24 replies to this topic

[Chris G.]

Help me here. I'm a little confused about Ron Dennis' comment that the problem with the Merc engines are "minor."

I'm not an engineer (really), but my instinct tells me that the valves on an engine are INTEGRAL to an engine design. Could this really be a case of simply changing a seal compound and all is well, OR is it more likely that a change with this pneumatic valve system is a fairly major engine redesign problem.

I guess what I'm getting at is that I wouldn't be surprised if this problem takes more than 2 weeks to fix. Are there any engineers that could shed some light on this for me? Thanks.

[RedFever]

I don't have an answer for you. In the specialized paper I read, they only mention the problem (valves get into the combustion chamber and then cause holes in the pistones, while getting damaged as well), but not the cure. They however stated that both the Research and Development in Stuttgard and the Ilmor guys in the UK will be at work full tim on this. They might consider new materials for the valves.

I agree with you that it's not a minor problem, but this are also the guys that produced the best F1 engine in 98 and 99. They might pull it off in time for Brazil.

[mono-posto]

Even if they had to redesign the entire cylinder head and fabricate new ones for all the engines, I'm sure they could do it in 2 weeks with the incredible resources that they have. However they wouldn't know if the solution actually worked untill Brazil. Such an extreme situation would either fix the problem or put them two steps back.

[Ricardo F1]

Does anybody know why this didn't happen in testing??

[FerrariFanInTexas]

Ricardo F1:

If I were feeling snippy, I'd say this didn't turn up in testing because McLaren were sand-bagging it and never pushed the engine as hard as it was pushed in practice and qualifying.

[130R]

Are you feeling snippy??

[F1DADDY]

But unfortunatly for you FAIRYINTEXASS you'd be wrong the reason it did not show up in testing is because no tests were done in the kind of heat (44 degrees centigrade) that was present in Oz. the valves just melted and the pace car didn't help much either.

------------------
F1DADDY, Who's ya Daddy

[FerrariFanInTexas]

Very nice F1Daddy.

Let's all make fun of our nicknames. Obviously, you're feeling snippy.

But what about it? You really think heat was the sole issue? There's no way they can anticipate that, is there. Good lord above, you'd have to be a freakin' psychic to know that the first two races are in the freakin' Southern Hemispehere, where it's sort of warm right now. And of course it's so cool in Europe over the Summer. There's no heat at Monza, or Spain. So let's all close our eyes and not input a little heat stress into the CAD work being done on the engine. Very brilliant!

My point to all of the "winter testing times do not matter" people is that they bloody well shuld matter. How the hell do you actually test the car/engine package if you're not actually pushing the damn thing to see when and how it breaks? That's why I think the sand-bagging to gain an advantage over the opposition doesn't really work.

[Chris G.]

Why the name calling f1daddy? The tenor of your comment didn't seem to indicate you were joking, so I can only assume it was just basic name calling. The texas d00d~ has a point too.

I'd say your insinuation that they didn't factor for hot weather is much less plausible than what ffantexas said. Either way, shouldn't beget calling people names.

[This message has been edited by Chris G. (edited 03-13-2000).]

[FerrariFanInTexas]

Chris G.:

I only included the "sand-bagging" bit because it's been kicked around this Board for the past two months or more that McLaren SUPPOSEDLY sand-bag during winter testing to keep the lid on how fast they really are. I don't buy that, but a lot of folk here seem to. I'm only poking a bit of fun at them for asserting that testing doesn't matter.

[MN]

Man in command says it's a minor problem, so it must be a minor problem.

Pneumatic Valve Return System is to eliminate all Valve Return "METAL SPRINGs" and use "AIR" instead to close valves.
Now, V10 4valve/cyl engines have 40 of them to be pushed(open) and returned(close) in the very high reving engine.
Imagine, Pneumatic Valve Return System failes and one or maybe multiple valves remain open or not 100% closed then piston heads come towards them fast......Ouch!!!
To me it's a major problem.
But hey, they have at least three broken engines to analyze root cause, they may have answer and solution already by now.


[This message has been edited by MN (edited 03-14-2000).]

[mono-posto]

MN,
Do you know if they were using this system last year too and this is just a development of that, or is this entirely a new valve accuation system?

