Ricardo Aurelio

Hi everybody

Can you please inform the RPM you are achieving with the MVVS 49 engine?
Please specify the prop, the fuel and the kind of pipe.

I'm currently using:
1- Propeller: APC 10x7
Fuel : 80% methanol & 20% oil (no nitro)
Pipe: Mini tuned pipe from MVVS
RPM: 13800

2- Propeller: APC 11x6
Fuel: 80% methanol & 20% oil (no nitro)
Pipe: Mini tuned pipe from MVVS
RPM: 12300

Thank you all

Ricardo Aurelio

jaka

Hello!
Which MVVS minipipe do you use ...the long one (No 3248) or the short one (No 3246) ?

Regards!
Jan K
Sweden

BlackBart

Hello Ricardo-

If you are using the tuned mini-pipe, I believe you should be

using an APC 12.250 x 3.750 (12 & 1/4 x 3 & 3/4), O to 5%

nitro with the 20% oil, and turn the engine up around 16,000

RPM. Just about any name brand fuel is good, but if they don't

tell you the oil % on the label, and particularly if you call them

and they give you the run-around, DON'T use their fuel. There's

more than likely a good reason they won't tell you. Guess what.

Good luck, I hope this helped some. If i'm wrong about anything,

you can be sure people will come out of the woodwork to correct

me, and that can't be all bad, we'll both learn!! (I hope).

BlackBart

Taildrager-inactive

My Feedback: (11)

using your prop you should be getting over 15,500 rpm easly. You must be running it really rich, or lean or there is something wrong with the engine with those low numbers.

Ricardo Aurelio

Hi Jaka

I'm using the long mini pipe rear exhaust 3249.
The engine is new, with only one gallon of fuel.
Do you think the low top end is for the home made fuel?

Ricardo Aurelio

Hi BlackBart

I really can't understand whats heapening with my engine.
I did everything by the book.
The engine is new, with the best carburetor...
It has a very stable idle, and a good transition, but the top end rpm seams week to me.
I don't now what to do.

Thank you

f2racer

I've got a near new 49, I'm using FAI (0% nitro). About a quart or so through the engine and I'm already getting 15,000 rpm with an APC 11.5x4 prop. I'm expecting over 16,000 rpm from this prop after break in (about 1 and 1/2 gallon or so). I have an MVVS 40 that picked up over 1,500 after about that much glow run through it...

rsieminski

I don't have a MVVS, I hear they are strong runners though. I have a Tower .46 on a tuned pipe (MCP), and with the MA 11 x 6 I get 16.1K (much less load than APC). I have a new MDS .48, that I'm breaking in today, I'll post the numbers here for reference. But, here's what I found for numbers with close displacement, with other engines(I couldn't find anything on MVVS):

OS 50 SX
10x8 APC = 12800 RPM
11x7 APC = 10900 RPM

OS 46 SF 'Ring'
APC 10 X 6 14,400
APC 11 X 6 12,600

From these numbers, it sounds like you are in the ball park. Yours may seem a tad low, but who knows what % of Nitro they were running (prob 10 or 15%). You could try removing the shims under the head, to raise the compression a smidge.

BlackBart

Hi Ricardo,
I looked up a couple of resources and I believe I found where
you need to look.

(1) P'e, from Arcen, south-east Netherlands;
www.mvvs-nl.com/index.html
(2) to reply:
[email protected]

Don't ask me to explain it because it confuses me, too. I think
it's just a language difference in syntax.

Secondly, try Morris hobbies at

(1) mvvs.com or-
(2) morrishobbies.com

Again, good luck with these two sources, I'm sure you'll find what
you're looking for.

Steve (aka BlackBart)

jaka

Hi!
Well I think your rpm figures are not that bad ...if you use the old 7mm carb that is!
The new MVVS .49:s are now delivered with a 8mm carb and then the rpm will be better.
Do you want one of these carbs?
just lett me know..!


Regards!
Jan K
Sweden

canardlover

Howdy folks, my rear exhaust MVVS .49 just reached 17000 in bench test with a 10x6 prop and an open tuned pipe(pylon style- terrible roar) and regular 20/80 castor/methanol fuel.
Yes, I know that prop is too small for the engine but it is my "reference prop" I use to compare engines and the above figure is by far the best i have achieved with my collection of OS and Enya engines in the .40-.49 range. Strong engine for sure...!and at the same time it throttles beautifully with the std. carb - not he butterfly version......Cheers/Harald

Ricardo Aurelio

Hi everybody

Thank you all for your help.
Steve the site you sent is very interesting.

