We were watching the (tape delay) race last night. Bad, bad crash.

It's so sad when we lose someone in racing. Darrell Russell was a winning TF driver. He will be missed.

EDITED 6/28 5 PM: I just spoke with a friend who knew Darrell and the team principals. He said Darrell was a great guy and the team is hurting.

It's somewhat the same feeling one gets when a friend dies in combat. BTDT.

I have been at two races where fatalities occurred in the last 40 some years. All I can remember from those races is the drivers who died.

 

Exactly. There is a limit as to how much torque you can get per cubic inch or cc near power peak so producing that torque at a higher rpm results in more hp. The "torque per cube" limit raises a little with tech development, but the rpm at which it is produced keeps climbing.

An 800 hp @ 8800 Cup engine has about 477 lb-ft at that rpm. IMO that relates to airflow there. If you backed that rpm down to 7800, where it was 10+ years ago, the same 477 lb-ft (at power peak) is only about 709 hp. Same airflow or torque per cube, but faster cycling = more hp.

To rehash my old example: Assume a 850 hp @ 9000 Cup engine (maybe a little optimistic) and a 850 hp @ 18000 F1 engine (maybe a little pessimistic for the top guys).

At Power Peak the Cup engine has 496lb-ft/358 cu.in. or 1.386 lb-ft per cubic inch. The F1 engine has 248lb-ft/183 cu.in. or 1.356 lb-ft per cubic inch at power peak. Both are NA endurance engines that run on (good) gasoline. Airflow limits are set by Mother Nature, and that seems to be about the current amount we've been able to coax from Her. She's not easily seduced.

Drag engines which only run a few seconds in anger are maybe 1.6 lb-ft per cube at power peak. Is that close for a PS, Larry?

F1 engines are still 3.0 L (183 CID), but will probably go to 2.4 L (146 cu. in.) soon. That will probably mean going from V-10 to V-8 and keeping the same individual cylinder displacement (300 cc or 18.3 Cu. in.)

My $.02

 

What sort of ignition would an F1 car use to fire a plug a BILLION
times per second?

I'm thinking their cylinder pressure is quite high, obviously nothing
like a drag engine, but enough to become an issue at 18,000 RPM?

Would be similar to coil on plug with a high turn coil?

 

Interesting question. At 19,000 the plug(s) only fire about 158 times a second, or about every 6 milliseconds. If you were thinking of multiple spark discharge, I'm not sure that applies. Even on a MSD distributor, above about 3000 rpm you don't get much in the way of multiple sparks, if I understand the system correctly.

I think complete burning might be a challenge @ 19000 with a cylinder bore about 96-98 mm (3.78 to 3.90 inches) in diameter, which current F1 engines seem to be. Flame fronts travel about the same speed in the engine regardless of rpm. I think composition of the fuel might speed it up, just like nitro slows it down. F1 teams have to submit their fuel (gasoline by definition) for FIA approval of ingredients. I suppose the blend has things that speed up the flame travel.

I've not seen much on F1 engine ignition systems, but a couple of plugs wouldn't surprise me. Correctly spaced, I think you could achieve complete burning @ 19K. Evidently they do!

I suspect dynamic compression ratio on an F1 engine not to be much different from a good Cup engine given approximately the same octane fuel. Think about combustion chamber size on a 13:1 Static CR 300 cc cylinder. Try 25 total cc's of clearance volume in a cylinder about the diameter of a stock LS1! I'd surely like to see one torn down!

 

Here's some good insight into F1 spark plugs I read a few years back: http://www.motorsportsengineering.sa...eijan03-f1.htm

It's a little dated (as it suggests that in 2003 some F1 teams may have been running 2-plugs/cylinder, but as of 2002 1 per cylinder was still standard), but interesting plug design.

