Break-in method
10-06-2005, 11:57 AM
#11
Aircraft break-in procedures do not deal with the same concerns
seen in car engines. They get regular oil analysis, and then torn down after so many hours of operation, with parts that show too much wear, getting replaced. Not a luxury we have with cars ;-)
BTW annealing is often mentioned in aircraft engine break-ins. It softens the metal and reduces fatigue. Both annealing and tempering require heating that can be within the realm of measured EGTs of regular turbo engined cars.
http://www.moldmakingtechnology.com/articles/110002.html
http://www.efunda.com/processes/heat_treat/softening/tempering.cfm
http://www.avweb.com/news/maint/184932-1.html
Here is why aircraft engines don't equate directly with car engines:
The average car puts in 11,000 miles a year. If the car travels at 60 miles per hour from the times it first sets out until it stops, that's close to 200 hours a year. (Of course that isn't the case, given urban traffic, so overall hours of operation are much higher). Personal aircraft with piston engines appear to be overhauled on average between 1400 and 2000 hours. Following the aircraft overhaul guidelines and using minimum average car miles/time, that would indicate every 7 or 8 years between aircraft engine overhauls. But if cars followed those hours guidelines, they would be overhauled every 77,000 to 110,000 miles. Factor in hourly guidelines for aircraft engine rebuilds, along with real world driving times, and you'd probably be overhauling your car engine at far fewer miles.
"Most airplane owners think that the manufacturer-recommended time be-tween overhaul (TBO) is an hours-of-operation figure. They focus on TBO being 2,000 hours, or in my engine's case, 2,400 hours. But the same Lycoming service bulletin that outlines the hourly TBO numbers also includes a calendar TBO. On most Lycomings, it is recommended that the engine be overhauled every 12 years. My engine was only 19 years over TBO, even though it had accumulated just 1,650 hours of flying time."
http://www.aviationtoday.com/cgi/am/show_mag.cgi?pub=am&mon=0304&file=0304pist onengines.htm
My point is that I have real cars with actual mileage, that have been broken in the conservative way - and kept far longer than most people ever keep a car. They work easily as well, if not better than other cars like them with similar miles. It doesn't take a website to tell me that I'm doing something right. I know this method has worked many times for me and many many other people.
In the end, your A3 is your car and you can break it in any way you want :-)<ul><li><a href="http://forums.autoweek.com/thread.jspa?forumID=228&threadID=21112&mes sageID=471222">same old thing</a></li></ul>
BTW annealing is often mentioned in aircraft engine break-ins. It softens the metal and reduces fatigue. Both annealing and tempering require heating that can be within the realm of measured EGTs of regular turbo engined cars.
http://www.moldmakingtechnology.com/articles/110002.html
http://www.efunda.com/processes/heat_treat/softening/tempering.cfm
http://www.avweb.com/news/maint/184932-1.html
Here is why aircraft engines don't equate directly with car engines:
The average car puts in 11,000 miles a year. If the car travels at 60 miles per hour from the times it first sets out until it stops, that's close to 200 hours a year. (Of course that isn't the case, given urban traffic, so overall hours of operation are much higher). Personal aircraft with piston engines appear to be overhauled on average between 1400 and 2000 hours. Following the aircraft overhaul guidelines and using minimum average car miles/time, that would indicate every 7 or 8 years between aircraft engine overhauls. But if cars followed those hours guidelines, they would be overhauled every 77,000 to 110,000 miles. Factor in hourly guidelines for aircraft engine rebuilds, along with real world driving times, and you'd probably be overhauling your car engine at far fewer miles.
"Most airplane owners think that the manufacturer-recommended time be-tween overhaul (TBO) is an hours-of-operation figure. They focus on TBO being 2,000 hours, or in my engine's case, 2,400 hours. But the same Lycoming service bulletin that outlines the hourly TBO numbers also includes a calendar TBO. On most Lycomings, it is recommended that the engine be overhauled every 12 years. My engine was only 19 years over TBO, even though it had accumulated just 1,650 hours of flying time."
http://www.aviationtoday.com/cgi/am/show_mag.cgi?pub=am&mon=0304&file=0304pist onengines.htm
My point is that I have real cars with actual mileage, that have been broken in the conservative way - and kept far longer than most people ever keep a car. They work easily as well, if not better than other cars like them with similar miles. It doesn't take a website to tell me that I'm doing something right. I know this method has worked many times for me and many many other people.
