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Posted previously by CDELONG
my personal tuning guide- This assumes you are getting fuel to the carb and have a good glow plug and ignitor!! Always start with the top end when tuning!! Top end adjusment affect the bottom end settings, so never adjust the low end needle first. FOR TOP END TESTING (you may need a friend to help with this one): 1). Pinch test: Hold the vehicle off the ground and hold the throttle steady at about mid to 3/4 throttle- then pinch the fuel line (midway between the carb and tank) for ONE second. The engine RPM's should increase slightly and return to normal without stalling. If it stalls- too lean if RPM's do not increase- too rich 2). Spit test- OK, spit (water) boils at 212F, so spitting on the head is a rudimenatry way of checking temp. If the spit evaporates away in 2-3 seconds you are golden!! If it boils off immediately- I means sizzles in an instant- you are most likely too lean (HOT)- richen it up a little. If it just sits there and does nothing, you are too rich- lean it out a little. 3). Another way is to monitor temps with a temp gun. A temp gun is the best investment you'll make in Nitro RC'ing. At $75 dollars it may allow you to save your engine someday. It will always come in hand tuning. 4). The last and hardest method is plug reading. - Plug wet and shiny- playing it safe- probably blubbers at full throttle. - Plug dry and shiny- getting there- if it runs strong, leave it here!! - Plug has a dull sanded look and not pitted at all- just right!! - Plug has a highly sanded look and is pitted and possibly distorted- STOP- replace the plug and richen it up. The element may break off and damage the engine!! Either way, the engine should emit a good amount of smoke while "pinning" the throttle. Keep temps in check if you are a beginner- I'd say less than 220F for racers new to nitro. Ask someone who has a temp gun to check for you if you don't have one. LOW END TESTING 1). Pinch Test- after the engine is warm and the top end is set- bring the vehicle to an idle. Pinch the fuel line midway between the tank and carb and see how long it takes for the engine to stall. 2-3 seconds is optimal less than 2-3 seconds- too lean more than 2-3 seconds- too rich 2). Temperature tuning the low end: If you have a temp gun- get the engine warm and check the temp. Let's say it's 200F. let the car idle after a good hard run and see if the temp goes up or down while idling. If the idle temp increases- it's too lean on the low end needle- richen it up a little. If the idle temp decreases- it's too rich- lean it out. Do this until temp remains roughly the same at idle when you pull it in after a good hard run. 3). Idle speed testing Bring the engine to an idle after a good hard run- - if the idle creeps up and keeps increasing- it's too lean - if the idle decreases and stalls- it's probaly too rich and loading up the plug. Either way you go about it- the engine should be able to idle for 30 seconds without loading up when you nail it. GOOD LUCK and happy tuning!! Corey |
Originally posted by Rapid Roy Posted previously by CDELONG my personal tuning guide- This assumes you are getting fuel to the carb and have a good glow plug and ignitor!! Always start with the top end when tuning!! Top end adjusment affect the bottom end settings, so never adjust the low end needle first. FOR TOP END TESTING (you may need a friend to help with this one): 1). Pinch test: Hold the vehicle off the ground and hold the throttle steady at about mid to 3/4 throttle- then pinch the fuel line (midway between the carb and tank) for ONE second. The engine RPM's should increase slightly and return to normal without stalling. If it stalls- too lean if RPM's do not increase- too rich 2). Spit test- OK, spit (water) boils at 212F, so spitting on the head is a rudimenatry way of checking temp. If the spit evaporates away in 2-3 seconds you are golden!! If it boils off immediately- I means sizzles in an instant- you are most likely too lean (HOT)- richen it up a little. If it just sits there and does nothing, you are too rich- lean it out a little. 3). Another way is to monitor temps with a temp gun. A temp gun is the best investment you'll make in Nitro RC'ing. At $75 dollars it may allow you to save your engine someday. It will always come in hand tuning. 4). The last and hardest method is plug reading. - Plug wet and shiny- playing it safe- probably blubbers at full throttle. - Plug dry and shiny- getting there- if it runs strong, leave it here!! - Plug has a dull sanded look and not pitted at all- just right!! - Plug has a highly sanded look and is pitted and possibly distorted- STOP- replace the plug and richen it up. The element may break off and damage the engine!! Either way, the engine should emit a good amount of smoke while "pinning" the throttle. Keep temps in check if you are a beginner- I'd say less than 220F for racers new to nitro. Ask someone who has a temp gun to check for you if you don't have one. LOW END TESTING 1). Pinch Test- after the engine is warm and the top end is set- bring the vehicle to an idle. Pinch the fuel line midway between the tank and carb and see how long it takes for the engine to stall. 2-3 seconds is optimal less than 2-3 seconds- too lean more than 2-3 seconds- too rich 2). Temperature tuning the low end: If you have a temp gun- get the engine warm and check the temp. Let's say it's 200F. let the car idle after a good hard run and see if the temp goes up or down while idling. If the idle temp increases- it's too lean on the low end needle- richen it up a little. If the idle temp decreases- it's too rich- lean it out. Do this until temp remains roughly the same at idle when you pull it in after a good hard run. 3). Idle speed testing Bring the engine to an idle after a good hard run- - if the idle creeps up and keeps increasing- it's too lean - if the idle decreases and stalls- it's probaly too rich and loading up the plug. Either way you go about it- the engine should be able to idle for 30 seconds without loading up when you nail it. GOOD LUCK and happy tuning!! Corey |
Rapid Roy
This was good tip thanks...... Bring the engine to an idle after a good hard run- if the idle creeps up and keeps increasing- it's too lean The other possilibity could be due to the movement of the xhaust joint tube movement due to crashes..... but will try and find out. cheers ZiiZo |
guys: would engine tuning change if i change to a bigger head??? like the one by zac/kawahara head??? also, what's the effect of putting more shims between the glow plug and the piston and sleeve??? thanks:D
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Originally posted by doki_doki guys: would engine tuning change if i change to a bigger head??? like the one by zac/kawahara head??? also, what's the effect of putting more shims between the glow plug and the piston and sleeve??? thanks:D adding shims - yes too...imo anyway:D |
guys: what benefit do i get if i add shims between the engine head and piston/sleeve??? thanks:D
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Originally posted by doki_doki guys: what benefit do i get if i add shims between the engine head and piston/sleeve??? thanks:D after awhile when compression decreases u reduce the shims;) |
You only add shims if you are experiencing pre-detonation. It will lower the compression and retard combustion.
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Originally posted by Racing4Evo You only add shims if you are experiencing pre-detonation. It will lower the compression and retard combustion. |
Originally posted by doki_doki so you decrease the power the engine generates if you add shims??? did i get you right??? |
Originally posted by Marcos.J yes you loose compression |
rd logics
just got the rd logics turbo 2pipe....can't wait to see how it performs....
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Re: rd logics
1 Attachment(s)
Originally posted by rcabj just got the rd logics turbo 2pipe....can't wait to see how it performs.... |
1 Attachment(s)
:D ;) pics 2
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OS TR12 Efra version
Is the TR with the stainless steel heat sink quicker that the normally blue ones? Is it worth the $25.00 extra?
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