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Your most unliked engine , petrol, glowor diesel.


Engine Doctor
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6 minutes ago, Jon H said:

 

 

 

Although i am yet to fly it, i have been experimenting with an rcv120sp and believe half the problem is the props rcv recommended. To me, they had insufficient pitch and my testing so far seems to back up this idea. Once i get back to flying again i plan to fit the 120 in an old wot4xl and see how we get on. If you decided to experiment with yours use a minimum of 12 inches of pitch...something like 18x12 or 16x14 would be my choices after a little napkin maths

   My SP 60 is well happy driving a 15x10 and would likely be ok with more diameter but with just an inch of prop clearance with tail up on take off is limit for SNJ. Should think a 120 will be swinging something pretty large.

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17 hours ago, J D 8 - Moderator said:

   

   My SP 60 is well happy driving a 15x10 and would likely be ok with more diameter but with just an inch of prop clearance with tail up on take off is limit for SNJ. Should think a 120 will be swinging something pretty large.

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JD8, your SNJ must be virtually unique for an engine powered R/C model.  The prop actually looks larger diameter in proporting to the airframe than on the real thing.  The AT-6, SNJ, Harvard family was notorious for the noise from its relatively small propeller though.

With regard to the original question, the DC Bantam glow engine is probably my least favourite, having wasted several hours trying to get some in my friend's Ebenezers going at a recent free flight event, then when I finally coaxed some live out of one it didn't have the power to keep the attached model airborne.

I've never had a lot of luck with Irvine 40s, they either have gummed rings or are just worn out by the time I see them.
Strangely enough given the comments from others, I've had a fair amount of success with a Flash 35 I bought recently, purely out of curiosity.  Ok, the crankshaft bushing leaked a bit, but I had no problem getting the thing started.  I might even put in an MFA Yamamoto just for the hell of it.

A G-Mark 06 is another engine I just could not get going, again it seemed deficient in the compression department.

Edited by Robin Colbourne
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1 hour ago, Robin Colbourne said:

JD8, your SNJ must be virtually unique for an engine powered R/C model.  The prop actually looks larger diameter in proporting to the airframe than on the real thing.  The AT-6, SNJ, Harvard family was notorious for the noise from its relatively small propeller though.

 

   Having seen and heard six AT6's racing each other one has to say the noise level was impressive.

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7 hours ago, Robin Colbourne said:

With regard to the original question, the DC Bantam glow engine is probably my least favourite, having wasted several hours trying to get some in my friend's Ebenezers going at a recent free flight event, then when I finally coaxed some live out of one it didn't have the power to keep the attached model airborne.
A G-Mark 06 is another engine I just could not get going, again it seemed deficient in the compression department.

I have a Bantam stored somewhere. Pretty finicky for a so called beginners engine, good advert for a Cox 0.49

I had a G-Mark 06 in a RTR 1/10 mini years ago. The engine was started by spinning a rear wheel. It ran well. Unfortunately the chassis being plastic just fell apart. in the end the engine went in the spares draw. Years later 2 of us built DB Rookie powered gliders. My mate didn't have an engine for his, so I gave him the G-Mark. With a 7 x 4 it regularly pulled a Rookie 86  aloft to phenomenal heights. Not seen him since I moved away but it was a cracking engine. My only complaint was the silencer errr.... didn't.

 

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On 07/10/2024 at 13:15, Brian Cooper said:

MDS. . . Dreadful engines. The only that worked properly was the guarantee. 

 

When returning anything under guarantee, there are reasonable expectation that the replacement will work and make your life wonderful once again. 

But not with MDS. .  .The guarantee just prolonged the nightmare. 

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Sitting at home getting over a dose of Covid (Mrs C8 has it as well) and your post made me laugh out loud. Many dead sticks....metal door stop....mine doesn't start etc etc what a load of junk they were.

Had a big row in a model shop over one that they'd sold to a beginner as a package years ago and it was useless.

Got satisfaction in the end when they agreed to take the heap back and sell the new chap a new OS.

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Just wondering why all these so called dreadful engines got this reputation.

Surely if it starts and runs without seizing it's not an engine fault, it's a carb or set up fault.

We've all seen the faffers having problems getting their os's and lasers amongst others running and people jump in to help.

An mds and everyone runs away.

 

 

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My contribution to this thread is not as such a dislike, or least favourite, but more of a genuine fear. Out of my extensive engine collection there is one engine which is both a Cox Tee Dee 09 and a portal to hell itself, providing a physical entity to which lucifer can manifest. Upon starting, the engine note, is one of a seething frustration of being strapped down, and I am convinced if it were to unshackle itself it would come for my throat. I dare not sell it, as it would surely track me down and reap revenge on me. If it were a dog it would be an XL bully, it should have a dedicated psychiatrist, it should come with a straight jacket in the box. My local priest regrettably refused to bless my tank of 25% nitro fuel, so I am stuck with it. To this day, I refuse to be left alone in a room with the 09.

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13 hours ago, Engine Doctor said:

The Bantam is a bit of a waste of time. Its veeerrrry noisy , worse than any similar size cox and with a fraction of the power. The Wasp is a bit better

Engine Doctor, that's exactly the conclusion I reached.  If only I could convince my 90 year old friend to convert his fleet to DC Wasps or Cox 049s my life would be so much easier.  Personally I would probably stick DC Merlins in them all, given the price of glow plugs these days.   He is mostly blind and not that quick on his feet, so I do the starting and chasing.