In the end, your A3 is your car and you can break it in any way you want :-)<ul><li><a href="http://forums.autoweek.com/thread.jspa?forumID=228&threadID=21112&mes sageID=471222">same old thing</a></li></ul>
10-06-2005, 01:01 PM
#12
Did you read those articles you linked to?
And if you did, did you notice the lower temp numbers were Celsius?
No engine is running 800 - 1100 degrees.
Aircraft engines are still piston engines, and the materials and mechanics of piston seating are identical to automotive engines.
Also, FAA 100hr inspections don't inlcude anything remotely close to tearing down and rebuilding an engine. If you go to the FAA site, you'll see the engine checklist reads more like a 15,000 mile service.
When your cars have 100K and show better HP and compression than new, and UOAs with little to no fuel dilution and low insolubles, that's when you've broken it in right.
Better or as good as everybody else's poorly broken in engines doesn't mean squat.
No engine is running 800 - 1100 degrees.
Aircraft engines are still piston engines, and the materials and mechanics of piston seating are identical to automotive engines.
Also, FAA 100hr inspections don't inlcude anything remotely close to tearing down and rebuilding an engine. If you go to the FAA site, you'll see the engine checklist reads more like a 15,000 mile service.
When your cars have 100K and show better HP and compression than new, and UOAs with little to no fuel dilution and low insolubles, that's when you've broken it in right.
Better or as good as everybody else's poorly broken in engines doesn't mean squat.
10-06-2005, 02:47 PM
#13
EGT can be as high as 1600 degrees. Where does that exhaust come from.......?
Sure, the block and head(s) have cooling systems, but the combustion gases are plenty hot. It's the boundry layer in the combustion chamber that keeps the metal from melting (since aluminium melts around 1300 degrees). Now if extra heat is created by rings pushing hard against the liners......
http://www.mattituck.com/articles/engbrkin.htm
http://piled-arms.com/tech32.html
A much better than average leakdown test means nothing at two and half times your benchmark, eh? How about zero oil consumption once at thos miles? I'm sure it would pass any oil contamination test with flying colours.
I personally know of only a few people who have any kind of car approaching 255K miles on any kind of gas engine, let alone one that visits the race track a few times of the year. If it was a crappy break-in, it wouldn't be running now, let alone above 5000rpms all weekend in the hot desert, with 300 mile trips to and from the track tacked onto each end. It also passes on the smog dyno in the lowest 10 percentile allowed for this type of car.
Just because it's on the interenet doesn't make it better or true. That link to the crate motor place in your previous post was actually kind of funny. Got a buddy who has burned up two motors in his race Camaro. He sent me an email with that very link enclosed, asking for ideas. I told him to try the gentle method next time. He's kind of tired of throwing engines in the car, so I am waiting to see what happens;-)
There are endless websites espousing both methods of breaking in an engine. We can both post until the cows come home and not convince one another.
http://www.stealth316.com/2-breakin.htm
http://www.steelthundercc.com/enginebreakin.html
http://www.eci2fly.com/Tech_Ref/bi/BIRunInvsBI.htm
blah, blah, blah, blah..... ;-)
I already have cars with mega-miles that run extremely well - and it sounds like you don't - for now anyway;-) Polish, not grind is my way of thinking of a break-in. Like I said, you do it your way, and I'll do it mine :-)
http://www.mattituck.com/articles/engbrkin.htm
http://piled-arms.com/tech32.html
A much better than average leakdown test means nothing at two and half times your benchmark, eh? How about zero oil consumption once at thos miles? I'm sure it would pass any oil contamination test with flying colours.
I personally know of only a few people who have any kind of car approaching 255K miles on any kind of gas engine, let alone one that visits the race track a few times of the year. If it was a crappy break-in, it wouldn't be running now, let alone above 5000rpms all weekend in the hot desert, with 300 mile trips to and from the track tacked onto each end. It also passes on the smog dyno in the lowest 10 percentile allowed for this type of car.
Just because it's on the interenet doesn't make it better or true. That link to the crate motor place in your previous post was actually kind of funny. Got a buddy who has burned up two motors in his race Camaro. He sent me an email with that very link enclosed, asking for ideas. I told him to try the gentle method next time. He's kind of tired of throwing engines in the car, so I am waiting to see what happens;-)
There are endless websites espousing both methods of breaking in an engine. We can both post until the cows come home and not convince one another.
http://www.stealth316.com/2-breakin.htm
http://www.steelthundercc.com/enginebreakin.html
http://www.eci2fly.com/Tech_Ref/bi/BIRunInvsBI.htm
blah, blah, blah, blah..... ;-)
I already have cars with mega-miles that run extremely well - and it sounds like you don't - for now anyway;-) Polish, not grind is my way of thinking of a break-in. Like I said, you do it your way, and I'll do it mine :-)
10-06-2005, 03:33 PM
#15
Perhaps you didn't understand the first paragraph? Perhaps I wasn't clear.
