Proper engine break-in technique - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Reply
 
 
 
LinkBack Thread Tools
Old 05-27-2010, 12:53 PM   #21
Elite Member
iTrader: (10)
 
Join Date: Oct 2008
Location: Seattle, Wa
Posts: 1,780
Total Cats: 30
Default

Quote:
Originally Posted by neogenesis2004 View Post
Also, I disagree that things don't continue to break in after the first like 5min. Although, I would rather use the term "wear in". Sure your motor will continue to loosen up, but the initial ring seal is achieved mostly during initial warm up, then you get it on the road and beat it (with a good tune) with high rpm/very high vacuum to get maximum seal.
Point taken, things will wear for sure (otherwise engines would last forever ). The point I try to get across though is that after that initial warmup and seating period, its either going to work or it isn't.
Jeff_Ciesielski is offline   Reply With Quote
Old 05-27-2010, 12:54 PM   #22
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

Quote:
Originally Posted by Jeff_Ciesielski View Post
Point taken, things will wear for sure (otherwise engines would last forever ). The point I try to get across though is that after that initial warmup and seating period, its either going to work or it isn't.
Agreed.
neogenesis2004 is offline   Reply With Quote
Old 05-27-2010, 12:54 PM   #23
meatbag
iTrader: (50)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Houston, TX
Posts: 7,357
Total Cats: 26
Default

Quote:
Originally Posted by neogenesis2004 View Post
I'm not kidding at all, the rings will not flex more at first start than they will during the duration of their lifetime. The purpose of getting high RPM soon and quickly is because the principle that ring seal works on is applying gas pressure to the top and back of the ring through load. The more load the more pressure.
What's the correlation between load and rpm?
gospeed81 is offline   Reply With Quote
Old 05-27-2010, 12:56 PM   #24
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

Quote:
Originally Posted by gospeed81 View Post
EDIT: A few other posts were made while writing...I definitely don't recommend just sitting on the highway at 5K rpm for an hour. That would be the stupidest possible way to break-in a motor. But if you seriously thing that engine speed doesn't have a negative impact on part wear you my friend are the one using the crack. There is absolutely no reason to "rev it up" from the get go. Yes, vary rpm, yes, increase rpm, yes, you need to be using the whole rev range in less than 100 miles, but have you done any real research on just how many revolutions it takes to seat the rings? I've seen UOAs from 250mile break ins that were still showing cylinder wall material removal.
Go, the entire ******* point of an engine break in is you want the ******* rings to wear.... So yes, I do think engine speed impacts wear, but not negatively.
neogenesis2004 is offline   Reply With Quote
Old 05-27-2010, 12:56 PM   #25
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

Quote:
Originally Posted by gospeed81 View Post
what's the correlation between load and rpm?
ve
neogenesis2004 is offline   Reply With Quote
Old 05-27-2010, 01:07 PM   #26
meatbag
iTrader: (50)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Houston, TX
Posts: 7,357
Total Cats: 26
Default

Quote:
Originally Posted by neogenesis2004 View Post
ve
Right, and that's it...and it varies maybe 5% across the rpm band we're discussing. Therefore you still have sufficient BMEP to do the job. You kept stating load load load. I agree. Full load is available at any rpm.

Now consider how engine speed does affect the rings as they glide (or are dragged) across the cylinder walls. How does the friction vary? Wouldn't you want to condition the rings, and smooth the ridges for every range of engine speed. And my arguement for starting at normal speed ranges is that this is where the motor will spend most of it's life unless it's a race motor.

Now consider harmonics and how much they will play into proper piston ring seating. Where do the uglier vibrations come out? Do we even know? We can safely assume they're higher up the rev range.

Now consider lubrication. When new, the grooves are still deep, and the rings aren't yet functioning in their "hydroplaning" fashion, but skipping across the tops of the ridges. Yes, you want it to wear, but without work hardening. If you do work harden the tops of those ridges you will actually work against the wear you desire, and likely damage the rings.

