Nitro Guide and FAQs
#29
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"At this point, it is okay to do 1 second WOT (wide open throttle, aka 100% throttle) bursts."
(Q-1)when you say it is ok to do this, do you mean it is recommended? you say to drive the car through it's rpm range. does this mean drive it like normal, but not at wot for too long? my question is how gingerly should i be driving the car during the first 20 minutes? if you could explain a little more in detail how much throttle i should give the engine in detail i'd appretiate it. like should i just squeeze the trigger fully and let off wait a second and do that again, and again, etc? after 20 minutes of breaking the engine in i can assume the engine is broken in and drive it as i please?
(Q-2)is this what people consider the "heat cycle method"?
(Q-3)what's a good way to measure temp? venom temp meter? what temp gun? some are better then others.
i commend you for writing such a thorough engine guide. thank you. i just got my 4th engine, a rb 928 and want to make sure i break it in properly. i've been in and out of the hobby over the years and when i started i was told to let the car sit and idle for the first 3 tanks.
thank you again
(Q-1)when you say it is ok to do this, do you mean it is recommended? you say to drive the car through it's rpm range. does this mean drive it like normal, but not at wot for too long? my question is how gingerly should i be driving the car during the first 20 minutes? if you could explain a little more in detail how much throttle i should give the engine in detail i'd appretiate it. like should i just squeeze the trigger fully and let off wait a second and do that again, and again, etc? after 20 minutes of breaking the engine in i can assume the engine is broken in and drive it as i please?
(Q-2)is this what people consider the "heat cycle method"?
(Q-3)what's a good way to measure temp? venom temp meter? what temp gun? some are better then others.
i commend you for writing such a thorough engine guide. thank you. i just got my 4th engine, a rb 928 and want to make sure i break it in properly. i've been in and out of the hobby over the years and when i started i was told to let the car sit and idle for the first 3 tanks.
thank you again
#31

Wow this thread has bein here this long and only has 1 page???? i rember mine got 3 or 4 pages before it got deleted becuase u copied mine..............

#32
Senior Member
Thread Starter

i made it easier to find then i got tired of people asking the same questions over and over and over again so i made my own
#34

ORIGINAL: JetTech101
So you wrote this or you copied it from someone? Im confused.
So you wrote this or you copied it from someone? Im confused.
i made one of these threads but with info i got from a website...........it was a big hit people really liked it and it had very very good info............for some reson HPI APOLLO compied and pasted the same info that i posted and made him self his own thread (why i have no idea) becuase of him doing this the modds got upset and deleted BOTH of our topics............and now he has his own thread again with info he wrote himself................but it will never be like the thread i had............thanks for geting my thread deleted

#35
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Thread Starter

I copied and pasted it because it had such a long title like "wunna know how to tune your nitro engine" or something like that, so i copied and pasted it as "how to tune a nitro engine"
i wrote this myself to help people
i wrote this myself to help people
#39
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Nice article, I do have one question though. I have been told, and admittedly have not experimented enough with it at 30 dollars a gallon, that higher OIL content actually will make the engine run a little hotter, while lubricating better.
Something about the alcohal in its unfired state cools, and the more oil, the less it cools. I know, this sounds wierd.
Also, when a car idles down, at idle, and then 10-15 seconds later, idles out, and stalls, this is actually 'loading' from the high end needle being too rich correct?
If you lean out the high end, then the low end could go either way. It could be too rich or too lean, so you will have to adjust accordingly.
Lastly, if the low end is too 'lean' will it rev up and out, or again, just idle stall. This low end idle is always the hardest thing for me to get to the sweet spot.
Ciao
Something about the alcohal in its unfired state cools, and the more oil, the less it cools. I know, this sounds wierd.
Also, when a car idles down, at idle, and then 10-15 seconds later, idles out, and stalls, this is actually 'loading' from the high end needle being too rich correct?
If you lean out the high end, then the low end could go either way. It could be too rich or too lean, so you will have to adjust accordingly.
Lastly, if the low end is too 'lean' will it rev up and out, or again, just idle stall. This low end idle is always the hardest thing for me to get to the sweet spot.
Ciao
#40
Senior Member
Thread Starter

