Nitty-gritty, on the MVVS .49? Tell it like it is!

OK, I've got this NIB MVVS .49.

I expect to use it on my new model which isn't completed yet.

I know nothing about the MVVS engines or their pipes, which I also have.

I want the truth, so you don't have to be kind.

Is this a good engine?

Power enough for a 36", full fuselage model?

Thanks,

CB



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You probably won't want to know this, but the MVVS 49 in diesel form is an absolute gem. It has all the good diesel attributes, swings larger props than the equivalent glow engine. Has an absolutely constant speed run (every bit as good as a piped OS VF 40 and I run both.) Uses very little fuel so a lighter weight setup than the glow plus the extra fuel. I can't fault it, just the usual anti diesel majority knock it.
Try it, you will be amazed! I ran mine in as a glow and it performed well, so you won't be disappointed even if you ignore the diesel advice!

Regards,

Andrew

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I had a MVVS .40 on Eather pipe and it ran well. The .49 should be fine. Making it Diesel good luck.You have a decent engine just try it. I have heard all the Brovado about Diesel's and know nobody who uses them for a big stunt ship. They smell horrible and wait till Moma gets a wiff. Not to mention getting fuel as compared to glow fuel. Plus the cost of conversion. Anyway good luck and it should work fine.

I did my diesel stuff when I was a kid. All I can remember is my models shaking apart and not being able to get the engine running in the winter.

Putewie, on the diesel. Although it's fine with me for those that love diesels.

This engine can have the sleeve rotated to side exhaust. Then I have to search for a muffler?

Rear exhaust it would have to be mounted inverted in the model.

This is IMHO a very desireable engine. Mac's sells a RE header for it, Randy has pipes that will work on it. I have found that they like FAI fuel, strong 4 stroke run. Heavier than some but not by much. The problem with the stock muffler is that it comes straight out and is difficult to mount. Randy could probably set you up with a RE header/muffler if you don't want to go the tuna pipe route.

>I did my diesel stuff when I was a kid. All I can remember is
>my models shaking apart and not being able to get the engine
>running in the winter.

The diesels of old never had crank shaft counter weights any thing like a modern engine so put that vibration stuff out of your head.

>Putewie, on the diesel. Although it's fine with me for those
>that love diesels.

>This engine can have the sleeve rotated to side exhaust. Then
>I have to search for a muffler?

Simply contact any MVVS dealer or the factory (I can give you the part number if you like and personal contact details.)

>Rear exhaust it would have to be mounted inverted in the
>model.

Not necessarily, side mounting will still entertain a rear exhaust quite well (as will being upright but the looks may not be to your tastes.)

Cheers.

I have heard all the Brovado about
>Diesel's and know nobody who uses them for a big stunt ship.

Oh, red rag to a bull!

Try Keith Renecle (MVVS 49) in at least one world championship and Tony Eifflaender (owner of PAW engines and Gold cup winner many times over).

I have a second hand MVVS 49 diesel conversion destined for a stunter, just reduce the venturi size and it will spin a 12x6 prop at 9500rpm at a very constant speed.

Back on topic, the MVVS 49 is the largest capacity in the 40/45/49 series of engine, and although they are undeniably heavy for their capacity when considered for stunt use, they are very strongly made.

The overall weight (if it really is a problem for the glow version is marginally offset by the 2 ozs of less fuel it has to carry for the pattern and they seem to be very thermally stable.

Another plus with the range is the rotatable upper barrel enabling you to choose any 90º position for exhaust facing, and yes you could front exhaust it if you wish!

The factory supplied black canister mufflers are extremely light too, further offsetting the weight issue (avoid like the plague the standard mufflers and the quiet series version of them.)

And parts can still be obtained from the factory if you ask the right people.

Are they still viable as a competitive stunt engine? I would think so and doubly so if you can get your paws onto the MVVS 51 GRR.

Things to be wary of, there are three styles of liner out there and the one that you want is labeled 'Akrobat' and it is stunt timed for glow use. If you happen to have a higher timed liner then it will still work well enough as a diesel, but not as a glow (or so I am told!)

