Is 10w40 okay for breaking in a newly rebuilt engine? I know people recommend 5w30 or 10w30 but it was the only oil i had laying around. Thanks!

 

go ahead and use it and then change it after you put some good miles on it. it shouldnt be a problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CERRITOS.562 &raquo;</TD></TR><TR><TD CLASS="quote">Is 10w40 okay for breaking in a newly rebuilt engine? I know people recommend 5w30 or 10w30 but it was the only oil i had laying around. Thanks! </TD></TR></TABLE>

A little on the thick side of things, but I honestly don't think it will cause any problems. I'd change it out (like I would any oil) after 50 miles. Make sure its dino oil and not synthetic.

 

use cheap non detergant for a few

 

what kind of effects would a thicker oil have on the motor??

 

I wouldn't worry about it. You can also use a synthetic on breaking but it wouldnt be cost effective.

 

yea, im just being paranoid since i have a fresh new motor and don't want anything to go wrong..especially with all x is bad x is good talk on h-t.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18bEKcoupe &raquo;</TD></TR><TR><TD CLASS="quote">I wouldn't worry about it. You can also use a synthetic on breaking but it wouldnt be cost effective.</TD></TR></TABLE>

Synthetic is a little TOO thin, so I have been told. I have reason to believe it also from previous experience. To this day, I will use dino oil as many builders also reccomend.

 

btw, i live in so cal if the weather has anything to do with the oil grade

 

u just want the rings to wear for a small period of time to seat. synthetic is really good oil and prevents it,so they say. i use cheap oil for the first 2 oil changes

 

I wouldn't be too concerned about the weight of the oil, so long as it's not on either of the extreme ends like 0W30 or 20W50, but your's isn't so it's all good. And yes you want to break in a new engine on conventional oil, not on synthetic. Give the engine a few thousand miles for the new rings to properly do their thing then you can switch over to the synthetic if you wish. I personally ran my rebuilt B18C1 on conventional for 5k miles before I switched over to Mobil1.

 

thanks for the input

 

Myth: You should break in your engine with conventional oil, then switch to a synthetic oil like Mobil 1.

Reality: You can start using Mobil 1® in new vehicles at any time, even in brand new vehicles.

http://www.mobiloil.com/USA-En....aspx

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18bEKcoupe &raquo;</TD></TR><TR><TD CLASS="quote">Myth: You should break in your engine with conventional oil, then switch to a synthetic oil like Mobil 1.

Reality: You can start using Mobil 1® in new vehicles at any time, even in brand new vehicles.

http://www.mobiloil.com/USA-En....aspx</TD></TR></TABLE>

Um, did you really think that car manufacturers give you new cars with motors that haven't been pre-broken in? Also, your posting a link to a bias source. I would go with whatever the engine builder tells me because he actually KNOWS what's up, whereas the mobile website is just trying to sell you their oil because you cant do **** if it ***** your motor up.

 

Mobil 1 sells both synthetic and and non-synthetic oils so i don't see why they would give false info. They are a very well respected company and don't need to risk making a bad name for their company for such a small amount of income.

Also, yes i really do think that car manufacturers give you new cars with motors that haven't bee pre-broken in. Thats why they often detail the break in process for an initial period of time in the owners manual. Since it seems that you dont know what is generally done on a new automotive engine i will fill you in.

First the engine is assembled. Then most engine manufacturers do what is called a cold test. This is where they spin the engine with an outside power source for an initial test. This primes the oil system and makes sure everything is working properly. Some manufacturers stop here but most continue to a hot test. This is where the engine is fired up and a technician can look over the engine with a black light to check for any fuel or oil leaks and make sure the engine is running properly. This test is about 2 min or less.

The company i work for sells their engines with synthetic inside and they are not "pre-broken in." Are you trying to say that your engine builder "KNOWS what's up" but the engineers i work with and engineers throughout the industry don't?

The truth is that you can use a synthetic or a non-synthetic on breaking and it isn't going to make any difference. I see many opinions otherwise but no proof.

There is no one right way to break in an engine. There are several methods in practice today that are successful. People need to find one they like and are comfortable with but shouldn't be telling someone else their method is wrong just because it is different.

In my opinion the nickel content in the oil is much more important for break-in than the type of oil.

 

One of the reasons i choose to use a non-synth oil for initial start-up and 500 mile flog/break-in is because even a "good" dino mix is about half the cost per QT of a synthetic oil. And when its only going to be in the crankcase for 30 minutes and then drained i dont need M1 protection. Ill fill her up with Castrol GTX again after that, and flog her on the dyno, then drive her home. Then she gets drained, and the synth goes in.

 

the conventional oil allows everything to mate properly unlike synthetic oil that is too slippery

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Combustion Contraption &raquo;</TD></TR><TR><TD CLASS="quote">One of the reasons i choose to use a non-synth oil for initial start-up and 500 mile flog/break-in is because even a "good" dino mix is about half the cost per QT of a synthetic oil. And when its only going to be in the crankcase for 30 minutes and then drained i dont need M1 protection. Ill fill her up with Castrol GTX again after that, and flog her on the dyno, then drive her home. Then she gets drained, and the synth goes in. </TD></TR></TABLE>

Exactly. That is the same thing i do.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1 fast DA &raquo;</TD></TR><TR><TD CLASS="quote">the conventional oil allows everything to mate properly unlike synthetic oil that is too slippery </TD></TR></TABLE>

Please explain what wouldn't mate properly with a synthetic due to oil being too slippery.

I'm not saying that anyone needs to use a synthetic oil for break-in. That would be pointless if you plan to change the oil in 500 miles or less. I am just saying that a synthetic isn't going to hurt anything other than your wallet.

 

Back to the guys original question. You should be fine running that 10w-40 for break-in. My only concern with those types of oils are the amount of viscosity modifiers that are needed for such a viscosity range. 10w-40 inst too bad but when you start getting into 0w-50 and stuff like that its worth researching.

 

thanks

 

I did not actually mean manufactures fully break in the motors before being shipped off to dealers. There are tests that are performed which obviously require the motor being started and evaluated to make sure everything is mechanically sound. These steps would also require oil in the motor (which oil?)

Not once did I claim that synthetic oil was not the way to go. My major point was that you are trying to debunk a myth with a bias source. No matter how credible the company is, it still does not change the fact that it's bias source.

 

We use the New Torco Break-in Oil on our race motors and are extremely happy with it!