hey guys,
put my motor together over the week end car is going sweet. had to put in new rings and bearings, got the cam done (290) just looking for a 32/36 to top it off.

how many km sould i do to run it in?

many thanks
nicholas

0 running in is bullshit

flog it as soon as it warms up to get it used to it

otherwise shell glaze up

just don't use mobil one for the first couple of oil changes. Use regular mineral based engine Oil.

And maybe don't totally thrash it until 500 or 1000kms. A few short trips to the shops, and a couple of winding road runs. The glazing over bit is true, but I wouldn't use the "get used to it" approach.

When you do the winding roads bit, be careful not to lose it. I've had a few friends rebuild their cars and smash them into poles within a week...
Chris.

well i over reacted a little yes you gotta wear in a tiny bit but not 5000km or so many hours or anything, just run for 20min redo the gaps ect. then baby it a little for a little while

Crickey!!!
The amount of run in depends on the type of rings used, the grade and type of oil used and the bore finish.

If you want to get a quality ring seal you have to wear the rings in to the honed surface in the bore to get maximum sealing and ring life.

If you use "barrel faced" chrome top rings, and a moly double rail style second, these need a very careful break in for the first 2 hours operation as with the reduced cylinder wall contact surface you get increased pressure per unit area of ring in contact with the bore. The smaller contact patch reduces drag/friction in the engine and helps get a better cylinder seal.

If you just give it heaps first off, the chances are the ring will over heat. If the ring gaps are not sufficient, the rings will seize in the bore. If the gaps are large enough, the rings will lose tension and cost you power and give blow by.

Normally I use a maximum of 20% throttle and Penrite HPR30 when cruising for the first hour, changing up and down as necessary.

Every 3 - 5 minutes give it full throttle for 5-10 seconds then allow about 2 minutes to cool down at very light throttle. Cruise for another 3 - 5 minutes before repeating.

The frquency of full throttle operation is gradualy increased over the next 3-4 hours operation and by that time the engine is fully bedded in with perfect ring seating on bore and ring lands.

For a new camshaft, is it still recommended procedure to run the engine at 2,000 rpm for 20 minutes to break it in?