Hope this helps.

Maybe in oveseasland they use Diesels for stunt. Here a Diesel is as popular as rasins in a bowl of grits. Only Diesels I have seen in a stunter was a very beat up OTS model. Maybe small ones for 1/2A. I could care less who uses them O/S's, good for them.
Dan

OK guys, thanks for the information.

It appears as though this engine will be fine to use.

The second photo above is this the muffler or tuned pipe?

Certainly I'd like to side exhaust the engine but will need leads for muffler options. MVVS muppler options that will bolt to the engine footprint.

The muffler/pipe above will only work if I keep the engine as a RE. Obviously.

One advantage with the RE setup, is I can hide everything inside the fuselage. With a side exhause engine, hiding the muffler is difficult.

I do have extra head gaskets, actually three AND a couple of venturies. No explanation in the box.

I don't remember who I purchased the engine from, but I did buy it some time ago on ebay.

I did offer it up for sale once, but a Lad suggested I keep it. "You'll never know when you my need it." He said.

Leads for MVVS parts, mufflers, pipes would be nice.

Thanks all!

Charles

>OK guys, thanks for the information.
>
>It appears as though this engine will be fine to use.
>
>The second photo above is this the muffler or tuned pipe?
>
>Certainly I'd like to side exhaust the engine but will need
>leads for muffler options. MVVS muppler options that will bolt
>to the engine footprint.
>
>The muffler/pipe above will only work if I keep the engine as
>a RE. Obviously.
>
>One advantage with the RE setup, is I can hide everything
>inside the fuselage. With a side exhause engine, hiding the
>muffler is difficult.
>
>I do have extra head gaskets, actually three AND a couple of
>venturies. No explanation in the box.
>
>I don't remember who I purchased the engine from, but I did
>buy it some time ago on ebay.
>
>I did offer it up for sale once, but a Lad suggested I keep
>it. "You'll never know when you my need it." He
>said.
>
>Leads for MVVS parts, mufflers, pipes would be nice.
>
>Thanks all!
>
>Charles

Try this email direct to the man who actually designed the engines himself - "Josef Švajda - MVVS, spol. s r.o."

You can hide a side exhaust by canting the engine 45º and having the header pipe point directly down the fuselage tunnel though but why do this when you have the rear exhaust system available for use?

The extra head gaskets are for nitro use, just use one to start with when using 0% to 5% nitro fuel and see how you go.

Oh, and the standard peripheral jet venturi may not work as well as you like, but try it first up anyway.

Cheers.

You could rotate the head on the early ones BEFORE being run which gave you the choice of side or rear exhaust. They had a green head. I don't believe the later gold heads gave you that option. I'd keep it RE.
With a proper header muffler it would be a great engine for 46-60 sized planes. It would handle a 56' plane no problem, prop it like a Supre Tigre 60. I experimented with a SE exhaust version on a 72 ounce Top Flite Score, plenty of power. If you want a side exhaust, there are plenty of other choices out there. Use it as a RE in appropriate airframe and it will be a winner.

I'm using the engine on a model with a built up fuselage.

CB

Dan, over the years, in OTS at the VSC, I have flown a ST G20-15 diesel on two different Dmeco Sportwings, a Trixter Profile and a #5 Easy, and a converted Tower 40 on a #7 Easy. I flew both patterns in a recognizable manner on all occasions, and finished 19th with the Trixter. Last two times I flew OTS at the VSC I flew a Fox 35, with no problems. So diesels and Fox 35's can be made to work and work well. I have not flown a diesel on a modern stunt airplane, however.

That particular version of the .49 was timed for top Czech flier Jiri Vejmola and they used it with great success on their own aluminum tuned pipes. I did not get to try this version with a diesel head but I did fly one on glow with the standard side silencer and 12 x 5 prop. It runs slower than the older versions but with a nice break and loads of power, so it will most likely work well with a 12 x 6 prop on the standard silencer. Since I started on electric power I just did not get the time to play with it some more, but I will do this sometime soon.

