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lots of diff. theories on this subject.. but when you buy a nice new Ford Chevy Toyota etc.. you just get in the car and drive it.. i sold honda and ford for many years,, some with as little as 4 or 5 miles on the clock.. and yet customers never complane about oil usage. etc..your thoughts?
 

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Lots of different opinions here.
Alfa Twin Cam engines etc
After starting a new engine and running for about 30 min,,a few laps around the block under 4000 RPM
Then,,after everything is checked and happy,,take it for a Long drive and get it hot and dont abuse it.
I usually take the owner for this 2-3hr drive,,half way we get a hamburger,drive it back,recheck everything.
Get the engine Hot= operating temp,and keep it hot
If it is built properly,all should be OK.
With race engines,,,30 min on a chassis dyno,check everything,,then start giving it some,,then plenty.
Running in oil is used
Changed with usual oil after about 500 kms,,=,,road car engines
After more than 35 years using this method,all engines are happy.

BTW,,have you seen the Video of the 105s at the factory,,straight off the production line being dynoed ?
They Rev the **** of them straight away,,then abuse them on the test track.

Let the Opinions begin
 

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With advancements in materials, coatings, ring design, oil innovations, tighter machining tolerances, 100% automatic measurement, robotised assembly methods etc etc you cannot really compare a modern engine to an old one.

Break-in is a thing of the past. Customers nowadays do not accept that they have to bring a new car in for service after 1000 miles, or that they have to break it in, in any way, shape or form. This is taken into account when engineering/testing a new engine design.

Also, any factory that still does hot-testing (testing the engine under load) doesn't have the time for a break in period, they need to check for emissions, power, fuel economy and leaks in the shortest possible cycle time. So warm coolant is pumped in and the engine goes full power almost immediately. Again, this is taken into account in the design.
Not many manufactures do hot-testing though, if you have proven assembly quality and suppliers that produce up to spec, a cold-test is enough: so simply driving the crank, oil priming it, and checking for compression via the ports. Also a pneumatic leak test on the coolant/oil beforehand.

However, a rebuild engine is something different entirely. Tolerances are going to be different, materials might not be OEM quality (for better or worse!) the cleanliness of parts is different, different oil is used compared to the factory fill etc etc. So a bedding in procedure might be beneficial.

Also for a rebuild engine, the cost/benefit analysis is different to a new engine. A few extra miles of break in and some extra oil, doesn't matter in the grand scheme of rebuild costs and time. So why not get the extra peace of mind and do it.
 

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Frommy piston aircraft background, the key to good ring sealing is to maintain good pressure in the bore so they don't glaze from light running during run-in (I think the recommended factory running in process was ideal for causing glazed cylinders, thus the notorious smoky-Alfa reputation, IMO). This means 75% plus power, varying, until oil consumption stabilizes, as a guide (hard to do on the road legally). Maybe 20 hours or more. A straight mineral oil is used, no friction modifiers or detergent. Once oil consumption is stable change to your preferred oil.
 

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Alfa750 has nailed it. In a previous life, I've rebuilt many, many compression ignition and petrol engines and then dyno'd or driven them into life. Trick is to initially vary the Brake Mean Effective Pressure (BMEP.. e.g. load) to allow a cycle of loading for 15 seconds or so say to 70% power, then reduce allowing oil to by-pass the scraper ring and cool the micro heating that happens at a microscopic level on the cylinder wall and piston ring interface. Continue to cycle thus, increasing both the level and duration of load, but always allowing a period to cool and flush the liner/piston ring area as the rings relax under lower combustion chamber pressures. Worst thing to do is a steady, light or medium load.

You want the rings to expand against the liner under high BMEP so that the high spots on rings and liner are taken off, then cool with a lower cylinder pressure and oil by-pass at the microscopic level. Should all be done in about 30 to 60 minutes, then drive it like you stole it. It's done.

I don't believe the manufacturers when they say the engine is factory run in - thermal and BMEP cycling is a must for the at least the first hour of a new build. Harder to do on the road as traffic can get in the way, but easy to do on the track or dyno.
Cheers
 

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20 years ago my dad bought a Nissan and was given a sheet with recommended break in instructions. He followed it. Nobody I've asked has ever kept this info or thought to ask. My little piece of psychoanalysis is this. The average car buyer intends to own the car for 10-15 then buy a new car. If we assume the engine is ready to go from the factory as far as ring sealing, breaking in all the other parts properly for longevity isn't any concern under this mentality since when the odo hits 80k or it's been 10 years they're already thinking the car is busted and ready to be replaced. Doesn't matter if it runs perfectly. As far as oil usage, if you don't know what a dipstick is and you bring your car for an oil change as soon as the odo hits whatever the "change oil in X miles" sticker says, I doubt you would notice even if the car was using oil.

Lots of different opinions here.
Alfa Twin Cam engines etc
After starting a new engine and running for about 30 min,,a few laps around the block under 4000 RPM
Then,,after everything is checked and happy,,take it for a Long drive and get it hot and dont abuse it.
I usually take the owner for this 2-3hr drive,,half way we get a hamburger,drive it back,recheck everything.
Get the engine Hot= operating temp,and keep it hot
If it is built properly,all should be OK.
With race engines,,,30 min on a chassis dyno,check everything,,then start giving it some,,then plenty.
Running in oil is used
Changed with usual oil after about 500 kms,,=,,road car engines
After more than 35 years using this method,all engines are happy.
Can't speak from experience [yet], but this reminds me of a method I read about somewhere on the forum. Fill with SAE30 oil and break in additive, run at 2500rpm for 30 minutes unloaded, drive for an hour or two varying speed and load, then limit revs incrementally increasing for first 500 miles. Then change to standard wt oil. Don't take this as reliable information. Can't find where I read that to describe with reliable accuracy.
 