Block temps and exhaust temps are not the same, but that exhaust heat is generated and then removed from the engine.
Point being I've got hard evidence in the form of good running super-high-mile cars, that a gentler break-in is a perfectly sound choice. Not some website. Not some second hand info. Not just one car - several cars. And more cars in the past. It's not a fluke. There is nothing that can refute that.
Point being I've got hard evidence in the form of good running super-high-mile cars, that a gentler break-in is a perfectly sound choice. Not some website. Not some second hand info. Not just one car - several cars. And more cars in the past. It's not a fluke. There is nothing that can refute that.
10-06-2005, 06:51 PM
#17
Re: Perhaps you didn't understand the first paragraph? Perhaps I wasn't clear.
OK, as I already knew, block temps and EG temps are not the same.
You neglected to explain how a block temp running 700 degress lower than the temperature needed to anneal anything can manage to anneal the piston rings.
And if the rings are running at a temp high enough to be annealled, how do they manage not to vaporize the oil film on the cylinder walls?
How do they not ingnite the fuel the instant it's introduced into the chamber given that the autoignition temperature of gasoline is lower than that needed to anneal the rings?
You neglected to explain how a block temp running 700 degress lower than the temperature needed to anneal anything can manage to anneal the piston rings.
And if the rings are running at a temp high enough to be annealled, how do they manage not to vaporize the oil film on the cylinder walls?
How do they not ingnite the fuel the instant it's introduced into the chamber given that the autoignition temperature of gasoline is lower than that needed to anneal the rings?
10-06-2005, 07:03 PM
#18
Heat generated by rings rubbing walls...... in addition to combustion chamber temps - some do
vaporize oil and weld to walls ( rare but not unheard of) - and pre-ignition does happen if overall temps are not controlled adequately via boundry layer and engine cooling systems. Remember unburned fuel itself can act as a coolant.
Actual combustion temps are between 2000 and 4000 degrees Fahrenheit.
Which still doesn't touch on why my way, way, way over 100K cars manage near new leak down test numbers and don't use any oil ;-)
Actual combustion temps are between 2000 and 4000 degrees Fahrenheit.
Which still doesn't touch on why my way, way, way over 100K cars manage near new leak down test numbers and don't use any oil ;-)
10-06-2005, 08:10 PM
#19
Re: Heat generated by rings rubbing walls...... in addition to combustion chamber temps - some do
You're not answering the questions.
How does an 900 degree piston ring not vaporize oil on every stroke?
How does a 900 degree piston ring not ignite fuel on every stroke?
If you want to to say you're comfortable with an easy break in because it's worked for you, that's fine.
When you try to say a hard break in leads to oil comsumption and lower compression (despite hundreds of reports of the exact opposite) because of 'annealling' of piston rings, that's when you need to answer the questions.
How does an 900 degree piston ring not vaporize oil on every stroke?
How does a 900 degree piston ring not ignite fuel on every stroke?
If you want to to say you're comfortable with an easy break in because it's worked for you, that's fine.
When you try to say a hard break in leads to oil comsumption and lower compression (despite hundreds of reports of the exact opposite) because of 'annealling' of piston rings, that's when you need to answer the questions.
10-06-2005, 08:15 PM
#20
I didn't claim a 900 degree piston ring - if you read and understood my posts.
But I have seen enough glazed cylinder walls to know it's a risk if you go too extreme or too conservative.
The biggest dog's breakfast I've ever owned was a Toyota pickup truck broken in the aggressive way. I didn't break it in, but spoke to the owner, and from wheel bearings, to gearbox, to steering rack, to engine, it was pure crap. Because I couldn't make myself neglect it, it lived, but I hated every moment with it. Maybe it's just people who believe in breaking in cars that way don't believe in taking care of them in any other way? Seen plenty of other cars with the same issue.
The biggest dog's breakfast I've ever owned was a Toyota pickup truck broken in the aggressive way. I didn't break it in, but spoke to the owner, and from wheel bearings, to gearbox, to steering rack, to engine, it was pure crap. Because I couldn't make myself neglect it, it lived, but I hated every moment with it. Maybe it's just people who believe in breaking in cars that way don't believe in taking care of them in any other way? Seen plenty of other cars with the same issue.