Running in oil

martymoose

martymoose

Hero member
Location
Sydney, Australia
About to fire up the SF2 enduro. I usually use penrite 25w 70 in the lavs, mineral, non friction modified. High zinc content, 1750ppm. I can see a reason to not use this as a running in oil, bores where honed. Dedicated running in oil i can find is 15w40, and lower zinc content.
 
On roller bearing engines you're only running in the bores and possibly a new cam.
I tell my race engine owners to use a straight mineral oil for the first session using full revs by the end of that session.
Then drop the oil and change to whatever you're going to race on.

Compression is by then at it's peak. Then the trick is keeping it there.
 
I'll chuck some cheap 20/50 in my motor and do what Greg suggests. This 1000's of km running motors in dates back to 1930's clunkers. Once the rings have bedded in, it's fang time. I've read that high load open throttle spin ups aids in creating ring pressure, which aids in rings bedding in. Slugging the motor at low revs will only harm it!!
 
50ks and ride it like you stole it was what i was told, recent compression test confirmed that on the gelati, happy to run the race bikes in for you Boss
 
I would run in a long stroke ,air cooled motor like a Laverda , a modern/ Japanese short stroke thin ring motor you can pretty much run them straight from the crate. When I was working with Hinkley Triumph we would get oil burners that hadn’t run in - put them on mineral and ” birch them “ was the official line.
I have built engines that have gone straight on the Dyna for an hour of neck wringing- that works.
 
we run our race bikes in on the Dyno, 10 mins of partial load varying the RPM and checking AFR readings, than full power runs to 9,500 RPM
works well

customer engines I tell them ride the bike normal for first 50 klms with no restrictions on RPM, then thrash the crap out of it
mineral oil only to 1,000 klms
 
redax5 said:
we run our race bikes in on the Dyno, 10 mins of partial load varying the RPM and checking AFR readings, than full power runs to 9,500 RPM
works well

customer engines I tell them ride the bike normal for first 50 klms with no restrictions on RPM, then thrash the crap out of it
mineral oil only to 1,000 klms
Click to expand...
Very much the same as running in an aero engine. About 20 minutes warmup ....... then takeoff normal and then from low altitude full power climb as high as legally possible ......... then throttle back to about 30% (so as to keep lots of heat in the engine) and descend to near ground level and repeat the full power climb. After three full power runs it is back to the hangar and change out the mineral oil for regular oil, replace/clean oil filters and away you go. This is per the manual ..... not backyard mechanics.

Jim
 
There is traditional cast iron barrels, hard chromed rings top and oil, second compression ring is without hard chrome.
This is very traditional technology without any kind of attempts to make running-in more easy.

Are you guys completely sure that best way to run-in them in street bike is just to thrash them?
And there is no any kind of valid reasons why the manual says something else?

-Jouni
 
That's a big debate, two ways to run in. The traditional very easy 1000ks with gradually increasing revs. You risk glazed bores or the more modern 3 heat cycles with solid hard engine pulls, and that risks breaking shit. But if shit brakes it's going to happen anyway. So I like a little bit of both and cross my fingers.
 
I think the idea of a long run in (and a sit did back in the 80s) just harks back to the way things had been done since the start of the 20th century. If you imagine even back in the 1940s people who had dedicated race bikes - big 4-stroke singles - there's no way they could go out for thousands of miles running these things in - and if running in hard was going to damage the motor, then it was never going to perform at its best in a race.
 
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