gcoad76

i have o os cv-rx on the way and i would like to know the best break in method. how much fuel am i going to need? how many glow plugs? i read that its going to take a few. exactaly how many can i expect to use. also should i just go ahesd and seal the motor as soon as i get what is the best stuff to use to seal with. i got some green slime where do i applythis stuff. any other helpful insights would be much apprieciated thank you

Anthoop

If there was a best break in method then you would not be asking the question?
Every person you ask will have a different opinion on how you should do it, my recommendation is to follow the instructions from the engine manufacturer if you are in any doubt.

SLAYERDUDE

http://www.osengines.com/faq/product-faq.html#q590

llkoolskillet

Everyone will have a different answer, pick and choose and make your own. Its all roughly the same in the end

johndavis

anthoop is correrct  follow the manufactor's recomendation.

nitroexpress

On the surface, it would seem that a manufactor'srecommendation would bebest.

But RCUniverse engine/fuel expert had a different take.

"The entire car community has been brainwashed by some pretty magnificent marketing efforts over the years.
I am refering to break in instructions; If car parts manufacturers want to sell lots of replacement engine parts, they will give you a very short warranty (usually 30 days, where the normal airplane engine is at least one year and are as long as 5 years) and they will tell you how to break in an engine to minimize the service life so rebuild kits can be sold on a routine basis. They have also made everybody believe that the cold burbly ideling break-in is some law etched in stone and they've made everybody believe that these engines are suposed to only last a couple gallons of fuel.
I talked to one of the original importers of very high end racing car engines and asked him (before he died several years ago) why he recommended such a crazy break in and why do the engines have too much cooling where they will not get hot enough? His reply was "I want them to wear them out and buy lots of parts, I make more on a piston / sleeve set for a car engine than I do for any other part, and as you know, I warranty NOTHING"

Well, there you have it.

_____________________________

Fuelman
Cooper Fuels LLC
www.cooperfuels.com

Anthoop

That post must be a few years old by now then. One could argue that the plane engine should most definately have a longer warranty period for many reasons.
I have not seen any car engine break in methods that seem as though they are intended to cause wear, not to say that they do not excist.

Slayerdude linked the instructions for the O.S, I do not see a problem there (note the oil content).

1QwkSport2.5r

The above post by NitroExpress is spot on, and to add to it, many engine manufacturers have their sales and marketing people write the instructions versus the engineers that designed the engine.

I'm a firm believer in a hot (over 230*F) and fast (high rpm) running in over several heating cycles. What's really taking place is heating the sleeve so the bore straightens and seating the conrod ends. You want the engine to break in at the temperature it's going to run at in it's service life. Run it in too cold and imagine jamming a perfect cylinder into a funnel over and over. (over exaggerated obviously).

Many will tout this method, but ask any airplane guy that's ran the same ABC engine for 20 years on the original piston/liner set. If it works on aircraft engines, it will work on a car engine. Simple as that.

1QwkSport2.5r

Fuelman is an active member here as I've corresponded with him in the past. I'll bet his opinion and advice hasn't changed.

OS engines are not setup nearly as tight as a number of other manufacturers and this is the main reason hey break in so easy. They are one of the few engines that are hard to screw up breaking in. The tighter the pinch on an ABC, the longer it will last. OS will not last as long as many other imported engines, and I am not referring to the cheap RTR engines either.

If you want a premium engine builders opinion on tapered bore engine break in, Email Dub Jett at Jettengineering.com

Anthoop

It has been a long time since I saw Fuelman post around here is what I meant.
The amount of pinch an engine has when new/cold will not tell you how long it will last.
Has Dub Jett got much experience with the OS car engines? The point is every engine will be different and with experience you will know when it is loosening up and when to lean it..etc. We can find many break in methods from respected people but not many are even similar let alone the same..

1QwkSport2.5r

Well, I'll agree to disagree on a few things. I will say a tapered bore engine is a tapered bore engine. Regardless if it's in a car, boat, or airplane, they all operate in the same fashion. The tighter the pinch when new simply means it will retain a good piston seal longer and thus last longer provided it is not run too lean and good oil is used in the fuel. Tight engines take longer to break in for good reason. The looser the piston fit when new means it breaks in faster but won't last as long.

