Is This True???

[terribleturner]

Someone on a forum i frequent has asked about running in an engine. Now i know nothing except what i have read on hear and been told. So what do you make of this??? They were saying about how a new engine should be run HARD for the first 20-30 miles.

 

 

An all new engine should be build will all contact parts lubricated.

Light oil is good for bores but you should use special assembly compounds for cams and shells.

 

Prior to first start up the engine should be filled a basic oil, then the pump and oil galleries should be primed.

 

The following is how you should start up/run in an all new engine;

 

1) You should get the engine to start as quickly as possible

 

2) Then hold the engine at the highest rpm you can bare (the higher the better), for as long as you can bare, the longer the better.

 

3) For the first 500 miles or so you should drive the car hard (contrary to popular opinion), using as much of the rpm range as possible but avoiding heavy load situations, like selecting a high gear to go up hill.

 

4) The oil should be changed for one of good quality at this point and head bolts etc. re-torqued.

 

You thought the info you were previously told was bizarre but I bet this has shocked you even more.

 

This is why you need to follow the above guide;

 

1) The most abrasive particles in an engine are generated by the cam followers rubbing on the cam.

 

2) Most of these are generated in the first few minutes of running the engine.

 

3) The faster the engine rotates the less friction there is between the cam and followers because there is less load for less time being applied to the contact area.

 

4) The faster the cam and follower move, the finer the surface finish and the less wear will follow.

 

5) To a lesser degree the same applies to the rings

 

6) Parts like the big end and main shells should not make contact with their journals and therefore you don't need to worry about them.

 

7) The only people who tell you to take it steady when running in are;

i) The guy who built your engine that isn't confident he's done the job right

ii) People who have yet to learn the truth

iii) Fools

 

For your information, I (like most racer) used to rebuild my motors after each race meeting and raced them straight after they were built. If racers had to run engines in carefully (as some people would have you think), most races would be very boring.

[SupraStar 3000]

depends on engine I would have thought.

 

ie, isn't it good to run the mazda rotary engine in hard due to carbon buildup on the internals

[terribleturner]

The top was started by a UK Celica owner.

[RobSheffield]

Its right about the running in without labouring.

 

Im not sure about the logic behind running it VERY fast as soon as it starts.

[terribleturner]

Yeah im fine with the no labouring and using running oil for the start up etc... But "For the first 500 miles or so you should drive the car hard"?? and after the first start.... "Then hold the engine at the highest rpm you can bare, for as long as you can bare"??

[RobSheffield]

i suppose driving hard is like using lots of the rev range, but i wouldnt be wanting to push it hard or race the engine....

 

As for the second bit - im unsure that would be wise!

[JustGav]

Hmmm, I'll admit to being an old school follower, ie run an engine in carefully... but I have heard stories of bikes being ragged to death from the beginning and the engines being better for it.

[Matt H]

is the point here that there running in performance engines or new engines for everyday cars that have come from the factory?

 

to be honest i have no idea, but surely if your nailing a motor in a race then building it again after a race and so on it either a) doesnt matter or b) a totally different ball game?

[terribleturner]

I was under the assumtion from the tone of the thread it was an engine for everyday use.

[Matt H]

I was under the assumtion from the tone of the thread it was an engine for everyday use.

 

umm, interesting. i dont know, but like with anything you take it easy from the start, but perhaps it is true.

 

Maybe if all car produces told customer to go out and nail their new car of the blocks then there would be a lot more people rapping up their new cars before they new how to drive them.

 

"your honour" i was told that i was best for my engine to do 170 across the the A6 for the first 500 miles!

[paul ashton]

No expert on car engines but used to own bikes and rebuilt them myself,they always had to be run in,not exceeding a certain rpm for X amount of miles,can't see it myself.They were 2 strokes though.

[SimonB]

It sounds like a version of the motoman break-in technique which has been doing the rounds of forums for a while. Even he doesn't suggest holding it at max rpm straight after starting though, that's just bollocks, and that stuff about the cams and followers looks like bull to me. If that was true you'd have to run in you engine every time you changed cams!