Again, all speculation, and you've apparently had success (and not puked any rings). But it's something to consider, and I don't see a downside to prudence in this case.
gospeed81 is offline   Reply With Quote
Old 05-27-2010, 01:07 PM   #27
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

I wish we still had the chat, waiting for your replies is killing me....
neogenesis2004 is offline   Reply With Quote
Old 05-27-2010, 01:08 PM   #28
meatbag
iTrader: (50)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Houston, TX
Posts: 7,357
Total Cats: 26
Default

Quote:
Originally Posted by neogenesis2004 View Post
I wish we still had the chat, waiting for your replies is killing me....
No ****. ******* firefox crashed while typing that last post.
gospeed81 is offline   Reply With Quote
Old 05-27-2010, 01:12 PM   #29
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

**** it, im going to lunch. Go break in ur ringz!!!!
neogenesis2004 is offline   Reply With Quote
Old 05-27-2010, 01:13 PM   #30
Elite Member
Thread Starter
iTrader: (11)
 
Join Date: Feb 2009
Posts: 2,982
Total Cats: 10
Default

I have found a continuing theme where new "performance oriented" rings (material used) seem to seat very rapidly. Some suggest that the rings are practically seat before the first start simply from rotating the engine to align the crank and cams. Others say 5 min and some say up to 50 miles of driving. The real debate seams to arise with level of load that should be place don the motor. I would agree with high load with no turbo i.e. keep out of boost with a turbo engine.

Maybe a better question is: How much pressure does it take to seat a ring for a given initial gap. At some point a threshold will be crossed where you are just creating more wear on the rings and cylinder walls. This is why a turbo engines running high boost are not expected to last as long as an NA version of the same engine.
miatauser884 is offline   Reply With Quote
Old 05-27-2010, 01:16 PM   #31
Elite Member
iTrader: (10)
 
Join Date: Oct 2008
Location: Seattle, Wa
Posts: 1,780
Total Cats: 30
Default

Quote:
Originally Posted by gospeed81 View Post
Again, all speculation, and you've apparently had success (and not puked any rings). But it's something to consider, and I don't see a downside to prudence in this case.
This pretty much summed up what I was going to type.

While I respect the theory behind what you propose, in the real world I've yet to encounter a problem with my method of breaking a motor in.
Jeff_Ciesielski is offline   Reply With Quote
Old 05-27-2010, 01:20 PM   #32
meatbag
iTrader: (50)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Houston, TX
Posts: 7,357
Total Cats: 26
Default

Quote:
Originally Posted by Jeff_Ciesielski View Post
While I respect the theory behind what you propose, in the real world I've yet to encounter a problem with my method of breaking a motor in.
In reality there isn't much difference between our methods. Not using enough load will do much more harm for your break-in than any level of rpms, save lugging the motor.

I'm simply saying don't go straight to redline.

And djp:

The guideline for wear I've always heard is 50-100 miles for the rings to finish seating, although they continue the process for another 1000 miles or so to some extent.

The most important part of this all is to vary load, to both extremes, cover the rpm range withing that period, and then drive it as you intend.
gospeed81 is offline   Reply With Quote
Old 05-27-2010, 01:21 PM   #33
Elite Member
iTrader: (10)
 
Join Date: Oct 2008
Location: Seattle, Wa
Posts: 1,780
Total Cats: 30
Default

Quote:
Originally Posted by djp0623 View Post
I have found a continuing theme where new "performance oriented" rings (material used) seem to seat very rapidly. Some suggest that the rings are practically seat before the first start simply from rotating the engine to align the crank and cams. Others say 5 min and some say up to 50 miles of driving. The real debate seams to arise with level of load that should be place don the motor. I would agree with high load with no turbo i.e. keep out of boost with a turbo engine.

Maybe a better question is: How much pressure does it take to seat a ring for a given initial gap. At some point a threshold will be crossed where you are just creating more wear on the rings and cylinder walls. This is why a turbo engines running high boost are not expected to last as long as an NA version of the same engine.
I guess that is the question, but arguably one that can only be answered by trial and measurement.

