Map

 CCS / ASRA Racing Forum

Author Topic: Engine break in proceedure???  (Read 6244 times)

0 Members and 1 Guest are viewing this topic.

zeroice

  • 250 - 500 posts
  • ****
  • Posts: 278
  • Karma: +27/-24
  • Buddha: compassion and wisdom are inseperable
Engine break in proceedure???
« on: August 03, 2007, 05:35:19 pm »
What is yours?

The rumors and myths that I've heard/read is that the piston ring - cylinder wall break in is the most important factor for producing good power.

Here's what I've heard:
The compression ring needs to "break in" the cylinder wall instead of the cylinder wall "breaking in" the piston rings. I heard that if the throttle isn't opened wide (obviously you get less pressure in the chamber), the piston rings move around radially and don't "cut" any burs on the newly honned cylinder walls. [i don't know if this is true which is why I am posting]

I thought about it quite a bit this week and tried to figure out a few things:
1. if the throttle is wide open, you get the maximum air/fuel mass into the chamber. During combustion this produces lots of pressure, more then when the throttle is not WOT (duh).
2. The surface area of the piston compression ring  (exposed to the combusiton chamber) is subject to the same combustion pressure.
3. pressure is a force acting on a surface. In this case the surface force is proportional to the ring area and the magnitude of pressure; F=P*A
4. The surface force acting on the piston ring is equal and opposite to the thrust force of the piston ring groove thrust face acting on the piston ring thrust face (reaction force).
5. Friction between the mating surfaces of the piston and piston ring are present; it has some coefficient of friction value (static and kinetic), which I'm assuming has some significant value.
6. Because of the thrust forces and proportional friction, the piston ring does not move radially (expand/contract), or its movement is reduced (in comparison to a closed throttle=no pressure -> no thurst force = no friction). Ff (friction force) =F (thrust force) * Us (coefficient of friction)
7. Because the ring doesn't move, it has a cutting action on the cylinder wall thereby breaking in the cylinder wall and maintaining good compression. As opposed to using no throttle, ring moves along any ridges on the cylinder wall thereby wearing grooves into the piston compression ring which causes for poor compression.

Does any of this sound reasonable? Any thoughts or opinions? Tell me if I'm right/wrong.
« Last Edit: August 03, 2007, 05:40:25 pm by zeroice »
Like
0
Dislike
0
Agree
0
Disagree
0
No reactions
No reactions
No reactions
No reactions
Krishna A. Pribadi
CCS #707

EX_#76

  • 500 - 1,000 posts
  • *****
  • Posts: 861
  • Karma: +224/-127
  • Wooooo Hooooo!!!!
Re: Engine break in proceedure???
« Reply #1 on: August 03, 2007, 05:47:25 pm »
When combustion takes place, the pressure on the top of the ring forces it to the bottom of the piston groove.  Combustion pressure can now get past the top of the ring and apply pressure behind the ring forcing it to expand around its circumference, and driving it (so to speak) against the cylinder wall.  Piston rings are actually designed to use the combustion pressure to aid the ring to piston wall seal.  That is why there is a top grove and a bottom grove ring, often with a dot on the ring to indicate the top of the ring.
Like
0
Dislike
0
Agree
0
Disagree
0
No reactions
No reactions
No reactions
No reactions
Guy Bartz
MW EX #76
Mass Reduction LLC Home of the Grip Doctor

George_Linhart

  • 250 - 500 posts
  • ****
  • Posts: 301
  • Karma: +88/-58
  • bored beyond belief
Re: Engine break in proceedure???
« Reply #2 on: August 03, 2007, 05:49:27 pm »
Do you want to know:

1) How to break in a motor; or,
2) why motor break in occurs?

Frankly, what you posted is just way too technical for me.  Hell, I don't understand what you are asking much less undersand the dynamics behind what you wrote.

The only thing I know is what I have read here:

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

Several engine builders have told me to follow these instructions.

Does that help?

