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"the engine break in bible"

Old 08-27-2018, 12:57 PM
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https://www.rcmag.fr/reviews/techniq...ito4/mito4.htm

Here the comparisation of the Mito 4 and 7

Looking at the Mito 7 it has:
- a 3 port exhaust port, the small high placed ports next to the middle exhaust are also exhaust ports
- the 2 small holes under the exhaust are to splash fresh fuel to the hot side of the piston for cooling and lubrication.
- the 2 lower placed holes an eah side are so called bypass ports. Trapped mixture under the piston can make a shortcuit through these holes.

A nice recent topic:
https://www.rctech.net/forum/nitro-o...ification.html

A real good post is there to find from Nitrovein post nr #17 that explains it all. Most RC racers want to see the visual changes and improvements while the most performance comes from the timings alone although the 3 huge differences in my mentioned list do help.
But a good timed Mito4 will outrun a Mito7 with its fancy and very technical looks but Novarossi will not alow that so by timings each motor has the performance for its price range.
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Old 08-27-2018, 02:39 PM
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Originally Posted by Roelof
A tuned engine is an engine with higher specs than normally sold. Tuning is a same word like modifying.
Most of the time a tuned engine from factory does look the same as the standard version but the difference is with the timings like higher ports and/or a wider opening on the crankshaft. On a 14mm crankshaft a 3 degee timing is like 0.2mm more opening, you can not see it but you can meassure it and for sure notice it on the track.

Modified engines from a 3rd party modifier is taking care of the flow by rounding edges, cuts away matrial from the piston to make it lighter, adds extra lubrication ports and all other kinds of tricks. And there are some who also enlage the timings.
I wonder... how can you meter the performance enhancements of a modded engine vs. a stock engine?
Driving it on the track and comparing to what? I don't believe there are dynos for glow engines, but I might be wrong.

Last edited by kwhunter; 08-27-2018 at 03:06 PM.
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Old 08-27-2018, 02:52 PM
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I'm glad I can read French

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Old 08-27-2018, 03:18 PM
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Originally Posted by kwhunter
I wonder... how can you meter the performance enhancements of a modded engine vs. a stock engine?
Driving it on the track and comparing to what? I don't believe there are dynos for glow engines, but I might be wrong.
For reading french there is google translate.... but pics says it all.

There are dyno's but if you know how the stock engine feels you will for sure feel the difference with a modified. How it starts, accelerate and the top rpm. And do not forget the comparisation with others on the track.
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Old 08-27-2018, 05:06 PM
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Originally Posted by Roelof
For reading french there is google translate.... but pics says it all.

There are dyno's but if you know how the stock engine feels you will for sure feel the difference with a modified. How it starts, accelerate and the top rpm. And do not forget the comparisation with others on the track.
You really know your stuff, kudos!
My NOVA is tuned at the factory; I polished here and there, but since I'm not a modder I stopped at that. They also have a version they say is tuned and modified, I wonder what is changed from the tuned engine.
The sad fact is that there are very few, if any tracks here where I live; unlike the US, the sport is not popular here. So I only race by myself...
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Old 08-27-2018, 07:07 PM
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Originally Posted by Roelof
For reading french there is google translate.... but pics says it all.

There are dyno's but if you know how the stock engine feels you will for sure feel the difference with a modified. How it starts, accelerate and the top rpm. And do not forget the comparisation with others on the track.
You were mentioning timing: how can you change the timing other than changing the compression ratio? Nothing else is adjustable on these engines.
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Old 08-27-2018, 11:38 PM
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With a dremel.....
On the sleeve both intake and exhaust you can do it by adding a shim under the lip of the sleeve.

You can dremel all the way but that can result in a bad engine, only touching some edges will stretch the tolerances what always will work. If you want to do more and try to understand it you should first start wil measuriung timings on several engines.
Messuring engine timings
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Old 08-28-2018, 06:39 AM
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I see, modifying the ports; it's kind of hit or miss job if you don't know what you do.
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Old 08-29-2018, 09:38 AM
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Are REDS engines brothers & sisters of NOVAs?!
The silicone filling in the shaft is meant to smooth the rough surface of the bore, no? So it can be thrown away and a proper finishing touch applied.
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Old 08-29-2018, 10:32 AM
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Originally Posted by kwhunter
Are REDS engines brothers & sisters of NOVAs?!
The silicone filling in the shaft is meant to smooth the rough surface of the bore, no? So it can be thrown away and a proper finishing touch applied.
Reds are made in the Picco factory. The silicon is there to fill the void that's been drilled out to reduce weight.
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Old 08-29-2018, 10:32 AM
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Mario Rossi from Reds is indeed family from Novarossi, the engines are Picco made.

