I needed to chose a plane (trainer)  for Sharma model 3.2 cc diesel engine. Apart from keiser MKII (sold by the same website), is there any other model i can use it on ?. Most models are labelled as per Nitro / Glow engine requirement, so its difficult for me to chose the plane. There is a lot of information on electric to nitro conversion but my quick search failed to give any information on diesel to nitro conversion...

Experts help please... Sanjay Rai sir, KK Iyer sir... 

Doc, that is technically a 0.2 cu. in. engine

However, modern glow engines develop a lot more power than Diesel cu. in. for cu.in. So consider it equivalent to a .15 Glow

In fact, I have built and flown the Kaiser Mk !!, and used an electric, approximately equivalent to a 0.15 Glow

http://www.rcindia.org/electric-planes/kaiser-mk-2-from-sharma-models/

Thank you Sanjay Rai Sir...

Just adding to Rai saheb's reply,
The difference is in how they deliver power.
A Cox .049ci (.75cc) glow will turn a 5x3 prop at say 13,000 rpm (or much more with nitro)
A Mills .75cc diesel (which has a much longer stroke) will turn an 8x4 at perhaps 7000 rpm
(25% E&OE, as its been a long time since i ran either)

A light streamlined fast model benefits from the Cox (see Col Sundaram's thread)
A large, slow, draggy model benefits from the larger prop capability of the Mills.

I think the Sharma 3.2cc diesel will take a 9x6 (phone them to check)
A .15ci glow will probably take only an 8x4.

So for a trainer the diesel may be a good choice (once you learn how to start it in one flick )
Best of luck.

Thanks Iyer sir... will try to master the one flick start...

+1 on KK Iyer's advice. A diesel with it's ability to deliver higher torque can swing a larger propeller at slower speeds that makes it a hauler. Consider it as low gear.  A same size glow will swing a smaller prop at higher rpm which is good for speed and cruising. Therefore a same capacity (as of glow) diesel will pull a heavier plane around. 
If you are ok with learning nuances of diesel engine go for it. But if you need simplicity in starting and tuning glow is better. 

Power = Torque X RPM (speed)

Yes, a Diesel will have a lower RPM and higher Torque

Power is also =  PLAN

where

P = BMEP (Brake Mean effective Pressure - dependent on Compression Ratio and Calorific Value of the fuel)
L = Stroke Length
A = Cylinder Area (L X A = Swept Volume => cc or cu. in.)
N = RPM

As a Diesel has a lower BMEP for the same engine volumetric capacity, the total Power will be less. But certainly, it will be torquier, capable of swinging a much larger prop, albeit at a lower RPM

I am an uneducated guy, and I know what I know through experience. All that English is French and Latin for me. For me power simply means what it can do for me rest everything is theory.
   

   

That is one way of looking at it   To put it simply, a diesel of the same size has less total power

Well..... the Sharma 3.2 cc does take the 9x6 prop well and gives good power.  I have used the same combination for many many years.  First on the control line and later on the RC flying. 

The Sharma 3.2 is slightly bigger in power output than a .15 c in glow or nirto as people call it.  The .15 is equivalent to a Sharma 2.5 cc engine.

Well... all other models weighing about 1-1.7 Kgs (AUW) can be flown on the Sharma 3.2 cc as I have been doing it for long.  In fact if its a slow flier maybe 2 kgs will also go.  But it is ideal for up to 1.5-1.7 Kgs model.

Quote from: shobhit17 on June 13, 2015, 08:33:46 AM


The Sharma 3.2 is slightly bigger in power output than a .15 c in glow or nirto as people call it.  The .15 is equivalent to a Sharma 2.5 cc engine.

I think we must agree to disagree on this. I say so because the Glow will spin the same prop faster

Sir if I may say something to be different.... the Glow plug akin to a petrol engine and less a much less torque than a desiel one.  Therefor it turns a smaller propller to a higher RPM.  Whereas a deisel engine has a much higher torque and it can tuen a bigger propeller better though at a relatively lower RPM.  

The .15 glow is similar to 2.5  cc diesel.......  The Sharma 2.5 cc goes with the .15 glow in all competetions whereever people take part in them..... the 3.2 cc is slightly bigger......

Also.... the sharma 2.5 cc diesel pulls the Sharma's Sr Pacemaker or the Windson H quite well.... just as the OS Max .15.  WHereas the 3.2 cc one is a tiger and it shows it definative extra power much better than the OS Max .15

The Sharma's 2.5 goes on these control lines with a 8x6 or a 9x4 prop well.... whereas the 3.2 goes extremely well with the 9x6.  I have flown them all for years..... remember.... I won the WIngs open in 1985 flying the windson H with a Sharma 3.2 on a 9x6 prop......

The BOTTOM LINE is.... the glow plug has a lesser compression ratio and hence a much lesser torque than a Diesel engine..... thus it drives a smaller prop maybe at a higher RPM...

I don't wish to argue on this; it could go on forever

As I said, agree to disagree

Well.... Best wishes

Power is what one can use, the difference lies in how and when a glow or diesel engine delivers the power. While the glow engine delivers it's peak power at higher RPM's a diesel delivers the max power at lower RPM levels. As said earlier consider it like gearing. A diesel excels in lower gear for hauling and glow excels in higher gear for cruising.
Just have a look at this video.
A 8 cc diesel (cross flow scavenging) hauled around that 120 size GP Super Sportster (although grossly under powered). Let's see a modern Schnuerle ported 8cc glow do that.
Note - We are talking model engines  

my two bits ...

diesels have a unique smell
diesels are much more fuel efficient than equivalent glows.
diesels have a beautiful sound

@saikat sir,
And they bite your finger only on the other side!