| Author |
Message |
John Delvac (Johndelvac)
Member
Username: Johndelvac
Post Number: 326
Registered: 11-2001
| | Posted on Friday, April 18, 2003 - 5:38 pm: | |
This is a no brainer for anyone who has been to Maranello. A test driver runs the everlivinghell out of every car. Then, they put on new tires/wheels and reset the odometer. Every new Ferrari is run harder before delivery than most will ever be run. The factory has always believed in a ballstothewall beark in. Therefore, it makes since that a new replacement Ferrari engine should be run HARD. I have always heard that a car broken in slow will be slow. Also, newer car computers do defintly have a memory for driving skills. |
Mfennell70 (Mfennell70)
Junior Member
Username: Mfennell70
Post Number: 113
Registered: 7-2001
| | Posted on Friday, April 18, 2003 - 12:28 pm: | |
Isn't new different from rebuilt? IIRC, brandee-new engines benefit from heat cycles. As they heat and cool, internal stresses are relieved (and I'm just parrotting this info - I don't know anything about metallurgy). Hard running on that brand new block can cause excess wear. A rebuilt engine already has a "seasoned" block so that's not important.
An anecdote I read years ago, from Kevin Cameron, who wrote for a number of motorcycle magazines, explaining concepts so that Joe Average could understand them: he put to pistons in an oven. One old, one brand new. Turn oven on. The brand new piston came out misshapen. The old one did not. That's those internal stresses causing it to expand unevenly. |
JRV (Jrvall)
Intermediate Member
Username: Jrvall
Post Number: 1278
Registered: 11-2002
| | Posted on Thursday, April 17, 2003 - 6:38 pm: | |
>>With these, it's 5 minutes, no leaks, no squeeks, NAIL it.<<
Yep that's about it. They live or die in the first 15-20 minutes.
There's a little tweak , set timing, idle, misc. tinkering time...then it's around the block slow 1st 2 gears while you check for traffic & cops, then it's ...HAMMER TIME !!!
How's the saying go?
You're Breaking in the motor for the first 30 minutes and wearing it out from then on. |
Matt Morgan (Kermit)
Junior Member
Username: Kermit
Post Number: 125
Registered: 8-2001
| | Posted on Thursday, April 17, 2003 - 3:25 pm: | |
This will stir things a bit, but should provide some insight. James hit it pretty close in a way. As my experience as a builder includes Blown Alky motors, as well as Nitro powered, there is no break in period. The blocks are either cast solid, or epoxy filled to support the cylinders, the lack of water limits running time. I use a "Plateau" finish on the sleeves, that being the last half thousandth being done with a 500 or 600 grit for a very smooth finish that seals immediately. Bearing surfaces are all mirror polished before assembly, much smoother than they would get running them in. I have had great luck with street motors being put together this way, with the tolerances being tighter than needed for 1/4 mile rigs. With these, it's 5 minutes, no leaks, no squeeks, NAIL it. |
James Selevan (Jselevan)
Member
Username: Jselevan
Post Number: 499
Registered: 6-2002
| | Posted on Monday, April 14, 2003 - 9:04 am: | |
Mark - good points. Manufacturers have to design for the guy/gal who gets in the car on a cold morning, starts it up and drives away. They probably run the car for a few minutes for final tune-up, and this accomplishes most of the break-in.
Your point concerning performance and racing, where a few percent different in output makes a difference, is well received. When re-thinking this in the morning, a guess it makes sense.
However, I still think that the break-in process is analogous to the "Extra cream, Extra sugar" buttons on the old-style coffee machines, where you put a cup in the slot and it filled it with coffee. There were no wires on the back of those buttons! They were just placed there to make you feel better.