About the silicon a lot is written on these forums but basically it a simplifying a production process with a fake interesting story
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Old 08-29-2018, 02:41 PM
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Thanks, that's what I thought.
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Old 02-24-2019, 07:41 AM
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Originally Posted by houston
here are a few methods for you guys to choose from

++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++

My personal method which I use is as follows

Mount engine in car , preheat engine using competition heat engine warmer (easiest most prefered method) , prime engine by blowing into the pressure line and holding carburetor open until fuel has reached all the way into the crank case .

Preheat to a temp of at least 170 fahrenheit , start engine , you might have to keep it idled up a lil at first until engine settles into a smooth idle (hotter plug helps with break in). Monitor temps frequently , if temps start climbing higher unplug comp heat unit , use low speed needle and idle screw adjustment to get engine to idle between 190-210 . Let idle for 5 min then shut down , leave head covered while idling , repeat this process three times , preheat , idle , shut off , cool down with piston out of the pinch area or BDC .

Next step is similar , preheat , start engine , idle for a minute or so , make sure carb is fairly close to "in balance" but hsn fairly rich lsn 2-3 hrs rich of a race tune and run car on the ground for approx. 10 min. , you will have to tune engine so it stays at 190-210 while running the car around in a parking lot with the body on (do not over rev, use 40'-50' lengths so as not to gain too many rpm's) , no head cover . Repeat this process 3 times - preheat , run car on ground for 10 min., shut off , cool down with piston at bdc .

Next step is same as on ground intervals but this time do 30 min intervals on the ground with the body on no head cover . You can start to drive car on track for this but do not over lean engine , do not over rev!!!!!! , keep temps between 190-210F and do not "blip" the throttle , all these steps are important .

hope this helps ,
Monty Houston
Houstons Engine Service

++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++

If you are still idling at least a tank through during break-in, you're using the old-school accepted method (still works well for some!) but it's not the method that the top engine guys (Ron Paris, Dennis Richey, Rody Roem, Michael Salven are just a few I've spoken personally with about this) recommend anymore.

From the very 1st time you start your engine, plop the car on the ground & begin running it in a parking lot in 2-3 minute intervals, tuned only *slightly rich* getting the temps up in the 200F range on a normal day. Every 2-3 minutes, shut the engine down & let it cool completely with the piston at BDC, and then fire it back up; continue this cycle until you've run 15 min or so, and then bump up to 3-4 minute intervals. Vary the RPM and don't be afraid to get the temps in the 200's. What you want is heat cycling of the components without the incredible stress that comes with breaking an engine in when it's overly rich & cold. After cycling the engine in this mannerfor about 20-25 total minutes, it'll be ready for the track and race tuning. I realize this method goes against the old-school "idle on the box" routine, but you'll be amazed once you've completed this break-in routine, your engine will still have amazing pinch w/out sticking at the top AND your engines compression will last far longer than it will with the "old school" method.

You say you run the engine at "factory settings" for the first FIVE tanks? That alone causes lots of stress, as the factory settings are very rich on every engine I've ever owned or tuned. The piston & sleeve haven't expanded to operating temps, and every time the engine turns over, the piston slams into the pinch zone at TDC. The not-so-surprising result can be a cracked con-rod at the crank pin--that's where the majority of the stresses occur as the engine turns over. I've only heard of about 6-8 engines breaking con-rods, and they're ALWAYS during the first gallon...and almost every time it's because the guys have performed the break-in procedure you described. Doesn't seem like a mystery as to why it's happening. Drawing out the break-in routine really stresses the engine & actually wears away compression along the way. This method I've outlined will feel weird at every step, but after you try it once, you'll notice a big difference in your engine's performance & lifespan.

Hope this helps; give this break-in method a shot--you have nothing to gain except longer life & more power

not written by me , stephen bess wrote the article
Do you know what percentage of nitro and oil I should run through this engine
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Old 02-24-2019, 02:23 PM
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It is impossible to answer that question with zero context provided.
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Old 03-16-2019, 08:16 PM
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I have been following the method OP laid out, but I am wondering how long I am suppose to keep a rich mixture? I have ran the 3 intervals of 30min but i am not sure as to when to start leaning it out or apply full throttle as well. 1 gallon seems to be a common standard to run before racing, does that go for tuning as well or can I start to lean it out now? I have a little over 1 qt through it right now.
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