What's your favorite break in procedure?

cdnp6

cdnp6

Member
Now that I have my car licensed and back on the road, running in the engine can begin.
There seems to be two ways of doing this.
The conventional method of going easy on the throttle, not exceeding 90 kmh, and varying rpm's such as you would get with stop and go traffic,
and a hard run in process involving short bursts of acceleration to "seat the piston rings".
As far as oil goes, I am using a running in oil with zinc additives.
What break in method would you use for your car?
 
I think the really important part of the process is not to have too many cold starts! Modern cars may manage the start up mixture strength OK, but cars of our era don't! There's lots of scope for bore wash and you really don't want that with a new engine. Also all the clearances are better and oil viscosity etc better at operating temperature - and I primarily mean oil operating temperature. Try and do long cross country drives with light throttle openings, but don't be too fixated on the revs - let them drift up occasionally provided it doesn't involve big throttle. I had a new engine to run in in an MGC 3 litre six once. I'd had the pleasure of turning the key for the first time on it and I was lucky enough to live around 45 miles from work, so used it to work for a fortnight going up a wide deserted major A road. A particularely good engine resulted.

Chris
 
When I ran mine in I changed the @ 100 miles, 500 miles then at 1000 miles. I now change the oil every six months. I think I may have gone over board on the oil change although I would say the one after 100 miles is worth it. One thing I really recomend as I did'nt and paid the price. After a few 100 miles take time out and check every bolt there is to check. I did'nt and missed a slight error on my part. The sproket on the cam shaft came loose and fell off!!! The only way it could have happened is if I did'nt do the locking tabs but to this day I can't explain how I made such a rooky mistake. Destroyed four values and three value guides!!!!! So take your rocker cover off in a few weeks time and check it the nuts are tight.
 
In terms of "running in", I used to work with an old timer who reckoned the best way was to start the engine and leave it running at a high idle for the working day (e.g. 8 hours). Then repeat this for another 2-3 days. I suppose the theory is that this would be equivalent to several hundred miles, reduces cold start wear on the engine and allows components to bed in without the excessive wear of having the engine on load as per normal driving? Most certainly would go for frequent oil changes in first few days to flush all the debris out of the engine.

Have often wondered if these big magnets you can buy that clamp round the oil filter make any real improvement and if this would be especially effective during running in?
 
I would do all of the original posters plans combined :)

The fast idle for three days with no load or variation makes me cringe though :eek:
 
Yes my first start up was at fast idle. Before I did my first start up I watched a few youTube videos and one was from a top tuning shop and they said the engine it under stress at normal low 'tickover' so for a first run a high idle was recomended. I'm sure I read the same in a book too.
 
I realise you don't have a new cam; but if you had, the recommended start up procedure is for 20min @ 2000rpm before attempting to drive. So there does seem to be a body of opinion that initial start up should be with a period of fast idle. I can think of a few justifications for this, but to my mind the only one that counts is that numbers of people I respect who do engines for a living recommend it.

Chris
 
Apparently there is greater load on the cam lobes at idle / low rpm, as the rpm rises the load reduces as the valves begin to "float", obviously they don't actually float (unless you rev it way too hard !), but the inertia of the valves reduces the load on the cam lobes. That's the way I understand it anyway.

I also saw something once about running-in aero engines, the guy said that they should be run-in in the same way you would expect to use them, and not to give them an easy life during run in. Mind you aero engines have totally different load characteristics to car engines, much less shock loading.
 
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