the alcohol is burned, therfoer gives off heat, the amount of coiling that 5% alcohol would have is minimal at best
when a car idles and dies after 10-15 seconds it can be lean or rich, the best way to test is to get it up to running temp (as i mentioned in the article) and then let it idle for 30 seconds then floor it, if its slow to react then tune accordingly
if you lean the hsn, the lsn leans out by a small degree too
if the low end is lean, at idle, it will shut off without even lowering the tone, its running, then its not
when a car idles and dies after 10-15 seconds it can be lean or rich, the best way to test is to get it up to running temp (as i mentioned in the article) and then let it idle for 30 seconds then floor it, if its slow to react then tune accordingly
if you lean the hsn, the lsn leans out by a small degree too
if the low end is lean, at idle, it will shut off without even lowering the tone, its running, then its not
#41

ORIGINAL: MugenSickly
Something about the alcohal in its unfired state cools, and the more oil, the less it cools. I know, this sounds wierd.
Something about the alcohal in its unfired state cools, and the more oil, the less it cools. I know, this sounds wierd.

The needles are tuned to allow the correct amount (flow) of the methanol/nitro mix regardless of how much oil is in the fuel. If you add oil (or go to a mix with more oil) then the needles have to be opened a little more to keep the same flow of methanol/nitro. Both methanol and nitro help keep an engine cool by evaporating inside the crankcase so even if more oil is used then the needles have been reset to keep the same amount of fuel (methanol/nitro) in the crankcase to do the cooling. I might add that seeing there's still the same amount of methanol/nitro being burnt in the combustion chamber then power will remain the same within reasonable limits of oil quantity.
All that oil does is reduce the heat from friction to a minimum so adding more of something that reduces friction can't add heat to an engine.
#43
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Awesome info guys! I'm just breaking in a motor for the first time and for sure I'll be following your advice. One question, there seems to be tons of different options on what people should use for after run oil. Should I use the real thing from the hobby shop, WD-40, Castor Oil (don't have a clue where to get it), or something else.
#44
Senior Member
Thread Starter

if you dont ahve an idea, its best to stick with something that is actually made for after run oil, go buy some at the hobby shop for $3 a bottle or get some air tool oil frmo a hardware store, either works
#45
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NNNNNNNOOOOOOOOOOOOOO!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!! Why are you the only guy in the world that thinks that running an engine rich is bad. STOP IT!!! Lean=hot, hot=bad. I wil agree that there is some good info in here. NOT THAT!!!
#46
Senior Member
Thread Starter

before you go insulting my guide, talk to fuelman, otherwise just stop, i did my research, i talked to experts, debate it with them, not me, more people have found this guide helpful than hurtful, i also find it ironic that out of all the experienced people that have read this, you seem to be the only one self'qualified enough to say that running rich is good in break in
#48
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I tell you what. If this is the kind of bull**** that is spread on this forum. Apollo, you and RCU can eat a big steamy pile of dog ****. I'll stick with intelligent conversation.
#49
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Thread Starter

ORIGINAL: goose7896
I tell you what. If this is the kind of bull**** that is spread on this forum. Apollo, you and RCU can eat a big steamy pile of dog ****. I'll stick with intelligent conversation.
I tell you what. If this is the kind of bull**** that is spread on this forum. Apollo, you and RCU can eat a big steamy pile of dog ****. I'll stick with intelligent conversation.
A. checked out my sources in the other thread finding that Fuelman was real and that he had expertise beyond yours in nitro engines and now are retaliating
or
B. You are just trying to find a tiny flaw in a home-written nitro guide which has been revised by experts and long time nitro-ists before it was even posted, and then try to exploit that making you feel superior, if you beleive that this is an unintelligent thread and/or website, then you should do yourself a favor by staying off of it
I wrote this guide merely to help people and not to have a debate war over whether rich is good or bad, while running slightly rich is ok, anything more can be harmful, end of story
have a nice day
-Sean
edit: I'm sure at least half of the 2500 people that have read this thread have got something useful from it, everybody feel free to report goose7896's rude message to the admins, thanks
#50