It looks like I might end up putting together 2 engines this summer. If that happens, I'll have to break them in differently. One will be my low comp high-boost monster, which I'm planning on breaking in around 5psi and 6k-1k overrun. The other will probably be a ~9:1 1.8l block. If I can, I'll try to break that one in using your method and then compare results.

edit: Although this won't necessarily be apples to apples, I can compare the resulting compression #s against the factory spec, which will tell how well the rings seated in.
Jeff_Ciesielski is offline   Reply With Quote
Old 05-27-2010, 01:23 PM   #34
Elite Member
iTrader: (10)
 
Join Date: Oct 2008
Location: Seattle, Wa
Posts: 1,780
Total Cats: 30
Default

Quote:
Originally Posted by gospeed81 View Post
The most important part of this all is to vary load, to both extremes, cover the rpm range withing that period, and then drive it as you intend.
This.
Jeff_Ciesielski is offline   Reply With Quote
Old 05-28-2010, 03:51 PM   #35
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,662
Total Cats: 1,560
Default

Since some of my background is in piston engined aircraft, I knew that manufacturers were specific about the need for high load and varying engine speeds to be applied to an engine during break-in (run-in). So, I did some digging. The specific procedures were a bit dry, but this overview from Lycoming is insightful. http://www.factoryengines.com/docs/H...20Break-In.pdf

One of the specifics that was common to both Continental and Lycoming's break-in procedures was the bold print insistence that the engines not be run in a high vacuum condition during initial break-in. It was stated that high vacuum conditions promoted ring flutter which stressed the rings and could cause failure. I knew you were supposed to descend gradually without cutting power much after a break-in flight, but have not heard of ring flutter being the reason until now.
sixshooter is offline   Reply With Quote
Old 05-28-2010, 05:13 PM   #36
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,662
Total Cats: 1,560
Default

Please delete this double post.
sixshooter is offline   Reply With Quote
Old 05-28-2010, 07:35 PM   #37
Senior Member
iTrader: (5)
 
Join Date: Jan 2008
Location: Central, TX / Bay area, CA
Posts: 1,272
Total Cats: 3
Default

When I worked for Griggs racing we would fill the engine with GTX and run 3 laps then pit and change to synthetic.
Gotpsi? is offline   Reply With Quote
Old 05-30-2010, 01:09 AM   #38
I'm Miserable!
iTrader: (33)
 
Join Date: Jan 2009
Location: San Jose, CA
Posts: 1,066
Total Cats: -3
Default

After reading all these break-in methods I think my new motor is ready for its street tune ;D

250miles so far
railz is offline   Reply With Quote
Old 06-02-2010, 12:17 PM   #39
Junior Member
iTrader: (2)
 
Join Date: Nov 2008
Location: Olathe, KS
Posts: 119
Total Cats: 2
Default

Two major considerations for break in.
Cylinders- Cylinder prep and ring pack choice need to be considered. Using high precision rings with well prep'd straight cylinders should be "broke in" by the time the motor is fully assembled. Going back a few decades. Cast rings adn cylinders you could sharp[en your fingernails on took a bit of low load "break-in" to wear in the ring to the cylinder.

Camshafts - Since most here likely use precision rings, the break-in would most likely be about the camshafts. This will vary with the cam type. If not roller cams they most certainly need to wear in before they are exposed to high RPM. (Many a bike cam was severely damaged due to this). V8 cams need the 20 minute run then a 24 cool down to work harden the cam. They run 2k on those for proper oiling during the run. Sometimes a light spring is ran for breakin then heavier springs that belong in the motor. Point is with proper cylinder prep rings really dont need a breakin. Other parts can though.
Justaturbo95 is offline   Reply With Quote
Old 06-02-2010, 12:40 PM   #40
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

My builder told me that he burnished the cylinder walls and there was no real break-in other than pulling some vaccum with some RPM. He told me to drive it to the dyno, tune it and change the oil, then race it the next day...and after a few days at the track it will make about 20% more on the dyno than the first time you tuned it.

They guy has a pretty solid record with FI engines in general, everyone around here uses him.
hustler is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 57 07-19-2017 05:11 PM
Buzzing from driver side of engine bay? (MS3 install) nick470 MEGAsquirt 7 06-16-2017 02:53 PM
Changing from 460cc to flow force 610cc in diypnp 90 Turbo MEGAsquirt 19 10-19-2015 04:23 PM
Expected intake temps on the track? tazswing Race Prep 20 10-03-2015 12:04 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 07:10 AM.