Someone at the recent Free Flight Meeting at RAF Odiham pointed out that the age differential between the model owner and the fetchermite is still the same as in the old days, its just that they're both fifty years older!

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14 hours ago, Engine Doctor said:

The Bantam is a bit of a waste of time. Its veeerrrry noisy , worse than any similar size cox and with a fraction of the power. The Wasp is a bit better

My first engine was a Bantam. I struggled to get it to run even with that "spring and cam" starting device.


One day a schoolfriend said he wanted to get an engine, so I said he could buy mine.
He came round to my house and we bolted the Bantam to a test stand I had made.
Fuel in, glow battery connected, engage spring starter, -------  and it started and ran immediately!!!!!!! 😁
He bought it, and I never heard about it again.


I went out and bought a Merlin next day and never looked back.

 

Dick

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2 hours ago, J D 8 - Moderator said:

I fired up my Tee Dee 051 at a public event my club attended last year. Many came to see what the racket was others ran and hid behind the man in black.😁

 

My 051 is a happy springer spaniel compared to the 09.. It has the after market US fine needle (forget the maker) in it and it is sweet!!!

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8 hours ago, Learner said:

Just wondering why all these so called dreadful engines got this reputation.

Surely if it starts and runs without seizing it's not an engine fault, it's a carb or set up fault.

We've all seen the faffers having problems getting their os's and lasers amongst others running and people jump in to help.

An mds and everyone runs away.

 

 

They run away because they can spend hours on some of these engines and they still wont run reliably . Hours of your life you will never get back 😶.

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24 minutes ago, Engine Doctor said:

They run away because they can spend hours on some of these engines and they still wont run reliably . Hours of your life you will never get back 😶.

But why, 2 stroke glow engine are so basic there is not much that can be wrong?

Why does my mds 40 run fine and others have so much trouble. 

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18 minutes ago, Learner said:

But why, 2 stroke glow engine are so basic there is not much that can be wrong?

Why does my mds 40 run fine and others have so much trouble. 

 

That's what I thought when I bought the engine for the trainer I built and chose an MDS 40.  The engines are so simple, what difference does it make?  Yet it behaved as the vast majority of MDS 40s did - it was unreliable and no-one at my first club (RR Hucknall) could get it to run.  Some MDS 40s were OK (very few) and I think it was down to poor quality control.  The later MDS 38s were much better.  I had one in a Limbo Dancer but the ST34 I fitted was much better and the brushless motor better still.

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12 hours ago, Learner said:

But why, 2 stroke glow engine are so basic there is not much that can be wrong?

Why does my mds 40 run fine and others have so much trouble. 

You probably have an ok 40. Ive had a couple over the years and provided you dont ask too much of them they run  ok. 

Problems often arrise from poor quality materials . The piston material seems to vary and one fault that often occured was the gudgeon pin fit in the piston. Once this became oversize or oval usually on one side the timing is thrown out ,then extra friction is generated as piston tilts generating more heat and its just a matter of time before it becomes unuseable. Many seemed to have gouges in the piston and liner suggesting debris from manufacture or ingestion of debris. Whatever the cause so many people cant be wrong and MDS were thankfully consigned to history. It seemed the bigger the engine the worse they became and the 58 was horrid. 

I have a 148 MDS in my box of engines . Not much chance of it ever being used....even for spares.*

Ive told this before but here goes. We had a club member who was an MDS fan and he yold me this ?  His wife was Russian . At harvest time she would go back  home to help her family . He asked her if she could get some spares for him while in Russia. She apparently found a shop that sold modelling items and gave the shookeeper the list . He started laughing . When she asked him why he said we dont use that rubbish we sell it to other countries! 

So there you go . Built to a price and you get what you pay for but every now and then a half decent one turns up a bit like the computers etc made by a sweet man .

 

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On 10/10/2024 at 12:39, J D 8 - Moderator said:

             I recon the main issue with the MDS RC range was the carb, to large a venturi perhaps. A friend had a fixed venturi MDS in a control line model that started easy enough and ran like the clappers until tank empty.

MDS weren't helped by being supplied with the needle out of the spraybar and the carb off the engine.  Generally the needle would be wound in dry on the model shop counter, often shaving lumps off the outer diameter on the less than perfect surface in the mating surface of the spraybar.
Add to that the o-ring which was meant to be seated at the bottom of the carburettor spigot that went in the mating hole in the fronnt housing.  Frequently the o-ring was stretched over the spigot so it sat visible between the housing and carb barrel housing.  This allowed air to leak in around the pinch bolt, thus messing up all carb settings.
If MDS or Ripmax had only assembled the engine completely before thrusting it into the hands of, usually, beginners, many of these engines might have actually run ok.
You only need to run an OS 35FP or 40FP to see what a beginner's engine should be like.  My 35FP generally starts first flick and holds its settings from one day to the next.   Not an o-ring in sight!

 

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As with a lot of Soviet - later Russian exports, they were Dollar earners made in quantity and with little thought to quality control.

If anyone has old magazines around with the original  Ripmax adverts for MDS, you can read between the lines and determine that we were simply sourcing yet another cheap supply of products to take on the Japanese brands. Unlike the later Chinese products, the Russians never got it right with their mass produced consumer goods.

Same sort of issue with Zenith Cameras in the 70's - looked good, were the fraction of the cost of a Nikon or Pentax, but just didn't last because of the inferior quality and manufacturing.

I had one for a year or so and it was originally fine, but then the shutter mechanism became sticky when out of warranty....game over.

Shop took it back in a good part ex deal on a Pentax.

 

Edited by Cuban8
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