[MN]

mono,

I asked same question elsewhwere.
The answer is that they(Ilmor/Benz) have been using it from begining(1993), not only Ilmor but other teams as well.
That make sense actually, McLaren had Honda V12 with Pneumatic Valves until '92 then Honda pulled out from F1 and Ilmor/Benz came in.

-AND-

Honda's chief engineer Gotoh moved to Ferrari for 93 season instead of comming back home(Honda).
Ferrari's 5valve/cyl engine suddenly changed to 4valve/cyl, and I'm sure it had Pneumatic Valves in it too.
(Honda also tested 5valve/cyl but they concluded 4valve/cyl has advantages over 5. It's a bit funny that Ferrari's production cars still have 5valve/cyl.)


[This message has been edited by MN (edited 03-14-2000).]

[GoAlesi]

I only got my Autocourse a couple of days ago and as it happens I've just finished reading the Melbourne review. Remember last year both Stewarts going up in flames on the grid, and Rubens being lucky to get the T-car to the finish before it too expired? That was caused by an oil seal in the engine rupturing under pressure, due to the higher ambient temperature. Obviously we don't know if this explains what happened with McLaren, but if it has happened before then it deserves consideration. That both engines failed soon after the safety car was out tends to support the heat arguement as cooling efficency would be much reduced at the slower speeds, and the radiators are designed to be as small as possible to minimise drag.

I think Ilmor will have the problem sorted well before Brazil, as mono-posto says they have the resources and the above posts indicate pneumatic valve actuation is not a recent development so Ilmor is quite familar with the system.

Though it outwardly seems like the McLaren will be unreliable this year, I'm pretty sure that the car actually will prove to be the opposite once the current problem is fixed. The car is evolutionary not revolutionary and McLaren have been focusing on reliablity over the winter. These efforts must of paid off, so I think that the problem experienced in Melbourne was a one-off. Of course if they overlooked this problem, there is the possiblity that they could of overlooked others. But looking back at last year again, at Melbourne McLaren was plagued by numerous problems, (certainly the sign of a unreliable car) while this year 3 out of 4 engine failures were caused by the same problem. McLaren will be hoping that fixing that problem will give them the reliability they were looking for over the winter.

[tak]

Something Haug said gave me the impression they may have a bad lot of one of the components in the pneumatic valve system. I beleive they refilled the nitrogen bottle on DC's car during his unscheduled stop. Ie his developed a small leak in the valve pneumatics that they picked up on telemetry. They refilled the tank only the the small leak to become a big leak. Mika's car skipped the small leak and went straight to failure. Although personally, I would expect the electronics to sense the failure and shut down the motor....

[slix]

Though the ambient temperature last weekend was a little higher than for testing, with combustion chamber temperatures well over 800'F (yes I am an American, 427'C) the extra 36'F (20'C) ambient should have little effect on the engine.

These engine spin to something insane, like 19,000RPM, that means that the valves move a LOT. Each valve actuates up to 9,500 times a minute.

Worst case, grab a set of 1999 cylinder heads! And figure out the problem. Maybe its as easy as using last years pneumatic bladder and further developing whatever space age one they have for this year.

Aside: BMW had a really neat electromagnetic valvetrain setup at the SAE show this year. Although it maxes out at 6,000RPM (engine, not valvetrain), it may not be long before it can handle the speeds in F1. The opening and closing can be controled MUCH more than when using a camshaft, and it reduces mass (maybe) , and a lot of moving parts. It could/should increase power too...

[Yelnats]

Slix, I'm not so optimistic about ElectroMagnetic Valves as you are. These valves are limited to 6,000 rpm at the moment but note that this is peak RPM, not running for two hours at maximimum revs in a race. It took 60 years to develop the Mechanical valves from 5,000 rpm to 19,000 so I don't see the Electromagnetic valves catching up any time soon (5 to 10 years).

There are other factors to consider also such as the power required to run these valves will be over 100 hp and this will be a huge weighty electrical system to install in an F1 car.

[slix]

Yelnats, yes, I agree with what you say, but its still neat to think about the possibilities. The engineers I spoke with said that the benefits outweighed the power needed, and this was with a 42V system. It may never be seen in F1...but I do hope to see it on passenger cars. I would like to have a "sport" setting that really did something! You could have some real fun with valve-timing and overlap.