George
Like
0
Dislike
0
Agree
0
Disagree
0
No reactions
No reactions
No reactions
No reactions

EX_#76

  • 500 - 1,000 posts
  • *****
  • Posts: 861
  • Karma: +224/-127
  • Wooooo Hooooo!!!!
Re: Engine break in proceedure???
« Reply #3 on: August 03, 2007, 06:00:06 pm »
As far as my procedure, one or two heat cycles just letting it idle until the engine oil is warm enough to rev it.  Then it goes on the dyno or the race track, and WOT.  the moto tune article George pointed out is good reading.  I have never experienced any issues using this procedure, and my motors seem to last
Like
0
Dislike
0
Agree
0
Disagree
0
No reactions
No reactions
No reactions
No reactions
Guy Bartz
MW EX #76
Mass Reduction LLC Home of the Grip Doctor


zeroice

  • 250 - 500 posts
  • ****
  • Posts: 278
  • Karma: +27/-24
  • Buddha: compassion and wisdom are inseperable
Re: Engine break in proceedure???
« Reply #4 on: August 03, 2007, 08:13:19 pm »
Do you want to know:

1) How to break in a motor; or,
2) why motor break in occurs?

Frankly, what you posted is just way too technical for me.  Hell, I don't understand what you are asking much less undersand the dynamics behind what you wrote.

The only thing I know is what I have read here:

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

Several engine builders have told me to follow these instructions.

Does that help?

George

very nice article! I dig it!
Like
0
Dislike
0
Agree
0
Disagree
0
No reactions
No reactions
No reactions
No reactions
Krishna A. Pribadi
CCS #707

123user

  • Guest
Re: Engine break in proceedure???
« Reply #5 on: August 03, 2007, 08:44:53 pm »
Here's a few hints.

1.  pressure from combustion travels between the piston crown and the wall.  It then enters the top ring groove, pushing the ring down and out against the wall.  It does not have the same pressure/force as the combustion pressure... just a percentage, maybe 15%  If you have vertical or lateral gas ports this force is increased significantly. 

2.  You only want enough pressure getting to the top ring groove to effectively seal combustion, so if you have zero blowby... you actually are losing horsepower because of large ring to wall friction.

3.  almost all rings made today are pre-lapped round.  That mean they will seal perfectly right out of the box.  At this point oiling is more of an issue in break-in. 

4.  The "ring break-in" is really a function of ring to groove sealing and the ability of the second ring to seal and regulate oiling properly.  So, breakin is really most important for the second and oil rings.  Not enough oil leads to micro welding and poor cylinder to ring mating.  This is the same problem associated with "washing out rings".  Gasoline wipes off the oil, causing top ring damage and poor sealing.

5.  Using oil is preferable to using none-  except from the EPA's point of view!

6.  So, I'd be concerned about the break-in on the cam lobes...  for that just don't let it idle... in fact, don't ever let your race motor idle too long!!!

Hope this is extra confusing.

Scott Schaefer
Piston ring Engineer
Mahle Engine Components
(Formerly Sealed Power/Perfect Circle Piston ring division)
Like
0
Dislike
0
Agree
0
Disagree
0
No reactions
No reactions
No reactions
No reactions

Super Dave

  • I hate salad...
  • More than 1,000 posts
  • ******
  • Posts: 11407
  • Karma: +1260/-454
  • I'm the ghost with the most...
Re: Engine break in proceedure???
« Reply #6 on: August 03, 2007, 09:35:01 pm »
I usually have one to three holiday dinners with Motoman.  I've used that technique for years. 

Even cast iron cylinders have been plateau honed for some time, so you're just working on building pressure to generate heat to develop the seal.  I broke in my R6 motor last Friday and Sunday.  I'm ready to go now.
Like
0
Dislike
0
Agree
0
Disagree
0
No reactions
No reactions
No reactions
No reactions
Super Dave

badmonkey

  • 100 - 250 posts
  • ***
  • Posts: 227
  • Karma: +7/-7
  • I'm not fast, your just slow!
Re: Engine break in proceedure???
« Reply #7 on: August 03, 2007, 10:23:40 pm »
run it like you stole it. usually do it on a dyno but the principle like motoman says is load the motor for better ring seal
Like
0
Dislike
0
Agree
0
Disagree
0
No reactions
No reactions
No reactions
No reactions
Do you want to touch my Monkey?


