# Radial engine plans/kits



## d65 (Feb 18, 2020)

Title says it all I am a newbie to model engine building


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## johnl (Feb 18, 2020)

Here's one for plans.
http://www.agelessengines.com


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## petertha (Feb 18, 2020)

As a newbie myself I would say less cylinders is a big enough bite to chew. If you go glow plugs, that simplifies ignition system a bit over spark if that's a consideration. There are 3 I can think of with pros & cons.
- Edwards 5-cylinder plans are free, there have been a number of build posts with pictures and Q&A on various forums. Methanol fuel, oil pump, imperial dimensions & gears
- Jung 5-cylinder, similar displacement as above, metric plans & gears, mist lubrication (no pump). I believe some common components to 7-cyl radial also offered separately
- Ohrndorf 5-cylinder, similar displacement, metric plans & gears, mist lubrication (no pump). Need to buy both 5 & 9 cyl plans to complete the 5 cyl as many parts are common. Not ideal but its the way he did it & I guess a head start f you think you will build a 9 one day

There are other 5's out there I'm forgetting. Some involve castings, some are bar stock.
Radial engines with lower cylinders count (i.e. 3) are rarer, a bit more obscure documentation wise, but they are out there


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## Jasonb (Feb 19, 2020)

PIP 3 cylinder radial in MEB is a fairly straight forward barstock build, bcak issues available digitally (you need 3 issues)
https://www.modelenginebuilder.com/store/p27/issue-24.html

Few Anzani 3-cyl casting sets still available if you know where to look.

Jung range also includes a 3 cyl
http://www.cad-modelltechnik-jung.de/shop/bauplaene-modellmotore.html


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## Peter Twissell (Feb 19, 2020)

If you'd prefer something more substantial, I will at some point make available a full set of drawings for my 2.3 liter 7 cylinder engine.
Not until I've had it running and proven!


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## WOB (Feb 19, 2020)

d65 said:


> Title says it all I am a newbie to model engine building


If you have never built a model engine of any type, I would strongly suggest you build  one or two single cylinder glow plug or diesel engines to begin to understand the processes and the required tooling.  There are many plans free online and build instructions to go with them.   There are also kits with raw materials furnished.

If you are successful, then try to build a simple 5 cylinder glow plug radial.   If successful,  you might be ready to try a 7 or 9 cylinder radial with spark ignition running on gasoline.  It is not a trivial pursuit.   It takes lots of time, determination and cash money.

WOB


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## mnay (Apr 15, 2020)

Maybe the wrong place to ask this question but:
Will most gasoline engines run on glow plugs?  What is required to make the conversion?


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## Peter Twissell (Apr 15, 2020)

To run on glow plugs requires a different fuel. Usually methanol with additives.
The fuel will require a different mixture, so bigger jet orifice in the carburettor.


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## mnay (Apr 15, 2020)

Peter, 
do you know of any reference material I can access to learn more about converting to glow plugs?
thanks for taking the time to respond
Mike


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## deverett (Apr 16, 2020)

If you want to run on glo plugs, also think about the electric power requirements for multiple plugs.  This issue has been discussed in other topics (much) earlier on this forum.  From memory it was concerning the use of Cox glo heads in multi cylinder applications.

Dave
The Emerald Isle


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## oldengineguy (Apr 16, 2020)

The Kinner 5 cyl radial  is made from bar stock. from plan published in Strictly I.C. in # 36 through 40 starting in Dec 1993. It was designed to run on gasoline with spark ign .with points ,cond. and a fabricated distributor.  Dad put 4 stroke glo plugs in it and ran it on model engine fuel  to check it out before making the distributor. It ran fine. He ran out of time and the dist. was never built. The engine still runs once or twice a year. The big problem is finding a source of old style lead car batteries to tap into one cell to get a supply of 1 1/2 volts with enough amperage to light up 5 glo plugs at once.


