Engine running in methods?

[Trevor]

I've been reminded that I will need to run in the engine on Lil' Blue once I've finished rebuilding it. From what I've heard there are 2 methods to do this.

There is the old slow and steady method, don't go over 40 MPH for the first 500 miles, change oil and then don't go over 70 MPH for the next 1000 miles, change oil and then it's run in.

There is a book kicking around somewhere written by an F1 engine expert who says the first 30 minutes of running is the most crucial and that the vehicle should be driven reasonably hard in all gears without staying in the higher revs for a sustained period, this apparently will ensure high compression for the life of the engine.

Given that Lil' Blue does very few road miles (at most 1500 miles a year) and lives its life with short bursts of high revs doing climbs and getting through mud, what is the best way to run this engine in and when should I change oil and oil filter.

Should I even consider bringing it to Lincomb before it's been run in?

This is really all outside of my knowledge, so what are the recommendations remembering that it will have a hard life. I do want to get this bit right after all the work and expense put in to date.

I'm expecting as much debate on this as a tyre thread

 

[fridayman]

I've used the Motoman method on a couple of bikes and both made very good power.

 

[Shayne]

I used to re-bore and rebuild 2-stroke bike engines all the time adding bigger pistons and I am a firm believer that the longer you can leave it ticking over and parked the better because the engine temperature heats as slow as possible then remains as static as possible allowing imperfections wear away in the gentlest possible manner . That's on day 1 , then drive it for a week not going over 2500rpm .

Your actual speed don't matter its the engine speed or rev counter you need to watch .

 

[Trevor]

That was an interesting read, he's saying not to use synthetic oil for the break in period and flush after 20 miles. So I put 10/40 non synth in and then put my semi synth in after breaking in. Mind you he's also talks about "modern" engines and the fine honing. Lil' Blue R plate, does that count as "modern" ?

Do the same rules apply to 4 stroke as 2 stroke methods?

 

[uHu]

Assuming you have serviced cylinders/pistons.
As I 've understood it, it's better with revs than with high load on low revs. The whole point is to avoid getting a blow-by of the piston rings. With new rings and honed cylinders, they don't match up perfectly until they have adapted to each other. So: Very little load for the first few 100s of miles.

 

[Shayne]

Do the same rules apply to 4 stroke as 2 stroke methods?

Its a piston in a cylinder 2-strokes rev much faster than 4-strokes and use much lighter parts hence are far more prone to failure . Ultimately the goal is tight fitting rings in a smooth bore , if it works for a 2-stroke it will definitely work on 4-stroke pistons .

 

[clivehorridge]

IMO and from my (medium) experience rebuilding 4 & 2 stroke car, bike & outboard boat engines, running in should involve the whole rev range, but not the limit, and care should be taken not to labour the engine, meaning keep the revs in the mid range of the selected gear, not struggling at low revs or up to the limit.

Power should not be excessive, so a lighter right foot is recommended. Bike & outboard 2 strokes generally have ball bearing bug ends & mains, so they don't need to be hardened off like plain bearings do.

Bores need hardening off in both 2 & 4 strokes and as said before, the important thing is not to use too much power that may encourage blow- by before the bore has time to match the profile of the rings.

IMO LB needs a good few k miles of Sunday driving before being thrashed in a mud hole! 2 or 3 k at least, I would say.

Job well done Trevor and good luck!


Sent from my iPhone 5 using Tapatalk

 

[Shayne]

Running in is simply polishing using the rings to polish the barrel and/or using the barrel to polish the rings in order to remove imperfections . Whatever the rev range the piston just goes up and down the full depth of the barrel . More revs means more violent scrubbing which might result in a cracked ring and scored barrel . High revs mean a higher temperature and more expansion , not good until the barrel is smooth . Low revs to gently polish in IMO .

 

[Graham]

In Toyota engine plants, they use electric motors connected to the engine to spin the engine over, without any compression, or fuel .
I see that as the way engine plants run in the engine, so when the engines are eventually dropped into the car body, the engine is pretty well run in, hence running in of old, isn't much required in new vehicles.

Gra

 

[AndycruiserguyLomas]

If the engine had been fully re-machined then I think a degree of running would be prevalent but if it was mine with rings and shells and a degree of wear already I would drive it normally. This method is from years of building truck engines, usually quite a lot bigger than a cruiser engine. When a truck leaves the workshop and goes down the road it gets used, not pampered. Everyone has their own take on running in and to be honest a lot of it is still stuck in the 1960's.

Andy

.

 

[Trevor]

Thanks Andy, actually a very valid point that my project is essentially an overhaul rather than a full on rebuild. Interesting view on the drive and go approach and your success with that, does this mean I can just turn the key and then go play at Lincomb or should I play "steady Eddie" once I've arrived?

 

[AndycruiserguyLomas]

If it was mine I would use it normally on the road and this, including the run to Lincomb should bed it down enough to use it normally round the course. Others may have a different opinion but like I said, if it was mine.

Andy

 

[Gary820]

Rebuilt quite a few engines and usually just drive them normally, usually run it upto operating temp and road test for about 30 miles then it goes back to the customer, not had one go wrong yet. Only engines we run in are M power stuff but they still have a 1200 mile running in service.

 

[karl webster]

Experience I've had is run at half load or normal. Never let them tick over for a length of time.

 

[DVSLUX]

Ive rebuilt and run in a lot of engines, The only time ive had a failure was when I sat one idleing for a while, no load on it caused the bores to glaze over. Ever since then I have just driven them normally, not thrashed, and not pussy footed. Just drive normally, but accelerate then decelerate to bed in both sides of the rings, and never use synthetic oil during run in, only use a mineral oil.

 

[Beau]

I think you should take it for a long motorway cruise (50 miles or so) so engine temps are near peak so that the bores will get settled in, too low engine temps can cause problems within the head and block, along with the motorway cruise you should also use the full rpm range but not for heavy times, I shouldn't think you'll need to do a lot of miles to get it settled in, once you start it you'll be able to tell how good and successful the re build was by the engine idling and how smooth it is (no tappety noises)

Do a video of the first start up trevor and share

 

[Piero81]

^^What he said!^^

 

[MuckyPup]

If you haven't fitted new rings then semi-synthetic or even basic oil, start it up and run at fast idle for 20 min, then check over and you're good to go. If you've done rings then on and off the power, power strokes push the rings into the bore which beds them in, coasting lets them cool down.
Too much of the power stroke overheats the rings and softens them, too much coasting means they glaze over and never seal.
All in all, 100 miles of b road will run anything in nicely.....

As taught by Kawasaki UK and Honda UK with advice from Kubota and Perkins

Wow, old thread alert !!!!!!!