Jim S. |
Mark Eberhardt (Me_k)
Member
Username: Me_k
Post Number: 478
Registered: 5-2002
| | Posted on Monday, April 14, 2003 - 7:08 am: | |
James,
I can tell you this. Most of my dyno experience is with my Harley roadrace bike. After about 1/2 a season of racing, the measured HP would be down by about 10%. Scuff the cylinder with a flex hone and a new set of rings and it was back up. So rings do go bad. Gapless ring make 2-3% more power than standard rings. Rings put in with oils on them make 10% less power, my assumption was that they did not seat properly. Crome moly rings are support to last must longer under race condition than cast iron. I don�t know that�s true, I just trusted the ring makers advise.
On break in procedure, I�m pretty sure, although it is a guess, that the auto makers know they can not trust customers to follow a very complicated break-in procedure, if any at all. So they do what they can at the factory to either do the critical parts at the beginning for you or use parts that don�t have anything critical about them. If it�s a stock rebuild, the manufactures break in is probably what you should and find out if the engine is run at the factory before it goes out. If it�s a performance engine with non-OEM parts, that should be taken into account.
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James Selevan (Jselevan)
Member
Username: Jselevan
Post Number: 498
Registered: 6-2002
| | Posted on Monday, April 14, 2003 - 1:13 am: | |
Ben - pardon my ignorance, but if the Japanese use "iron" rings on Honda Civics, which last for 1,000,000 miles before oil change, then why do fancy cars like Ferraris use chome moly rings? Now, I'm setting myself up for criticism on this one, but how many have had to break down an engine because of bad rings? Valves or guides, okay. Cam lobe wear, okay. Rod knock, yeah, I can hear that, but rings gone bad is pretty rare these days. I can remember, yup, it must have been in the summer of 62, when I heard some piston slap in a Austin Healy sprite that I owned, but rings, no, can't remember bad rings. In the days when car mechanics made their own rings on an anvil out of whatever iron they found on the floor, I could see ring failure. But with metallurgy what it is today, and tooling vis-a-vis cylinder bore honing, it just doesn't seem to be a major cause of concern.
Finally (and yes, I will be quiet), what percent of cylinder pressure leakage is attributable to leakage past rings? At 1,400 psi, for a few milliseconds, do you think it is the rings that lead to performance compromise, or is it valve seats or valve seals that contribute the lions share of leakage? I do not know the answer to this question, but it is at the crux of the issue - are we splitting hairs on this Emperor's clothing?
(Sorry for the sarcasm, but it's so much fun to question authority).
Jim S. |
Ben Millermon (Brainsboy)
Junior Member
Username: Brainsboy
Post Number: 242
Registered: 5-2001
| | Posted on Sunday, April 13, 2003 - 9:29 pm: | |
James you are correct if your dealing with a honda civic or some jap car, because they have iron rings, they seal quick and fast. The problem is that most cars do not have a chrome moly ring. They are one of the hardest rings you can buy. If you dont break the engine in correctly they will never seal. Thats why alot of people install the CM rings with no oil. With no oil on the rings this aids in getting the rings to do a quick seat. The first 1/2 hour is most important to accelerate hard and left off the gas hard. The pressure in the chamber is used to press the rings to the walls, you need to do this before the walls get flooded with oil. I believe thats why alot of companys have switched to a plasma moly ring, because people tend to want to baby there baby on a break in. |
James Selevan (Jselevan)
Member
Username: Jselevan
Post Number: 497
Registered: 6-2002
| | Posted on Sunday, April 13, 2003 - 7:29 pm: | |
Gentlemen, forgive my skepticism, but those purporting an aggressive position on break-in seem to be weaving an acre of embroidery over a pin-head of fact. Perhaps this theme, of no oil on rings and aggressive break in should be delegated to folklore until well substantiated by reason (or fact). I read with humor the site referenced by Jeff Davidson. I do not wish to diminish the value of experience, but in medicine we turn to double-blind studies in large numbers of patients to come to a conclusion. There are so many variables that could influence a mechanics interpretation of pistons and cylinders and rings (upon dismantling), not the least of which is personal bias (agenda), that I would be loath to draw conclusions from one person�s observations.
First - car manufacturers may or may not recommend certain driving patterns for the first 1,000 miles or so. If they do, then I suspect they have studied this. When a manufacturer has warranty liability for 100,000+ engines, they begin to pay attention to this sort of thing.