[PDA]

Slix - a generally agreee that the electromechanical valve operation has tremendous potential, but at the moment, the bulk and weight of the solenoids etc. make this unsuitable for racing engines. Speed of actuation is also far to slow at the moment. This will change as more research goes into it. In the meantime, they have perfectly capable mechanical means of varying valve timing and overlap (Honda VTEC etc.) and I am sure that these are being used on the current crop of F1 engines.

re the Imlor engine failures - the compressed nitrogen is retained in something much stronger than a "bladder", as these systems operate at comparitively high pressure. One speculates that the sealing mechanism (O rings, whatever) were what failed. Thge pressure in the system is monitored by telemetry, so they would have known that the pressure was dropping and the system about to fail. you may remember that in the Brazilian GP last year, HHF had to make an extra pitstop to recharge his pneumatic valve system after the engineers detected that the pressure was beginning to drop.

Ambient temperature - considering that all testing had been done in the depths of the European winter, I think it is very possible that the 30+ C ambient temperature in Australia may have contributed a great deal to the failure. Although combustion temperatures may well be as high as previously stated, the temperature of the cooling fluid leaving the block/heads is far lower than this, and the temperature gradient to ambient air would be much smaller than that experienced in winter testing.

I expct they will have fixed it before Brazil, so expect Mac to be much better.

[desmo]

Two points: Could the apparent overheating of the Macs after running slow have to do with the "chimney" rad exits atop the sidepods in Oz. They appear to me to utilise the high speed airflow above the boundary layer over the car to draw air through the rad ducting, courtesy of Bernoulli's Principle rather than exiting between the rear tires. This could account for the McLaren's tendency to overheat at low speeds.

High ambient temp should only make the rads work incrementally harder. 10C warmer air would tend to make the coolant 10C warmer. Newey may not have designed in an adequate safety margin in an effort to get more air to the rear wing. Did you see how all the cleaning of the ducting going on durng the stops? It appears all the teams are very close to the edge as far only diverting enough air to the rads to do the job in an effort to maximise aero efficiency.

[Yelnats]

Desmo, I think your on to something though I belive the problem was caused by reduced airflow though the engine compartment when the pace car came out. As the McLaren slowed from racing speeds the temps in the engine compartment would soar as everything was at racing temp and the reduced airflow could cause items like seals in the pneumatic valve systems to cook. Things would cool after a few laps but by then the damage was done. This problem would be aggravated by the small clearances around this year's components in the engine compartment.

The tiny fire we saw when DC was in the pits confirms my suspicions and probably was small amounts of melted materials dripping down unto the exhaust and posed no danger to other drivers or DC himself (as events confirmed).

The cure? Increased ventilation, upgraded heat rating for seal materials, increased clearances in engine compartment or all of above. (And most important, no saftey cars ];-> )

[This message has been edited by Yelnats (edited 03-15-2000).]

[desmo]

Yelnats, the PTFE (Teflon) seals used in the pneumatic springing mechanisms are rated for up to 550F in some other applications. I would think this would be an adequate margin for the environment they work under, but there are probably other factors I am not aware of.

[Yelnats]

Desmo, 500F may be the melting point of teflon but no way it can operate at 18,000 rpm at that temp. Amyway I read that McLaren is going to increase the clearances on the Valve Systems. Apparently they had binding at the higher than anticipated operating temperatures. This will require more onboard compressed gasses due to increased leakage but presents no engineering challenges.

[This message has been edited by Yelnats (edited 03-19-2000).]

[Wishbone]

I could be totally wrong but I thought I'd read somewhere that the problem wasn't with the valves themselves but the filter used to keep grit out of them. Because of the high temperatures the filter had failed and allowed dirt into the pneumatic valves causing a failure. I've been trying to track down where I'd read it but to no avail. Has anyone else read the same thing anywhere?

[Yelnats]

Wishbone, I hadn't read this but it is quite credible also. Anyway the point is (to this post) that there are many simple things that could go wrong with the valves and I expect McLaren to be running at or near the front in Brazil for the entire race. I am looking to a rare direct confrontation between MS and MH this weekend, O Joy! Oh Joy!