How to break in a new engine

[Joel W.]

I have done a few rebuilds and I always have taken it easy for the first 100 miles or several heat cycles. I also try keeping the idle time to a minimum and varying the RPMs as much as possable without beating on it untill I am sure all is good to go...

 

[figgie]

is that guy in the article reffering to turbocharged motors or would the boost from the tubo actually seat the rings even better?

yep as it builds pressure that the N/A don't ever see.

 

[Jaguar_5]

Beating on the motor makes perfect sense to me, but what about the first time you start it up, and it's still cold, and possibly not running 100%? Is it ok to shut off and fix problems, then try again? Or in the case of it running fine, do you idle until it warms up? or do you start driving on it?

 

[Joel W.]

Don't ever beat on a motor that is cold or not running correctly IMO...

I idle it only long enough to verify the thermostat has opened and the system is burped of air for the initial startup..

 

[IJ.]

Jag: My point exactly!

You risk doing MUCH more damage if something fails at this point.

If the tune isn't right ie: too rich you might wash down the bores and we all know first hand how finiky the 7M's cooling system is......

 

[figgie]

ok perhaps you didn't read the motoman instructions well

On a Dyno:
Warm the engine up
completely !!

Then, using 4th gear:

Do Three 1/2 Throttle dyno runs from
40% - 60% of your engine's max rpm
Let it Cool Down For About 15 Minutes

Do Three 3/4 Throttle dyno runs from
40% - 80% of your engine's max rpm
Let it Cool Down For About 15 Minutes

Do Three Full Throttle dyno runs from
30% - 100% of your engine's max rpm
Let it Cool Down For About 15 Minutes
Go For It !!


and

On the Street:
Warm the engine up completely:
Because of the wind resistance, you don't need to use higher gears like you would on a dyno machine. The main thing is to load the engine by opening the throttle hard in 2nd, 3rd and 4th gear.

Realistically, you won't be able to do full throttle runs even in 2nd gear on most bikes without exceeding 65 mph / 104 kph. The best method is to alternate between short bursts of hard acceleration and deceleration. You don't have to go over 65 mph / 104 kph to properly load the rings. Also, make sure that you're not being followed by another bike or car when you decelerate, most drivers won't expect that you'll suddenly slow down, and we don't want
anyone to get hit from behind !!

The biggest problem with breaking your engine in on the street (besides police) is if you ride the bike on the freeway (too little throttle = not enough pressure on the rings) or if you get stuck in slow city traffic. For the first 200 miles or so, get out into the country where you can vary the speed more
and run it through the gears

never ever pound a cold engine!!!!

 

[figgie]

and just to make sure everyone gets it

Q: What is the most common cause of engine problems ???
A: Failure to:
Warm the engine up completely before running it hard !!!

READ FOLKS WARM THE ENGINE UP!!

 

[IJ.]

LOL thought that was a given

 

[figgie]

LOL thought that was a given

well yes but with the coment from jaguar5

but what about the first time you start it up, and it's still cold, and possibly not running 100%?

thought i mention to WARM THE ENGINE UP!! lol

 

[K.I.Covert]

dont know if this applies to inline 6 but on all the v8's ive ever helped build or freinds have we run them at like 3000 rpm for 20 minutes before we ever put them on the street.

 

[Doward]

That's for seating the cam/lifters of an OHV engine... and you actually want to vary between 2000-3000 rpm. Never sit at one rpm, you've got to vary it!

Now, on a roller cam - no need for it. OHC - no need for it. Just let her warm up at a varying fast idle, verify all fluids are working correctly (coolant system, no oil leaks, etc) and then let her rip - gotta seat those rings in!

 

[mkiiSupraMan18]

I am not looking forward to this w/ my rebuild... Al explained the whole process to me once and really ripping on it made total sense. I don't really remember what he said though. My dad is really old school, so he's gonna crapp himself when he finds out I'm basically beating it to death from the get go. :icon_bigg

 

[IJ.]

That's for seating the cam/lifters of an OHV engine... and you actually want to vary between 2000-3000 rpm. Never sit at one rpm, you've got to vary it!

Now, on a roller cam - no need for it. OHC - no need for it. Just let her warm up at a varying fast idle, verify all fluids are working correctly (coolant system, no oil leaks, etc) and then let her rip - gotta seat those rings in!

Still have to vary the engine speed at cruise as our block material is quite hard for cast Iron and glazes easily...

And of course a single weight Non Friction modified Oil helps this process!

 

[Supra]

Don't hold us responsable if YOU grenade something either
eric

Funny you should say that, eh IJ. :biglaugh:

Edit: I 'grenaded' a coolant line on my first boosted run - soaking every piece of my polished motor with red coolant and water wetter.

 

[IJ.]

Rich: I guess it showed exactly what I was talking about!

 

[miggles]

at least the red coolant helps to pinpoint where the leak is coming from,though if you sprayed everything with coolant it mite make it a bit harder to locate.

 

[Supra]

at least the red coolant helps to pinpoint where the leak is coming from,though if you sprayed everything with coolant it mite make it a bit harder to locate.

Watch the video to it's end, and you'll see it wasn't hard to find. :nono:

 

[CBatstone]

This thread has been pretty excruciating to read.

Break in process is defined in time by the amount of time you have before the cross-hatching in the cylendar honing is still there. It is there to wear the piston rings into the exact shape of the cylendar wall. Once the cross-hatching from the honing process is worn smooth, your pistons rings are set for the life of the current motors build.

Someone burns oil with 2k miles on a new engine because they took it easy in the first 20 absolutely critical miles - because -

If you do not build up the correct manifold pressures on both sides of the rings, due to heavy acceleration AND deceleration, you will not seat the rings in those critical 20 miles and you will be stuck with what you have.

YES you want to make sure your engine will run correctly before you drive it, thats a given.

The person who answered himself, has the right answer, although does not mention cooldown and durations. You'll want to let your motor cool off to ambient temperature after the first round of driving and filter/oil change.
You'll "beat" on your car initially IF you want a clean burning, efficient and powerfull engine. I'm building my 7M-GTE right now, and thats sure on my adjenda.

- Craig
www.thirtythree.org

And Never, ever break in a motor with synthetic. That goes in after 500-1000km

 

[bountykilla0118]

Sounds like an Eminem song... :icon_bigg

CLASSIC LOL

 

[Jaguar_5]

Kinda bringing back the dead here, but...

and just to make sure everyone gets it
READ FOLKS WARM THE ENGINE UP!!

Well I'm definitely not planning on turning the key, and driving, i was thinking more along the lines of what Joel said:

Don't ever beat on a motor that is cold or not running correctly IMO...

I idle it only long enough to verify the thermostat has opened and the system is burped of air for the initial startup..

This was more on the lines of what i was thinking, to avoid waiting for full operating temp, since you want to avoid Idling as much as possible