2.5 NA Break-in after rebuild

Started by xmod109, May 04, 2019, 05:10 PM

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xmod109

Finally have the SIII running with a 2.5 NA and want to break it in as properly as possible.  Besides avoiding too much cold idle and not giving full throttle til warm, what are your thoughts?
I've been keeping it in higher gear to put a load on the engine. Don't have to worry too much on excessive reving and speed.

Is there a recommended additive for the oil?  How long between oil changes? I am open to all recommendations. Thanks

Red90

It is actually important to work the engine fairly hard right away over a full range of engine speed in order for the rings to bed in. Use a lightish mineral oil. The first half hour is critical. Then change the oil. After that it does not matter much.  A few frequent oil changes after that are good as there will be lot of wear particles to flush out.

https://www.enginelabs.com/news/dispelling-engine-break-in-myths-with-high-performance-academy/

binch

High Zinc mineral oil for the break in... that's what they do with the older style engines at the shop and it seems to work.   But John has it right...frequent oil changes to clean out the stuff that will wear hard on the engine.
Cheers, Bill

Red90

The high zinc is for flat tappets which require special break in procedures. These engines have roller tappets so it is not an issue. The focus needs to be on bedding in the rings while the crosshatching is fresh.

On the subject of tappets. Do not use aftermarket tappets as they are not hardened correctly and wear out very quickly.

xmod109

Thanks all, I had read that 15w40 was recommended for its high zinc properties.  I'll be doing an oil change again shortly to clean it up and hopefully it all works out.  Had a slight blue haze on its last run so I think the crosshatching and rings still need a bit more breaking in.

Red90

Blue smoke on a diesel has nothing to do with rings. That is a gasoline engine thing. It is fuel that is injected too late to burn.

ugly_90

#6
I didn't expect engine multiweight to determine zinc values in oil. The Rotella 15W40 seems to have more ZDDP than some competitors, but the Rotella 5W40 seems to have it as well. The military manual seems to state not exceeding 80km/hr in the first few hundred km, as I recall.

I don't know what the advantage of 15W40 over 5W40 might be in Canada, other than 5W40 conventional is hard to find. I was coating an engine block this winter in 15W40 at below -20C, and it was as thick as honey or grease.

When I was changing 11L of sump oil at a time in my Cummins diesel, the 15W40 low price was appreciated. I used most of a pail! In a landrover, less so.

Red90

It is nothing to do with the weight. Diesel engine oils have more zinc than gasoline oils due to limits set by API in order to protect catalytic converters.

You would not want to use a 15W40 in the winter. The first number sets the minimum cranking temperature.  15W is -20. 5W is -30. 0W is -35.

binch

Quote from: xmod109 on May 16, 2019, 10:14 AM
Thanks all, I had read that 15w40 was recommended for its high zinc properties.  I'll be doing an oil change again shortly to clean it up and hopefully it all works out.  Had a slight blue haze on its last run so I think the crosshatching and rings still need a bit more breaking in.

Glad to hear you out and running there Del!!!!    ;)
Cheers, Bill