 

Here is the link to the original motoman article, which talks about running in using increasing load (only after the engine is warmed up though, and not just holding at max rpm) to bed the rings in properly. Thing is, he's talking about 2 stroke bikes not cars.http://www.mototuneusa.com/break_in_secrets.htm

 

And here is one from a magazine who looked into it.

http://www.motortrend.com/features/editorial/112_0603_technologue_race_performance

[Bob]

I'm certainly no expert, but that sounds like bollocks to me.

 

Surely, friction remains constant irrespective of speed - hence the generation of heat. If friction was less at higher speeds then theoretically at a high enough speed, friction would be negligible; doesn't sound right to my limited physics knowledge.

 

As for the finer surface finish?! The only way a surface is going to get finer, to my understanding, is if the friction of one surface is reduced - like a finer grade sand-paper. I just don't see how speed can come into it.

 

Of course, I may be completely wrong, but at least I'm now subscribed to the thread so I can read answers from people who know what they're on about

[JustGav]

http://www.mototuneusa.com/break_in_secrets.htm

 

And here is one from a magazine who looked into it.

http://www.motortrend.com/features/editorial/112_0603_technologue_race_performance

 

That makes an interesting read and I suppose does raise some interesting points....

[JustGav]

But the microfinished bores, high-tension rings, and precision-build tolerances in today's automotive engines yield excellent ring sealing from new, so any change in power output attributable to such a radical procedure would be miniscule if measurable at all. He notes that power and fuel economy generally improve throughout the break-in period as friction diminishes in all moving parts.

 

They aren't exactly saying no though are they?

[Kranz]

All new engines have an initial run in called a hot test.

 

The initial start up is followed by about 30 seconds at idle to confirm oil pressure, then it is run up at 500 rpm intervals no load to about 2/3 max rpm.

 

It then runs a couple of part load speeds around 2000 to 4000 rpm for about 5 minutes.

 

The engine is then fitted to the vehicle and run in, or not if the driver doesn't bother!

 

Full running in for the engine (if it goes on a test bed after hot test) is about 24 hours continuous running starting at low speed, low load... say 15% load to start. This is run for about 30 mins at each speed (500 rpm increments) until max speed, then back down to the lowest speed and moving up the load range a notch. Essentially its running load range curves until at 24 hours it does a full power curve then oil change.

 

I wouldn't do what it says on that post, unless there were some 'special' hard piston rings in chrome or other hard bores being used.

[colsoop]

Im not technical so a lot of that went over my head, however my experiences of owning a saxo vts from 0 miles.

 

I thrashed it from day one ignoring Citroens advice about keeping it under 4 k.

 

I was a member of the saxo owners club back when and it was probably one of the quickest stock saxos around it also made 20 hp (above ) factory figures on 2 different dynos.

15.03 second quarter mile stock.

 

Maybe just a coincidence but i thought i would chime in.

[Tricky-Ricky]

I would say that the deception is pretty near spot on, except for one thing, the RPM yes when first started ( and this also applies to running in new cams) hold engine RPM at least 2.5K no lower and 3.5 is better, the reason as stated, the valve train is the most highly stressed part of the engine at low RPMs therefore it will wear the most on start up and idle! the thrash in part is also true, but build up RPM rather than use max RPM from start, the secret is as said not to let the engine labor, use the gears and RPM;)

[kslb]

Wallace performance in aberdeen have done 100mile run ins on their dyno and have to date not had a problem. They use this for performance engine rebuilds and say it is a recognised method although not as popular as the traditional method.

[Stevie Boy]

depends on engine I would have thought.

 

ie, isn't it good to run the mazda rotary engine in hard due to carbon buildup on the internals

 

The vavletrain theory wouldn't apply there and can see the theory in the running in strain on idle an engine which uses valves in it's operation.

 

I guess the proof in all the theory puddings would probly all be related to the service life of the engine internals. The variation in wear from varying rpm load techniques would purhaps need to wait for the entire service life of the engine before, valves cams, followers etc would need replacement due to wear which could be a few miles to say the least!

 

Alternatively you could try each technique strip the engines and have the microscopicly examined for which had sustained the least damage and wear whilst the components bedded in???

 

Just my pennies worth.