resurection

  • Guest
Re: Engine break in proceedure???
« Reply #8 on: August 04, 2007, 02:24:31 am »
Thermal expansion is only a good guess at what's truly round at temp. when we build molds that have tight tolerance.
We must build metal safe ,meaning theres metal to adjust for perfect sizing of finished part .
We must modify tool for perfect shutoff after heat adjusts sizes.
'Break in' is no more than heat teaching the metal where it should be .
Don't use too slippery an oil to soon.
Get the bike hot and cold several times.
Then loosen studs and re-torque allowing stresses to find a new sweet spot .
                                            And race it!!!
Like
0
Dislike
0
Agree
0
Disagree
0
No reactions
No reactions
No reactions
No reactions

gixxerzoli

  • Backmarker
  • **
  • Posts: 46
  • Karma: +24/-2
Re: Engine break in proceedure???
« Reply #9 on: August 04, 2007, 10:17:59 am »
Okay!
Last year I bought my 06 gixxer 600 with 0 miles. I started up at home couple of times, warm it up and that's it.
I took her to the racetrack /Summit Point main/ and race it. Today, a year later I have about 2000 race miles on my bike. Never had any problem, bike pulls strong. Im always changed the oil /Motul 5100/
So I can tell,....Buy the bike, warm it up several times and than ride it like stool it!!! 
Like
0
Dislike
0
Agree
0
Disagree
0
No reactions
No reactions
No reactions
No reactions

EX_#76

  • 500 - 1,000 posts
  • *****
  • Posts: 861
  • Karma: +224/-127
  • Wooooo Hooooo!!!!
Re: Engine break in proceedure???
« Reply #10 on: August 06, 2007, 11:56:20 am »
Here's a few hints.

1.  pressure from combustion travels between the piston crown and the wall.  It then enters the top ring groove, pushing the ring down and out against the wall.  It does not have the same pressure/force as the combustion pressure... just a percentage, maybe 15%  If you have vertical or lateral gas ports this force is increased significantly. 

2.  You only want enough pressure getting to the top ring groove to effectively seal combustion, so if you have zero blowby... you actually are losing horsepower because of large ring to wall friction.

3.  almost all rings made today are pre-lapped round.  That mean they will seal perfectly right out of the box.  At this point oiling is more of an issue in break-in. 

4.  The "ring break-in" is really a function of ring to groove sealing and the ability of the second ring to seal and regulate oiling properly.  So, breakin is really most important for the second and oil rings.  Not enough oil leads to micro welding and poor cylinder to ring mating.  This is the same problem associated with "washing out rings".  Gasoline wipes off the oil, causing top ring damage and poor sealing.

5.  Using oil is preferable to using none-  except from the EPA's point of view!

6.  So, I'd be concerned about the break-in on the cam lobes...  for that just don't let it idle... in fact, don't ever let your race motor idle too long!!!

Hope this is extra confusing.

Scott Schaefer
Piston ring Engineer
Mahle Engine Components
(Formerly Sealed Power/Perfect Circle Piston ring division)

totally off subject, but how did you recover from your in t6 crash at RA?  I had one hell of a time trying not to run you over as you were rolling down the road.  Do you know what caused the crash?
Like
0
Dislike
0
Agree
0
Disagree
0
No reactions
No reactions
No reactions
No reactions
Guy Bartz
MW EX #76
Mass Reduction LLC Home of the Grip Doctor

123user

  • Guest
Re: Engine break in proceedure???
« Reply #11 on: August 07, 2007, 01:45:16 pm »
Guy, I have no idea what happened in T6 at RA.  Thanks for not hitting me  I talked to Lon and Steve... both said my crash looked pretty spectacular.  Unfortunately, I didn't have the presence of mind to go ask the photographer standing under toyota bridge for a business card.

I was just toodling along,  la-tee-da, and boom... the front just tucked... It didn't squirm then tuck, or push then tuck, all front traction just vanished.  It was exactly like when you hit a submerged log in a deep mudpuddle (uh... another dirtbike comparison) it was almost that instantaneous... hopefully I killed a chipmunk!

Actually, the bike defied all of Newton's laws.  The clutch lever was bent a little (thanks for helping Craig)and a very small scratch on the end of the clip on.  The front axle had a little grinding done, but really, I just ground about 1.5" off the left rearset peg.

I was pretty adrenalized after the crash, I rode the bike back to the pits, fixed her up (you've seen all the tubs of tools and spares I carry!)  Then laid down for a couple of minutes to breathe.  I was still a little dizzy for the second race... but I still didn't come in last, just 2nd to last.

By the way, I know I rolled and tumble for a pretty long time... how far was it?  Did you ever see the Simpson's episode where Homer becomes a boxer... the doctor shows him an X-ray of his head and there's a little-bitty brain surrounded by a 2 inch thick skull.  That's me...  I mean, I am German, and an engineer... thus my skull is nearly impenetrable.
Like
0
Dislike
0
Agree
0
Disagree
0
No reactions
No reactions
No reactions
No reactions