engine run-in period
 

what is the average/recommended run-in period for a re-built engine???
my guy says 500 miles off boost (<4k rpm) should be fine

just wondering what others have done....................:notworthy

When I had my block done, well a new block was put in, they had told me that you don't have to run it in. I found this very strange, so ran mine in for about 1000miles to be on the safe side, but it is very hard not to just put your foot down. Good luck

I was did well over 1000 miles with no boost and < 4000 rpm but that was for a new block

Or was it just a blueprinted engine using standard/existing internals?<< if it was this 500 to 1000 miles is more than adequate.

When you say rebuilt.....do you mean new pistons? rebored/honed? rods? crank?

If it's had a rebore/hone and new pistons/rings then will have to be a minimum of 1000 miles.

mine is existing block but new bearings,shells,pistons,rods etc

will be bloody hard not to put my foot down, have only put 6k on the car in 3 years......................

A certain Engine-Builder on here quoted 3000 miles if the rings are new, few people stop to consider that the bores are horizontal, and this makes a difference.

I used to use 500 for 1st oil change, 1000 for the second, and 3000 for the third oil change.

HTH

dunx

P.S. For a new bottom end, I would do 500 & 1000 before giving it lots !

i had a fully forged engine built early this year and was told to run in for 500 miles so i did then when mapped to full boost started having major oil breathing problems.whether that was due to not running in for long enough who knows but the engine has been back in now and rebuilt again but this time i will be doing atleast 1,000 to1,500 miles maybe even more.better to be safe than sorry.as for running in on no boost i have been told by the engine builder that you need a certain amount of boost on running in as this helps to push the rings out and make a better seal against the bore,if you run in on no boost then the rings are just basically going up and down in the bore and not bedding in properly.

Having bought my last two cars from new, the recommended running in period from Subaru was to keep below 4000 rpm for 1000 miles.

However the engine needs to be worked to bed the bearing surfaces in, I can remember buying a Volvo 850 20 valve from a elderly chap. The engine would not rev anywhere near its max even though the engine had done 40000 miles when I bought it.

Talking to the local Volvo garage mechanic, they did state that the engine was probably still tight due to it not being occasionallly taken up to its max rpm.

After a few weeks of ocasionally runnning hard, it was as sweet as a nut.

The moral of the story is, dont thrash it but work it up to max rpm over the running in period. But dont let the engine labour under load for long periods.

The main thing is to NOT hold the car at constant revs.
The worst thing you could do is just do 70 mph for 1000 miles all in top gear.
Agree that a little boost is o.k., but just work the gears and don't put too much load on the engine at low revs. I would stick to 1/2 max. revs up to 500 miles, oil change and maybe 5K rpm max. for the next 500 miles.

All imho

dunx

Agree new car, main thing is to avoid excess load on engine and to occassionally use full revs. Too little revs/constant revs can affect bedding in of piston rings. I also believe all new engines are run at factory so "running in" is not really needed.

think i'll go along the lines of 500 or so off boost and then take it easy for another 500 winding it up gradually on occasion

it won't be done at constant revs as the roads down here don't allow!!

so the next question would be once run-in, would i need to do the same after havin the simtek fitted???

Ran mine in like this ~

500 miles below 3000 rpm then oil change - another 500 miles below 4000 rpm - the oil change and filter.

Then off to Powerstation for a tune up and on the rollers.:thumb:

Red.

No !

Simtek is just a smarter(?) brain, Me likey please !

dunx

I recommend first 500 miles, nothing above 4500rpm, whilst driving occasionally build approx .5 bar of boost and then snap the throttle shut to help settle the rings.
Oil change at 500, then allow to 5000rpm and 1 bar boost again building and snapping the throttle shut (If on a map that you know is good for a bar obviously) for another 500 miles.
Another oil change and then give it the beans, seems to work for us.
We also recommend 3000 miles on mineral oil before switching to a good quality semi synthetic.

Drive it like you stole it:norty:

just completed my first 500 miles yesterday building her up to around 3500.gunna change the oil today and do another 500 taking her up to 4500.not going to change to fully synthetic until well over 2000 miles want everything to go right this time dont fancy having to have the engine out again.

Seems to be lots of conflicting advice- not saying anyone is right or wrong. Have had two recent rebuilds where the rings were replaced. I've done a 1,000 mile slow and steady run in (10psi and 4k rpm, limited by ECU) and a 50 mile run in before giving it some beans. My experience is that that the latter worked better, whereas the former meant the rings didn't bed in. Wonder if it's more luck than science?

mmm........

getting bit confused now, like your advice though martyn (perhaps cos it won't take me a year to do!!)

seeing as you'll be doing me simtek!!!

It seems to be the art of pushing the engine a little to get things bedded in. But not over doing it and at the same time not cruising along everywhere.

i got a bit to tempted after mine was rebuilt and within two weeks big ends went again. completly my fault but the place that rebuilt it offered to do it again at a fraction of the price and has been sweet as a nut since. So i agree in running in for atleast 1k