F1 engine warm up

[djones]

Can somebody tell me why they rev the engines on off on off on off kind of thing instead of just rev to a constant rpm and keep it there, or even just rev gradualy up and down?

[DaveKillens]

Because it's cool to rev an F1 engine..... lol

[manchild]

All racing engines are optimized for higher RPM and working constantly/smoothly on low RPM even when the engine is warmed isn’t common to them. Also, it isn’t “healthy” for any engine to be started and than blazed into very high RPM and therefore they tend to as you said rev them up and down. This method provides heavier fuel consumption because throttle is being constantly pressed and released. More fuel burnout naturally means faster warming.

Another thing important for warming of the engine (including ordinary passenger cars) is not to do it like some drivers do – start the engine and than have breakfast. Engine including the gearbox & diff. has to be warmed in motion under variable RPM in order to achieve equalized warming of all elements.

There isn’t much difference in wise warming between passenger cars and racing cars including F1. You just need to start it and as soon as the engine had stabilized a bit its pace, you should start driving the car and that is what they do in F1. Obviously, F1 engine needs much shorter time period to get warmed compared to ordinary engines.

[manchild]

Because it's cool to rev an F1 engine..... lol

If I wrote such reply there’d already be a pile of s... all over me

BTW, it is cool to rev any engine - I even rev my lawnmower and it took me awhile to stop reving vacuum cleaner too

[Monstrobolaxa]

djones is thinking of why CVT isn't used in F1.

viewtopic.php?t=1424

[West]

I think it's best to just drive the car slowly when u start it (road car). Of course, mine isn't a four banger, so it might differ. My thermo book says it's not a good idea to just idle it after start.

[djones]

Monstrobolaxa - no I mean just revving it in the pit lane.

e.g 5000 - 12000 - 5000 - 12000 - 5000 - 12000 - 5000 RPM as a rough guide.

It does sound awesome (I always call it a barking dog).

"rev them up and down. This method provides heavier fuel consumption because throttle is being constantly pressed and released. More fuel burnout naturally means faster warming. "

Thats it then it just gets hotter faster than keeping it at say 10000 RPM.

Thanks


ps. I always thought the reson why your car handbook says drive straight away is for emmisions. They dont want you sat there doing nothing other than ticking over.

[Guest]

With regards to emmissions; the sooner you can get your catalytic converter/02 sensor to it desired operating temperature less emmisions will be created.

[Guest]

Forgetting emmisions and concentrating purely on whats good for the car (road cars) - Is it a good idea to just let the engine tick over for 30 seconds then drive slowly or is driving slowly instantly ok?

[RH1300S]

If you run the engine at a steady speed you can glaze the bore and ruin compression. Same when running in, you need variable loads to ease the parts together (too hot and you can harden high spots, so it's a compromise).

I tend to to fire the engine up with a few "dummy" starts to get a little oil moving through (easy to do with Webers as they won't light the fire unless you want them to ). Then I alternate between a fast idle (2000rpm ish) and higher revs (about 3500/4000rpm) until I start to show some water temp' then I drive off normally.

I have heard that too much blipping from cold can damage the cams as the skid over the followers.

With F1 cars they will be concerned about getting the moving parts warmed up together. I once read that if the engine is not pre-warmed before fire-up that bearings can spin and all sorts as the working tolerances are designed only for hot use.

[Guest]

If you've ever seen the data acquisition for throttle position on an F1 car (or any race car for that matter) you will note that the engine is at Wide Open Throttle (WOT) for about 90% of the lap time. Also, race car cooling systems (like F1 or Champ Cars) are designed to produce minimum drag, and thus will only provide adequate cooling at race speeds.

Proper fits and clearances at operating temperatures, within a high performance engine, are critical for maximizing performance and engine life. And the tolerance for those fits can be as little as +/-.0005 inch (.013 mm).

Take for example, the fit of a piston in a cylinder bore. At room temperature, the cylinder bore is bored and honed perfectly round. The piston, however, is very carefully machined to a distorted shape at room temperature. It is tapered, top to bottom, and has a "cam" profile when viewed from above. At operating temperatures, it assumes a cylindrical shape to match the bore.

[DaveKillens]

Actually, when I made my "Because it's cool to rev an F1 engine..... lol" post, it was both tongue in cheek, and a bit true. There's a tendency by many to rev a racing engine without logical reasons. If you think I'm blowing hot air, just go to any motocross race and watch the start. Many riders just wind the throttle up and down, their wrists moving in a blur. The accomplished, rational riders wind the throttle up to it's high RPM, hold it, and dump the clutch when the gate drops. But many, many still have that tendency to rev the engine.