Now I'll tell you what I saw in my MVVS 49.
I agree with rsieminski, the APC propeller seams to be heavier then MA, maybe it makes some difference in the final rpm, but anyway since I was not achieving what seams to be an usual rpm I opened the cylinder head and I noticed that the exhaust opening in the sleeve was not aligned with the engine body exhaust outlet. They were 1,5 mm (sorry by metrical system) out.
I could not measure the rpm after fixing it since there were no sunlight in our field at that afternoon, but I noticed an sensible increase in the final rpm!
I'll let you now latter what I'm achieving now.
Thank you all.

bobi

Friend has a Mvvs .49 which is about a month old. Got about a gallon through after run in.

Plugs is OS# 8 , 5% nitro fuel , 11*7 ma prop,
the engine has minipipe 3248 . carb is the new looking # 3216.

tach rpm on ground 12000.

What do you make of these numbers?? Or will these improve to what levels??

Ricardo Aurelio

Hi Bobi

I thing that is a good number.
Mine couldn't get more then 11300 rpm with a APC 11x7 0% nitro fuel.
The APC propeller is quite heavier then the MA.
I'll try a long MACS pipe next week. I'll let you now the numbers.

Ricardo

bobi

another friend of mine has recently run in the new mvvs .49 with the standard silencer 3245 . Using 80/20 fuel and OS # 8 plugs he is getting 12000 spot on using 10*7 ma??

f2racer

Just an observation, I broke my MVVS 40 in using an OS #8 plug, which seemed to work well at first. But after about 6 or so tanks, it started to run like sh*t, and I swapped the plug out with the one that came with the engine from Morris Hobbies (I still don't know exactly which Rossi plug they send these engines out with). It transformed the engine! Also allowed me to lean the high speed needle a bunch without any signs of detonating... With that experience, I've only run my 49 with the original plug without issues. BTW, I'm using 15% on both my 40 and 49 right now with no issues.

grazzhopper

I'm gonna have to get a tach and fake my own results so I can replicate them at will...

BlackBart

Meaning what?

GAGAK

To Canardlover or anyone,

[Howdy folks, my rear exhaust MVVS .49 just reached 17000 in bench test with a 10x6 prop and an open tuned pipe(pylon style- terrible roar) and regular 20/80 castor/methanol fuel.]

I'm in the process of tuning my side exhaust MVVS .49 using the mini pipe. I'm aiming for speed having fitted the engine on a WM Mustang. My prop is 9x8 MA. Fuel Coolpower 15% spiked with a little bit of castor. Plug OS 'F' (two washers fitted).

Up till now I have achieve 15000 RPM peak. I have seen my engine run at 17000 RPM briefly while breaking in when I accidently broke :stupid: the tune pipe header. Prop was 9x7 APC. This tells me that the engine is capable of that hi RPM.

What I would like to know is whether, the engine can withstand a sustained run at 17000 RPM or am I asking for trouble? Thanks!

Hisham

jaka

Hi!
No problem!!
But use a APC instead and do not use a OS F plug and so much nitro!
5-10% nitro is okey!
Rossi 4-8 glowplug
Also check which pipe you have ...the 3248 or the 3246 (3246 is for higher rews , 16000-24000..........3248 for lower rews 10000-14000rpm.

Regards!
Jan K
http//hem.passagen.se/airracing

GAGAK

Thanks Jaka,

Alas, I want to use APC, Rossi plugs proper fuel.......but the nearest hobby shop would have me crossing a border to another country with a 2 hours drive and they don't stock APC's or Rossi's.
15% fuel I have on hand.

But now that I know the engine can deliver.....I might make an order for the said items. Mean time can u tell me which plug is better suited for me at this time. I have OS (No.8, A3, F) ENYA (No.3, No.4). BTW the reason I use 'F' plug was because the idling is superb with it (~2000 rpm on 9x8).

