Frequently Asked Questions
1.
What fuel should be used for MVVS glow engines?
Good quality fuel with ricinus oil in ratio 1:4 ( 20% oil ). This ratio is suitable for run in also. Please don´t use untried synthetic oils.
2. What fuel should be used
for MVVS gas engines?
The suitable fuel is 95 octane gasoline with Mobil Racing 2T oil or some
different full synthetic two stroke engine oil for racing use. Right
ratio is 1:40 (for run in 1:30)
3. What glow plugs should be
used for MVVS engines?
Glow engines 2 - 4.5 ccm: Novarossi C5S
Glow engines 6.5 - 35 ccm: Novarossi C6S
Gas engines : NGK CM-6
4. Can nitro be used for all
glow MVVS engines?
Nitromethane can be used up to 5% without any engine modification, if
using more than 5% (5 - 15%) it´s necessary to change the compression
ratio. An extra shim has to be added under cylinder head. During max.
RPM running and after unplugged supply for glop plug, the RPM can not
fall or rise. If RPM falls the compression ration is too low. If RPM
rices the compression ration is too high.
5. Why the piston do not go
smooth over top dead center (TDC) in glow engines?
The MVVS glow engines are ABC style. ABC engine has bigger piston
diameter than liner at TDC. This is not fault and piston is never seized
for this reason, when is used good fuel with ricinus oil.
6. Why the engine has
angular clearance?
Slide bearing need about 0.04 mm clearance for creating oil layer. This
clearances of piston pin and con-rod pin are add to crank-shaft bearings
clearances. All of this make final angular displacement.
7. The crank-shaft is free
motion in the bearings and it has axial clearance.
Free motion of crank-shaft is normal and it´s necessary for temperature
differences.
For engines up to 40cc volume: The axial clearance is delimitated after
propeller final tighten.
8. Is it possible to turn
nozzle on the carb?
No, the characteristics of carb would be changed. Right position of
nozzle is necessary for good carb work.
9. How care for glow engine
after using?
Especially when engine will not run longer time. It is important pass
through the engine some paraffin and after used conservation oil. This
is really needed, when fuel with nitromethane is used. The rest of
ricinus oil in the engine can cause crank-shaft and bearings corrosion.
10. How can I know right
engine idling speed?
When you close throttle from wide open, The RPM go down, after 1-2 sec.
little bit increase and than stay constant.
11. The engien has a lot of
carbon on the piston and exhaust port and engine is heated fast.
Reason can by using engine at very low RPM, which are below recommend
RPM for muffler. The lighter propeller is needed.