vwitte

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I see advertisements for the MVVS engine and MDS PRO engines on EBay quite often. Many reviews I read are also somewhat supportive.
i was wondering what the general consensus was on these engines??
what are the most reliable sizes .40 , .48 , .68 ?
thanks I appreciate it.

rgburrill

The early MDS had leaky carburetor o-rings but that got fixed after a few years. I initially had a .61 that had a lot of power but developed a leaky o-ring after 2 years. Believe or not they replace the engine free with a .68 which worked like a charm. The biggest issue I knew of with them was a bias against a (whether true or not I don't know) "Russian" engine. I think the .48 and .68 were later engines, the .40 could be either.

1QwkSport2.5r

They’re decent engines of good metallurgy. The only problem with a few of them are poorly made carburetors. Otherwise they last a long time. I put a piston/liner from a 10 gallon MDS .40 into a Fox .50 case and it still runs to this day with a little pinch left. I have a couple other MDS .21 engines too - all decent runners.

MVVS are made in The Chech Republic and are a different breed of engine. Good engines, just distinctly different from MDS which were made in Russia or Ukraine. I’m actually looking for a piston and liner for an MDS .21 rear exhaust Marine Diesel. I have a boat I’m going to put it into, but the piston fit is a little loose for good diesel operation. (EBay buy touted as nearly new. Looked it, but didn’t run like it)

aspeed

MDS took over the old Ucktkam line. They were very rough quality with sand in the castings and were machined in high schools I have heard. When MDS too over, they seemed much better. I have a few .15s and a .40. The .40 runs well on the stand but not overly fast. Got an MVVS .21 that runs very strong, and an MVVS .15 that looks like a high performance Rossi but runs slower than an LA .15. Whenever I see a good deal on either brand, I would not hesitate to get more. I would not pay more than $50 but maybe that is just me.The MVVS often come with a nice tuned muffler.

jaka

HI!
MVVS engines are of Chech manufacture and MDS are made in Russia /Ukraine.
All MVVS engines are good engines as with all glow engines today , like OS, Enya, ASP, Rossi you name it!
All MVVS engines are ABC engines which means they have use an aluminium piston running in a chrome plated brass cylinder liner.
Their 2,5cc glow engines (Which are sadly not manufactured today) are racer-type engines and does not like too large props. 7x4 or 7x5 APC is what works best. The cylinder housing can be turned either to the right ,left or backwards to suit what works best for your application by removing the for bolts under the cylinder head..
These engines can be equipped with the MVVS mini-pipe which give added power. You should not compare the MVVS 2,5cc glow engines with an OS .15 FP or LA as those engines produce their power at lower rpm than the MVVS 2,5cc engine. A suitable prop for the OS .15 is a 8x5 APC which it spins at around 13000rpm, a prop size that the MVVS cannot cope with as it produces it's power much higher up, at around 20000 rpm.-That's why it needs 7x4 or 7x5 to run good.
The MVVS .15 is also (Was also) made as a diesel engine and as such could spin larger props as a 8x4, 8x5, 8x6 or 9x4.

aspeed

Yep. Maybe my .15 is a dud. I tested all my .15s on a 7-5" prop. The MVVS was just at the bottom of the stack. Maybe sometime I will try a 7-4" I run most of my .15s on a 7-5, even the OS LA seem happy on them. I have noticed that you sell MVVS. What are they still making, and where are the dealers? I am sure others would like to know as well.

jaka

Hi!
Well! To say I´m a MVVS dealer is not correct. I have been selling MVVS engines 10 to 15 years ago but not anymore, though I have some MVVS engines left.
To have the MVVS 2,5cc glow engines run well you have to use the mini-pipe and correct prop size, glow-plug and fuel.
I fly at sea level so all my engines MVVS as well as all other brands have (OS, Webra, Thunder Tigre, ASP/Kyosho (Same engines) ENYA, Rossi, etc ) are run on just 5% nitro.In fact some MVVS engines (older 15cc) cannot even stand 5% nitro.
20% Castor oil is the norm, though many of my .40 and .90 (6,5cc and 15cc ) engines, MVVS and others , are run on 15% syntetic oil (Motul "micro").
The MVVS .15 (2,5cc ) glow engine uses a Nova Rossi 5 glow plug as standard but a warmer Nova -Rossi 4 or Rossi 3 could be used too. There are naturally many more glow plugs thats works too. But those mentioned works well at sea level.
Try a an APC 7x4 and do not use any more nitro than 5% if you fly att sea level!
If you go to MVVS home page you can see what type of glow engines they still manufacture, which are not many, sad to say. Electric motors seem to taken over.

aspeed

Maybe I'll fire it up when it is warmer outside. I have a bunch of F2D props that might be good. They are about 6 1/4 - 4" or whatever it works out to from metric. May be alright if they get up to 30,000 rpm. I still think those Foras don't need to rev that high. We are at around 600 feet ASL, I have some 5%.. I have an MVVS .21 that runs quite strong.

Mr Cox

Pe Reivers said that he found the MVVS .15 engines to be a bit sensitive to the deck height (squich band height). His recommendation was to set it for 0.18-0.22 mm. The regular muffler is also quite restrictive, they run much better with the "tuned muffler"
I haven't checked the deck height on mine actually, but I have one engine that runs quite well, here are some data on 10% nitro, and the exhaust pointed straight back and using the straight tuned muffler:
APC 7x4 prop: 20300rpm
APC 6.5x5 prop: 22000rpm
With a Rossi tuned pipe it will go a little higher on the APC 6.5x5 but it is also a bit more sensitive to set up, might need a lower prop load for that pipe.

The MDS .18 engines are a little under rated, sure the quality varies but they are true ABC engines. I have one engine that is too tight on the bearings, I'm still struggling to get it right. but another one is running very well. Similar in size, weight and performance to most good .15 engines, but a lower price tag. On 10% nitro and the stock quiet muffler it will spin the APC 7x4 at around 19800rpm.

aspeed

In my notes the MVVS .15 was only giving me 13,900 rpm with the M Airscrew 7-5 with or without pipe in the rear exh option. I just checked the head space at .010" or 0.25mm. I was just making a Nelson type head button for a Rossi .15 yesterday, and the measurements are almost exactly the same as the MVVS button. The bore is about .0015" smaller on the MVVS. For comparison on the same prop and fuel being 10%, an LA .15 was 17,200, Taipan 18,300, Ucktkam (MDS early edition basically a rough Rossi copy) 18,500 for the combat version, and the real MDS around 15,000 with or without the pipe. I think the MDS needs a smaller prop to get on the pipe though. I have not seen an MDS .18 here. When I bought my 'combat' Uctkam at the Toledo show way back in the early 1980s, I went through all 5 motors that he had to get this one. Two were too loose, two were way too tight and the bearings were all crunchy. I got the one that was just a bit tight, and the bearings were OK after they got fuel on them as is often the case. The newer piped MDS Uctkam ones were fitted much better although one starts easier than the other, and they both leak a lot of fuel out the front bearing.