The Break in MYTH
10-18-2003, 03:43 AM
#22
i think its all bs.... i got a buddy who works at a chevrolet dealership and they have corvette z06s coming in that need the engine to be rebuilt to some degree due to people beating on them instead of properly breaking them in
10-18-2003, 08:22 AM
#24
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Originally posted by suvh8r
no, that would be due to chevy quality.
no, that would be due to chevy quality.
Sorry the ZO6 is a technological marvel.
10-18-2003, 08:58 AM
#25
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Then how did you lose? Mabey there is something he knows that you don't. Did he launch harder? What about the tires?
The other races were also from a roll. The car with the PRM intake also had a slight head start. My friend still won. The s2k with intake and exhaust and the grippy clutch was also from a roll. The two cars were dead even.
The thing with the break-in from factory I've heard also. I personally know some of the people in my honda dealer and the manager of the place (who is a big car enthusiast) told me that the engines go through vigorous testing from factory. Have you ever seen what they do with a brand new ferrari? Each and every single one is taken around their track....HARD. Brand new.
I think the 600 mile break-in is more for clutch, brakes, and like the manager at my honda dealership said...for the customer to get used to the car and also to try and get people to not drive the cars hard...hoping for less warrenty repairs.
Also, another thing...motor oil on a "soccer mom" driven motor does not need to be changed for about 10k. All due to the improvements in oil filtration materials from the dinosaur car ages. The manufacturers still recommend 3500 miles even though it's been well agreed upon by "the oil gods" that 10k intervals is safe. Just something to think about. Also, the units that time is measured at isnt the best. 60th increments instead of 100? But the world is just so used to going by 60ths....why change it? I think the automotive industry is basically using the same train of thought here.
10-18-2003, 09:14 AM
#26
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There is a lot more to breaking in the engine than just setting your rings. Has anyone given any thoughts to your rod bearings, crank bearings, cams, entire transmission, and other moving parts? Honda has the break in period specified in the owners manual. It is there to hopefully ensure that the engine/transmission is finished being broken in properly once you take possession of the vehicle.
First let's address the setting of the piston rings. Does setting the piston rings require you to take the engine all the way redline? Well lets think about it. The cylinder pressures created from combustion is what generates the pressure to push the rings out. During break in you want to make sure your rings get set early on. I think everyone will probably agree to that. The next logical step would be to look at how the peak cylinder pressure varies with engine RPM under wide open throttle(WOT). Since cylinder pressure is directly proportional to the amound of TQ your engine makes we simply need to look at an engine dyno that displays the TQ curve vs engine RPM. For those unfamiliar with what the TQ curve looks like on the F20C simply click on the link below.
http://www.randdmotorsports.com/images/pro...o_stockpull.jpg
As you can see the TQ curve is relatively flat. That means you can generate the cylinder pressures needed to set the rings as low as 3000 RPM at WOT. So you can see it is not necessary to take the engine all the way to redline to set the rings.
Has anyone given any thought to how taking the engine/transmission to redline affects other moving parts during the break in? During the break in of many moving parts there are frictional surfaces that haven't completely adapted to each other. That means there are points of friction that will be greater in certain parts of the surface area than others. Increasing the engines RPM is going to magnify this effect and create hot spots on the frictional surface. The end result is premature wear of the parts. Now I know that particular article mentioned that crank bearings and such only touch briefly during startup and then it rides on a cushion of oil. I imagine in a perfect world where engine parts are free from imperfections this would be okay, but that is not the truth. The truth is there will be imperfections in the building up of an engine. By keeping the initial RPM's low during the break in you are allowing those imperfect parts to adapt to each other at lower frictional temperatures. Once they have adapted to each other you can then take the engine to full RPM.
First let's address the setting of the piston rings. Does setting the piston rings require you to take the engine all the way redline? Well lets think about it. The cylinder pressures created from combustion is what generates the pressure to push the rings out. During break in you want to make sure your rings get set early on. I think everyone will probably agree to that. The next logical step would be to look at how the peak cylinder pressure varies with engine RPM under wide open throttle(WOT). Since cylinder pressure is directly proportional to the amound of TQ your engine makes we simply need to look at an engine dyno that displays the TQ curve vs engine RPM. For those unfamiliar with what the TQ curve looks like on the F20C simply click on the link below.
http://www.randdmotorsports.com/images/pro...o_stockpull.jpg
As you can see the TQ curve is relatively flat. That means you can generate the cylinder pressures needed to set the rings as low as 3000 RPM at WOT. So you can see it is not necessary to take the engine all the way to redline to set the rings.
Has anyone given any thought to how taking the engine/transmission to redline affects other moving parts during the break in? During the break in of many moving parts there are frictional surfaces that haven't completely adapted to each other. That means there are points of friction that will be greater in certain parts of the surface area than others. Increasing the engines RPM is going to magnify this effect and create hot spots on the frictional surface. The end result is premature wear of the parts. Now I know that particular article mentioned that crank bearings and such only touch briefly during startup and then it rides on a cushion of oil. I imagine in a perfect world where engine parts are free from imperfections this would be okay, but that is not the truth. The truth is there will be imperfections in the building up of an engine. By keeping the initial RPM's low during the break in you are allowing those imperfect parts to adapt to each other at lower frictional temperatures. Once they have adapted to each other you can then take the engine to full RPM.
10-18-2003, 10:26 AM
#28
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And regardless of the performance aspects of the z06, quality is still a concern over at the chevy camp.
Dealerships use "break in" or the lack there of as a coverup for quality and to cover their own and their manufacturer's A$$ (image).
Dealerships use "break in" or the lack there of as a coverup for quality and to cover their own and their manufacturer's A$$ (image).
10-18-2003, 11:14 AM
#29
My 2 cents. I have followed break-in procedures on all my hondas and acura's. None of the cars I purchased new (2 accords, 1 civic, 2 integras, 1 s2000) burned any oil. The one used honda I bought (1997 prelude sh with 3300 miles) burned oil. Also, a friend of mine used to vtec his new RSX-S before the 600 mile limit. I warned him while he did this. His car now burns oil at a rapid rate for a honda/acura. When I purchased my S2000, the engine felt really tight. I can't imagine wanting to rev it up to 8900 rpm while it was this tight.
Regarding aircraft engine break-ins, the engine is run full rich during this period and should be flown ideally less than 3000 feet msl. Full rich settings will keep the engine cool. Piston aircraft still require the pilot to set the mixture manually. No way to do this in a car.
Also, the s2000 eventually develops peak horsepower at around 10,000 miles.
Regarding aircraft engine break-ins, the engine is run full rich during this period and should be flown ideally less than 3000 feet msl. Full rich settings will keep the engine cool. Piston aircraft still require the pilot to set the mixture manually. No way to do this in a car.
Also, the s2000 eventually develops peak horsepower at around 10,000 miles.
10-19-2003, 06:50 AM
#30
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I did a poll on this, and the vast majority of owners have followed the break-in procedures and have had no problems with ring seating or anything like what that guy recommended in his motorcycle thread. I am skeptical of his science. It is entirely anecdotal, and flies in the face of the major mfr's world wide.
http://forums.s2ki.com/forums/showthread.p...&highlight=Poll
http://forums.s2ki.com/forums/showthread.p...&highlight=Poll