N99JH

My Feedback: (66)

Has there ever been a diesel head available for this engine? Anyone with experience running it as a diesel?
Joshua

pe reivers

Don't know if MDS metallurgy is up to the demands of diesel operation.

AMB

Jousha if you look at some of the reviews on MDS less than stellar, one chap went thru several rods, think a quality issue I think not a good idea as a conversion


martin

JUst noticed Pe Reivers post right after I posted, that sums it up

AMB

N99JH I assume that 2.18 is a 2cc size you can go to 15 and get an MVVS diesel ) (from reivers) or Fox15 with a diesel head From Davis both top notch martin

or wait and get a Taipan 15

fiery

My Feedback: (2)

Nope .. near enough to 35 cc!

AMB

WOW WAS I WRONG CUBIC INCH NOT CC MARTIN

at that size go gas

my brother in law had a MDS 60 or 61 years back terrible

N99JH

My Feedback: (66)

I have one and the metal sure does not look any different than any of my other engines. Pe - when you say you are not sure the matallurgy is up to the task of diesel conversion - do you have first hand knowledge or just guessing? To the best of my knowledge MDS is based in the Ukraine and is sort of a reincarnation of a well known former soviet engine maker. They sure have the know how given the soviets track record in sciense and engineering?
Just my 2c.
Joshua

AMB

Joshua you are right but when it drifted down to model engines no incentive under the Commie regime to do it right they just went in and tossed them together
true of a lot of their consumer items too in their own country
in scientific and medical field some outstanding discoveries

N99JH

My Feedback: (66)

Martin
I just got off RCGroups - engines thread after doing a search on MDS engines. I cannot say I was surprised with what I found, and one guy summed it up very well. I am quoting:

"When I started flying a gentleman at our club flew nothing but MDS and had the same or better reliability than any other group of engines being used.

IMHO there are two kinds of engine people.

1. Don't bother me with the details I wanna fly.

2. I want to understand when my engine is "talking" to me and enjoy the mechanical bent to the whole process.

This is not meant as criticism IMHO one group is not better than the other they just have different needs.

If you are in group one stick to the major name brands built for the "everyday" flier.

If you are in the second group you shouldn't shy away from an MDS."

I belong to group #2 and may be prejudiced, but - believe that most nay sayers have not tuned too many engines properly in their modelling career. That realization came pretty loud and clear going through the postings. It reminded me a guy who was lamenting his ST 4500 was going through 32 ozs. tank in 8 minutes. At the end he admitted that he runs 30% nitro and 20/20 fuel in a TF P-51 clocked at 125 mph. To me - that clearly demonstrates utter ignorance!
I will bench test my MDS 2.18 and report the results.
Joshua

dennis

My Feedback: (90)

There were considerable posts on the MDS engines in the day, most were pretty unkind in their remarks about the engine. Many were about the carbs and there were quite a few carbs that were substandard and many did not put the base o ring down and only used the body ring which did not give an effective seal.
The most damaging though was the R/C addiction to 15% nitro in an engine that really did not use more then 5% and did better on FAI fuel. Without adding a few head shims you literally beat the engine to death, the continuous overheating with cheap fuel with little oil didn't help either.
Suprisingly it also was an engine that did benefit from some running in before you slapped it on your model and left it to self distruct.
With these defects it was no suprise that the engine line got panned. I had seen heli engines throw the rod in 1-2 runs simply because of 30% nitro and no run in or reading the instructions.
The problems were eventually too much for Horizon and they dropped the line and created the Evolution line.
In defense of the MDS it wasn't all bad but it required some common sense to get them up and running properly. Given the prevailing mentality of many in the R/C game that made it a doomed project from the start.

N99JH

My Feedback: (66)

Thank you so very much Dennis for the well informed and reasoned explanation. I truly appreciate it, and, it seems to re-enforce my opinion that the product was not as much at fault as the intended (mostly) no brain end users. It is probably one of the major reasons why electrics displace internal combustion almost entirely.

AMB

Interesting as stated my brother in law had the 60 , I spotted the carb O ring issue and fixed engine then right off, think he was running 15% nitro
Was not paying that much attention to his fuel since I was flying my Irvine 40 diesel martin

earlwb

I think most of the problems with the MDS engines had to do with the carburetors. They tended to make a lot of bad carbs. But the engines were OK otherwise. Some carbs can be fixed if you know what the problem is, but you may have to make new carb parts though. Otherwise you have to find a third party carb to fit and work on the engine. Perry carbs are probably the easiest to get. OS carbs would be great but they cost a lot more though, even used.

pe reivers

MDS was also known for broken cranks (two in our club). In diesel operataion, the crakshaft is the mainstay. If shafts fail in glow operation, no way will they hold up after diesel conversion.
This apart from the several small quality control items that added up to very haphazard fitness for use of the engine.
True, SOME Russians make SOME of the best diesels in the world. That does not mean that ALL Russian engines belong to that class.

mike109

G'day

For what it is worth here is my brief experience with MDS engines.

