The Bucket Foundry

[ken seeber]

Attachment 321101
Top view of a Formula 1 piston. The head looks the same, only mirrored: all cluttered up with valves. There's barely room for a spark plug, so forget a second piston.

Piston is very well made with lots of detail features. They are very obviously chasing compression ratio, ie the projections under each valve to reduce the volume of the combustion chamber. Overall its surface area/volume ratio must be very high, particularly when compared to a classic 2 stroke chamber. If the head matches, then there must be many areas of close clearances, leading to quench leading to unburnt fuel or unburnt HC emissions. Seeing there isn't any LA4 or ECE emission cycle testing, I would think they just don't care. However all this is about a conventional SI process, so if HCCI is present, then it is an entirely different ball game and all this could be meaningless.

Frits, how old is the pic and do you think it is from an "HCCI" engine?

[Frits Overmars]

if it's being used in F1, no reason it can't be used in MotoGP - except they make too much power now, so we probably won't see it.

Yamaha, Honda and Suzuki would agree that Ducati makes too much power. But power would not be the main issue in MotoGP; HCCI would permit a lighter fuel load.

[Frits Overmars]

Piston is very well made with lots of detail features. They are very obviously chasing compression ratio, ie the projections under each valve to reduce the volume of the combustion chamber. Overall its surface area/volume ratio must be very high, particularly when compared to a classic 2 stroke chamber. If the head matches, then there must be many areas of close clearances, leading to quench leading to unburnt fuel or unburnt HC emissions.... However all this is about a conventional SI process, so if HCCI is present, then it is an entirely different ball game and all this could be meaningless.
Frits, how old is the pic and do you think it is from an "HCCI" engine?

It's an oldie, from a 3,2 liter V-10. And they certainly did not employ HCCI at the time. If you look closely you'll notice that the valve pockets give away the radial valve arrangement. And you're right about the cluttered-up combustion chamber. These engines revved to about 19000 rpm and they needed 55° ignition advance at WOT, and even more at part-throttle.

[Grumph]

It's an oldie, from a 3,5 liter V-10. And they certainly did not employ HCCI at the time. If you look closely you'll notice that the valve pockets give away the radial valve arrangement. And you're right about the cluttered-up combustion chamber. These engines revved to about 19000 rpm and they needed 55° ignition advance at WOT, and even more at part-throttle.

Yes, that's pretty much what Blair said when he was here. Refer my earlier comment about the chamber being a sheet of paper with 4 recesses.
We had an interesting chat about 5 valve heads - he'd just come from doing some work in japan - and agreed they were crap, LOL.

Is squish - or for that matter, chamber shape, relevant if you can initiate HCCI ?

[eldog]

Haven't they got some gay single motor per round rule?

1 Motor thousands of spare parts?we can rebuild them
Would be a real bugger if you had to rely on one

[breezy]

The cam idea would be possible (if one didn't hate cams so much) but yes strict sense HCCI is compression based but I guess that covers anything not spark plug or direct injected. I just like to use timed high compression as it does not rely on hot previous gases so will start cold and run at any rpm without a spark plug, under control, although you wouldn't think so by the video
Right, lets start putting some of these ideas into practice, anyone / everyone.
I'll have the AG fitted up to the dyno next week (thanks to Drew and the clutch).

how about starting from scratch, with high compression engine started up with spark ignition then at various rpm levels reduce the spark energy at even gaps slowley down to 0volts and see if it continues to run...

[eldog]

Lathe's big enough, what's taking the time is using a 25mm boring bar 300mm long in 420 stainless.

Bloody noise is still in my head...

Stst 300 stick out I can almost hear it.
I don't remember having to m/c 420 grade

Is it magnetic? Some of those Stst grades really tough.
Used to m/c H13 hardened liners out of extrusion presses
As per usual all of that equipment gone overseas. Still some smaller presses working here and there.

[Frits Overmars]

Yes, that's pretty much what Blair said when he was here. Refer my earlier comment about the chamber being a sheet of paper with 4 recesses. We had an interesting chat about 5 valve heads - he'd just come from doing some work in japan - and agreed they were crap, LOL. Is squish - or for that matter, chamber shape, relevant if you can initiate HCCI ?

Squish won't be required for flame spreading; maybe it can help homogenizing the mixture at the last minute.
I'd say chamber shape could return to the old ideal of minimal surface area.

[Ocean1]

Attachment 321101
Top view of a Formula 1 piston. The head looks the same, only mirrored: all cluttered up with valves. There's barely room for a spark plug, so forget a second piston in the head.

So move the spark plug down.

It's not like we're talking much volume...

Edit: I guess it's only worth pursuing if there's enough benefit in controlling ignition independently of crank rotation. Given the speed of HCCI combustion tdc might be OK across enough of the rev range to work just fine.

[Grumph]

So move the spark plug down.

It's not like we're talking much volume...

Edit: I guess it's only worth pursuing if there's enough benefit in controlling ignition independently of crank rotation. Given the speed of HCCI combustion tdc might be OK across enough of the rev range to work just fine.

If we could see current F1 motors clearly we'd see if for instance they have side plugs. In a 4V head there are only 3 possible places to put the sparklers - the sides - or ends of the pent roof chamber - or in the middle. If it could be seen they use side plugs it could possibly infer there's something in the center of the chamber. Given the FIM supplied software they have to use and it's fixed RPM limit, turning the ignition off - as a rev limiter would do - when they're sure HCCI has started would allow bypassing the max revs allowed...

[Ocean1]

If we could see current F1 motors clearly we'd see if for instance they have side plugs. In a 4V head there are only 3 possible places to put the sparklers - the sides - or ends of the pent roof chamber - or in the middle. If it could be seen they use side plugs it could possibly infer there's something in the center of the chamber. Given the FIM supplied software they have to use and it's fixed RPM limit, turning the ignition off - as a rev limiter would do - when they're sure HCCI has started would allow bypassing the max revs allowed...

Which, if correct infers a compression ratio suitable for HCCI even when the mixture is fired normally. What happens if the magic compression rate occurs before the normal combustion propagation process finished? If they're running anywhere close to HCCI pressures then the normal combustion event must increase pressures over that at some point during the burn.

Which means there may be an incremental change from normal combustion to HCCI... Anyone got a good sound clip from on board a modern F1?

[Haufen]

Injection position should be central on the current Ferrari F1 engine, if they use the prechamber direct injection system as stated here

The Mercedes F1 engine is using HCCI from what I heard, but only to save fuel during safety car phases etc, not for peak performance.

[breezy]

Maybe it would work if the insert thingie was a flintstone

Fred or Wilma?

[Frits Overmars]

Maybe it would work if the insert thingie was a flintstone

Fred or Wilma?

Pebbles

[Frits Overmars]

If we could see current F1 motors clearly we'd see if for instance they have side plugs.

You'd not only have to see them, you'd have to take'm apart.

Given the FIM supplied software they have to use and it's fixed RPM limit, turning the ignition off - as a rev limiter would do - when they're sure HCCI has started would allow bypassing the max revs allowed...

Do you believe for one second that the competition would let that pass? Sound analysis would easily reveal the true revs.