Current thinking on new engine break-in

[Jim Bronson]

I'll soon be picking up my bike from my local indy shop. They had to replace cylinders, pistons, studs, gaskets, and o-rings. Does the usual 500 mi. break-in still apply?

No WOT
Lots of throttle variation
No long idle periods
Generous warm-up time
No lugging (that's bad on any engine)

Is there anything else that would help to break it in properly?

Thanks.

[rbabos]

I'll soon be picking up my bike from my local indy shop. They had to replace cylinders, pistons, studs, gaskets, and o-rings. Does the usual 500 mi. break-in still apply?

No WOT
Lots of throttle variation
No long idle periods
Generous warm-up time
No lugging (that's bad on any engine)

Is there anything else that would help to break it in properly?

Thanks.

Avoid traffic so there's plenty of cooling.
Ron

[Ohio HD]

Assuming no tuning required, I'd follow this, it's tried and true.

https://www.sscycle.com/tech-info/tech-tips/new-engine-installation

[kd]

Cool it down after it reaches operating temp then restart and do it again.  A cold drink or hot lunch should be plenty of cool down time. You can tell by the touch.  All of the advice aside, your best results are on a dyno with controlled temp and AFR. 

That said, don't be afraid to do some heavy throttle applications early in the first 50 miles.  It helps rings seal.  Open the link and read the procedure and reasons.  This is not like the S&S recommendations but is what I have always done until my last engine which was done on a dyno.

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

[Jim Bronson]

I talked with the tuner when I dropped it off. He said it wouldn't need to go back on the dyno, since I was using the same parts.

[Hossamania]

New cylinders and new pistons and new to be are not the same parts. Did he have the new build on the Dyno for break-in already? Has it been heat cycled?

[Jim Bronson]

The original build was a SE 110 kit installed by a dealer about two years ago. According to the tech, the heads weren't torqued properly, which is likely the reason for base oil leakage. Both the cylinders and pistons are damaged. The replacement parts are the same as came with the original kit. No changes; just replacing the bad parts.

[kd]

Back to Hoss's question.  Has it been heat cycled?

[ThumperDeuce]

My last few builds had 3 heat cycles and then off to the dyno.

[kd]

 

[No Cents]

My last few builds had 3 heat cycles and then off to the dyno.

   ^ ^ ^ ^
this   

[Jim Bronson]

Back to Hoss's question.  Has it been heat cycled?

I don't know. I'll ask.

The S&S procedure is quite different from that in the PowerNews article. The S&S procedure recommends heat cycling, while the PowerNews article does not. The guy at PowerNews says "run it hard", while S&S advises the easy approach, going progressively to higher RPMs over the 500 mile break in period. No wonder people get confused.  I'll see what the shop tech says. He's been building engines for 20+ years, so he should know something. Many thanks for the inputs.

[kd]

Back to Hoss's question.  Has it been heat cycled?

I don't know. I'll ask.

The S&S procedure is quite different from that in the PowerNews article. The S&S procedure recommends heat cycling, while the PowerNews article does not. The guy at PowerNews says "run it hard", while S&S advises the easy approach, going progressively to higher RPMs over the 500 mile break in period. No wonder people get confused.  I'll see what the shop tech says. He's been building engines for 20+ years, so he should know something. Many thanks for the inputs.

I suppose it's because both methods will work.  Your results will vary.  There are so many things that can effect a break in in the early few miles that everything settles in.   

Heat is not your friend especially in the first few start-ups.  Fresh engine cylinders have lots of sharp peaks in the hone pattern and the pistons are actually not smooth to the bore yet.  If the AFR is off and too fat, it can wash cylinders or lean can cause heat damage and that's why dyno break in is recommended.  I think any combination will work as long as you know why you are doing it and you do it from first fire.  Beginning a break-in without knowing your AFR is safe is a bad idea.  That includes short heat cycles (and I recommend doing them).

Break-in is mostly for ring seating and getting the components familiar with each other.  Different engine heat varies that relationship. Heat cycles allow the rotating assembly and cylinder components to become familiar with each other without creating heat that can be damaging to the new (pistons ?), rings and cylinder finish. Many commonly agree an engine is for all intents and purposes broken in by 50 miles anyway and that part is out of your control.  Nothing really changes after that point.  I like to put those first 50 on fairly aggressively (but not insane) with a few cool down intervals to allow a few more shrink and expansion cycles. It's also a good time to monitor for leaks and sounds on each shut down or startup.  I use the Moto Tune method as early as possible to get good ring seal.  I have never had a bad result with respect to that method.  The pics of the pistons in that article speak for themselves.   IMO All other aspects are controlled by observing proper tolerances when assembling.

[rigidthumper]

I am monitoring AFR, in addition to engine parameters, from first fire- that way if the AFR trace doesn't follow expected warmup AFRs, I can adjust immediately.  No sense in washing down the cylinders during heat cycles.

[wfolarry]

If your rebuild is the same motor as it started out [meaning it doesn't need another tune] then you have nothing to worry about.
If it needs a tune get it broken in on a dyno.
S&S is the safe method. By being careful you can catch a problem before it turns into a major problem. For the number of complete motors they sell this is good advice.
The other one is a crock of chit.

Doesn't hurt to play it safe. Make sure everything is OK. Once you're comfortable with that ride the bike & don't worry about it.
Change the oil after the first 50. That's probably the best advice.