Second - Ring to cylinder wall contact, at a microscopic level, likely has peaks and valleys. But as the ring does not rotate, why would one assume that eventually the ring (or cylinder wall) would not conform to the other. Maybe it acts something like brake pads, that I assume ultimately take the shape of the rotor.
Third - Early in automotive history, break in, I believe, had more to do with crank journal and main bearing issues. The break in period was to avoid a less-than-perfect but soft bearing shell from seizing on a crank journal or main. By slow break in, it allowed the soft bearing to "be shaped" by the journal and eliminate high spots.
Fourth - My opinion only, but I don't believe it makes a bit of difference how one drives their car in the first 1,000 miles. Today's precision machining of bearing shells, cylinder walls, rings, pistons, etc., all preclude the need for careful attention to this issue. HOWEVER, if the manufacturer thinks it is important, than I think it is important.
Just some thoughts to stir the pot. Not that this crowd needs inciting comment.
Jim S.
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Philip Airey (Pma1010)
Junior Member
Username: Pma1010
Post Number: 205
Registered: 7-2002
| | Posted on Saturday, April 12, 2003 - 10:21 pm: | |
John
Assume you have the OM specs, but if not:
to 600 mls: 4500 rpm limit
600 to 1800: 5500 rpm limit
1800 to 3000 miles, progressive to 7700.
I've always thought the worst wear comes from "lugging" an engine at low revs.
Also, my Warranty book has engine oil, filter change at 300 miles (Coupon A) and same at 1200 miles plus gearbox oil (Coupon B)
HTH |
Mark Eberhardt (Me_k)
Member
Username: Me_k
Post Number: 476
Registered: 5-2002
| | Posted on Saturday, April 12, 2003 - 10:01 pm: | |
I've had good luck with a couple things.
First, absolutely no oil on the ring when you put it together, I use BrakeKlean to be sure. This eliminates the problem the guy in Jeff�s post is trying to solve.
Second, load and recovery. That gets to what brake in is. No matter how well the machine work is done, there are still peaks and valleys. You need to knock the peaks off and flush out the debris. I start at about � redline and half throttle and a low gear, accelerate, then back down to flush it out. Then again with more throttle, more, then higher gear, until your full throttle in high gear this should happen at about 100 mile. Add 1000 rpm every 100 miles. You should be done at 500-600 miles. The last 100 mile you�ll be pushing it pretty hard the load and the recovery time will be pretty short. If you need to exersice the whole power band.
Third, you�re done, change the oil. For break in I like the cheapest (least slippery) stuff I can find and I use the lightest oil recomended.
JMO
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rich (Dino2400)
Junior Member
Username: Dino2400
Post Number: 165
Registered: 10-2001
| | Posted on Saturday, April 12, 2003 - 9:15 pm: | |
the chrome moly rings on my dino engine never did seal properly and i'm now convinced that i babied it too much at break in. i've since sold the car so i don't know if the new owner will have any luck at this point but some have suggested taking the car out to the country and get going like 2000rpm in 3rd or 4th and then steadily add throttle all the way until redline, coast back down to speed and repeat, repeat, repeat... but what the heck, the car runs strong as hell and just blows a little smoke. |
'75 308 GT4 (Peter)
Advanced Member
Username: Peter
Post Number: 2641
Registered: 12-2000
| | Posted on Tuesday, April 08, 2003 - 4:20 pm: | |
I just read it.
I'd like to know what honing system he used on his engines. I've had private discussions with members from this board about honing. All agree that using stones is sufficiant. But I'm still curious about those "Flex-Hones". They are carbide-balls on the ends of plastic "fingers". According to Guy Croft's Twin Cam Fiat tuning manual, they are the cat's ass. They smooth off the rough peaks and this leads to better oil retension on the cylinder walls. Also can reduce running in time to minutes instead of hours. He even suggests that you can bore up to 0.0005" and finish hone with the Flex-Hone alone.
