Need better understanding synthetic oil break in

[MrRPM]

So threw this site I have seen 2 sides to using synthetic oil during break in. many say its fine to use synthetic and MANY cars come with synthetic from the factory. Alot of people say this is because of new manufacturing processes and the break in is not as crucial as It once was.
others say you need to stay away from synthetic during break in to allow the rings to seat properly. this seems to be an "old school" thought.

well what about building an engine at home? I have an engine I need to break in that was recently Honed with honing stones. Also the piston is a NOS race piston and is from the late 70s to early 80s.

I am looking for a Motorcycle oil that is safe for wet clutches and also has a robust add pack for this engine. Its going into an 1984 atc110 that i have modded. (race cam, stiffer valve springs, big bore piston 10.5:1 compression (cylinder is bored to max) larger carb ect...) Its an air-cooled single cylinder SOHC engine. I really like the looks of Mobil 1 4t and its the correct oil weight and I would like to use a synthetic because it is winter here in Michigan.

But im unsure about using a synthetic oil for break in on this engine since its "old school" and not built like new cars today.

I have actually already built it once and used it for a few hours to find that it was burning alot of oil. the cylinder was lightly scored on the top and bottom (the cylinder sits horizontally) of the cylinder. Now I theorize 2 reasons for this. when i broke it in i did not put load on the engine. we ran it alot on our barn in neutral as we were trying to get the carb and intake dialed in. I read articles now that say the engine needs to be put under load in order to seat the rings properly.

I also used Honda GN4 which appears to be (thanks to this site) a very boring oil with nothing going for it. it is conventional. Because my engine is not stock i worry it needs more then what GN4 offers.
so this time breaking it in I want to use a different oil thats better and Im not sure if I can use synthetic. I am having a hard time finding a Conventional oil thats JASO MA rated that has a robust add back like ZDDP levels higher then 800...
the only thing being broken in will be the rings and cylinder. the cam and rest of the engine already has 2 hours on it.
after it is broken in i plan to use synthetic because it will mainly be used In cold winters.

 

[Artem]

my

An engine should be put through it's paces within the first few hundred miles. By 500-600 miles, it should have experienced everything - max RPM, wide open throttle acceleration, engine braking, plenty of cold starts, long highway cruise of 50 miles or so at sustained high speeds (70mph-ish) etc etc.

Within a few thousand miles, the engine should be done breaking in and it's perfectly fine to remove the factory oil and all metal shavings floating around in it. Refilling with an oil close or better then the factory spec.

Most cars produced today come with some kind of synthetic blend oil from the factory. With oil change intervals hitting close to 7-10k miles, the oil has to be strong enough to withstand this.

I think most people OVER THINK this TOO much. I have 3 automobiles that were bought new. All went through an identical break-in cycle i mentioned above. All run great and produce fantastic UOA results, with engines wearing below average. All 3 were filled with synthetic at the first oil change. 200,000+ miles later, no engine related engine whatsoever. Take it as you will.

 

[MrRPM]

to ask my question a shorter less detailed way, if you guys built an engine the old school way from home and cost of oil was nothing would you stay away from synthetics for break in?

 

[Artem]

There are break-in oils available for engine builders. Not sure what's in it but i'd definitely use it for the recommended interval specified by the manufacturer.

Engine assembly lube coupled with regular oil mixes and becomes a special blend or break-in oil, if you will.

Like i said, i don't think the choice of oil is as important as the actual engine parts and assembly itself. If everything was done right, the block will be a success.

 

[Ken2]

Quote:
There are break-in oils available for engine builders. Not sure what's in it but i'd definitely use it for the recommended interval specified by the manufacturer.
This sounds like the best plan. Modern engines are better machined at the factory, but a rebuilt engine needs a traditional break in.

 

[chubbs1]

Originally Posted By: Ken2
Quote:
There are break-in oils available for engine builders. Not sure what's in it but i'd definitely use it for the recommended interval specified by the manufacturer.
This sounds like the best plan. Modern engines are better machined at the factory, but a rebuilt engine needs a traditional break in.



What does the manufacturer recommend? The most important thing is to follow the manufacturer procedure.

I would use a mineral oil/semi-syn, like Brad Penn and make sure you change after the first 100 miles and then run the next fill to 1k. Run it conservatively until the oil is warm (you should have a temp gauge/pressure) and open her up on the open road giving good throttle up to 60-70mph and let her come back down to the 40's. Repeat 6 times at least. Change oil and you should be good with most any type of driving.

Do you have a pre-lube pump? Or some way to lube the engine before her first start?

 

[SLCraig]

Originally Posted By: MrRPM
to ask my question a shorter less detailed way, if you guys built an engine the old school way from home and cost of oil was nothing would you stay away from synthetics for break in?



I broke my car in on dino, but I can honestly say I don't think it would have been or will be a problem had I used synthetic instead. I think they're pretty close thesedays.

 

[Highline9]

rotella 15w40

 

[Donald]

I got a reman engine from Marshall Engines. (Through RockAuto). They have done 250,000 remans so far. They must know what they are doing or they would not be in business. They told me dino for the first couple hundred. Dino or a blend to 3000, then whatever I wanted.

They know what kinds of rings they use and what kind of boring & honing they did, so I followed their directions. They also see the engines coming back for warranty.

On their website is says they just bought a $50,000 crankshaft polisher. Who can afford that kind of equipment. Certainly not your local rebuilder.