Dub Jett is world renowned for building some of if not the best aircraft racing engines. OS engines are on the same level with SH engines when compared to Jett's. It's too bad he hasnt built many car engines, they would be first class.

This is just my opinion, so take it for what it is.

gcoad76

i thank everybody for your input. since i posted i have read threads, watched videos, btw there is some real jokers on you tube, i have kinda decided how and what method(s) i will be using.................

should i seal the backplate before i start the break in or should i wait until i get the process finished?

again thanks for the input it has really helped me alot, my nw engine should be here in a couple more days i will keep yalls up to date and mayby shoot sum pics

Anthoop

Yes the engine still operates in the same fashion regardless of car/boat/plane, but what about the fuel used or the intended rpm range or load or cooling efficiency?
Just because an engine has a tapered bore will not mean it will need breaking in the same way as another tapered bore engine, as you have pointed out (in general) OS engines require less break in.
The amount of pinch when new/cold will not tell you how long the engine will last. What if you have a piston that is made of a different material than another...what if you have a piston/sleeve that is left with a courser finish after machining than another...
Remind me how much oil plane guys use in their fuel and at what rpm do they operate?

Anthoop

If you have not removed the backplate then it should not leak. Personally I strip new engines to check/clean/oil before running them, invariably I do seal them with a small amount of RTV when rebuilding. Do I need to use sealer?....probably not.
I would not remove something just to seal it unless I was chasing a problem.
Researching something on Youtube is always a case of sorting the wheat from the chaff.

1QwkSport2.5r

Regardless of how we look at the nitpicky details like fuel used, and oil content, the fact still remains that a tapered bore engine needs to be brought up to operating temp very quickly, and in order to do this the mixture can not be too rich and the engine needs to be revved up to heat it up quickly. The longer it takes for the cylinder to expand, the more the poor piston is getting hammered to oblivion into the pinch.

If you choose to run your engines in at slow speeds and over-rich fuel mixture, thats your deal. You aren't breaking my heart any.

downunder

While this is a commonly accepted belief it isn't actually true. As an experiment I once ran a brand new ABC engine horribly rich from the first start and continued this for 45 minutes. The pinch, measured wih a degree wheel and the plug removed, was exactly the same at the end of the 45 minutes as when I took it out of the box. The piston was totally unmarked and rod clearances were unchanged.

What's overlooked in this hot/cold thing is the oil film between the piston and liner. So long as the film is continuous it keeps the parts seperated so there can't be any metal to metal contact. As the piston enters the pinch area it tries to squeeze out the oil film and this generates a hydrodynamic pressure in the oil film. This pressure, which is very high, pushes out on the liner, slightly expanding it, but also pushes in against the piston, compressing it very slightly. At TDC when the piston stops moving for an instant this pressure is then called hydrostatic and begins to reduce as the oil film sqeezes out but there simply isn't enough time for the pressure to get low enough to allow metal to metal contact even at very low revs.

The caveat to all this is that the oil film must be kept continuous and this may not be possible with the usual very low oil content of some car fuels and generally a lack of any castor.

1QwkSport2.5r

I remember reading of the experiment you spoke of. However, I can't go all in on this one. Maybe it was coincidence, but I've seen friends ruin several ABC car engines from using what Traxxas recommends for break-in. Sloppy rich and taking 6 tanks of fuel. I have never ruined an engine yet, but I use obscene amounts of castor in my fuel.

I see no reason not to just fire it up, rev it up and get it warmed up, tune it, and go play. Then again, there are a lot of crappy fuels on the shelves these days, so that may play the part in so many engines getting ruined.

To each his own, I guess.

Anthoop

I am not disagreeing with you per se, I am simply trying to point out that it is not a black/white process. (FYI I have never idled a new engine)
Many here have their own specific way to break in a new engine but when someone asks for the best method, then there is no answer. Hence the reason we see so many different methods from respected people...if in doubt follow makers recommendations.

SLAYERDUDE

I recently bought a modded .21 engine for my race truggy from a respected modder and pipe builder, his break in was similar to the OS method of hit the ground running and not too rich so the temps can get to 200+F, keep it running as long as possible because cooling down just stresses the rod and bearings, continue until mechanical pinch loosens up.
PITA with a tight engine, and me being skeered to run it lean enough to achieve 200=F temps even with a sock on the head and not being "boggy rich" like I'm used to, also instructions were to not hit any high revs, even tho with the leaner settings for higher 200F temps it wanted to just rip.
Broke in for a gallon and the pinch loosened, still has killer pinch and runs like a top at 3 gallons.

