is it possible to tune a nitro engine to not overheat when bashing in grass?

pelicanprentice

Active Member
Messages
104
hey all, i got a savage x and i believe i am decent in my abilities to tune the engine with my temp gun. when i am tuning on pavement, i can get it at a good temp range that i like and i barely have to move the needle. however whenever i play in a grass field (grass is probably 6 inches high i would say?) the temps easily get in the 300f range or above pretty easily. i have tried richening it but then it ends up getting sluggish and or still stays pretty hot. i couldnt seem to get it a good temp. is this just due to the nature of playing in grass? or does my engine probably have a leak or something?

so my question is, if i strictly wanted to bash in grass and i wanted to tune my engine for that, would it be possible to find a needle setting that would not make my engine get past 260f for example? or is grass just too hard on the motors such that they overheat regardless?

thanks!
 

pelicanprentice

Active Member
Messages
104
thanks for the reply! to clarify, i don't think it was 6 inch grass. its a nearby field/park and its probably like 3-4 inches high the grass, not long at all, its like easy enough to play soccer on but the grass is thick.

since i gotta get a new spur gear ill prob get a clutch bell too
 

Ingolf

Active Member
Messages
94
Yeah just get a setup with lots of bottom end
 

pelicanprentice

Active Member
Messages
104
my stock was a 47t spur and a 17t clutch bell, i picked up a 48t spur and am looking for recommendations on how low i should go on the clutch bell?
this is purely for grass usage

thx
 

Ingolf

Active Member
Messages
94
With the 48t spur gear the small the bell gear more bottom end . I would have to look but it believe I have a 16 . I’ll look when I get home tonight and see what I have
 

Blackie287

Member
Messages
43
Location
Horicon, WI
To give you an idea of how much it taxes a nitro engine/drivetrain running in grass of ANY height, try jumping on a skateboard and zip down the sidewalk or street in front of your house...no prob, right? Now put your skateboard in 6" grass and make like Tony Hawk...not going anywhere, are you..? There is a LOT of rolling resistance going thru grass of any height...3" grass is enough to force you to richen the engine as it is. I firmly believe these trucks were meant for dry dirt, so running in grass definitely has its downside. I run 15/52 on most of my Savages which seems to be fine in grass; I tend to run rich anyway. My RC10GT's with a "street" tune don't do well in anything other than short grass, the engines heat up. Just my .02
 
Last edited:

pelicanprentice

Active Member
Messages
104
To give you an idea of how much it taxes a nitro engine/drivetrain running in grass of ANY height, try jumping on a skateboard and zip down the sidewalk or street in front of your house...no prob, right? Now put your skateboard in 6" grass and make like Tony Hawk...not going anywhere, are you..? There is a LOT of rolling resistance going thru grass of any height...3" grass is enough to force you to richen the engine as it is. I firmly believe these trucks were meant for dry dirt, so running in grass definitely has its downside. I run 15/52 on most of my Savages which seems to be fine in grass; I tend to run rich anyway. My RC10GT's with a "street" tune don't do well in anything other than short grass, the engines heat up. Just my .02
thanks for the reply! how tight are u setting the slipper clutch? I'm gonna be going heavy grass from now on so i did full compressed and backed off 1/4, gonna test and see how that goes!
 

Ingolf

Active Member
Messages
94
Ok I have a 52 t spur gear and used to have a 16 t bell . I installed a 14 t bell and it fits fine . I’ll give her a rip tomorrow evening and let you know what I think of the bottom end . Which is what you need for grass . Get your parts yet ?
 

pelicanprentice

Active Member
Messages
104
Ok I have a 52 t spur gear and used to have a 16 t bell . I installed a 14 t bell and it fits fine . I’ll give her a rip tomorrow evening and let you know what I think of the bottom end . Which is what you need for grass . Get your parts yet ?
thanks bro! i got a 48t spur and a 14t clutch bell. i will test this weekend, let me know what you think of your combo thanks
 

pelicanprentice

Active Member
Messages
104
I tightened the nut for the slipper clutch tight .
thanks! on thick grass do you still wheelie? i think i did mine to full tight and 1/4 turned back. i will test this unless its absolutely necessary to be fully tight. i am a noob so always open to suggestions ahah
thanks
 

Ingolf

Active Member
Messages
94
I used to do it to the manual which is back off 1/4 turn like you are saying and kept burning out slipper pads . The hobby shop I bought the truck at said just tighten it right up , which I did and never have that problem anymore .
 

pelicanprentice

Active Member
Messages
104
I used to do it to the manual which is back off 1/4 turn like you are saying and kept burning out slipper pads . The hobby shop I bought the truck at said just tighten it right up , which I did and never have that problem anymore .
ahh gotcha yeah i heard the same thing, maybe ill just go tighten it down
 

Blackie287

Member
Messages
43
Location
Horicon, WI
Just be aware that with your slipper tightened all the way, you could be trashing pinions, differentials or the plastic 1st gear inside the transmission....hence the purpose of the slipper clutch in the first place....maybe back it off ⅛ from tight & try that
 

pelicanprentice

Active Member
Messages
104
hey all, so after changing my exhaust gasket, making sure everything was sealed, i also did the uniflow tank mod, unscrewing hsn and applying green slime. tried the 48t and 14t combo.
i gave it a run today. this time it wasnt completely overheating, it did get better. temps stayed under 280f
which is still a bit hot but i noticed my hsn was barely screwed in.

i remember when i used to bash with my truck 1-2 years ago, the hsn would atleast be turned in 1-2 full turns.

i also noticed i was like 1/4 of a screw turn between being too rich and groggy and not shifting into second and shifting into second with good amount of power. is this a normal scenario?

still want to get the temps a little lower or is it probably not possible since the grass is a bit too thick?

i attached a video, this wasnt the best tune i had. the video was taken when it was a tad too rich because it didnt seem to go into second and seemed a bit sluggish. the grass is short but its very thick so it does have some resistiance compared to a soccer field or something..

what do u guys think of the engine noise? sound normal? and is that a good amount of smoke? it was a wot run
WOT RUN GRASS (make sure u unmute it to hear the audio)

sorry for all the q I'm a noob
 

Deku

Member
Messages
10
Running your nitro rc in any type of grass requiers more from your engine, causing it to heat up faster and run hotter. To make you realise how it is effecting it: grab a skateboard and try to roll it in the grass.. it wont really roll.

To cancel this heat out you have to run the needles richer, and use a hotter plug then normal to burn that extra fuel. Why you want to run it richer: to keep engine temps in check/not overheat it.
Usually i run my hsn rich and lsn lean to get that extra punch from standing pisition into rolling/driving position. And keep engine temp in check when i run open throttle a lot.
 

Ingolf

Active Member
Messages
94
Well I finally got a change to try out the truck with the 48t spur and the 14t bell . And she’s got lots of bottom end jam ! Honestly running in grass I suggest go low in your gearing . You will always run a little hotter but you can only richen it up a tiny bit to reduce the heat before it is bogging to much .
 

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