 

[rrounds]

This is how I work in new engines, works every time
http://www.mototuneusa.com/break_in_secrets.htm

ROD

 

[MrRPM]

ok, so thats a no to synthetics then.

Im probably going to find something thats conventional and run it for atleast an hour before going to synthetic. possibly even longer. i plan on breaking it in a little like www.mototuneusa.com says.

hmmm, i would run rotella 15w40 but im trying to find something thinner at start up. i mean we are looking at anywhere below 30 degrees Fahrenheit. possibly below 20 degrees by the time we actually get it done.
anyone have 10w or 5w recommendation? remember i need it to be wet clutch safe.

 

[MrRPM]

aslo, is shell rotella 15w40 JASO MA certified.
i don't care if you run them in your wet clutches and dont have problems
does it actually have the JASO MA rating?
I know t6 does but again thats synthetic lol.

no where can i find in gold its safe for all wet clutches.

 

[chevrofreak]

Originally Posted By: MrRPM
aslo, is shell rotella 15w40 JASO MA certified.
i don't care if you run them in your wet clutches and dont have problems
does it actually have the JASO MA rating?
I know t6 does but again thats synthetic lol.

no where can i find in gold its safe for all wet clutches.


Rotella T6 5w-40 and Triple Protection 15w40 are both JASO MA certified. http://www.shell.com/home/content/rotella/products/tpl_pro/

The whole "safe for wet clutches" thing is completely blown out of proportion.

 

[MrRPM]

Its may be blown out of proportion but,

This 3 wheeler really means ALOT to me.
i have had it since I was 6 years old.
I have just recently done a FULL restoration with the engine build
(new fender$ and everything)

i plan on being buried with this 3 wheeler, so basically i care about this 3 wheelers health then my own own health.

so is it still "out of proportion"? lol

i just want what best for my baby. im am actually thinking about using the rotella 15w40. ill probably have the oil heated right before putting it in which will be right before running the engine. (putting the jug over a heater that i have in the barn)

ill run it for a while (1 hour atleast) then dump it (depending how cold it is outside) and run a synthetic oil thats better suited for cold temperature

does that give a clue on how anal I am willing to be? lol

 

[Donald]

I assume before starting it they have you turn the oil pump over via a drill. They want that done with car engines. Or some method of pushing oil through before its started. That is critical.

 

[MrRPM]

don't you think oil residue from assembly will be enough to keep it lubed for first start up? i plan on running the engine right after putting it together so oil shouldent have a chance to run down, plus since the cylinder is horizontal the oil cant really run down to the crank too quickly.

good news is this sunday should be 47 degrees...horrible because it will be a muddy mess but good for oil flow. using rotella 15w40 scared me because i want to get it up to full temperature before riding it and it will take a while with the rotella. luckily its not going to be super cold.

 

[Jeff_in_VABch]

Mr.RPM:

Below are some of my comments and answers to your questions. I was actually given an ATC 90 with a bad engine in the early 70s as payment for cleaning the Honda shops garage a few times.

About for synthetic oil for break in. This is really a non issue. Synthetic oil generally posseses no additional friction reduction or additives above a premium conventional oil. Some of the synthetics state they "cling" to metal better. If so, I dont see this as a downside during break-in. Synthetic oil allows longer intervals between changes and possibly some better protection at extreme heat levels. You will see neither of these during break in, hopefully.

A home assembled engine is great. You can actually see if the rings are put on with the correct ring end gaps, ring end gap clocking and correct positive and reverse twists (the right side is towards the top of the piston and in the correct 1st or 2nd groove). You can also measure the heck out of the bores and determine your piston/wall clearances very accurately. A home bored/machined engine is impossible to create with any uniformity, accuracy or control. Don't do machine work at home.

As for your cylinder wall scoring after only 2 hours of run time, was the piston also scuffed? If so, where? This is not a break-in issue. A properly clearanced and assembled engine would never do this in even 100 hours. Sounds like the ring end gap was too low. What was it?

Post the clearances for your new bore and piston.

Ring end gaps, all four rings, top of bore
Bore dia max and min
Piston size from box
Piston dia at head 90 deg to pin
Type of rings and material

You dont want to scuff your new piston/bore.

Jeff

 

[Jeff_in_VABch]

Also, that Motousa break-in article is too broad based. No break-in procedure is one type fits all.

The type of piston rings, nodular iron, single or double moly or chrome makes a huge difference.

Although I not saying he is totally wrong, I dont believe he has any technical comprehension of how a piston ring seals.

He is right that bore finishes and concentricity as far better prepared and matched to the piston ring material, thickness and location than in the past. This allows you to go nuts on a break-in if you are so inclined without having a ring to bore friction and heat overload.

 

[Donald]

Originally Posted By: rrounds
This is how I work in new engines, works every time
http://www.mototuneusa.com/break_in_secrets.htm

ROD


I read the web page and I think while he may (or may not) be correct for racing bikes, he is NOT correct for your average car.

There is no way that manufacturers like GM have not tried breaking in an engine every way possible. They have a much bigger pile of pistons in their engineering area than he has. GM has done some dumb things over the years, but they do build a very good engine and I am confident they know what they are talking about in the owners manual with respect to breaking in an engine. So I would follow the owners manual, not some guy with a bunch of pistons in front of him.

 

[Samilcar]

Even if GM knew that breaking in an engine using the motoman process (high acceleration load followed by high deceleration vacuum) was preferable, they would never in a million years recommend it publicly in writing. New, unfamiliar vehicle + spirited driving + bone headed operator = accident and lawsuit.