[Jim Bronson]

If your rebuild is the same motor as it started out [meaning it doesn't need another tune] then you have nothing to worry about.
If it needs a tune get it broken in on a dyno.
S&S is the safe method. By being careful you can catch a problem before it turns into a major problem. For the number of complete motors they sell this is good advice.
The other one is a crock of chit.

Doesn't hurt to play it safe. Make sure everything is OK. Once you're comfortable with that ride the bike & don't worry about it.
Change the oil after the first 50. That's probably the best advice.

Yep, same everything. I agree that the S&S method seems reasonable, so I'll stick with their suggestions.

[JW113]

I can't say anything against S&S's procedure, but I sure don't have the patience for it anymore. I do the heat cycle thing, which consists of once around the block, let it cool, twice around the block, let it cool, up to maybe 4-5 times around the block. Change oil, then ride 'em like I'm going to ride 'em. Can't advise anyone else to do this, but I've yet to have a problem doing it.

-JW

[IronButt70]

I can't say anything against S&S's procedure, but I sure don't have the patience for it anymore. I do the heat cycle thing, which consists of once around the block, let it cool, twice around the block, let it cool, up to maybe 4-5 times around the block. Change oil, then ride 'em like I'm going to ride 'em. Can't advise anyone else to do this, but I've yet to have a problem doing it.

-JW

How far is around the block in miles. Just curious. I live on a cul-de-sac so there is no block to go around. 

[Jim Bronson]

My choices are limited. I'll be picking it up from the shop. I have the choice of riding it home 25 miles on the freeway or 35 miles on mostly back roads with the opportunity to stop occasionally. Fortunately, it is wintertime, and the temps don't usually get over 75. I'll probably take the long way. I plan to change the oil at 50 miles and use dino. Then I'll change it again at 500 and use Redline. I don't see the sense in using $20 oil for 450 miles in cool weather.

[kd]

Consider planning a couple of cool down stops for a break along the way. You get a chance to listen to it and check for leaks before you shut it down hot and when you restart it cool again.  Doing this will give you a couple of cool down (cylinder shrinkage) and back up to temp (cylinder expansion) periods. This takes the rings through a couple more cycles but with more throttle than the idle heat cycles if they were done. It will contribute to better ring seal. Throttle and decel are both good to do.  No low rpm lugging or extended idle.

[Jim Bronson]

Consider planning a couple of cool down stops for a break along the way. You get a chance to listen to it and check for leaks before you shut it down hot and when you restart it cool again.  Doing this will give you a couple of cool down (cylinder shrinkage) and back up to temp (cylinder expansion) periods. This takes the rings through a couple more cycles but with more throttle than the idle heat cycles if they were done. It will contribute to better ring seal. Throttle and decel are both good to do.  No low rpm lugging or extended idle.

OK I'll do that. How long do you recommend letting it cool down in 70 degree weather? I'll make sure they do the heat cycles before I pick it up. Thanks.

[kd]

I'm satisfied if it's still warm but not hot.  If I can, I prefer on the cool side of warm or just flat out cool to the touch.  As long as it isn't too warm to hold with bare hands. You want the engine growth to subside so you caan start it over.  Parking where there's a little air flow from a breeze across the fins would help. 

I've used Shell Rotella T 15/40 for these cycles up to the 50 miles because of the great additive package. Then I do oil and filter w/ 20/50 dyno for 200 more.  This makes me feel comfortable any fine debris from break in has been taken out of the system and the heavier oil handles the heat of longer run periods better.  I can then lengthen the interval. 

I use my regular good full synthetic (Liqui Moly) 10/60 after that but you can use what you are comfortable with.  I know I am not the only one here that uses this method.  In the big scheme of things oil is cheap for that warm fuzzy feeling you get knowing the break in was with clean fresh oil.

Enjoy your fresh engine 

[Jim Bronson]

Hopefully it will be ready early next week. Again, many thanks for the tips.

[JW113]

How far is around the block in miles. Just curious. I live on a cul-de-sac so there is no block to go around.

That is an excellent question, as I was being a bit figurative. My "around the block" is 2 miles. It's a course in my neighborhood that I can avoid stoplights (I live in an area with more stoplights than people!), with a one mile stretch on the freeway that is really just from an on ramp to an off ramp, but allows to roll through the gears up to 60mph-ish.. And close enough to home that if something goes south, not too far to push.


I don't want to knock S&S's break in procedure, but I also have to look at their circumstances. They are giving warranty for the engines/parts, and once they leave the factory, it's all out of their control. So of course they are going to lean heavy on the side of caution, not knowing who exactly is doing this "break in". When I'm doing it on my own bikes, there is no warranty. If I screwed up the assembly, then I'm the one paying to fix it. Which makes me a bit more liberal with the break in process.

-JW

[IronButt70]

How far is around the block in miles. Just curious. I live on a cul-de-sac so there is no block to go around.

That is an excellent question, as I was being a bit figurative. My "around the block" is 2 miles. It's a course in my neighborhood that I can avoid stoplights (I live in an area with more stoplights than people!), with a one mile stretch on the freeway that is really just from an on ramp to an off ramp, but allows to roll through the gears up to 60mph-ish.. And close enough to home that if something goes south, not too far to push.


I don't want to knock S&S's break in procedure, but I also have to look at their circumstances. They are giving warranty for the engines/parts, and once they leave the factory, it's all out of their control. So of course they are going to lean heavy on the side of caution, not knowing who exactly is doing this "break in". When I'm doing it on my own bikes, there is no warranty. If I screwed up the assembly, then I'm the one paying to fix it. Which makes me a bit more liberal with the break in process.

-JW

Thanks for the reply.