Running in ....... how many oil changes?

[SLR No.77]

Rebuilt the engine and I've taken a different approach to running in ....... usual it's 500 miles on mineral oil, limiting the revs to 4000, then swap to fully synthetic and steadily increase the revs over 1000 miles or so.

This time I've done the full guns'n'roses heavy rock approach .... engine in, cheapy Asda mineral oil, a few minutes to get some heat in then played with the mapping and took it for a blast 😬 Did approx 120 miles then had it RR'd and they totally ragged it - 222bhp @ 7300 😬 Very soon I'll get to my 500 mile limit and will swap the oil and filter, but what is the consensus of opinion ... straight to fully synthetic or another 500 miles on semi?

I'm on track in September and would prefer to get all the way to real oil by then!

 

Stu.

[Johnty Lyons]

Mineral again and change to synth night befor track day.

 

JJ

 

[AndrewGP]

Stu,

 

my rebuilt K series which was done by Nigel Keats went into my car on Friday and after a lengthy discussion with him, I've taken a similar approach to you....after warming it up it's getting a good thrashing! I limited the revs initially to about 4.5k to help bed in the cams and followers but with lots of hard acceleration all the way from 2nd to 6th to get the rings bedded in to the liners. This weekend I've racked up over 250 miles on the engine and I'm up to 6.5k rpm which I'll increase as the miles get greater.

 

I used Valvoline 20w/50 mineral oil and Nigel said this should be used up to at least 1000 miles before moving to synthetic or you risk not completely getting the rings bedded in. Obviously no harm in doing a change at 500 but I see the rational in continuing with mineral oil for a bit longer.

 

Andrew

 

Edited by - grenpayne on 23 Jul 2012 07:32:16

[Nick Chan]

Just looking at Pistonheads and Andrew's thread on how long to use the mineral oil, that's an interesting comment from Downsman here

 

Like Stu, I have got to run in TC's SLR after its rebuild and its got the usual mineral oil in now. I was going to change it after 500 miles possibly for some more mineral oil (its only £11 for 6 litres from Wilkonson's!) and then run it for another few hundred miles before moving across to fully synthetic. The question is, if the car isn't going on track in the foreseeable future why not leave it on mineral oil for a few thousand miles as suggested by Downsman's post about the Honda engine? Would that help it bed in even more?

 

What do people think?

 

Nick

[SLR No.77]

Well thanks Nick, having worked out what I was doing you've now put doubt in my mind! I'll hit 500 miles by this weekend so buying another can of cheap oil is on my to-do list for today! I'm suspicious now it might be better left alone and just keep running it - the oil's gone pretty dark already but that would be expected. Now I'm tempted to just keep it running on what's in and change it to "better" oil a few days before going on track. What's working out unfortunate is my first track use since the rebuild is likely to be the 'Ring and the trip down would make excellent additional running in. I still need to decide the spec for the "better" oil though and whether with the engine relatively young to go for a semi-synthetic, even on track?

 

Stu.

[Nick Chan]

Stu 😬. My thought process is that moving to the fully synthetic (or maybe even the semi-syn) too soon could stop the bedding in proocess as suggested by the Honda bit. Timing for the Ring trip is just a bit too soon I think 😬 I would think that doing the change just before and knowing its oil tight before such a long trip makes more sense than worrying about the bedding in process if you have put a few hundred miles more on

 

Nick

[SLR No.77]

No the timing isn't good! I feel the Honda comment has to be worth listening to because the Rover K and Honda engines are likely closer siblings than most engine comparisons. Thoughts now are leave the current oil in and get some miles done, then as suggested swap to full synthetic a few days before.

 

Stu.

[EFA]

You have already ruined any chance of getting the most power from your engine, by not thrashing the living daylights out of it the first time the oil temp hit 90 degrees.

 

Running in processes reduce piston seal, leading to blowby, hence loss of power.

 

 

[SLR No.77]

Thank you for your positive comments

 

Stu.

[AndrewGP]

Stu

 

Sorry if I've muddied the water with the thread on PH I'm at a very similar stage to you post engine rebuild, and wanted a second opinion, although in this case I'm not sure it's been overly healthy!

 

I had another long chat with Nigel yesterday and his advice is: Doing an oil change at 500 miles can only be safe as this gets the small particles out of the engine. You've said yourself this is your limit and I think we all agree this can only be a good thing. Since I hit 570 miles today post rebuild (I got a bit carried away on a blat today) the oil is currently draining from my car as we speak

 

I'm also going to do another change in 500 miles time again just to be safe and this is when I'll change to Synthetic.

 

Andrew

 

 

 

 

[Dignity]

I did 500 on mineral then 500 on semi. Like you, I didn't hold back on the revs but I made sure of a lot of variation.

The result was very good

 

Pretty sure my head was superior to yours though Stu

[EFA]

Stu,

 

My comments are based upon well founded theory. See here

 

I run in for 500 road miles on this oil here.

 

All the engines I have built for myself and others have always been very strong in terms of power as a result.

[SLR No.77]

Quoting EFA: 

You have already ruined any chance of getting the most power from your engine

Arnie, I know the theory it's been discussed many times and you might be surprise that this is the guide I have followed - you posted a link quite some time ago to the "Break In Secrets" page and I read it with interest - thank you. I've now read it again fully and it's answered my question ... the bit I'd forgotten was when to change the oil

If it had been a straight rebuild and was already mapped I'd have thrashed it as soon as I had any temperature in the oil. Unfortunately the closest map I had I knew would be wildely lean at higher revs and although I'm using a wideband lambda and could get a readout through the Emerald, I had to initially do some guesswork to make the map more suitable - hence it had a 5-6000rpm thrashing not the full bouncing off the rev-limiter thrashing. Stock vhpd engine running roller barrels, mildly ported head .... 222bhp at 7300. I think it's sealed fairly effectively And being realistic, 5000rpm would be rev-limit territory for some old big V8s!

 

Stu.

[Johnty Lyons]

To be fair Arnie Stu was under duress with no correct map. Otherwise I would concurr with you All the engines I built where thrashed mercilessly as soon as temp was reached with excellent results.

But still on here there are dimwits who insist on crazy running in techniques.

Obviously little or zero confidence in their ability to build an engine.

 

[Phil]

EFA has the right idea with the Millers running in oil as it is good quality 10w40 mineral base.

I am a little concerned about the cheap Asda oil being used, how cheap and what grade?

Cheap 20w50 is cheap because of a lack of additives used to stop the oil breaking down when hot, think it is about 93dg when the engine will run at 100dg plus, this means the oil is breaking down as soon as the engine is hot, you do not want to be varnishing moving part like the tappets and producing sludge which will hold the fine metal particles releasing them when a better oil is used.

If you think about it, cheap oil is dying as soon as the engine is up to tempreture so how will it survive 500 miles.