Sorry but how will a new engine still have any swarf in it??

I work in an engine manufacturing factory and trust me when I say that the wash that the blocks go through will blast any and all remains of the machining process away. They will be washed with high pressure coolant thoroughly and turned over several times by a robot to ensure all remains are washed away. A block should be washed twice in the machining process. It should be washed before the bores are honed then after the bores are honed also.

Sand from the casting should also not be an issue unless they are really shoddy, cheap, nasty castings.

Simple:- Improvements in mass production which is one of the reasons why most manufacturers don't stipulate running in procedures anymore.

Perhaps Subarus "are" full of sand....it would explain alot ;):lol1:

Run it in according to the manufacturers spec, after your 1k oil change add 1k rpm per 50-100 miles, thats probably the best way of running the car in, alot of people like the guy who recommends to rag it when warm as it only takes 10 miles to bed the rings in (most cars have that on the clock when you get them anyway) does not take into consideration the rest of the vehicle, things like the gearbox, brakes, diffs that also need bedding in.
My cars factory power is 276bhp and 290lbs of torque, at 17.5k with just a panel filter she is pushing out 318bhp and 356lbs of torque, she was run in as the above, nice and gently, so ill let you decide whats best ;)

Tony:)

wouldn't know about swarf but very unlikely to have sand floating about in a casting nowadays, it's normally flushed through with an acid to remove it and it's very effective.

bow to your superior knowledge mate but the old bugatti block i cut up to get sizes from had sand clogging issues around one of the bores on the water jacket, but when a new scrap casting was cut up it was totally clean from sand.

by the way, it wasn't THE bugatti block, it's for an old one:lol1:

Are you seriously trying to suggest that you gained 42bhp & 66lbft by running it, sorry she, gently? lmao

BTW I have a graph showing a vf35 making 420hp on 97ron, do you believe that too? ;)

The figures speak for themselves :p
You could use that yanks way and rag the ass off your car/bike etc and see the difference, he swears that the bikes as much faster :rolleyes:
Gentle also beds in everything else, transmission, diffs, brakes etc, but be nice to your car and she will be nice to you :p

Tony:)

Jesus guys, 1000miles is only 2 weeks of driving... we're not talking six months of tootling around.

"don't take it over 4000 except in an emergency"

;) depends on your definition of emergency.

Getting to Pizza Hut in time for last orders does not count!! :D

Ns04

Doh! :brickwall

i used the really gently approach to running my car in. I didn't take it above 3k for the first 1k then gradually built it up and now its over 2k i am getting it mapped ready to use properly. I very rarely ever go above 6k anyway as there is no advantage to doing this. After spending many thousands on the parts in my engine i thought it best to do it the gentle way and im really glad i did now as it seems to be perfect!