Manufacturer engine stress tests

[NateDN10]

Car & Driver article.

Quote:
For Ford’s global thermal test, for example, engineers run an engine up to peak power, and when the water temperature hits 230 degrees Fahrenheit, they shut it off and pump minus-22-degree coolant through it for 15 minutes. Then they start the frost-covered engine, allow it to idle for 20 seconds, and rev it to the power-peak rpm until the temp hits 230 degrees again, which takes about 10 to 15 minutes. During this test, the oil temperature goes from about 5 degrees to more than 280. Engineers repeat the process five consecutive times. Throughout the full durability-test regimen, an engine undergoes 350 such cycles, with other grueling programs in between.


Quote:
Ford tests pistons without their friction-reducing coatings at the tightest piston-to-cylinder tolerance. It also runs them for 10 hours at high load with the knock sensors disabled and the intake air heated to make the engines detonate like crazy. In some instances, this punishment bends the connecting rod before the piston fails.


Fun fact: I had to use TinyURL for the link, because the censor did not like the potty word in the actual C&D link.

 

[k24a4]

Very interesting. "Severe schedule" operating of a daily driver pales in comparison to these tests.

 

[dparm]

Interesting. What I don't see any mention of (and is probably a trade secret) is what's considered a "pass".

 

[supton]

Wish VW had done something similar for the interior. The cold weather squeaks are horrendous right now!

 

[UNC017]

I love testing like that! And the temperature cycling is truly impressive. I wonder about the detonation testing, though. Pounding it like that over a period of 10 hours might still not be like driving it around detonating a little bit over a period of years. Seems like the pistons might embrittle and work-harden so they would fail instead of the connecting rods as in the short-term testing.


Its been done for decades, too. The engineers who built the 2nd-Generation Hemi on a tight schedule to make it to the 1964 Daytona 500 have written similar stories. Bill Weertman, Tom Hoover, and some other "Ramchargers" alumni. They had to buy all new dynos to run sustained tests on those engines, since they were the most powerful they had tested at that time and the dynos had to absorb full power for something like 12 hours straight. Their dyno building could test several engines at a time, and the exhausts were routed up and out the roof of the building. One engineer said he would never forget the sound, walking in to work in the dark before sunrise in a Detroit winter, of multiple, un-muffled 426 Hemis running at full power during the extended tests. And they had cycles of load/no load, hot shutdown/heat-soak/restart and so on. Nothing like the subfreezing coolant through a hot engine that I recall, though. That's a really good example of how far gasket technology, cylinder head clamping force design, and things like that have come.

 

[d00df00d]

Originally Posted By: dparm
Interesting. What I don't see any mention of (and is probably a trade secret) is what's considered a "pass".

Indeed. Would love to see that, too.

 

[Ramblejam]

Originally Posted By: supton
Wish VW had done something similar for the interior. The cold weather squeaks are horrendous right now!


Indeed. People tend to forget that a vehicle is an amalgamation of various sub-systems. Just because you can pound on an engine via various synthetic benchmarks doesn't mean it's going to perform on the road.

http://www.autoweek.com/article/20130516/CARNEWS/130519889

 

[OVERKILL]

Originally Posted By: Ramblejam
Originally Posted By: supton
Wish VW had done something similar for the interior. The cold weather squeaks are horrendous right now!


Indeed. People tend to forget that a vehicle is an amalgamation of various sub-systems. Just because you can pound on an engine via various synthetic benchmarks doesn't mean it's going to perform on the road.

http://www.autoweek.com/article/20130516/CARNEWS/130519889


True, that issue described in the article depicts one of the caveats of doing extreme testing: You don't do "hey lets drive to the mall" testing.

This of course led to the moisture build-up in the intercooler and causes the symptoms described. Vehicles beat-on like red-headed step-children didn't have the issue.

 

[SwampSurvivor]

Or the Cadillac Northstar engines that were tested like this, only to be driven by little old ladies that never went above 2000 RPM and had a lot of issues because of such.

 

[ARCOgraphite]

i THINK i SAW THAT IN THE NEW c&d WITH THE NEW MUSTANG GLOBAL PLATFORM ARTICLE.
I'll break it. Ford put a MARGINAL ignition prone to crossfire and misfire on my 2.3dohc RANGER, ADD POOR QUALITY FUEL - AND THAT WAS THE END OF THAT TRUCK IN A COUPLE MONTHS. cHEVY 4.3 WT IGNITION AND MANIFORLD WERE WORSE, THOUGH.

 

[OVERKILL]

Originally Posted By: ARCOgraphite
I'll break it. Ford put a MARGINAL ignition prone to crossfire and misfire on my 2.3dohc RANGER, ADD POOR QUALITY FEUL - AND THAT WAS THE END OF THAT TRUCK IN A COUPLE MONTHS.


Yet you are like the only person in the world to experience this supposed issue......

