Switched to synthetic at 225km

I rebuilt my R06AT engine and without access to a dyno, spent the first 20km breaking it in on the street. I kept rev's moving around (not going over 5k RPM) with periods of mild beans and regularly let off the accelerator and engine braked to create vacuum. Obviously that's not going to be as effective at bedding the rings as on a dyno but it's what I've got :). After 20KM we put fresh mineral oil + filter on it, and kept up the regimen of "vary the RPMs" and "some beans, but not all the beans" and "plenty of periods of vacuum" for the next 200KM.

At 225km, following the fundamentals course, I did another oil replacement, this time with penrite 5W-30 full synthetic. My mates balked and said they'd have kept mineral up to 1000KM, largely because of the "easier" break-in that we've been doing.

How effed am I?

You're not.

Way back in the day, because of the poorer manufacturing processes, the materials used, and the lubricants available, "running in" was seen as an important part of ensuring good engine life. All those are no longer as critical.

I assume you used assembly lubes, and either a break-in oil, or "mineral" oil, for the first, and possibly second, oil fill?

You may find some re-assurance by the fact that many/most manufacturers use full synthetic right from their first fill on the assembly line, and leave that first change for a much greater period than you did.

Thanks. Yes to assembly lube and I did use mineral oil for the first two fills, switching to synthetic on the third fill at 225.

Those two oil changes had an amount of glitter in them, as was to be expected really, so there has been some ring seating done. It sounds like the course is actually conservative about oil changes, then?

I'm not sure what "the course" suggests, or recommends, and different engines' rings/bore finishes, and possibly cam' followers, may require slightly different proceedures.

Even then, people will have their own interpretation of what's required, you just need to look at the number of "professional engine builders" who will put a freshly built engine on their engine dyno', bring it up to a bit below normal running temperature, often with gently 'pulls', then do several full load and rpm runs with, literally, minutes of 'break in'. There's one well known, foul mouthed "builder" who spent some prison time - you might have an idea who I mean - who will put a fresh engine on and do COLD full load runs on the engine - I am NOT impressed!

It's been a long time, but don't recall 'glitter' in oil - but one's definition of that may vary. If you still have the filter(s), you could also cut it/them open with a cutter and see what's been trapped in the filter medium?

I'm not sure how much I can share here but the last bit of the break in module says:

"While around 80% of the break-in process will be completed during the first 20 to 50 kilometres of use, the break-in will still continue for some time, so at this early stage I still recommend running the engine on a mineral-based oil.

If you plan on swapping to a full synthetic oil, I'd wait until the engine has completed around 200 kilometres of use."

I do plan on cutting the filter open though tbh I'm not really sure what to look for, I'm expecting more remnants of assembly lube/rings and no big chunks but without experience I can't say what amount is bad or not.

At any rate the engine seems to be running great and the exhaust is clean.

I'd say they're being safe - but best thing is to check the ring manufacturer's recommendations for the ring bedding in, it should be with the recommended cylinder bore finish. Some ring designs are specially made for rapid sealing, others may take some time. Not sure what the Top Fuel engines use, that are rebuilt in the pits between runs, and are barely run before putting 11-12 thousand horsepower to the ground.

Some manufacturers will also specify the lubricant that should be used for the assembly of the rings on the piston, and coating the bores.

I used to do the first after bringing it up to temperature and doing the check for leaks, etc. Never had an issue, that I recall, maybe because I've a 'thing' about assembly lube and keeping things REALLY clean. Then the second after a few hundred, and the full synthetic after maybe a thousand kms.

BTW, I use a magnetic sump plug on the engines, and sometimes transmissions, where possible, which can also show up any fine ferrous debris - remember, to get to the filter, it has first to get through the pick-up's strainer and, more important, the pump gears! Anything the magnet pulls out of the oil isn't going to make it through the pump.

Good tip thanks.

This is all OEM kit, and the rotating assembly was installed by a reputable reconditioner because reasons. I don't think I saw anything in the manual for break in of new rings but I'll have a more thorough scour when I get home :)