I have the stock Nitrostar 21BB with my Savage 21, for those that aren't familiar with it, its just a 21 sized ABC car engine. I was wondering if running it for long periods of time at WOT would cause damage or premature engine failure, assuming that the engine was run rich enough such that there was always a trial of smoke and the engine temp remained inside the recommended range.

as long as the temp is fine and you see smoke you could run in there all you want. make sure if its not broken in you do that before doing extended periods of WFO.

sean

Car engines are designed to put out huge power at blistering high RPMs.
Most are only good for one or two seasons before compression drops and low end starts falling off.
The heads are big enough for sufficient cooling down the longest straight-stretch on a track with proper tuning and good air flow.
Anything more than this will definitely shorten the life.
If you're talking a mud bog or a pulling truck where air flow is non-existent and WOT can be as long as 40-60 seconds, you may want to put a fan on it and don't expect it to run long.

Kirk

anyone else want to chip in??? trying to figure out who's right here.... I read the FAQ on the engine board and I remember seeing a bit which said ABC engines were designed to run WOT... its getting awfully confusing...

Of course they're designed to run at full throttle.
You're not going to win a race if you worried about flooring it or it doesn't run it's strongest there.
But it's only floored on the straights-- a few seconds tops-- not it's entire life!!


Get on the car forum and see what the lifespan of a good .21 is with normal use & abuse.
I've raced 1/8 on and off road cars and buggies for years, and went through quite a few engines.

Maybe if you told us what you are doing with it and why you would need WOT for more than a few seconds, this would be less confusing to all of us.

Kirk

I don't race, just bash. Sometimes the ground where I bash is only light grass and dirt and its quite open so there's a lot of room to drive it at WOT without hitting anything, there's also long run ups for jumps or steep hill climbing.

How long max do you run WOT????? What fuel are you running??? What kind of track or area?? What body on the car/truck?? What head is on the engine?? How do you tune, safe or at the limit?? All these make a difference in the answer.

My Nitrostar .25 in my Savage runs at full throttle almost the entire time when I having fun bashing on the golf course in my backyard. I try to keep my temps at around 250 and am not worried about engine longevity. If you don't overheat your engine then running at WOT is NO PROBLEM.

Your best bet to extend engine life is to us a fuel that contains 16% oil with some of it being castor. The 10-14% oil blends for rc car fuels is what causes the engines not to last long.

My fuel contains 22.5% nitro and 17% oil by volume. It works perfect.

I sometimes run at WOT pretty much all the time, although every 30 seconds to a min I'll ease up on the thorttle, do a 180 in the dirt (which lasts a couple of seconds) and head back the other way at WOT... I mainly bash on a mixture of dirt, grass and loose gravel. There is the occasional stretch of bitumen (car park).

I'm running 16% and try to tune at least slightly rich, always making sure the temp stays within the recommended range (up to 135 C) and that there is always smoke coming from the exhaust.

What's WOT?

WOT = wide open throttle