Running in a rebuilt engine - what would the brains here suggest for oil? I’ve read about 20W50 for 100 miles or so and then back to SAE30 with a change after a further 200-ish. Any thoughts on whether that seems right?
It all depends . Changing oil , yes , changing weight not so important. If you had a JK Preservation Parts mostly new engine, to run other than 20W/50 for the first year, with oil changes as recommended at 500 then 3000 mile intervals would void your warranty.. More important is the cam follower break in procedure being completed on the first run of the engine, revving high to splash oil around as the parts get hot, if its a new cam. Or the cam lobes might go flat and the engine need a rebuild after 500 miles.... And I would be more interested in a flat tappet high ZDDP oil rather than its weight for the sake of the cam and followers. So I go to any Halfords and get a tin of green glop.
"Running In Oil has a High Zinc formulation to protect the valve train including camshafts, followers, rockers and pushrods. It allows the piston rings to bed in correctly with the cylinder walls, preventing glazing of the bores and it can be used for both dynamometer and normal road run in procedures." I used one of these specific running in oils. I'm no oil expert but I have 168psi on all 4 cylinders, my oil stays clean and the breather does not chuff, I can't even feel it on the back of my hand at tickover. I left it in for about 250 miles, I have an oil filter, if I didn't perhaps I'd have changed the oil sooner. If your bearing clearances are in spec 20-50 is probably OTT though I have to admit using it myself initially on the builders advice. Now I use 15-40 and I suspect that's also too thick really. A thinner oil is better, it squeezes through the bearings more easily for more flow and is able to retain it's shear (or something like that). Unless your motor can't maintain spec oil pressures, thinner oil - less energy wasted by high speed components thrashing through goop.
I threw some of this in for the cam break in Red Line 81403 Engine Break-In Oil, 16 Ounce, 1 Pack https://www.amazon.co.uk/dp/B002INKQD8/ref=cm_sw_r_em_apa_i_B5-ZEbA4A2MB1 Will change oil again now and add some more for a run in.. Sent from my SM-G930F using Tapatalk
Cracking, cheers chaps It’s not a new camshaft in there, old one was spot on (and new ones were pricey...), but new shells/bearings/seals etc so just wanting to be extra careful!
I didn't have a new cam either, but it appears it didn't do the rings/barrels any harm. I think thick 20/50 would bugger up the barrels, it's a big no no to slather your barrels in engine oil when assembling for this reason.
Valvoline VR1. Liquid gold high zddp quality oil. 20w50. Or if you would rather use a lighter weight oil there are plenty of running in oils out there. Check out Opie oils you’ll be spoilt for choice
I like Opie Oils too. I use VR1 for my buggy type 1 1600 and after running in the 2ltr type 4 in the bus I'll be using VR1 in that too. I had a chat with Opie and bought a 15/40 running in oil which I'll probably change around 250 miles and use the same again up to 500 miles then over to VR1.
