Opinions on 5mge engine break in.

[Sentara]

Hi all.

As some of you are aware, I recently Had the bottom end of my 5mge re-built. Pretty much everything down to the frost plugs was done. .02 overbore. No work to the rods were done. Head decked, and opened up/port matched........

So, How do you recommend breaking in the Cressy? Also when is it safe to switch over to synthetic?

For synthetic I've heard all sorts of answers, anything from 1500 km's to 15000 km's. As for the break in, I'm about 1500 km's in. The only rule I've had is to never keep the same constant load on for any long period of time. Also trying not too flog it too too much.

Any input is welcome.

Kevin.

[Deep_Blue]

I heard only 500kms, but longer is a bit better. I would change over to synthetic at around 5000km. That's what is recommended for new cars.

Cheers,

Tim

[James Earl]

MY motor ran for 3000 km then I went to synthetic.

I daily drove mine in the city only for the first 2000 KM and began to push it a bit after that. At 3000 KM I was practicing my speed shifting and testing my rev limiter.

Url

[slamd87supra]

I would probably go to synthetic after about 5 k or even less. Because you have 1500kms on the new engine it should be as "broken in" as it needs to be cuz the main issue when braking in an engine is allowing the piston rings to seat properly in the cylinder walls. Once the rings find their optimum postion yer good to go.

[Deep_Blue]

Also very important is breaking in the piston walls and the bearings, otherwise oil doesn't flow porperly. That's why you're not supposed to use syn. oil until breaking in is complete.

Tim

[Supra_devil]

I have done a break in on a 5M, we drove it at varying loads and rpm. Flogging the shit out of it, not reccomended.
The most important part is the first start and drive, this is when the rings break in. Revving the motor up to 5000 rpm and so is fine as well, and even recomended to a point, but they also say to let it slowly rev down in gear too, this is all for the initail break in, which you are done.
i would say to do an oil change around 1500kms, then start a regular 5000 kms intervals.
as far as synthetic, i would say after the second (6500km) oil change it should be fine.

[Sentara]

Thanks for the input all.

Some more info. The moment I started it up, I went for a short run, came back and changed the oil. Have since changed it again. I think I'll wait until 4000 or so to swap over. It runs very smooth. Way more go than before.

Deep Blue, which bearings do you have to break in? I thought they all just floated in oil.

I'm thinking some of you have read some of the same stuff on break in's as I have. If I re-call correctly the Toyota Atlantic cars have a break in where upon start up you hold it at 2000 rpm or so for about 20 minutes. Change oil, and repeat something similar then it's ready to go. Much different engine of course. There was also one I remember with bikes, the guy claims you have to rev the hell out them to get the rings to seat nice. 4cefed.com I think has the links...

I guess I could of asked you guys 1500 km's ago but luckily I'm pretty much following your advice.

One more question. What happens if you rev hard from day one [5m]. Other than "they won't seat correctly"... Anyone have a detailed explanation?

Kevin.

[Supra_devil]

seating properly allows the rings to wear properly around the edges, it slightly rounds the ednges of the rings. when seated it can seal really good, good, ok, bad, etc. this is what is meant, it seals better and allows less blow bye.

[James Earl]

Hey guys,
As this quickly becane a post on oil and not break-in I split the topics.

Sentara, sorry for jacking the thread. I will try to play better in the future.

Url

[Sentara]

No Problem Earl.

So, does anyone have an answer on bearing's being broken in? I thought they always floated from day one.

Supra devil, Isn't it more critical to properly wear in the cylinder walls as aposed to wearing in the rings? You don't want a super finish on the cylinder walls beacause the oil still needs a place to hide and adhere to...And vice versa.

Mike, I strongly disagree with the mixing of oil. One of the big reasons being different additives used in different oils will break each other down, bad news.

The only problem so far has been a leaky cam seal??, and a leak on the back of the motor leading to the EGR, that gasket was a bit of a bitch to replace.

Another thing that should questioned, Re-tourqing the head bolts. When? The next day/week??

Kevin

[GOT_BOOST]

Hi Kevin,

Thanks for the input. I see where you are coming from. I suppose I got off lucky as I was using the same make of oil. I went from the Castrol GTX to the Castrol Syntec. Yes, I know it is not real synthetic and is hydrocracked oil. I could see a problem mixing different grades, types and manufacturers of oil. I think since I use the same oil all the time it never occoured to me to post that earlier. LOL.

Thanks again Kevin.

Mike Nikolai

[Supra_devil]

Kevin, the walls are important too, but they aren't as smooth before hand as the rings are because they are honed when the block is redone. the surface and edges on the rings aren't.

either way, the break in is done at this point.