trx2.5maxx

if 30% has lower runnig temps the 20% how does the engine life decrease just wondering

ttoks

it doesn't, you can get just as much life running 30% as you can with 20%, as long as you get the right tune, and 30% will usually make you run slightly hotter, or the same temp as 20%.

Technito20

20% or 30%, your engine will last roughly the same amount of time. The 30% nitro will burn a little cooler than the 20%, but that's the only real difference. Just never mix the fuels, stick with one. Once you go 30% then you should never go back to 20% with the same engine. Some say this will damage your engine going from 30% back to 20%, but I haven't actually seen that happen yet. But to be safe stick to one or the other. You wouldn't want to keep re-tuning your engine every time you switch fuels anyway.

J_Bone

My Feedback: (1)

30% does run cooler than 20%. Nitromethane burn cool because it comes with its own oxygen atoms to help it burn. It's not a huge difference, but slight none the less is cooler.

You can go up or down in Nitro % as long as you make sure a few things:
- re tune the engine every time to calculate for the changes in Nitro % or different fuel.
- Make sure you don't mix different fuels or Nitro % in the same tank. Burn or drain it all out before changing.
- Head gap is set correctly (especially on going higher on Nitro)
I have changed up and down many times without any I'll effects, as long as you know what your doing you will be fine.

Super Bob

J Bone, can you explain your theory on head gap and nitro content?

slayerphonics

I was running JAC 20%.. and my OS was running hotter then I liked to see even with a good tune.
LHS suggested I try 30%. So I was like sure F it.. if i blow my motor i can get a new one.
Ran the 30% but forgot about changing plugs.. so it kinda ran hot and blew my plug first run out..
Got a cold plug and got it tuned.. and oh my I will never go back to 20%..
I have more power, and lower temps

218 at high tank and 240 at bottom of tank
And the WO throttle power is insane

The lower engine life didn't make sense to me either.. I thought it was the heat that can really kill and engine..
so if you need a lower temp plug to ignite the nitro then its going to burn cooler.. meaning lower temps.. just makes sense.. even to a novice.

And what is the rule on shimming the head.. I haven't shimmed my head on my OS .18 seems fine..

Let me know whats up

J_Bone

My Feedback: (1)

I went over it in your other post....