some ?'s about breaking in new motor on the dyno

first off i just want to say i lurk in this forum regularly and cant even begin to tell you how much ive learned just by reading and absorbing some of what you guys talk about. this really is the best place ive come across in terms of automotive high-performance knowledge:bow:. which is also why i thought id ask here regarding my issue...

my new motor is in (383 SBC, TPI, solid roller) and im trying to determine the best way of breaking it in. i have access to a local dyno so i was thinking this would be the best route to take (am i correct in assuming this?). now ive heard tons of things to do when breaking your motor in on the street...but i cant come up with much as far as what to do on the dyno.

so to those who have broken in their motors on a dyno....whats the best way to go about it? anything i should keep in mind? how many pulls do you think it will take for the rings to seat and everything to be set properly? any general advice/tips would be greatly appreciated.


thanks in advance
Damien

20-30 minutes to break in the cam then go for it. A race car can't drive 500 miles to break an engine in. Roller cams barely need a break in but are usually done anyway. Rings will seat during the cam break in. If they don't then there's something wrong with the buildup.

After the cam is broken in, change the oil and filter and the engine is ready to go. You could do another oil and filter change at 500 miles just to be safe.

Mine (381ci LT1, solid roller) was run on an engine dyno, at moderate rpm, under load for one hour. Changed the oil/filter, checked all the torques and set off on a tuning program that included more than 20 pulls, NA tuning first, then N2O pulls, many of them in excess of 750HP.

Like Fred said, just vary the RPM and load in the 2000-2500rpm range an it should be fine, 45mins to an hour is going to do everything you need to seat the rings since roller cams require zero break in. Drop out the dino oil and change the filter like everyone has said and you should be good to go.

Bret

You recommend against synth oil during this period?

Steve

Synthetic oil is not recommended for break in period because its too slippery so it won't let the piston rings seat properly, so just use normal Dyno oil.

Any comments from readers of "Bobs the oil guy.com" or others?

It seems Bimmers come with it from the factory as do Porsches, most, if not all Mercedes [not just Mercedes AMG], Aston Martins, Corvettes, and Vipers. It seems these manufacturers would follow that reasoning and not fill LS6s and megabuck engines w/Mobil 1 on the initial fill. Each car is capable of being taken to the open track w/race tires and running to red line for a long period at a time. It is totally w/in their character. Certainly their rings also have to seat thru the break in period, regardless of where that takes place.

Could it be a difference in the method of manufacturing or of tolerances between factory motors and custom builds?


Steve

Originally posted by steve-d
Any comments from readers of "Bobs the oil guy.com" or others?

It seems Bimmers come with it from the factory as do Porsches, most, if not all Mercedes [not just Mercedes AMG], Aston Martins, Corvettes, and Vipers. It seems these manufacturers would follow that reasoning and not fill LS6s and megabuck engines w/Mobil 1 on the initial fill. Each car is capable of being taken to the open track w/race tires and running to red line for a long period at a time. It is totally w/in their character. Certainly their rings also have to seat thru the break in period, regardless of where that takes place.

Could it be a difference in the method of manufacturing or of tolerances between factory motors and custom builds?


Steve

OEMs have a variety of reasons for their "factory fill".

If they filled with dino oil, and told customers to dump it in 500 miles, most wouldn't do that. You can't rely on a customer, so you make the engine as "maintenance-proof" as you can. Sure , many of us change our oil religiously, but not all of us.

OEM cars have to pass emissions and get their rated CAFE mileage as delivered to the customer. Synthetic oil helps a little in mileage.

Some folks ignore any break-in recommendations, and leave tire stripes exiting from the dealership parking lot. The engines/oil needs to be up to that.

Vette doesn't come with engine oil cooler (too heavy) and not needed for street use, so synthetic helps here too. Tracking C5 probably should have oil cooler.

Years ago OEM factory fills were a special "break-in" oil which you couldn't buy over the counter. It came in railroad tank cars to the engine plants. It was dino oil, of course, with a few special additives. I think the first change was recommended at about 3000 miles. Dumping that oil at 500 miles or so probably did a disservice to your muscle car engine. RTFM was recommended then as now, but many didn't bother, or thought they knew more than the OEM engineers. Many did not. :)

Generally OEM engines have tighter piston fits than custom builds not only because of cast pistons, but because they need to. Remember all the flap about piston slap when cold on LS engines?Most modified engines have loud enough exhausts and maybe valvetrain, that piston slap when cold would not be noticed.

FWIW: The closest fit parts, and therefore the tightest tolerances in a car are in the automatic transmission valve body. Transmissions have 100,000 mile oil life with no breakin recommended. Of course no combustion gasses and nothing like piston to cylinder wall wear.

OEMs don't use the excessive amount of assembly lube we do when we rebuild, so it's not mixing with and maybe contaminating the engine oil. I think GM still recommends a can of EOS during a rebuild. That's been around longer than most of us, and still works.

MY $.02

I agree with the previous posts. We run 'em for 20 min or so at varying speeds, get 'em good and hot. Fix any problems/leaks that develop, change the oil, and let it rip!

