Glow plug question about .21 Navo

[Jer_ry]

I have (what i believe to be) a navorossi engine got it used. I was wondering if the glow plug makes a difference on how well the enigine runs? I already got the sleeve pinched but i cannot get it tuned right. Thought maybe i have the wrong plug. Thanks

 

[niggle]

Yes, the glow plug will affect the ignition timing. Just as in a full size engine, altering the ignition timing can affect performance and the compression ratio and type of fuel used can dictate the optimum timing.

Using NovaRossi's own range of glow plugs by way of example, for a .21 size engine they recommend their #5, #6 and #7 plugs for fuels with 20%, 25% and 30% nitromethane respectively. Obviously this assumes that the engine has good compression and the head clearance/shim thickness is appropriate for the type of fuel used.

 

[Jer_ry]

Thanks...there are a few #5's i think i was looking at the t5-s and they say they are cold and the t5tf says hot filament turbo?? Which will work?? also which will work on a .21 ofna

 

[niggle]

Thanks...there are a few #5's i think i was looking at the t5-s and they say they are cold and the t5tf says hot filament turbo?? Which will work?? also which will work on a .21 ofna

Well a turbo plug won't work in a standard head button as the threads won't match (turbo plugs have a tapered thread and do not use a copper sealing washer). You don't specify which OFNA .21 engine you have but I can tell you that I have a fairly new Hyper 21 8-port running on 25% nitro fuel and a NovaRossi #6S works fine for me.

Your mileage may vary, of course...