My pipe is the 3248, the manual said it would increase engine power in the range of 10000 - 14000 rpm but I stopped cutting the header upon reaching 15000 rpm. I suspect that my I rpm would increase futher if I continue with my tuning but I want to be sure the MVVS can operate at higher rpm. Lastly where can I order the 3246 pipe?

Thanks!
Hisham

canardlover

GAKAK (and others) the best I could reach with the MVVS minipipe(3248, longer version) was a steady 15.900rpm but the real jump came when switching to the full length open pylon pipe which gave me a steady 17.000rpm in the bench.
All this on the same day and with 80/20 straight fuel, an OS A3 plug, 10x6 Ishipla prop, standard 8mm carb. and full length manifold.
Not sure if I could have done a bit better with the shorter 3246 and cutting the manifold a bit....??
Yes, indeed, I´m sure jaka is right that these engines can withstand revs in the 15-17k for extended periods.Also agree with jaka that you can cut down on nitro as well, personally I NEVER use it myself (not even on my 4strokes)
But GAKAK, keep the castor in there , that I think is a very good move, I ALWAYS have a bit of castor in the fuel, even in my 4strokes(now, let´s see if jaka or anyone reacts to this one )..Cheers/Harald

canardlover

While trying to interpret grazzhoppers rather acid remark in #17 it struck my mind that maybe he has a good point here in the following sense: how can we possibly arrive at such conflicting results with the very same .49 engine..? -some are struggling at 11-12k while others hit 17k with basically the same outfit.
Let me share some thoughts to see your responses. Having one MVVS .49(stamped A 78) and one .45(stamped A 261) I notice the following:
a).49 has 8mm carb but 45 has only 7mm venturi
b).49 has 7mm crankshaft but with only M6 propnut while 45 has M7 propnut
c)propdrivers differ slightly in shape
d)cylinders can be rotated to achieve side exhaust(SE) or rear exhaust(RE)
The .45 was recently thrown my way by a disgruntled owner who could barely reach 10k with the std silencer. Upon “interrogation” he admitted that he initially ran the engine in RE mode but then changed his mind and turned it back into SE. That is certainly a NO-NO if you want top performance.
My brand new .49 had one of its head bolts totally stuck by a metal chip trapped underneath it, I had to drill off the socket head to be able to remove the head. Further, Ricardo told in #12 that his cylinder liner was slightly misaligned.
Thus, my impression is that the MVVS is rather demanding if you want top performance - do not take for granted that it is free from chips and burrs inside (as you can with an OS) and do NOT run it in slobbering rich but rather run it at full speed in short bursts (as with any ABC engine).
Admittedly I initially “deburred” my .49 when I rotated the cylinder from SE (as delivered in the box) to RE mode.
Jaka , maybe you can shed some more light on the different versions of MVVS engines and whether we should expect SE and RE engines to differ in performance..?
Lastly, my tach is NOT calibrated (got your message grazzhopper ..!)so we have to be careful with the rpm figures here. However, my initial post #11 was more to put the MVVS in perspective and compare with other engines I have tested with that very tach. I still maintain that the MVVS is a very strong engine if properly set up.
I´m currently “hopping up” my .49 with a 9mm venturi OS 7B carb (and then the 8mm .49 carb will go to the poor .45). I think BlackBart has it spot on “NEVER enough horsepower” so wish me luck, maybe I can break the 20k barrier … …………Cheers/Harald(aka canardlover)

proptop

My Feedback: (8)

Hello everyone...Very interesting thread here, because I got an MVVS .49 from Morris a couple months ago. It's stamped C 774 under the mtg. lugs, and has the 7mm venturi carb. I was under the impression that it was one of the newer ones (?)...Anyway, I rotated the cyl. for rear exh. too and I'm looking for a header (fuse. type) for it. I already have the Mac's pipe (from Tower Hobbies) a 7.5cc size, but Tower doesn't stock a r. exh. header, and Mac's doesn't answer the phone (I tried to order one 2 mo. ago, but no luck) Does anyone have a suggestion as to where I might find one??? Would the GRRT header work? Maybe Jett? Didn't mean to butt-in, but I'm getting kind of fustrated, because I want to get this eng. going! Any help will be appreciated, thanks, Tom.

jmercer52

My Feedback: (14)

Tom, Did you ever try Morris Hobbies for the header you need?