Then there's my HPI K5.9, a "known bad engine" as stated on this and many other forums...
I did the factory 3 tanks idle on a stand.. in a garage while it was raining out, and continued the factory few tanks on the ground.
Ran the first gallon thru and didn't push the tune, and it still constantly did wheely induced rollovers, then leaned it out and hit third gear in the Savage XL on the second gallon.
3 years and 13 gallons later the engine finally took a crap because of the bearings, due to, IMO, the low oil content of the same O'Donnells Speed Blend fuel that took out the bearings in my 8.0 engine.
Byrons always kept the 5.9 nice and buttery looking on the inside, couldn't get it anymore.

IMHO break in is important, but not as much as diagnosis of air leaks (K5.9) and tuning skills over the life of the engine.

gcoad76

ok i am half way thru the break in for this os cvrx.15 i had gotten odonell fuel because i read that traxxas wasnt that good , after running a few tanks i have noticed that the odonnel fues isnt real smoky, i can barely see any smoke at all. i know that im not running to lean, i have the hsn set at 2 an half out, and i even tried going out further on the hsn to see if it would produce more smoke. so today as i was getting thru the rpms i noticed a lil exhaust smoke . is this fuel that low in oil content? i thought it would be better than traxxas but know im on the fence. i have some traxxas fuel left but i also read that i shouldnt switch fuels durring break in. what can i do to see more "smoke" or should i not worry about it till i get som wot tanks in? so thanks for everybodys input, so far so good on the break in. its kinda a pain but i can tell that it will be worth it in the long run

Anthoop

What fuel exactly are you using?
If you have bought a gallon of fuel you can tee some off and add extra oil for the break in period.....most car fuels have a very low oil content these days...too low for break in.

gcoad76

        i have odonell racing fuel its 8% oil  20% nitro. i also have some traxxas 20% but im not sure the oil mix. my LHS doesnt have any other odonell fuel blends and all the sell is gallons so im stuck with what i got. can i mix the traxxas with the other since i noticed that the traxxas top fuel is a litle bit "smokier".    also what oil can i add are you referring to castor oil??,

   should i get this castor oil; before i go any further i really cant afford to burn the engine up, i have already done 3 tanks.

   another problem im having is after preheating the engine the fuel is moving away from the carb making it really hard to prime. i tried manually priming but that is flooding as i really cant see because i dont have that much extra hose. i am puttin a piece on the fuel tank on the nipple for the exhaust line. will compressed air from a can help if i just blow it on the carb to try and cool it off. 

    i have a hard time preheating all i have is a hair drier, and i can just barely get the engine to 200 deg. 

nitroexpress

Plug in the numbers and bring your oil percentage up to 11 - 15% (for break in). Castor oil from the drug store is fine.

http://www.nitrorc.com/fuelws/oilonly.asp

A hair dryer is better than nothing, keep using it. Be sure and wrap the engine head.

llkoolskillet

Let me intervine here...You CANNOT add castor oil to Odonnells race fuel. It will NOT mix, I was told to do this by two very respectable engine modders in canada. The oil will seperate like oil and water and stain your motor, fuel tank, and anything else it comes in contact with. I used Benol castor oil and I ended up ruining a gallon of fuel doing this. It doesnt take much caster to but its not worth ruining a $30+ gallon of fuel.

The best fuel I have ever ran is Werks 30% it has synthetic and castor and allows me to run leaner than the odonnels race fuel.

I have a modded picco with over 10 gallons of fuel that was broke in with the odonnels 30% race fuel. There race fuel does NOT have castor in it and the insides are not stainded the motor still runs like a beast.

Heres my proof of the Benol and Odonnells race fuel do not mix

nitroexpress

Of course you know that the company that makes Odonnells also produces two other brands of fuel. And the only real difference between fuels is the oil package. So why do you single out the Odonnell brand? BTW, awhile back I talked to the producers of Odonnell and they said that the present formula does include caster oil (although the Odonnell site lists the Race as full synthetic).Perhaps your info is out of date. Any knowledgeable person would never run a full sythetic blend of fuel.

Sorry,I don't believe you.