Run in Time? and limits?

[WYATT]

Alrite i have replaced main bearing big end bearings and the piston rings i honed aswell , its on a 1800 8v and i was wondering what sort of run in time you think also what revs to keep it under would it matter going over the certain amount but just not for long periods of time like holding in hgh in the revs on the motorway?



Cheers Joe

[danny_p]

if youve built it well  be mean   to it  you need to work the piston rings to make them wear in properly before the bores smooth up to much

[Wayne]

keep it under 3000rpm for the first 1000miles and try not to load it too much or hold it at a certain speed for too long.

[Agreeable Slick]

As above, the bearings need to seat properly before they can take to much stick, also don't let the engine labour at low speeds as that will load the bearings too much.

[wil0]

i read an article a while back (http://www.mototuneusa.com/break_in_secrets.htm) that you should actually drive the car quite hard by accelerating in short busts to break it in. makes sense to me...

[danny_p]

i agree with that method,   old engine desings had to be drivenvery gently  for quite a long time due to tolerances of components been quite large compared too todays standards.  so if its been built well i see nothing wrong with giveing it some stick.   dose seem like engines that have been driven hardish from day 1 also keep there oil cleaner

[danny_p]

well proably depends on your skills then.

i think i can say i has built a fair few engines both petrol car engines and quite large diesel ( 10 ltrs + ) and they are expected to work HARD and for a long time.

with really old style engines you have to be gentel to them but most seem to get on very well with been broken in hard and never had issues with any of the car engines i've built and run in myslef and the diesels if they wernt averageing the same or more hours than motors built by others  i would have been told about it.  i started experimenting with running them in hard as it was more profitable to have them out the door and handed back to ( driver / monkey)  quickly and it's not like you chould expect them to take a blind bit of notice of any run in instructions anyway.   admitedly if you build it with out throughly checking you bearings  in this way is not a good idea.