My diesel .49 worked so well here at home, but mostly when I went overseas, I battled to get the right fuel stuff, especially ether. It was also very expensive as well. In 2004 at the USA world champs, I got very good fuel but then my Viper stunter with the side-mounted .49 broke its outer wing off in practice flight #5. I put the diesel head on my reserve model that had an inverted .49 rear exhaust in it, and that did not work at all. The engine overheated and just did not perform. The side mounted version worked well but needs to have the spare port blocked up that enables the cylinder to turn for side or rear exhaust. If you don't do this, it will burp or quit on outside loops. Upright or inverted works fine.

One more thing, this is one tough engine, and you will find it hard to wear it out. I tried for years with all my diesel experiments and never managed to wear one out or break a conrod. I could not manage to convince MVVS to continue production of this engine in C/L or R/C form. I still have a few of the R/C versions with meaner timing and they were fantastic R/C engines. The low demand is due to the electric revolution, and as I am a part of this too, I feel wary to knock it, but it's a real pity that there will be no more new MVVS 49's coming out of the factory.

The diesel version runs almost as good as my electric governor system, and contrary to what most people understand about diesels, the vibration was very low as well because you run it in a constant rpm, no 2/4 break mode. It is a very well balanced engine and always started in the first few flicks once you had the knack of diesels. The electric systems now, fly just as well or better, without the hassles of fuel, noise or goo/pong etc. My wife has remarked that I smell a lot better in general these days as well! Anyway, all in all this is a great stunt engine! Just by the way.....I'm still a MVVS person, and I now run the MVVS 6,5/910 electric motor in my stunter.

Show me someone who says a diesel is a "vibrating bone shaker", and I'll show you someone who has never seen a diesel, modern or otherwise, that has been set up and tuned properly.

Properly set up a big diesel can run like a well oiled sewing machine, with a near constant run that is reminiscent of a four stroke.

Each to their own, there's room enough for all forms of power in this hobby. Just don't dismiss something because you haven't seen it yourself!

I could use my Just Engines .57 instead of the MVVS .49?

I have no idea which engine is better?

CB

>I could use my Just Engines .57 instead of the MVVS .49?
>
>I have no idea which engine is better?
>
>CB

I don't mean to sound harsh here, but you may well know which engine is better for control line stunt.

Just do a google search for test reviews, model plans using that engine or simply heed the advice given above.

The MVVS 49 has a proven track record, whereas the J'EN 57 really is a radio engine with a control line venturi option to broaden sales appeal.

The 57 looks like a really nice engine but I highly doubt that anyone here is going to put their hand up and say "Actually I use one of those for CL stunt and I think that its better than the MVVS 49."

Go to You Tube and do a search for the MVVS 49 in flight, it sounds glorious!

Cheers.

This i the latest (and last) of the MVVS glow stunt engines.
I believe MVVS only make R/C glow engines now because of low demand for C/L engines.

It is basically very good and well built engine.
Also powerful if set up right. But: The black tube muffler is no good.
Far too restrictive and a pain to use.
A less restrictive muffler er better a header plus pipe.
I think the timing is 140/130.
Fairly high compression , low nitro.

It's predeccessor is tested in Stunt news july/august 2003.
Alberto Parra used so sell these.

I think the serial was:

MVVS 49 marked as 8,0cc GFS/R-ABC-Acrobat CL-Stunt (liner has item number 3077A )

But , as always in our hobby, ask the one with first hand exerpience:

http://www.youtube.com/watch?v=C9kMo3mCZBM

Signed : pampa9m
Fred Krueger i believe, based on this you tube film:

http://www.youtube.com/user/pampa9m#p/u/0/82K9_swy3HQ
...
Jordan Segal and Cris Rigott were also there.
......



Norvald

<Far too restrictive and a pain to use.>>

Thanks for the information and the links.

Can this muffler be modified?



CB

Well, Fred Krueger made a new one.
I know Randy Smith has knowledge of this engine as weel.
He has fitted them with header & pipe.

