sterman2004

ANY sugestions
I have bought my first gas engine an MVVS 35cc, any ideas on isolation mounts or rigid mounting the engine? if it matters it will be bolted to a cmpro yak 140 (glass fuse).
Anyone have any comments on what is a good oil to use and ratio of mix? or what size prop to use

Thanks for any ideas

Hans Meij

I have it on a enlarged Calmato. 135%

It has a KS 1050 Pipe and a 25mm header. It makes the engine rock. 7800 rpm on the mejzlik 20*10 prop
Excellent engine on a wide pipe.
1:30 MVVS / Mobile-1 oil.

sterman2004

Thanks for the advise & nice model
I was considering a bission muffler instead of the pitts style one the came with the engine.
Is your engine/mount bolted straight to the firewall or is it rubber mounted?

Hans Meij

It is directly mounted. Will have to see how vibrations will work out.
In general the MVVS engines do not have bad vibes.

SJN

heres mine

http://www.youtube.com/watch?v=VG9o9DkcxOk

sterman2004

Hans Once again thanks for the feed back,I think you are right there should not be any problems with direct bolting it to the fierwall, if it was a Zenoha or an convertited ag engine i would be concerned, but everything I have read about MVVS points to a pretty smooth run with lots of power. Godd to see SJN's starts nice and easy(thanks for the vid).
I am hopeing to bolt the engine up in the the next week and start to install all the radio gear etc... will send a pic as soon as its sorted
Havent installed a pull-pull rudder system before either so it should be interesting.


Thanks
Sterman(mal)

Hans Meij

Last year it was on a Big-Lift with semi-flex mountings.


Based on that setup I concluded it was not needed, but have not run it hard mounted.

The 45 is even a bit smoother to my opinion. The 45 a have hard-mounted on a 2m pattern ship.

BaldEagel

Have a look at this thread: http://www.rcuniverse.com/forum/m_4946730/tm.htm it shows the 45 mounted on the MVVS ISO mount with ignition lug, you don't have to have the lug on the mount and can have two of the straight ones.

Mike

BaldEagel

Forgott to mention, on my 45 the Brison muffler did just that it muffled the power, by fitting a MTW 75 cannister silencer I gained 1100 rpm with no additional tuning required, it was also smoother and picked up much cleaner with no intermediate burballing.

Mike

sterman2004

Thanks for the great feed back guys, I will definatly re consider the exshaust system. Cant wait to start puting it together. I will post some pics to see what you all think.
PCM or FM do you need to use PCM recievers on Gas aircraft? some people I have asked at my local model club will argue the piont eitherway. I have a JR PCM reciever that I think I will use for this aircraft.


Thanks again

Evelin

Try ROTO engine, its more friendly..www.rotomotor.cz

BaldEagel

stearman

Set up your ship on PPM first, that way will show if you have any interfearance problems that need to be sorted, once you have any problems eliminated then go to PCM to allow fail safe operation, the trouble with setting up on PCM first is that it can mask any problems, by holding the last signal and therefore, remain undetected until you fly. The whole purpose of PCM besides errant signal rejection is to prevent fly aways, so set up your PCM to cut the throttle and bring the aircraft down as soon as possible, I set mine up to spin into the ground, now you will get all sorts of advise on this, my permise is one of safety to people and property not the aircraft.

Mike

Hans Meij

I have it on PPM, use a short, I think you call it duck antenna, and with these tow-planes I will fly allmost out of sight.
No problems.

sterman2004

Thanks for the great ideas I will definatly take it all into consideration.
Mike you are right about the saftey concerns. i would have no hesitation of putting the aircrat into a death spin etc if it ment avioding a nasty accident, a 20" prop can casue some serious damage to the public or fellow modelers.

Thanks again
Sterman