 

Not sure if anyone has any additional info, but it appears F1 changes fuel composition by altitude / track design / and weather.

http://www.theprancinghorse.co.uk/ne...y/2004/54.html

This low-density Shell fuel must have some pretty advanced chemistry for Ferrari to be so dedicated to it. I imagine the octane rating is insane to tolerate the high-chamber pressures that would be needed to increase flame speed by 2-fold (for comparison, the speed-limiting reaction in Nitromethane combustion proceedes at twice the rate when pressures are increased 10-fold). I imagine the chemistry of this Shell gas is such that a 10-fold increase isn't needed, but I would suggest the F1 engine is probably the highest dynamic CR of any engine used in racing... if we could only get someone to spit out valve timing specs we'd know for sure.

 

 

Well maybe, but with variable cam phasing, it's probably adjustable throughout the entire rpm band based on load, throttle position, etc.

It's pretty much admitted that F1 is still using mechanical cams and pneumatic springs. I've never seen confirmation that actuators are used to open the valves in raceday engines. Possibly some are, but the one-engine rule may have slowed getting that into the engines.

A couple of points of conjecture:

3D cam lobes: Picture 3 inlet valves but at different angles, ala porcupine head, with direct acting cams (no rocker arms). The cam lobes would need to be ground at an angle to the cam centerline which matched the tilt. That's expensive, but practical with today's CNC grinding.

Wildy assymetric cam lobes: With gas springs you can probably really drop the valve off a cliff to close it, and still catch it just before the seat AND prevent most bouncing on the seat. This could allow long duration with lots of time near full lift and still trap enough air at inlet closing @ 19,000 to have a high DCR.

Variable inlet length: Probably so. You should be able to get many psi ram tuning virtually throughout the perhaps 6-7000 rpm band they use. (12-19k!). This might make up for low DCR (if that is a mechanical restriction) by packing in the air.

Direct fuel injection: I can't imagine otherwise.

There is precious little info released by the F1 teams. BMW seems to be the most vocal with performance specs but not specific measurements or layouts.

My highly opinionated $.02

 

Let me understand this:

Staggering the intake valve timing within the same cylinder with a
multi-valve head would allow at least one of the valves to remain
in the head's "sweet spot" a fraction longer.

Instead of having a crazy lobe ramp up and down, it's more effective and easier on the valve train to delay ONE of the intake
valves so the duration is slightly longer as the INTAKE VALVES
overlap their peak lift points?

(not to be confused with exhaust and intake overlap)

 

lol... yeah that was my thoughts too

 

back to the spark plugs real quick. what about this.
instead of a traditional spark plug, have one that is flush with the cylinder head wall. then you would be able to have a head that is very close to perfectly being smooth. then instead of having repeated sparks, have the surface of the flatfaced spark plug run to an optimum temp. so that when the air is compressed just before dieseling itself, the heated plug will have the small difference to get a flame; since the peak cr wont be reached until the intake valve is closed.

maybe if it doesn't spark its illegal?

 

side note: half a mil a year on just spark plugs.

 

I believe a spark plug that doesn't spark but just stays hot is considered a glow plug. So what you would end up withis a diesel F1 engine that runs on high octane gas.

 

I take it you would like to see some blueprints? Would you like them in .pdf or better yet, a solid model?

No, I'm not privy to that information. Nick Hayes of Cosworth Engineering is a good friend of mine, works a great deal with Jaguar's engine development program. He'd be your man. Tells me very little so you can imagine what that conversation would be like.

Take care

 

.pdf would be just fine, thank you! I think Nick posted here once or twice.

http://web.camaross.com/forums/showt...threadid=61084
(page 4 of 7)

BMW was kind enough to publish max rpm, avg. piston speed, max piston speed and piston g's at max engine rpm for their 2003 engine, or at least one iteration of it.

Knowing that it's a 300 cc/cyl V-10, backing into stroke, bore, and rod length wasn't all that difficult. Of course that assumes the info they gave Racecar Engineering was accurate.

Jon