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## Peter Twissell (Apr 16, 2020)

Hi Mike,
I don't know of a specific reference source. In one of my other lives, I run motorcycle engines on methanol/nitromethane, but with spark ignition.
The main difference is the vast volume of fuel consumed, when compared to petrol. A 750cc supercharged bike engine can use 5 litres of methanol/nitromethane in 10 seconds!
Methanol fuel allows higher compression without detonation. It also cools the engine to some significant degree. Thus small, high performance engines can produce a lot of power without overheating.
Glow plug drivers have been discussed at length in other threads. My approach would be to use one ore more cheap boost/buck converters in current control mode. Each plug needs about 3 amps, so a 20A output would comfortably run 5 plugs. With those devices, you can run from a 12V or 6V battery, as available.
Otherwise, you could use individual 2V sealed lead acid cells, available from RS Components etc.


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## tornitore45 (Apr 16, 2020)

Effective compression ratio is critical in glow plug engines since it define the ignition timing.  Some adjustment can be done by varying the nitromethane percentage.


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## WOB (Apr 16, 2020)

If you can find a copy of Harry Higley's book "All About Engines" , it contains a good explanation of the differences between gasoline and glow-fuel engines.  It is basically a model airplane engine book , but the info is applicable to any kind of model engine.   

WOB


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## josodl1953 (Apr 16, 2020)

I use two parallel lead acid gel batteries, 9 Ah each for my Edwards.. Glow plugs take 3 A on average, totalling up to 15 A which is enough to fire it up.





There are also glow plug modulators for multi-cylinder engines working on 12V, so from an electric point of view operating  these engines  is no problem.

Jos


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## mnay (Apr 16, 2020)

Thanks to all for the info on glow plugs etc.
I did not mean to take over the thread.
Lots of good info.
Mike


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## bluejets (Apr 16, 2020)

Essentially any engine currently running on petrol can be changed over to glow.
If you have around 6:1 compression should be fine.
Rubbish about compression levels being critical is just that, some old wives tale.

When using nitro ( normally accepted as being for higher performance) ratios of 10% increments for some reason are the most noticeable.
I would not use it except if absolutely essential as it leaves behind an acid after it burns and care must be taken to remove this each run.
Normal approach is to lower the compression in engine which go 9:1 or more. 
OS 4 stroke engines will show a much better idle, better transition from idle and a much broader needle valve setting.
Whole reason for nitro is the increase of oxygen into the burn without any mechanical alterations.
Similar (except for the latter) can be achieved with on-board glow.
Which ever way it is approached, the use of a four stroke is essential for any methanol 4 stroke engine.
Plug is more expensive and has a much smaller hole and element.

Fuel mix for alcohol fuel is a mix of methanol and castor oil at a ratio of 4:1.
So for 1 litre of fuel, 800ml methanol and 200ml of castor oil. (castrol M)
If you want to go synthetic oil, same same. 
Synthetic oils would be available from hobby shops but probably not so much these days as the trend went to electric probably 10 years or more ago.
With methanol, open up the needle jet, as it requires maybe 3 to 4 time more fuel for the same energy output BUT engine will run noticeably cooler.

In the design, most things are the same. 
Difference is the *big ends* of the con rods.
Open up the clearance to at least 3 thou and cross drill both the big and little ends for oil entry.
On the video below, this clearance was set at 6 thou.
Exception to this is when using needle roller bearings obviously.
Fuel oil ratios in this instance can also be changed.
What would be considered as normal would be 20:1 but the engine below runs at 50:1.

Then there is the OS G5 glow plug. 
O.S. Glow G5 Gas/Plug GGT15
Again, expensive critters but made especially to run on petrol oil mix.
These came out maybe 10 -15 years ago for one of OS's particular engines, the GGT15
Can't tell you anymore about any of the engine parameters but specs should be around somewhere on the net.

To see one of my many  engines running on methanol, take a peek here.
Not very clear video as didn't have the gear then that they have today for such things.
This thing runs out to 10,000rpm and currently live in a model boat.


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## mnay (Apr 17, 2020)

thanks again for the information.  Lot's of experienced smart people on this forum
Mike


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