginenews.org

Greg
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Old Mar 01, 2013, 01:38 PM
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Originally Posted by Reginald View Post
I was talking about those stationary engines, just try find one with a scale radiator, I do'nt know any.
That is what I mean: no or insufficient airflow so they oversize the radiator, same as what I have on my helicopter: idling, I do not even need a radiator, 50 cm of 10 mm copper pipe is sufficient.
Flying at full speed, I need a radiator approx 1/3 of its current size, that is exposed to the full airflow.

Only in hoover, I need this big radiator (the airflow that close to the rotorshaft, is surprisingly small in hoover). in order to keep a constant temperature in the widest possible operational range, I need to have a big radiator, that is shielded from the airflow.

And that is why you need a big radiator on stationary engines, to prevent overheating under all circumstances, because there is always some idiot that tries to load the engine to the max....


Anyway, it is not the law of quadrates, because an engine that is twice as small, has 1/8 the capacity (and thus theoretically 1/8 of the power and heat production) but only 1/4 of the cooling surface, so theoretically, a radiator could be "smaller than scale"...

Brgds, Bert
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Old Mar 01, 2013, 01:46 PM
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Originally Posted by Darkenor View Post
I think I've made a mistake. This thread has made me want to learn how to make my own engines from scratch. Check this forum out:

http://www.homemodelenginemachinist....building-8701/
You are quite right, there is a lot of deviation at times, do it myself sometimes, we get carried away... Here are 3 magazines, first two are American publications but I am not sure if they are still published ? they always carry one or another project with very good drawings and measurements inside and I am pretty sure one can still buy all back issues. The 3rd one is British and also offers possibility to buy the many many engine plans. In some cases casting are available.
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Old Mar 01, 2013, 02:17 PM
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Some Siedel engines from when they were in business


reference http://www.top-collect.de/Artikeldet...t.aspx?ID=7175



Some more twin row radial engine videos:

OHRNDORF 14 Zylinder Doppelsternmotor / 14 cylinder double radial engine (1 min 25 sec)


OHRNDORF 14 Zylinder Doppelstern Modellmotor / RC 14 cylinder double row radial engine (0 min 57 sec)
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Old Mar 01, 2013, 02:24 PM
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I think that one of the easiest engines to make yourself is the Hex 2 and Hex 4 engines.
www.jamesengine.com/index_files/Page486.htm

I have the plans and pretty much all the metal needed. I just haven't had the time to have a go at it yet. I happened on a small bunch of Cox .049 cylinder/head/piston and rod assemblies a few years ago as well. So I am pretty much all set to try to make a couple of them.

I think Reginald has a unfinished Hex 4 engine too.
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Old Mar 01, 2013, 02:52 PM
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It's rare that anyone flies an engine they spent thousands of hours building.

http://modelrotaryflyer.tripod.com/index.htm

Greg
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Old Mar 01, 2013, 11:50 PM
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Originally Posted by earlwb View Post
I think that one of the easiest engines to make yourself is the Hex 2 and Hex 4 engines.
www.jamesengine.com/index_files/Page486.htm

I have the plans and pretty much all the metal needed. I just haven't had the time to have a go at it yet. I happened on a small bunch of Cox .049 cylinder/head/piston and rod assemblies a few years ago as well. So I am pretty much all set to try to make a couple of them.

I think Reginald has a unfinished Hex 4 engine too.
Here it is
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Old Mar 02, 2013, 12:06 AM
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Ums

By the way it is Seidel not Siedel. This is the first one by UMS the 7 cylinder
35cc. But trough the grapevines I did hear that UMS are no longer producing the engines ?? Any confirmation welcome.
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Old Mar 02, 2013, 12:11 AM
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Kolm

Seems that Hans Kolm is now offering a put-it-together twin boxer BX 135
courtesy Modellflug International
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