Engine Break in Run in... Who knows!

Hello there, I am just about finished a full rebuild of a small block and after investing considerable coin into this thing I want to run it in correctly. I was always under the impression that a new donk needed to be run in slowly and cautiously etc etc etc, but I have recently been considering doing what this web page says...

have a look --->>>http://www.mototuneusa.com/break_in_secrets.htm

I have trawled the Archives but there does not seem to be a consensus.....Sooooo what is it Hard and Fast or Slow and Steady??

regards,
Andy

 

I didn't read the link. But it's pretty simple. Use good oil with zinc in it. Delo 400 still has the good stuff. John Deere break in oil also. Set your timing before you fire it up, this is real important. SBC's love about 8 to 12 degrees initial advance. Make sure you have primed the whole motor and have good oil pressure as you spin the drill while having a friend rotate the engine over with no plugs in it. MAke sure your tach is hooked up or use a handheld one. BUT DO NOT FIRE UP AN ENGINE WITHOUT A TACH, OIL PRESSURE, AND TEMP GAUGE HOOKED UP AND WORKING! Fire it up and run it to 2000 RPM for 20 minutes. No exceptions, this is critical to break in the cam. If you hear any noise at all shut off and check. This will ensure the engine will live a very long time. The 20 minutes makes sure the rings take an initial seat as well. Then when you drive it run it through a resonable RPM range several times and the rings will really seat well, special cir***stances aside I'm talking standard stuff here.

Good luck and enjoy your investment.

Tim

 

Thats all ********

Damn near down the page is says "smaller ports, 7% more power!"

Do that to a fresh motor only if you dont mind throwing a bunch of money at it later.

Use a good high zinc break in oil.

Whats a donk?

 

Thanks guys I know there will be some differences here, I am still leaning towards the Slow and Steady approach. A DONK is an ENGINE. Don't really know why though, just something we say over here. Great advice so far though.

I make it 2 Slow and Steady 0 Hard and Fast.

A

 

Ok, im glad that was just lost in translation.

Overhere, this is a donk

Dont worry, non of us "gets it"

 

2500 rpm for 15 minutes then 3500 rpms for another 15 would be a good break in then roll it ..jeffrey

 

dynaflash 8 your brutaL

 

Whats the deal with HIGH ZINC? Doesn't run in oil have any...

 

Run high zinc, especially with a flat tappet solid lifter new cam. It will help build a more durable surface as the zinc "treats" the lobes. I use Delo 400; however, even the Diesel oil's like Delo are containing less and less zinc and sulfides. Look for ZDDP in the ingriedients. I have also had good luck using a generic non synthetic oil with a ZDDP addative for break in 10w30. I use a grey break in lube that contains zinc on my cams as well. 2000 rpm for 20 minutes is what most cam manufacturers will tell you, and works for most especially with chrome rings.. ABove it was mentioned that timing be correct; and this is a necessity; as an advanced or retarded cam will build too much heat. I have found that plasma rings like 2500rpm, then a second break in after it cools; running it again. DO NOT USE SYNTHETIC for breakin on old technology motors!!!!

 

the break in procedure described in that link is great information. The 20 mins then another 20 or so at changing rpms is to take care of a hydraulic flat tappet camshaft (most engines on the HAMB)

That links shows how to get awesome RING SEAL and can be the difference between an ok engine, and one that runs real hard and real long.

I used both- i broke in the cam using the 15-2000rpm variations for 10 minutes, then a cool down and another 15 minutes. Then we pulled the big handle on the dyno and let 'er eat.

17 pulls each one stronger and stronger, yet. the idea that you need to baby your mill for 500 miles at half throttle, change oil, then take it easy for another 500 or so before changing the oil again. Screw that.

I break it in like I stole it. I only wish the dyno could have done engine breaking like described happens to the bikes to pull the walls clean.