A friend in our club was given two by his brother. They had not been used for about 15 years. One was a 46, the other a 60.

We put the 46 in a Kadet Senior. It fired up easily and was the best smoothest idling two stroke I have ever met. But, in the midrange it was hopelessly rich and spluttered and coughed when more power was asked for. Once it cleared, its top end was fine. In desperation I put the carby from a Super Tigre 40 on it. It was perfect so we left it like this.

The 60 was in a 96 inch Telemaster Senior. I was worried that it would be like the 46 but it just ran perfectly. Nice idle, like its smaller brother, smooth transition and mid range and good top end. It was perhaps not as powerful as modern 60s but ran well and pulled the Telemaster into the air on half throttle.

Neither was converted to diesel.

So one ran well, the other needed a different carby. That is about the same score I have had with Chinese two strokes.

Mike in Oz

N99JH

My Feedback: (66)

G'day Mike
Thanks for your input. Pretty much supports what others said: mostly carb related issues which is nothing unheard off with other engines as well except perhaps OS and Super Tigre which have exceptionally user friendly carbs.
Do you recall what kind of fuel was used? That seems to be the second most important issue with these engines.
Joshua

Prop_Washer2

My Feedback: (26)

MDS's of which I have 6 or 7, run superb on 5% or Zero Nitro fuel. Mine will out idle any O.S. at the field and turn up with the best of them. I have a .40, .46, .58, .61, .78, 1.48 and a NIB 2.18, The MDS line was created by the unemployed Russian Soyuz Scientist and Metalurgist after becoming unemployed when the Soyuz fellback to earth. They are my favorites in 2-strokes, and usually start first flip. Run 5% Nitro, use an O.S. Type "F" Four Stroke plug, and don't screw with the needle settings. Get them set after break-in, and 1 to 2 clicks only for future adjustments should work...

Hobbsy

My Feedback: (102)

At one time I had every MDS engine size from .40 to 2.18 and can say that they were very good engines. I had the good sense to run them on Fox 5% fuel with 20% 50/50 syn/castor blend. I had AJCoholic Diesel heads for three of them. The .78, the 1.48 and the 2.18. Nothing broke on them. I sold most of them a couple of years ago when we were taking care of our daughter who had a stroke. Her care completely broke us over a 2 and one half year period. Where I once had 140 engines, I now have about 35. I still have an MDS .58 which is awful looking being coated with years of cooked on castor but still runs very well.

N99JH

My Feedback: (66)

Dave

How did the 2.18 run as Diesel?

Joshua

Hobbsy

My Feedback: (102)

Josh, it ran very well easily besting a Zenoah G45 for power and nearly equalling the G62. It had some of the big Diesel crankcase loading up during extended idling when upright. It was mounted on its side on a large Sig Space???. It wore a Bisson Pitts muffler that gave it a booming throb that was pleasant and not loud.


Talking more about the MDS carbs, they had a short, steep taper on the LS needle which caused the sweet spot to be narrow requiring patience to find it.

N99JH

My Feedback: (66)

Do you remember what size prop you ran on the 2.18 diesel?

rgburrill

Funny, I had an MDS .61 and ran it for three years at least 20 times a month. The only problem I ever had was the carb seal would sometimes leak. Just prior to the 3-year warranty expiring I sent it back to Horizon for repair and lo and behold they had replaced it with the .68 and didn't have any spare parts. So I received a brand new .68 in its place.

That certainly is not terrible.

But the OS 32SX was a different story

airraptor

My Feedback: (66)

I have a 2.18. i bought it new for 100 dollars. The engine didnt seem as strong as i though after a gallon thru it. I replaced the ring with a Bowman ring, we looked it over. we raised the exhaust a tad and widened it, opened up the carb and did some minor port match. it now turn the XOAR 20x10 at 7,500 on 5% still not as strong as i though it should be but it is 200 rpm stronger than my Moki 2.10 on the same prop and muffler. Also any muffler/header that fits the Moki will fit the MDS 2.18 there are two Moki 2.10 on RCU for 150-175 dollars NIB.

Roo Man

My Feedback: (1)

Love my MDS 68's I have three. First came on a 60 size Twist that I got used from from my LHS. When I found out about the reputation of the MDS I was a little upset with the shop owner. Once I got it running and tuned properly it is one of my best running 2 cycle glow engine, by the way always run only 5% nitro. My first one had the latest carb from MDS which helped alot. Got two from Grey Beard one was complete and runs fine. The second was thrown in for parts as it did not have a carb or mufler and was gunked up so much it would not turn over. I cleaned it up and scrounged around and found a Super Tiger 40 carb from my parts bin and muffler located at local swap meet,it runs good also although it has not been on a plane yet.

I do think the MDS line was NOT built to consistent standards and suffered some design problems especially carb related but there are some very good engines wearing the MDS brand. My feeling is if they have lasted this long without being blown up or thrown out they have a good chance of being a decent motor.

Gary