Isn't dyno'ing a brand new motor brutal?

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Since I was a kid and started working on cars or buying new cars, I've always been taught that motors should be driven fairly "softly" and not push the motor too hard until maybe at least 1000 miles. Otherwise, you risk damaging a brand new rebuilt (or new, in the case of the new car) motor.

Yet, I often see people testing brand new rebuilt motors, like this "383 Chevy vs. 383 Mopar" ( https://www.youtube.com/watch?v=L-uV61qilqU ) and push the dog excrement out of them! I watch videos like this and cringe as I wait for the motor to blow like a grenade!

Isn't pushing, testing, etc., a new motor like this just brutal on the motor even if it survives your test? I can't imagine you'd get a "normal life" out of a motor like this after testing it?

Ed
 
Originally Posted By: bdcardinal
What you don't see in those videos is the break in they do on the dyno before doing power pulls.


Ah HA!...so they DO break in the motors somehow before pushing the $%^& out of them!

smile.gif


Ed
 
Originally Posted By: Ed_Flecko
Originally Posted By: bdcardinal
What you don't see in those videos is the break in they do on the dyno before doing power pulls.


Ah HA!...so they DO break in the motors somehow before pushing the $%^& out of them!

smile.gif


Ed


Absolutely.
 
See what he says at time 4:23 about Hennessey does a break-in.
 
Every time I dyno'd an engine we spent at least an hour or so doing low-med RPM load sweeps.

The super flow has a break in mode that does this automatically.

Then after making sure everything was thumbs up - we let er rip.

UD
 
Originally Posted By: UncleDave
Every time I dyno'd an engine we spent at least an hour or so doing low-med RPM load sweeps.

The super flow has a break in mode that does this automatically.

Then after making sure everything was thumbs up - we let er rip.

UD
Agree with this post: After dynoing over 10,000 race engines here at the Speed Shop over the last 50 years engines , very little history of failures, using 2 Engish built Heenan Dynos, now made by "Land & Sea" Gregg
 
Back in the old days when machine tools weren't as accurate and materials were inferior... sure. Baby it for a while. Today however, materials and machining are far ahead of those of yesteryear. Properly machined, there will be no rubbing or wearing in, lapping wearing together or whatever else people speak of (not referring to rings) and it will remain dimensionally stable for a very long time. So, fire it up, bring it to temp, run variable load pulls for the rings then give her Hades!!!
 
The engine is broken in before those pulls. When I redid the engine on my Grand Marquis, I waited 2,500 miles with four oil/filter changes before I ran the [censored] out of it, locked in second gear, for its custom tune.
 
I firmly believe in break-in of a new motor, but I personally don't feel "babying it" is the best way to do it, at least in the circles I run in we don't do it that way.

The beauty of doing it on a dyno is it is broken in under load, so your "gentle" pulls aren't as gentle as, say, cruising at 30 mph in an automatic transmission equipped vehicle. This should, as I see it, shorten the break-in time required considerably.

It's similar, to my way of thinking, to how I have broken in marine engines, where the prop in water pushing a relatively heavy boat (that is, one whose weight is appropriate for the engine size) is always putting the engine under load.

I don't remember the Yamaha 4-stroke procedure exactly since it's been about five years since I did my last one (a 90 HP Tiller 4-stroke) but it wasn't that many engine hours before you were running it a Wide Open Throttle (WOT) for brief periods and not many more before you were running it at WOT for as long as you want.

That is considerably more severe than taking it easy for the first 2000 miles in a car or truck. 1 always based one engine hour to be equal to 30~60 miles for a 4-stroke motorcycle break-in schedule. That also correlates well to Yamaha's guidelines; 10 hours being the equivalent to 300~600 road miles, making almost any engine ready to run as desired in 10~20 hours.

I am also a believer in that you should break in the motor in the manner you intend to run it. If it's a high performance application, you should be making runs under load to redline as soon as reasonably practical. Although I don't do it, I do know people who have built many well running motors who run them hard right from the outset after a very brief break-in procedure and early oil change (1 hour or 60 miles).

My break-in for a road vehicle is moderate operation preferably under load as much as possible with varying the cruise RPM often in the first 60 miles or 1 hour, an oil and filter change, run about the same with occasional very brief runs to WOT in the next 500 miles or 10 hours, oil and filter change, then run as you expect to operate it for another 1500 miles, oil and filer change, then go to your desired Oil Change Interval (OCI).

There are about as many break-in procedures people use as there are engines, almost. I don't expect anyone to copy what I do, if only because they probably have their own ideas.

I do follow the manufacturer's recommended procedure for early operation though in a factory fresh mill. But I follow my own ideas for rebuilds.

I doubt the dyno break-in is anywhere near that long ... anyone familiar with the programmed break-in regimen care to comment on how long it takes?
 
Originally Posted By: UncleDave
Every time I dyno'd an engine we spent at least an hour or so doing low-med RPM load sweeps.

The super flow has a break in mode that does this automatically.

Then after making sure everything was thumbs up - we let er rip.

UD


So basically you would break in a customer's motor for a hour's worth of dyno time? If that's the case, seems quite reasonable to me.
 
You all may not want to hear this but it is possible that the new engine in your brand new car with 3 miles has already hit rated power at the factory. Most manufacturers test a sampling of new engines that roll off the assembly line to ensure quality. So some will not have run at all, some will be cold tested, and others will run through a full torque curve.

I'll also add that during the durability test phase it can be standard practice to pull a new engine into a dyno cell. Start up and check for leaks then start running the torque curve to check for performance. After that the engine will then run through a test simulating the life of the engine and typically pass with no issues.
 
Originally Posted By: Johnny2Bad
Originally Posted By: UncleDave
Every time I dyno'd an engine we spent at least an hour or so doing low-med RPM load sweeps.

The super flow has a break in mode that does this automatically.

Then after making sure everything was thumbs up - we let er rip.

UD


So basically you would break in a customer's motor for a hour's worth of dyno time? If that's the case, seems quite reasonable to me.


Yes.

The sessions Im speaking of all happened to be my engines but yes thats exactly what you do - break it on the dyno.
(when you own a multiple boats and a boat company you deal with lots of engines)

I would absolutely feel comfortable breaking in any engine the same exact way.

With a dyno you can control and vary the RPM and load while watching every parameter of the engine.

There really is no better place to break it in especially if there is a problem.

When I did my 500/500 406 I had a leak in the intake manifold gasket which we discovered on the dyno, if Id have put it in the boat/car it would have been enormously more difficult fix vs sitting there on the stand where two guys whipped it off and back on in 20 minutes.

UD
 
I like the harder break in method with a couple of caveats.

Going easy on BI in a vehicle is for many different components, not just the engine. Driveline pieces like the differential and trans need some care in some applications.

That said, we get them to full temp and go like the dickens, just stay out of first gear, maybe second too with these many-speed transmissions. LOAD IT UP!
 
The diesel engine plant I retired from tested every engine on the dyno, with like a 4 minute break in, then full load for 10 more minutes. The coolant, and oil are pre-heated. Every so often an engine came off the line to a quality test cell, get a short break in, then run at full load for 24 hours straight, completely torn down, and inspected, then re-assembled if good.
 
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