Which failure would you rather have?

[stroker]

I'm not sure what forum to put this in. I was thinking about spec racing and limitations and couldn't figure this out (which probably shows how ignorant I am about real mechanics).

Let's say you're humming along at a nice clip of about 220mph at Michigan in your Champ/Indy car (pick your flavor--it doesn't matter).

Which of the following engine failures would you most want to have (defined as the one with the LEAST chance of causing you or other cars to wreck)?

1. Crank bearing failure
2. Rod end failure
3. Valve train failure
4. Head gasket failure
5. Exhaust gasket failure
6. Piston ring/Piston failure

[Andrew Longman]

I'm not an engineer, I don't play one on TV, but I've consulted to a few.

I''d say 1,2,3 are the least desirable. They happen suddenly and throw all sorts of parts and pieces into the works, throwing oil on the track and rapidly pitching the velocity of the car out of sorts.

4, 5, & 6 can be more progressive or at least simply cause a sharp drop of power. Much more controlled retirement

[cameraman]

My instincts as a biologist:p would have me choose 5.

[SteveH]

I didn't even stay at a Holiday Inn Express last night, but I'll go with 4 and 5.

[rabbit]

5

(not trying to start a countdown ;) , just sayin which one I'd pick, not that I'm an expert)

[JT265]

I'd go with 5 too.

[opinionated ow]

piston and ring. it will kill a cylinder but not the whole engine instantly

[miatanut]

I'm going with 5.

If it were a turbo, it might shift the balance to 4, because 5 could mean a sudden loss of boost, although a big plume of steam behind you could blind a driver and cause him to rear-end you, so 5 probably still wins.

[stroker]

Okay, lemme 'splain my thinking.

Yesterday I'm noodling the Handford device and all the other crap we use to keep the cars slower on ovals. My inspiration is that perhaps we're going about this the wrong way--instead of adding "load" on the system to bog the cars down (restrictor plates, aero, etc.) why not mandate a part on the car that will FAIL if the car is pushed too hard for too long? For example, you could run the car at 100% for 10% of the race, but if you try to run WFO or max gearing for too long, (cue Steve Matchett) KERBLAMMO! That way the cars have enough power for passing and can run whatever aero trim/suspension they want. If you spec the engine part that will fail, you should acheive the same result as bogging the cars down with rules without actually doing so. It also creates some dramatic tension. The question is, what part do you design to fail (perhaps catastrophically) without excessively increasing the hazard?

So it seems that alternative #5 is the way to go. How do you design a gasket to fail after X minutes at max rpm?

[SteveH]

:eek:

:yuck:

:laugh:

[G.]

It was probably better to not have known your motivations...




:p

[Rosco]

If you are running a Honda with a under preformed tune up by the Honda engineers, you would not have any of these problems

[oddlycalm]

For example, you could run the car at 100% for 10% of the race, but if you try to run WFO or max gearing for too long, (cue Steve Matchett) KERBLAMMO! I see, kinda like Honda in F1. :gomer:

You are right in the sense that until recently reliability had always been a limiting factor. Limiting revs to 10-12,000 to save money has also eliminated any remaining chance of enigne melt downs in an age when engines can be made to reliably run multiple weekend at 20,000Rpm's. Sure, we see the odd engine failure, but for the most part what few failures we see are chassis or tranny related.

To make things fair and interesting I suggest the engine design should be contracted to Italian firm of Girmi that specializes in gelato machines. The parts themselves should all be made in the UK by Cosworth, however, after machining they should be sent to Trevor Williams in Scumfordshire On Mudpuddle so he can mess about with them in some random way after he comes home from the pub hammered. That would bring back some of that 1960's verve to racing. Designs that weren't quite up to the task and team mechanics rebuilding engines they didn't always completely understand. :D

Another approach that the Indy crowd might like better would be to mandate side valve engines while banning rev limiters. They could advertise that their series had technology more primitive than NASCAR. :thumbup:

Sorry stroker, couldn't resist a bit of fun with this.

oc

[stroker]

Okay, I've obviously said something stupid, but in all honesty I don't understand in what way...

I don't see how a car that's open to development in all other aspects but limited for ovals in the way I've described is a worse situation than spec aero/engine/chassis/tire. At least if you've got the gasket-limited car you can pursue other means of increasing speed that your competitors can't in those other areas. From a spectator perspective you've essentially got Power to Pass but the car is limited in top speed, which is the same effect as the eunuch rules package we currently have. So how is the "designed to fail if exceeded" arrangement inferior?

Seriously, help me understand your reservations? :(

[miatanut]

Okay, I've obviously said something stupid, but in all honesty I don't understand in what way...

I don't see how a car that's open to development in all other aspects but limited for ovals in the way I've described is a worse situation than spec aero/engine/chassis/tire. At least if you've got the gasket-limited car you can pursue other means of increasing speed that your competitors can't in those other areas. From a spectator perspective you've essentially got Power to Pass but the car is limited in top speed, which is the same effect as the eunuch rules package we currently have. So how is the "designed to fail if exceeded" arrangement inferior?

Seriously, help me understand your reservations? :(

There's a much simpler way to go about this, and get better racing too!

Take away downforce. MOST of it. The drivers will have to lift in corners on ovals. Maybe even brake!

Step 1: Eliminate the rear wings. The front wings will shrink as needed to maintain aero balance. This also greatly reduces the turbulence the following car experiences, so they can get a run at the car ahead in a turn and then make the pass on the straight.

Step 2: Reduce the size of the tunnels in the undertray.

You see a LOT more passing in club racing and (I hate to even mention it, but also Grand Am), because of this sort of formula.

The bolder drivers will be able to make the passes. The cars will get a bit tail-happy, putting on a much better show. This would all make a bigger difference on road courses, but if you added lifting back to the formula on ovals, you would see a big difference there as well.

[oddlycalm]

So how is the "designed to fail if exceeded" arrangement inferior?

Seriously, help me understand your reservations? :( Failures tend to be expensive and a sudden loss of power is dangerous, particularly on an oval. Failures have caused a lot of wrecks when a car suddenly slows unexpectedly.

The practical stuff aside, it's a fun concept. Hope I didn't offend by having fun with it.

You're certainly correct that the current high level of reliability is a major variable that has been all but removed. Remeber at Fontana when 2/3's of the field "done blowed up...?" End of the season so they went for broke, win or bust. Most of them busted but it was racing at least.

oc

[dando]

Failures tend to be expensive and a sudden loss of power is dangerous, particularly on an oval. Failures have caused a lot of wrecks when a car suddenly slows unexpectedly.


Just ask Mr. Judd about that. Mr. Judd's wild ride last season was due to the car in front slowing quickly, and when he hit the rear tire, it was up, up and away! :saywhat:

-Kevin

[cameraman]

It would be a whole lot easier to design the spec tire to wear out in less than one tank of fuel. It would be up to the driver's skill to save his tires.

[Insomniac]

It would be a whole lot easier to design the spec tire to wear out in less than one tank of fuel. It would be up to the driver's skill to save his tires.

Unfortunately, the tire manufacturer doesn't want their tires to appear like they are crappy (even if designed that way).