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Everybody forgets that the factory runs every single car before they sell it. Alfa ran their cars on a rolling road and I am confident that they would have tested performance before "saying your car is ready".

On engines rebuilt nowadays the best way to run them in is on a dyno while monitoring the oil content in the exhaust gas, at around 2 to 3000 rpm with moderate load. Once that drops, time for wide open throttle and peak loads.

Being a pussy cat on a rebuilt engine is considerably worse than beating on it from day one.
Pete
 

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Unless your crank is NOS and you have brand new bearings and your block is NOS, you will have running in issues in 2020. Even though new cranks are available, most use a worn crank and encounter the limits of their engine and thus their car's lifespan with that engine.

The reality is that most don't understand what running in really means. I think it means the new bearings and the cranks are at different measurements 'gap/tolerance' running is supposed to wear the crank/bearing so over time a tight bearing is not as tight.

By listing the gap in thou the crank is on it's journals to the mains and the rods will tell you what is going on.
 

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Steve, you are thinking of white metal bearing days. Not an issue anymore
Pete
 

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Old cranks usually have issues and the limits of spend/skill of engine repairer you have the potential for issues. So are you saying you can't use today's new bearings to run your engine in and the tolerances needed to be the same on all journals . That would be great as the engine builder will need to tell you that the gaps are the same.
Steve
 

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I have worked as a lemon law arbitrator for many years. 10 to 15 years ago I did a recall on a European Turbo, you can guess the car. The company actually brought one of their engineers from Germany to the arbitration. They were claiming that because the engine was run at 8000 rpm by the client for short periods of time (165 miles an hour for about 10 minutes on a deserted stretch of I-5) it was abused and we should deny the repurchase. The company had a black box in their cars then that recorded everything from the time it came off the assembly line (some people don't realize that current cars record everything about your driving habits including where you go, speed, etc.)
When I looked at their graphs I noticed that there were two long rpm spikes when the car was new. They showed the car being run at between 10 and 14000 rpm for some time. When I asked about it I was told " We did that, we need to know if the motor is going to hold up to customer abuse so we put it on the Stuttgart test track for extended periods prior to sale." Those rpms were maintained for close to an hour each time. If the engine failed it was replaced, if it passed it was shipped.
Needless to say they lost the arbitration: how can you say 8,000 is abuse when your running it over 10.
Last thing I found interesting was they claimed the client should not be able to make a claim because the tire codes showed all 4 tires were not made within 7 days of each other. They claimed it was a customer defect to have tires on the car that were made several weeks apart. They claimed the possible difference in compounds could subject the tires to failure and performance issues.
 

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Someone told me many years ago that the engine should be connected to electric motor and run without combustion for 3-4 hours at different revs.

Sent from my motorola one vision using Tapatalk
 

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Old cranks usually have issues and the limits of spend/skill of engine repairer you have the potential for issues. So are you saying you can't use today's new bearings to run your engine in and the tolerances needed to be the same on all journals . That would be great as the engine builder will need to tell you that the gaps are the same.
Steve
I don't understand your post. Cranks that I have had ground have come back within the specs needed for today's shell bearings. I've watched members of this site plastigauge their bearing clearances, and I've also rebuilt many engines, some my own ... and my last race engine was run for a short time on the dyno, and then loaded tested. We got to 8500 rpm and still making power under load, and the dyno operator turned to me and said shall we go to 9000 rpm. I said no, we've proved the tuning is spot on. The race engine before was put together the night before and driven to the race track. Within 30 minutes it was tested a couple of times to full revs. Somewhere in Auckland there may still be the faint wheel spin marks that I left to see if she worked ... that one gave lots of problems, but not because of bearings or rings, but wrong exhaust

VenturaAlfa, Really 10 to 14000 rpm!. I guess this supports that all manufacturers have to test their engines before selling the car
Pete
 

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Hi Pete,
You have just answered your own question by saying 'Cranks that I have had ground have come back within the specs needed for today's shell bearings.'
The within spec really means: each journal has a dimension and that dimension is with in a bounds be it from factory or from a another source.
For example each journal's dimension from rod 1 to 4 are what?
Ans: different from each other most likely.
If they are different from each other: then some are tighter than others.
Thus the run-in period is to wear down the bearing down or the crank journal or both for the tighter one/s.
Regards Steve
 

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I see what you are saying Steve, but lets put it this way; If I had an engine that had already bed it's rings in and for some strange reason I needed to replace/repair the crankshaft and bearings. I would install the freshly machined crankshaft and new bearings in, and then after the warm up lap position the car on pole position. I do not believe running in is required for rotating components anymore.

Now back in my fathers early mechanic days, white metal bearings were used, and the machining and had scraping of those bearings back then, and I guess the crankshafts were not as accurate as nowadays. I've heard stories of rebuilt engines having to be towed to start as they were so tight.

I do not know why car manufacturers bother putting instructions in owner manuals about how to drive your car for the first X km's. I didn't take any notice with the only new car I have ever owned (leased), I just drove it like any other family car.


Actually it will be interesting to see how I drive my 1750 GTV when I finally get it legal and running again. I suspect my attitude will be so very different to any other car because it has taken me over 30 years to restore. While I might want to give the engine the revs it needs, there will be a very nervous driver worried about stone chips and other road users ... I might need to get over this by taking it to the nearest motorway and giving it a good old fashioned Italian tuneup => more for me than the car :)
Pete
 

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Discussion Starter #16
psk 30 years on resoration? how long have you been married?? just wondering witch one is longer..:oops::oops:;)
 

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Restoration

Pete
 

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Discussion Starter #18
cat was helping me 🐱... as soon as i open my laptop, she is on it,, even if she walks in from the bedroom, kitchen..etc...
 
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