But: The black tube muffler is
>no good.
>Far too restrictive and a pain to use.
>A less restrictive muffler er better a header plus pipe.

Now these comments puzzle me.
What is so restrictive about a muffler system that copies a mini tuned pipe with a straight through exhaust?

I mean, you can see daylight right through from the exhaust flange to the tail pipe, where are the restrictions?

If its about the inside diameter of the tail pipe or 'stinger' section then you could trim down the end length a bit since its tapered and will open up nicely by doing so but why do this when its a factory developed Akrobat muffler?

I have heard of fliers adding a Du Bro style silicon exhaust deflector and suffering slightly when they use the same style of pipe for high rev RC applications but this engine will never see those high rpm's and the state of tune will never be in debate.

I also have seen the same type of black canister in use on an engine almost double the cubic capacity, and it had to have a baffle added in order to GAIN some form of restriction.

You can indeed modify the Akrobat muffler by drilling holes into the rear cone and extending the body length by adding a rear section, and this is how some of the European RC combat fliers tame the scream from those high rev 18 000 rpm motors but here, in stunt form you will be lucky indeed to exceed 9 000 rpm.

I have a sneaking suspicion that proponents of the 'mousse can' system don't like the type of noise that a standard MVVS engine creates on a canister type of muffler and it can be quite different, and even a tad noisy. Here the mousse can designs that I have seen are far, far more restrictive with their perforated pipes, baffle walls and right angle gas flows.

Try the black canister pipe as standard before you come to any hard conclusion, and the only mod that I would entertain would be to slice the header pipe right through and place a silicon joiner across there to insulate the can from the engines vibrations - but that's optional.

Cheers.

>Here a Diesel is as popular as rasins in a bowl of grits.
>Dan

Only time I ever have grits is on road trips, at the inevitable Cracker Barrel breakfast stops.
Only way to actually eat it is to put the fried apples in there.
(Works both ways, only way to eat the fried apples is in the grits)

Raisins sound like they would work as well
Add a bit of cinnamon and it might even be tasty


Pat MacKenzie

>
>>Here a Diesel is as popular as rasins in a bowl of grits.
>
>>Dan
>
>Only time I ever have grits is on road trips, at the
>inevitable Cracker Barrel breakfast stops.
>Only way to actually eat it is to put the fried apples in
>there.
>(Works both ways, only way to eat the fried apples is in the
>grits)
>
>Raisins sound like they would work as well
>Add a bit of cinnamon and it might even be tasty
>
>
>Pat MacKenzie

Wise men talk because they have something to say; fools, because they have to say something.

I looked at grits once. Well, from a distance.

CB

>OK, I've got this NIB MVVS .49.
>
>I expect to use it on my new model which isn't completed yet.
>
>I know nothing about the MVVS engines or their pipes, which I
>also have.
>
>I want the truth, so you don't have to be kind.
>
>Is this a good engine?
>
>Power enough for a 36", full fuselage model?
>
>Thanks,
>
>CB
>
>
>
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>
>
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>


No doubt there are different views on what exhaust system to use on an engine. With the MVVS 49 RE and the MVVS 51 RE/RI you can't go past the supplied muffler. Even though the outlet is only around 6.5mm there's no restriction to power. In 16 years of use my engines have always used this system. The only difference with the one in the initial post to the ones on the rear intake version is that it's not hard mounted. It seals with an O-ring on the stub. No need for expensive taste nitro fuel. With the standard CR the max nitro is around 5% but they run just fine on standard 4:1 brew.

I must put my hand up and admit that I used the same muffler on an R & B 75 and found that there was too much boost in power compared with the standard muffler system on that engine. A baffle 1" from the rear cone with 4 x 4.5mm holes tamed the beast and now gives a powerful controlled run.

As for the Jen 56 (57??) they are better suited to R/C flying although Steve Foster in the UK was running one on a pipe around 3 years ago and it seemed to perform ok. The pinch on the P/L was a bit loose for my liking on the one I had. Gave that one to a mate to maybe use in an R/C job.

Hope this first hand knowledge helps in your choice of engine

HH



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