smartdriver

Motorman,I was wondering if you have any experience with this engine and what would be a good starting point for 1000 foot elevation ,high humidity,offroad. It currently has .21 head clearance and running 30% fuel.also do you have any reccomendations for break in processes as the novarossi manual is rather vague.....

stefan

In case Dennis won't have an answer, you'll find lots of info here:

http://www.rc-racing.com/cgi-bin/pw/...howforgotten=2

jag

Motorman, I am new to this site and have learned a lot from this thread but I do have one question. I have an RB X12 5 port turbo in my Serpent Impulse Pro and I want to change from 20% to 30% nitro. It has the stock shim (approx. .015", I don't have a digital micrometer) and I read elswhere that you are supposed to add a .01mm (?) shim if you want to run 30%. Based upon the info here that would seem incorrect. Do you agree? I would really like to know what you think. I live in So. Fla (hot, humid and +10' above sea level). I would also like a glow plug recommendation please. I have an MT-12 I am putting in my truck and the info you gave on that was perfect.

Thanks,
jag

afm

MOTORMAN or anybody with experience, can you post the basic guidelines for correctly shiming a .21 engine???

Lets say an Off-Road Nova .21 based engine using 20% Nitro at sea level, what would be the ideal total chamber?? and the recommended Glow Plug??
Air temps are between 15 and 21° C and humidity around 75% to 85%.
Thanks
AFM

afm

Anybody care to comment on above
Thanks
AFM

US_MATRIX

I am planning to get a Novarossi NSR12S5 or NS15S5 engine and they both come with 0.3mm head shim (correct me if i am wrong)
I will be running 20% fuel. In that case, Do i need to add 0.1mm head shim to get proper compression?

Thanks.

ziggy12345

I just got one and the manual says 0.3mm is perfect for 0-20% nitro and 0.4mm for 20-30% so should be ok with 0.3mm

speed006

Can anyone here tell me where I'd find a degree/timing wheel small enough to use on a .21? My best friend has been building some BALLISTIC engines by "making adjustments" to the port timing on his sleeves with a Dremel. I'd like to get him a timing wheel for Christmas.

keavze

quick question:

if engine is losing compression, will removing shims helps to boost compression?

razzor

Speed - you can buy yourself 2 protractors or print one from http://www.ossmann.com/protractor/

Keavze it can help but not for long.
Your options are to have the sleeve pinched or buy a piston/sleave set or just get another motor.

For 16% we found .35mm clearance to be ideal and .4/45mm gave a tad more rpm but lacked bottom end.

keavze

what do u mean by 'pinching' the sleeve?

Roelof

Pinching is expanding the piston or making the sleeve smaller for a tighter fit.

keavze

ok but how do i do that?

razzor

Check with your local racers, usually there is one or two guys that pinch sleeves. Even try the local hobby shop.

Basically its squeezing the sleeve just a bit to give the piston a better fit.
It does give just that little bit more life out of your engine and chanmging the rod would be recommended too.