I had to go back and read everything again and I didn't notice anything about running rich is bad...maybe there was some misinterpretation about getting the engine up to 200-240F for the running in process. However there's a very wide spread belief that running a new ABC type engine rich is bad for them and because of this belief no one takes the risk of running them rich so the belief perpetuates.
I've never really believed rich running would harm a new engine but I had no way of knowing if I was right or wrong until I managed to pick up a brand new ABC very cheap so I could consider it to be somewhat expendable. It had a very good pinch so I decided to run it extremely rich right form the start and monitor the pinch between runs to see what happened. Also between runs I'd take off the muffler to check as much of the piston as I could see.
I ran it for 45 minutes in a slobbering rich 4 stroke with a head temp of 145F and the pinch stayed exactly the same as from new. I stripped it down completely and the piston had virtually no sign it had even been run. The conrod however was running in beautifully
. Curiously, although the piston itself looked brand new, the chrome liner was also running in beautifully. I'll keep this short because if anyone's interested in the full test with photos I have it in the engines forum at http://www.rcuniverse.com/forum/m_28..._1/key_/tm.htm
OK, so why didn't it ruin the piston because everyone knows an ABC has to be up to temp to expand the liner and relieve the pinch (which is an interference fit)? This took me some time to figure out and I can only come up with one answer. Our engines are cooled in 2 ways, one by airflow over the fins and the second by internal cooling from the evaporation of fuel in the crankcase. Now when you run rich (or very rich in this case) there's a lot more fuel to evaporate in the crankcase. The piston spends most of its time down in this fresh mixture so the inside of the piston is continually wet with raw fuel which then evaporates off it's inner surface including under the crown and cools it down. The upper part of the liner however only has contact with heat from combustion (and some heat from compression) so it runs hotter and expands away from the piston. Leaning out the mixture reduces the internal cooling of the piston allowing it to expand more.
Since doing this experiment I've changed my method of running in an ABC type engine. I start with 4 stroking rich to start the rod bedding in then gradually lean out to slowly build up heat in the piston and let it gradually adapt it's size to the liner. My son used this system in his car and it worked extremely well.
I'm not saying this is the only way to run in an ABC because most seem to survive the usual hot method quite well, basically the experiment was just to find out if rich was bad. It isn't.
I've never really believed rich running would harm a new engine but I had no way of knowing if I was right or wrong until I managed to pick up a brand new ABC very cheap so I could consider it to be somewhat expendable. It had a very good pinch so I decided to run it extremely rich right form the start and monitor the pinch between runs to see what happened. Also between runs I'd take off the muffler to check as much of the piston as I could see.
I ran it for 45 minutes in a slobbering rich 4 stroke with a head temp of 145F and the pinch stayed exactly the same as from new. I stripped it down completely and the piston had virtually no sign it had even been run. The conrod however was running in beautifully

OK, so why didn't it ruin the piston because everyone knows an ABC has to be up to temp to expand the liner and relieve the pinch (which is an interference fit)? This took me some time to figure out and I can only come up with one answer. Our engines are cooled in 2 ways, one by airflow over the fins and the second by internal cooling from the evaporation of fuel in the crankcase. Now when you run rich (or very rich in this case) there's a lot more fuel to evaporate in the crankcase. The piston spends most of its time down in this fresh mixture so the inside of the piston is continually wet with raw fuel which then evaporates off it's inner surface including under the crown and cools it down. The upper part of the liner however only has contact with heat from combustion (and some heat from compression) so it runs hotter and expands away from the piston. Leaning out the mixture reduces the internal cooling of the piston allowing it to expand more.
Since doing this experiment I've changed my method of running in an ABC type engine. I start with 4 stroking rich to start the rod bedding in then gradually lean out to slowly build up heat in the piston and let it gradually adapt it's size to the liner. My son used this system in his car and it worked extremely well.
I'm not saying this is the only way to run in an ABC because most seem to survive the usual hot method quite well, basically the experiment was just to find out if rich was bad. It isn't.