Firm believer in that method. -rick

 

I believe in breaking in a cam, then thrashing the motor somthing good

Just dont break it your first time out

 

that's kinda what the article said--- and the other part is NOT ********- engines OFTEN make more power with smaller, intelligently sized ports.

ask anyone with a factory BOSS 429. or the kid that got some hogged out rectangle ports for his stock 396....

-rick

 

I call engines engines , anything else makes me feel funny (motor, donk etc) , I wouldnt follow that bike site, stick with what these guys have said. Zinc definately, low rpm initially definately, get it out on the street asap definately. I go up a local hill to load up the rings , open it up , let it slow down, open it up etc. no high RPM for a little while, no lugging, no fixed speed...
Roger

 

4 Slow an 1 Fast so far

I like the point the article makes about ring pressure against the bore only reaching max when fully loaded (using back pressure behind the ring to sort of force the rings out). Sort of makes sense that you have a limited window of opportunity to bed those rings before the hone rubs the high spots off. Perhaps a bit of both ideas could be used.

Top shelf input guys, I have been thinking about this for a while and it looks like differences are really out there.

A

 

if you want some proof of concept behind the pressure helping the rings seal, just google some articles, wiki, or other stuff about "gas ported pistons".

The gas is what does most of the sealing, taken to extremes with gas ports.

-rick


edit:
"The ultimate in ring seal is drilling the pistons for gas ports. Compression rings normally need about 0.002-0.004-inch (vertical) ring-to-groove side clearance to allow cylinder pressure to get behind the ring and force it to seal against the groove and cylinder wall. Gas ports apply combustion pressure directly to the back of the ring, allowing the virtual elimination of side clearance. Since the ring is restrained by the groove itself, there's less opportunity for high-rpm ring flutter.

Gas ports work best with short piston-compression heights (under 1.200 inches) on engines running 7,000 rpm or higher. The major drawback is that all this positive pressure greatly shortens ring life, so it's not recommended for street use." Carcraft Magazine.

 

20mins the bed the cam, then drive it like ya stole it

 

Donk is ghetto slang here. The leaping Impala on the Chevrolet Impala (a lithe, light and sometimes called a Gazelle), is/was somehow mistaken for a donkey. Hence "donk". Examples: http://www.rides-mag.com/DONK/premier/infinity.html

Not sure how much and of what you have to smoke, coupled with never seeing any wild animals, and ****py education system, it takes to come up with that one.

The locals here swear up and down that it is a donkey, and that "it ain't no Gazelle, whatever that is."

And, no, nobody can explain it.

 

Technically, driving it hard with the go pedal stuck to the floor is slightly above the recommended rpm to keep the cam healthy so running at high rpm from the start should not be an issue.

Seen the data over and over and over again about breaking in engines harder more than delicately. My last new bike was a Ducati, bought it at the stealership. I was hitting 6 grand within 5 seconds of leaving the parking lot. It was fine, not a single issue.

If you didn't put it together right, it won't matter how you break it in. If you did put it together right, giving it a good thrashing (without 9000 rpm screaming fits, please) shouldn't hurt it and will more than not give you a better break in on the rings.

 

Box a DONK DONK that's an enlightening link.....I still can't understand exactly what they are saying but thanks....I think.

4 Slow 3 Fast.

 

Donk,wonk,whatever the jacked up things are,that thing in the post looks like the old tractors with the steel wheels.Florida has its share of the Donks but thank goodness the fad is slowly going away.

 

This is pretty much what I do, just make sure it can run for the alotted time. Meaning, have enough gas, coolant in it so the break-in is not interrupted.

I do what the cam manufacturer suggests, as that is the most important thing to consider for initial wear.

Then I change the oil and filter and keep an eye on it. I do the varying RPM thing for a while until the rings are seated and happy.

Bob

 

Thats my method

 

Not to hijack, but I have a related question: if I fire up a fresh motor and for some reason I have to shut it down within a few minutes, am I screwed? Or can I just start it back up and continue with the break in?