??? |
Ben Millermon (Brainsboy)
Junior Member
Username: Brainsboy
Post Number: 227
Registered: 5-2001
| | Posted on Tuesday, April 08, 2003 - 4:01 pm: | |
This practice is usualy only for chrome moly rings. Thats why I asked him if it had chrome moly rings. Hastings, a company that makes rings has the same suggestions, dont baby it on the break in. Its important to seat the rings fast. It is common for chrome moly rings to have problems seating. In fact sometimes they never seat. Hastings also even suggests not even using oil on piston installation, they said just use a little on the skirts, this is help the break in. I read the website listed here and he is correct, the rings do use the pressure inside to seal the rings, thats why ring manufacturers are opening the second ring gap larger. What happens is pressure gets caught between the rings and will lift the top ring off the land, when this happens the rings doesnt seal completely. |
EFWUN (Efwun)
Member
Username: Efwun
Post Number: 469
Registered: 2-2003
| | Posted on Tuesday, April 08, 2003 - 2:43 pm: | |
WOW, did anyone read that article J.Davidson posted? Rob S, any thoughts?? |
Ron Shirley (Easy_rider)
Member
Username: Easy_rider
Post Number: 416
Registered: 12-2002
| | Posted on Tuesday, April 08, 2003 - 1:37 pm: | |
JohnR, I would follow whatever advice T Rutlands gives you. |
Jeffrey Davison (Jeffdavison)
Junior Member
Username: Jeffdavison
Post Number: 75
Registered: 7-2002
| | Posted on Tuesday, April 08, 2003 - 12:39 pm: | |
Here's a good article with practical examples on the proper method of breakin.
good reading!
http://www.mototuneusa.com/break_in_secrets.htm
Jeff Davison |
Mitch Alsup (Mitch_alsup)
Member
Username: Mitch_alsup
Post Number: 475
Registered: 4-2002
| | Posted on Tuesday, April 08, 2003 - 12:12 pm: | |
I tend to remain in the old school of engine break in.
Change the oil often--like 200 miles after startup, then again at 1000 miles, then on to normal change intervals.
{{I would use dino juice for breakin as synthetics can be too slipery to get the rings seated, then once broke in back to synthetics--however--do as you desire here.}}
Avoid more than 1/2 throttle for the first 300 miles, then stay under 3/4 throttle for the second 300 miles.
For the first 100 miles avoid more than 50% red line, then add 10% every 100 miles.
Spend time going up and down the rev band, never staying at one rev for very long (accelerate, decelerate, accelerate, decelerate) A nice winding ride in the country (with low constabulatory observation) works perfectly. Watch the oil pressure guages and water temp guages to stay ahead of the engine condition.
Once the engine has cleared 600 miles, it's basically broken in, however, I recommend another trip to the counrty roads where you can run the living snot out of the car using full throttle, and running up to red line then decelerating back to peak TQ then up to red line then back to peak TQ about 2 hours worth should do the trick.
Change the oil to full synthetic at this time. The engine may still seam a little tight, but continue to drive it as designed and it will get better as it ages towards 20K miles. |
JohnR. (Rivee)
Junior Member
Username: Rivee
Post Number: 175
Registered: 1-2002
| | Posted on Monday, April 07, 2003 - 4:33 pm: | |
Ben,
I don't know. It's a rebuilt from T Rutlands |
Ben Millermon (Brainsboy)
Junior Member
Username: Brainsboy
Post Number: 223
Registered: 5-2001
| | Posted on Monday, April 07, 2003 - 9:33 am: | |
Did you use chrome moly rings? If you have chrome moly rings you need to run it harder during beakin to seat the rings. As the rep told me from Hasting rings, dont baby it on the break in. |
JohnR. (Rivee)
Junior Member
Username: Rivee
Post Number: 174
Registered: 1-2002
| | Posted on Monday, April 07, 2003 - 7:51 am: | |
I am close to getting my 308 engine back together after rebuild and wanted some feedback on the best way to break in the new motor |
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