Check out this snippet I found while Googling:

>> Pulling apart a 308 V8 the other day, the top ring of 5 of the 8
>> pistons were broken. One entire bank, and one on the other bank. Now
>> why would they break, I'm told it's unheard of on new engines, so why
>> do old one's break 'em.

Most likely cause is that the engine was high mileage and had usually been
driven gently. A wear ridge develops at the top of the bore in a specific place
dependent on rpm. The higher the engine revs, the higher the piston rises due
to rod stretch, thermal expansion, crank flex etc. At 3000 rpm the stretch will
only be a few thou but on a high rpm race engine you can need 30 thou or more
piston to head clearance to avoid contact.

So it only needs one high rpm thrash on an old engine that has trundled about
all its life to whack the top rings into the bore ridge and break them.

Using the full rev range every now and then throughout an engine's life is
actually a good thing to help even out the wear at the top of the bore. Drive
at low rpm for too long and that's as high as you'll ever be able to run the
thing without risking a broken ring. Most engines that have been driven
normally i.e. a good thrash every now and then, have a sort of graduated wear
ridge spaced out over 15 to 20 thou. An engine that has never been past a
certain rpm can end up with a very defined, sharp edged ridge at exactly the
same height in each bore.


Dave Baker at Puma Race Engines (London - England) - specialist cylinder head
work, flow development and engine blueprinting. Web page at
http://members.aol.com/pumaracing/index.htm

This seems to make a lot of sense. Wondering what other people thought.

 

I've heard this before and i'd like to emphasize the keywords "now and then".
I just don't want people to think they should drive it like you stole it to go around the corner to buy some smokes

 

I think a healty hit of 8k rpm VTEC is good once a day to burn the carbon off while still maintaining a healthy engine. The only thing is that they were referring to a domestic motor. Those rods stretch like no other on those engines, but Honda engines don't seem to stretch quite as much. So that snippet doesn't have as much relevance to us as it does to them.

 

I guess I'm wondering why my car now consumes about 1/2 qrt of oil every 2500 miles wheras before it consumed a negligible amount. I still have never redlined, but I do VTEC on occasians.

I also switched to full synthetic (mobil1) and sometime after the oil consumption seemed to increase, but I can't tell if it's due to this.

 

That was part of a write-up on engine break-in wasnt it? I know I read that before somewhere. Makes a lot of sense.

 

1/2 quart is normal every 2500 hundred if you change it every 3000 miles, using your motor hard on occasians burns some oil up, its blow by, your piston rings can not catch all the oil that surrounds your pistons at the revs they have to take, its perfectly normal. just be grateful your not dumping in a quart every 3 days like some people.