 

[Clevy]

Originally Posted By: Miller88
Or the Cadillac Northstar engines that were tested like this, only to be driven by little old ladies that never went above 2000 RPM and had a lot of issues because of such.



No kidding.
The northstar should have gone into a Pontiac or something that would make use of the high rev potential and dohc tech.
Cadillac would have been smart to use a pushrod v8 with cams that made absolutely awesome torque down low and powered out by 5000 rpm.
Then the engine would have matched the driving demographic and far less issues would have plagued GM.
And then put the northstar into a performance platform with a 6 speed and really rev'd the heck out of them and those engines also would have had less problems because of being driven like they were designed to.
Just think,if GM would have switched engines they could have saved millions and also saved a lot of brand loyalty too,because of how many people just wrote them off because of the northstar problems.
In fact my favorite chev engine is the 5.7 dohc found in the 90's era ZR-1's. Those engines had so much potential on road courses because of the long powerband and high rev capability.
If those engine had today's vvt tech applied to them I would be weak in the knees.

Originally Posted By: ARCOgraphite

i THINK i SAW THAT IN THE NEW c&d WITH THE NEW MUSTANG GLOBAL PLATFORM ARTICLE.
I'll break it. Ford put a MARGINAL ignition prone to crossfire and misfire on my 2.3dohc RANGER, ADD POOR QUALITY FUEL - AND THAT WAS THE END OF THAT TRUCK IN A COUPLE MONTHS. cHEVY 4.3 WT IGNITION AND MANIFORLD WERE WORSE, THOUGH.


Try some mmo in the fuel and mos2 in the oil and you'll be good to go.

Why does it not surprise me when arco mentions a destroyed engine. Live and learn.

 

[RobertISaar]

Originally Posted By: Clevy

The northstar should have gone into a Pontiac or something that would make use of the high rev potential and dohc tech.


they did..... eventually. too bad it took until 2004 for it to happen, and even then, they threw the LO version in it, but the 04-05 bonneville GXP is a pretty nice car.

 

[OVERKILL]

Originally Posted By: Clevy
In fact my favorite chev engine is the 5.7 dohc found in the 90's era ZR-1's. Those engines had so much potential on road courses because of the long powerband and high rev capability.
If those engine had today's vvt tech applied to them I would be weak in the knees.


Actually, they'd closely resemble BMW's S62 and Ford's Coyote basically with a tad more displacement if you think about it

 

[dparm]

Originally Posted By: d00df00d
Originally Posted By: dparm
Interesting. What I don't see any mention of (and is probably a trade secret) is what's considered a "pass".

Indeed. Would love to see that, too.



Ford did have their "auto show tear-down" of an EcoBoost engine where they showed the required wear numbers, but that was just a motor that had gone through normal usage and not a stress test.

 

[OVERKILL]

Originally Posted By: dparm
Originally Posted By: d00df00d
Originally Posted By: dparm
Interesting. What I don't see any mention of (and is probably a trade secret) is what's considered a "pass".

Indeed. Would love to see that, too.



Ford did have their "auto show tear-down" of an EcoBoost engine where they showed the required wear numbers, but that was just a motor that had gone through normal usage and not a stress test.


I thought the Auto Show tear-down was the one of the Ecoboost run in the Baja, towing trailers of logs and accrued 160,000 miles?

 

[rjundi]

More like winter stress tests and design work. But this is likely how all the North American makers besides Acura do it. Note video plays about if goofing off at work.

http://www.trucktrend.com/features/consumer/163_1005_winter_testing_with_acura/viewall.html

My MDX works wonderfully in the winter including -20F temps and blast with SH-AWD. Obviously see the result of their work.

 

[A_Harman]

Originally Posted By: OVERKILL
Originally Posted By: dparm
Originally Posted By: d00df00d
Originally Posted By: dparm
Interesting. What I don't see any mention of (and is probably a trade secret) is what's considered a "pass".

Indeed. Would love to see that, too.



Ford did have their "auto show tear-down" of an EcoBoost engine where they showed the required wear numbers, but that was just a motor that had gone through normal usage and not a stress test.


I thought the Auto Show tear-down was the one of the Ecoboost run in the Baja, towing trailers of logs and accrued 160,000 miles?


Yes. Ford took an Ecoboost engine off the production line, ran thermal abuse testing on a dynamometer, ran the Baja race, dragged logs in the Pacific Northwest, and towed a race car on a trailer at 100 mph at Homestead Speedway for (I think) 24 hours. All on the same production engine. Then they tore it down in public at the Detroit Auto Show in 2011. I didn't see them tear it down, but I did look at the parts in the display cases when I went to the Show a few days later.

http://www.youtube.com/watch?v=8tEqwXrqzH4

 

[Garak]

Originally Posted By: OVERKILL
Yet you are like the only person in the world to experience this supposed issue......

I said ages ago they should hire ARCO to conduct these stress tests.

 

[GaleHawkins]

Thanks for sharing this great article.