 

depending on why you had to shut it down, yeah, you'll be fine- might as well let her cool a bit first

 

I thought a DONK was the big guy in Crocodile Dundee played by Steve Rackman

 

He was a big dude! I have also heard big guys called "machine" as well, perhaps also similar.

As for the FAST or slow. I am going to run in for 20min at 2000 to 2500rpm then get it out on the road and go up and down through the gears in an industrial estate finishing off with a nice run to Mt Cootha. (A reasonable climb close to me). Drive for a few weeks as time permits and drop the oil. (High Zinc if I can get it)

I hope all goes well, things I need to have tested/working well before hitting the ignition.
gauges
oil type
carb runs accelerates and idles
timing
gearbox (was refreshed)
brakes etc etc etc....perhaps a dyno is sounding better....
There is a lot of things that need to be "trusted" when you hit that key. In the past I would have just jumped in and booted off, but with age comes caution! Oh and wife would not like me toasting the new engine....

 

How I break an engine in would depend on the rings.

First, the wall finish has to be what's right to make the rings happy; if it's not, you might spend a long time trying to get them to seat well...

For good moly rings w/ a 'plateau' finish, in a cylinder honed w/ a torque plate, don't worry about breaking it in. It'll be most of the way there by the time you run the cam in anyway. At least, that's what I've been led to believe from my boss at the engine shop, and guys on speedtalk (forum full of engine builders; lots of EMC contestants hang out there).

Good quality ring + good machine work = very little surface irregularity to 'break in'.

When I fired my own engine the last time, I just hammered it as soon as the temps came up; it has a roller cam, and didn't need to worry 'bout the zinc problem.

I haven't built any real high-end stuff, or anything for power adders, so I haven't used anything other than moly rings. If I were to run anything else, I'd contact the manufacturer for bore finish specs and break-in procedure.

Edit: I forgot to agree w/ previous posters who advised having the temp and oil press gages operational, and ignition ballparked before turning the key. If you have to crank the engine all afternoon, you can end up wiping a bunch of that good ***embly snot off the cam, and if you don't have a temp gage, and let it get too hot... well, all that worry about bore finish and torque plates just went out the window, didn't it?

-Bill

 

Thanks Bill good advice for reference

350, 305 heads
020 over bored (Hastings cast rings with moly oil rings)
Honed for Cast rings
Standard cam, rods
010 under crank
KB pistons

A very reliable engine shop with all Sunnen kit. Hope this engine will outlast me.

A

 

good oil with Zinc , prelube. I add fuel to the float bowls through the vent tubes if it is a mech pump. if it is electric fuel pump then not required. Set timing as close as possible. Engine should light immediately. run at 2500 RPM for at least 20+ minutes (22 to 23 . )
DO NOT let it idle during this period. if you have to fix something like a leak or something shut it off with the key and restart it with instant return to 2500 plus. THis ensues good cam breakin which is the big obstacle to overcome these days. After that you can idle it, set timing with a light as required adjust carbs . double check everything and i do an oil change and filter right here after the 20 min cam breakin. Then drive it like you stole it. It will love it and the ring will seat well. If you baby it like in the old days it may be a piece of oil burning poop in most cases. A modern engine is preclearanced and fitted so other than the cam run in nothing else needs running in. the rings will seat quickly as you drive it a bit on the hard side. Usually within a hour everything is pretty happy. I fire my own engines or i dont cover them . Too many guys out there with dumb ideas like roll it over on the starter til it get oil pressure. by then the cam will be about half wiped and the starter probably half worn out too. Some dont prelube.often in the excitement they forget to put in the oil at first. (Dont laugh it happens probably once a month somewhere nearby.) Too much beer to much excitlement too much help are a fresh engine's bigest enemies. It takes 20 minutes to run a cam in and about 4 seconds of too early idle to wipe it out. That is the big obstacle to overcome. Once you by that you are generally home free.
Don

 

Not to hijack the thread or anything but I have a question...

My engine was rebuilt 2 or 3 years ago & I've never started it. Should I pull the cam & lube it again before starting the engine for the first time?

JH