Rich Krause

wow thanks for coming through with the goods again guys. :)

so to re-cap, run the car under load for a couple sessions of 20-30 mins at varying rpm's. am i correct in assuming to NOT go WOT during this time? what is the highest i should vary the RPM's up to? the redline on this motor will be approx 6500 rpms.

and yes of course change the oil right after. no synthetic during break in, but after that first oil change would it be wise to then run a synthetic? or should i wait like 500 miles or so?

altogether, would you say the best way to break a motor in would be on the dyno? i would think yes...but im not a pro engine builder.

thanks again for your help

Damien

Originally posted by i RoC U
....so to re-cap, run the car under load for a couple sessions of 20-30 mins at varying rpm's.

I have yet to find a superior method, of engine breakin, to cycling. When using the cycling method, putting a load on the engine, is alternated with high vacuum conditions. Monitoring vital statistics, engine is 'cycled' thru the gears, an X # of reps, at the same max rpm, B4 progressing to the next level of rpms. Start at about 2000 rpms, progressing at about 500 rpm increments, climbing the ladder of rpms to redline, with each successive cycle level. Even in the vehicle, this can be accomplished, in an afternoon. Closed circuit roadway recommended.

am i correct in assuming to NOT go WOT during this time? what is the highest i should vary the RPM's up to? the redline on this motor will be approx 6500 rpms.

It is better to not confuse WOT with high revs. They are not necessarily the same. Putting the engine under a load, can be done effectively, while at WOT. The idea is to put it under a load, not wind the hell out of it. There IS a diff. When the breakin is completed, you will be reving to redline.

...would you say the best way to break a motor in would be on the dyno? i would think yes...but im not a pro engine builder.

The more effective way to undertake the cycling method, would be in a controlled environment. On an engine dyno, would be more controlled environment, than in the vehicle, while on the road. On the road, it is also tougher to perform with an automatic, as compared to a manual trans.

Some additional notes to convey as well. It is less complicated, to breakin an engine equipped with roller lifters. The breakin process for cam/lifters is quite different from seating the rings. Seating the rings is done under a load, while the cam breakin is preferably done with a steady 2000-2500 rpms.

Using oem (recommended) method of breakin as a gauge, is flawed reasoning. The auto mfr. couldn't care less if the owner ends up a mediocre torque generating engine. Their primary (read that only) concern is the almighty dollar. They will jeoperdize a little power for less warranty and/or unnecessary repair work, (again $$) anyday. OldSStroker alluded to that (from my interpretation anyway) in his post. Why dictate a more effective method of breakin, from oem, if the risk of incorrect followthru is a possibility, causing unnecessary (again $$) added expense incurred by the mfr. A good example of 'break it in according to procedure in place, and not how it SHOULD be done', can be noted by observing cycle mfr. procedure. If the (the mfr.) would have the engine health, as it's primary concern, consider the number of rider deaths, or injuries would be a reality, in the process. What mfr. desires lawsuits?

ahh very good info. thanks for contributing! :)

OEM's not only have to warranty their engines, they also have to maintain their low emission character for 50 or maybe it's 100,000 miles.

To be crude about it, the engine, and really the whole car, is designed for "Barney Bumf@$k" who doesn't maintain his vehicle, starts it up cold and goes full throttle immediately, runs it hard then immediately shuts it down and lets it cook, and anything else you can think of...and a whole lot of things you CAN'T think of. It doesn't matter if it's the cheapest car or the most expensive, some Barney or another will abuse it.

An example of not anticipating the drivers is the oil consumption problem in early LS1 engines from "ring flutter". I believe the flutter was traced to runnning the engine at almost no load around 3000-4000 rpm. That occurs when one cruises in 2nd gear at maybe 40-50 mph in order to look cool, I guess. Sure if you need to cut an dive you pretty much have enough torque qvailable to spin the tires, but it's generally just a waste of gas and engine life. Without the power loading the rings found a resonant frequency the engineers had not, and the flutter let oil by especially with the very high vacuum developed when you lift in 2nd from 4000.

My first instinct would be to tell the people who drive like that to "Stop doing that, Dumbs&!t." Not the correct response! GM changed the ring package to eliminate the flutter and added that type of driving to the durability test cycle. Barney was saved from himself once again. No offense intended if anybody here drives like that. Well, on second thought......

Shoot, designing/building hot street or race engines is easy compared to that kind of stuff. :)

As to money concerns by OEM's, they have to fix things for 36-70,000 or more miles. Yeah, fixing is much more costly than designing and building it right the first time. That applies to Kia , GM, DC, BMW, MB and everyone else. Yeah, even Porsche has Barneys driving their cars.

FWIW, parts manufacturing is so good now that part tolerances are very tight, and a given batch of engines will dyno test within a very few % of one another, almost regardless of how they are "broken in". If this was not so, OEMs couldn't guarantee the emissions for the required miles. Platinum plugs really will run 100,000. I remember changing plugs at 5000 mile intervals if you wanted it to run well. I'm old.