New engine run in help?

Just had a full engine rebuild courtesy of Paul Roddison of Sheffield,just wondering if anybody knows how long to run the engine in for.
Was told so long as I don’t rag it around Donnington this weekend it will be fine,just want to be cautious.
Car is nc niseko 1.8.

600 - 1000 miles depending on what you read, modern engines just be sensible for a while, don’t over rev it early on and don’t sit at constant revs for sustained periods.

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OK thanks,just needed reassurance I was doing the right thing.

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This is one of those subjects that you will not get consensus on.

What i do is for the first 300 miles, keep it below about 50% rev range but NOT constant throttle. Every 100miles increase the revs by 1000rpm. Again, quick visits to the rpm ceiling rather than sustained periods.

Roddison’s advice aint that bad!

I agree with much of the above only to add, that when going on uphill roads keep in a lower gear as not to labour the engine…


Probably an early oil change after maybe 2k miles in case any swarf comes off the new components.

I’ve always sort of followed the advice in the handbook that came with my Triumph 21.
That told you to mark the twist grip, so you only used 1/8 throttle for the first 100 miles, then 1/4, then 1/2, then 3/4 until you could finally use full throttle at 1000 miles.

Engine production has come a long way since those days of course but I still think it’s sensible to follow the basic principle of progressively using more throttle rather than worrying too much about revs.
Not cruising for too long on constant throttle is sensible too, you need to lift off regularly to allow oil up the bores.


This may be a controversial school of thought, but to optimally seat the rings and remove the cross hatch you should do some progressively harder accelerations 3x half throttle upto 60% RPM, 3x 3/4 throttle upto 80% and 3x full throttles to 100% rpm each time the engine needs to run down with closed throttle to suck fileings off the cylinder walls. Use engine break in oil for this then change the oil/filter after this process, then 1000 miles of normal running with brake in oil, then change the oil/filter again with standard fully synthetic.

Thanks for all the help, looks like I’ll be pottering around for a while, just as the first frost hits, not looking forward to it, but it’s got to be done😕.