My engine is coming out soon for new rings and a hone, What oil do I need for the initial run in?

[lonesailor]

I'm planning to pull the engine in my NA8,(280K kms) as the compression is down at the bottom of recommendations. It's still running fine with no nasty noises, so I'm hoping all it will need is rings and a hone, I will of course measure everything up and replace anything outside specs. I'm curious as to what oil to use for the initial seating of the rings. I assume a straight 30 grade mineral would be best, but I haven't seen much of it around, at least in the usual places. What would others suggest, and where to get it. I figure that 100-200kms of city driving (stop-start) would see them seated. I will probably then change to a synthetic. I haven't been prepared to change yet, opting to use use Magnatec 10-40,and change it at 5000 k intervals, because I have had bad results changing oil brands /types in industrial settings, particularly large refrigeration compressors. What are others thoughts.

[manga_blue]

Use a good quality mineral oil for bedding the rings in. Castrol RX Diesel has always been popular for this. Then swap to synthetic after 700kms.

If you fill with synthetic initially then there's a high risk of glazing.

[manga_blue]

If you're doing rings then there's virtually no reason not to do mains, big ends and crank seals at the same time. It's mInimal additional time and cost.

[Ned Loh]

Refreshing the head also?

Most important thing to get the rings seated is to get some load into it quickly

[greenMachine]

I'm planning to pull the engine in my NA8,(280K kms) as the compression is down at the bottom of recommendations. It's still running fine with no nasty noises,

So, why pull the engine? If you track it, fine, that makes complete sense. But for road use, even 'mountain driving', not so much.

I'd leave well enough alone, and on the basis it's a road-only car, just drive it and enjoy it. When it begins to show signs of tiredness - smoke, low compression, rattles in valve train - by all means break out the spanners.

I'm a believer in Castrol Ultra oil. I used it in the racecar as recommended by Gary Stewart. When the engine was returned to Gary for a refresh after six or seven seasons, he said it was as good inside as the day he finished it.

[lonesailor]

Regarding bearings, I intend to measure journals and oil clearance, if both are within specs I'll leave them alone, if not I'll fix it. Of course I'll do the rear main seal, the clutch will depend on condition. I have plans for a serious road trip later this year, Covid permitting, and I do do a few trackdays a year, which is another reason for the tear down. I had to replace the head around 30k ago so I am hoping it will be OK. The bores then looked good, although highly polished, so hope they wont need much work. I try to ensure it gets to run for at least an hour every time it starts, which should be good for it, and it seldom revs much over 4000 (except on trackdays). A tip, I wanted a MLS headgasket as I couldn't get one when I did the head. I found one on ebay from Amason in the US. it cost $106aus landed and I got it in under 2 weeks, undamaged, it was made in Taiwan, I have had good results from Taiwanese machines and parts, much more so than from the mainland. Local suppliers are quoting around $200 Au.

[Red_Bullet]

I'm a believer in Castrol Ultra oil. I used it in the racecar as recommended by Gary Stewart. When the engine was returned to Gary for a refresh after six or seven seasons, he said it was as good inside as the day he finished it.

Any more info on this "Castrol Ultra Oil" A quick google search reveals "Castrol ultra clean", which seems to be semi synthetic.

[greenMachine]

Brain fade!! Castrol Edge.

[StuwieP]

I used Penrite's run-in oil.

I still have a spare bottle - where are you located?