Break-in oil for new engine

[Djordje1]

Hi there,
I hope you all doing well.

Yesterday I saw the new exciting video from @Prawn he talks about break-in/running-in oil and the way he prefers running the new engine.

I just wanted to do a recapitulation to make sure I understand correctly because this looks like the only correct way to treat a new engine. I'm doing a build of 1.8t(450hp expectation) planning to use 82mm pistons, a new camshaft, valves, springs,g,25-550, and most of that, and want to make sure I'm treating a good new engine...


Mineral oil exclusively for eg. Millers CRO 10W-40
Fire it up run for a little time avoid sit on idle...driver around next 25miles on a different revs

25miles drive
drop the oil(fil with new oil) and change the filter

100miles drive
drop the oil(fil with new oil) and change the filter

100miles drive
drop the oil then fill with a Full synthetic oil for eg. Titan race pro-S 5w40 change filter as well
oil and is ready for a DYNO.

@Prawn, I have a question what's wrong with 10w50? and is there any problem to use mineral oil and then swap for a synthetic? Is it necessary to do some flushes or just to drop the mineral oil and use a straightaway synthetic one? Sorry for this question, don't have too many experiences. Just want to understand and learn about that.

When I finish the dyno what is the routine? When do I have to change the oil next time?


Please, guys, let me know what do you think and what is the way you prefer?
Thank you, everyone,
All the best!

Djordje

 

[Rainbird]

The general thinking is that either a specific running-in oil (like MIllers CRO) or cheap mineral oil offer a little less protection and so allow rings to bed against the cylinder wall more effectively to create a seal early on. Fully synthetic oils tend to be more effective at protecting against this to minimise lifetime wear, so running FS would stop the rings from sealing so well, at least in theory.

The reason for the short intervals initially is that all this bedding in, plus anything that's not been properly cleaned out after machining the engine, will lead to metal in the oil which you clearly don't want there for long. A few quick oil (and filter) changes helps to flush the system through, which is generally considered "done" within a couple of cycles.

You want to minimise time on idle while bedding in, as it's the loading up of the engine that forces things together to bed them in. Idling for too long can cause more harm than good, so in a perfect world you want to turn the key and get driving, although this isn't always possible and it's nice to give everything a leak check too. The intervals aren't necessarily gospel, but starting with short intervals and increasing the distance between them is the way to go.

After the first half hour or so of running I'd expect everything to be pretty much done in terms of bedding in, but still important to get that system flush in there IMO

 

[desertstorm]

I have run two engines in using pretty much the process above and find it worked really well for me. Engines had good compression and made over 500bhp.
Millers CRO is a mineral oil designed for engine running in. It is the best oil for the job and isn't that expensive, you can buy 3 5L tins for £60 so only works out at £20 for 5l. The main thing you are doing with this process is bedding the rings in to the fresh hone you have on the bores. There is only a limited amount of time for this to happen really. The process is not just about using the mineral oil and changing at certain mileages, It's as much about the way you drive the car and what RPM's you use to keep the engine safe as well as bed it in.

Millers CRO 10W40 Competition Mineral Running In Oil 15L 15 Litres + FREE GIFT | eBay

Millers CRO 10W40 15 Litres. Competition running in oil for testbed running up to 4 hours. Ideally suited for testbed running. CRO 10w40 provides full protection of highly stressed components whilst allowing optimum bedding in process for piston rings and bore.

www.ebay.co.uk

 

[Djordje1]

The general thinking is that either a specific running-in oil (like MIllers CRO) or cheap mineral oil offer a little less protection and so allow rings to bed against the cylinder wall more effectively to create a seal early on. Fully synthetic oils tend to be more effective at protecting against this to minimise lifetime wear, so running FS would stop the rings from sealing so well, at least in theory.

The reason for the short intervals initially is that all this bedding in, plus anything that's not been properly cleaned out after machining the engine, will lead to metal in the oil which you clearly don't want there for long. A few quick oil (and filter) changes helps to flush the system through, which is generally considered "done" within a couple of cycles.

You want to minimise time on idle while bedding in, as it's the loading up of the engine that forces things together to bed them in. Idling for too long can cause more harm than good, so in a perfect world you want to turn the key and get driving, although this isn't always possible and it's nice to give everything a leak check too. The intervals aren't necessarily gospel, but starting with short intervals and increasing the distance between them is the way to go.

After the first half hour or so of running I'd expect everything to be pretty much done in terms of bedding in, but still important to get that system flush in there IMO

@Rainbird
Thank you so much, this is an amazing explanation.
Do I have to follow some rules for the RPM? something like first 25miles not more than 3000rpm, next 100 not more than 4500rpm?Or I have to stan under 6500rpm for these 250,300miles?
Also, do I have to stay in one specific gear or go true all of them?

Thank you so much,
Djordje

 

[Djordje1]

I have run two engines in using pretty much the process above and find it worked really well for me. Engines had good compression and made over 500bhp.
Millers CRO is a mineral oil designed for engine running in. It is the best oil for the job and isn't that expensive, you can buy 3 5L tins for £60 so only works out at £20 for 5l. The main thing you are doing with this process is bedding the rings in to the fresh hone you have on the bores. There is only a limited amount of time for this to happen really. The process is not just about using the mineral oil and changing at certain mileages, It's as much about the way you drive the car and what RPM's you use to keep the engine safe as well as bed it in.

Millers CRO 10W40 Competition Mineral Running In Oil 15L 15 Litres + FREE GIFT | eBay

Millers CRO 10W40 15 Litres. Competition running in oil for testbed running up to 4 hours. Ideally suited for testbed running. CRO 10w40 provides full protection of highly stressed components whilst allowing optimum bedding in process for piston rings and bore.

www.ebay.co.uk

Thank you for joining @desertstorm can you please share more details about the way your driving when your running in a new engine? What is max RPM your driving, gear, throttle?
I'll definitely go with Millers CRO oil, sounds like a very nice solution and is cheap.


Thank you so much,
Djordje

 

[Rainbird]

There's no set rule (and you'll see conflicting thoughts around running in techniques all over the internet) but my thought process is similar to Prawn's on the subject.

Give it some revs and some boost from the start (arguably the first few miles are most critical) but not full bore hammering it at WOT everywhere. I don't expect running at 30psi isn't going to make any significant difference over running at 20psi or even 15psi during run in. Keep it below around 80% and you'll probably be in the right territory. Up the revs, overrun back down, get it through the gears a bit (3rd will let you explore the majority of the rev range at semi sensible speeds) and as little steady state as possible.

Realistically, I'd imagine things to be pretty well bedded in after the change to fully synthetic oil sometime between 50 and 150 miles of driving or so. At that point, you should be fine to remove any self-imposed limits (although for peace of mind I think I'll probably build myself up to 100% anyway)