Running in?
 

Running in after engine rebuild,how many miles how many revs?Had new rings,valves and heads skimmed ect.Thanks Paul.

After my rebuild I did 250 miles not exceeding 3000 rpm, the next 250 miles not exceeding 3500 rpm and then another 250 miles not exceeding 4500 rpm.

My experience isn't with an aircooled car so others may help more.

But i was told with my rebuilds from my old race engineering company i used:
1: Never use running in oil,
2: Never use fully synthetic,
3: Combine various types of driving you do, don't try to get it all done at one rev range on a motorway you won't optimize the bores/engine. Town work, motorway, B roads need to be used.
4: Don't mother it but don't work it under load at low or high revs for an initial period. ease it in and occasional use of 1/2 and 3/4 throttle use, but not exceeding the rev limits like Jim says.


You will get much better advice i'm sure, that may be very specific to the 964 but i don't see a lot of replies so chipped in. :thumbup:

My was run in using the same approach as Unkle gives above. Oil was then changed at 1,000 miles and then I let her loose.

This is definately useful info! So Steve, Uncle, whats best engine oil to use if not running in oil or fully synthetic?

A good oil for this purpose may be Mobil S 10w40 semi synthetic. Its a very good quality oil and yet only semi synthetic (hard to find a suitable 10w40 mineral up to the job)

They didn't explain why not to use running in oil, they just shook their head in a "you must be joking" way. On the subject of fully synthetic the explanation is fairly simple, fully synthetic doesn't allow wear to bores at a medium rate due to its properties and this is precisely what you need to happen to bed everything in prior to giving the car some stick. You need metal to metal contact to wear the engine in and fully synthetic does its best to prevent this, while mineral oil or semi can allow some wear. This can result in slightly raised engine temps due to initial friction on a rebuild.

An interesting article on the subject even though its not air-cooled related pumaracing running in

as i say others with air cooled experience like Boxsey can help further

Thanks lads im picking it up tommorow after about 6 weeks and many probs,gearbox and engine rebuild,new clutch and god knows what else.I m dreading the bill!!!

If you can trust the shop with thousands & thousands of dollars of your cash, then you should be able to trust their running-in advice! :)

Not something i would want to pay tomorrow but as long as you keep the car for a good while it will show a healthy return in reduced running issues. :thumbup:

I see from another thread that you left the car to idle for approx 2hours, unless i'm mistaken (possible). the worst thing for any engine and especially the cam is to be allowed to idle for extended periods. The stress required to idle a cam is immense, thats why most cams are run in at 2000 rpm and not idle. We used to get a few brand new cams come back in, all rejected under warranty as they weren't run at 2000rpm during the run in. (BTW we didn't reject the cam but the manufacturer did). But all cars are different and the process of manufacturer on a 964 might not put additional stress on the cam during idle, worth mentioning anyway

Good luck with the car, got any pics? :D

Ill have to keep it forever now.ill try to download some pics this week

All day out in it today FANTASTIC....

you didn't put black turbo twists on and stray south of the river did you?

my run in was to push it on hills, vary rpm all over the place, work the dickens out of the rings.

I am not kidding. I guess everyone has their own run in.

Good tip dood!