Disc Valves

[Formula None]

Thanks Sayshina, interesting post. It brings up some existential questions F1 needs to answer. The big one in my mind is: how to justify the end of reducing lap times.

I know you don't want to look at the 3.5 formula, but humor me for a moment.

Don't mind that as an example at all, its a good one, and with a fuel limit only series, many ideas would similarly be tested and abandoned as the ideal solution is proven. But that would be the fun part! Anyway, what do you (or anyone else) think would have been the ultimate evolution of the 3.5/3.0L formula, had budget caps and material restrictions not been put in place?

Bernie is the guy in charge and he's shown us which direction he's going. Nascar it is.

You know, scary thought, nascar does not have buttons that drivers have to push that unlock different car options. So, you could argue that next year it will be the more legitimate racing series.

And speaking of the W12...





^Looks like it uses a camshaft and poppets, though, yeah? Not disc valves?

And speaking of two strokes...

[flynfrog]

Where do I get the last engine? Would make a sweet locost

[Formula None]

Its a Kohler flat 6 from an SCCA sports racer entry. Not sure what level.

http://sports.racer.net/index1.html >Chassis>Wynnfurst



Thouroughly awesome stuff. Interview with owner Jeff Miller:

http://www.vintagemotorsporttv.tampadig ... ler-racing

[Sayshina]

Well, that engine clearly has cams and one would assume poppet valves. And I have to admit I'm very hazy on the details because it was 20 years ago and at the time I thought the whole thing was ridiculous anyway.

But here goes. I know for sure there was talk of a W12 with disk valves, and I saw pictures of one, unpainted and looking fairly raw. I'm not sure if there were 2 of them or if the disk valves were later abandoned. I'm not sure if a W12 ever actually qualified, but I would almost swear at least 1 tried a few times. I do remember it being in a car and the word was it was heavy, unreliable, didn't make any power and had horrible aero.

There was a lot of fear heading into the atmo formula that the engines were going to be too big and or heavy. There was a lot of talk about the possibility of using a transverse layout (like the old Honda). The W configuration was an attempt to get a V12 without the length. When the engines finally showed up they were not much bigger than the turbos and all that talk turned out to be silly.

On the 2-stroke, I would think a flat layout would not be ideal. I do know there was a V6 outboard marine motor, somewhere around 2.6 liters, some 10 or so years ago. That could possibly be of use in a car project but I doubt it.

For one thing, highly tuned 2-strokes are hardly "locost". They're very cheap to tune but for the home tuner there's no good way to know where you are on the spectrum. They'll run like a top and seem to run almost forever, then the weather will change and they'll start melting pistons. 2-stroke tuning is still very much voodoo.

I suspect you'd have to keep the tune pretty conservative, and I suspect you'd still find the heat rejection to be rather high. All told I'd say stick with 4-strokes. They're expensive in terms of parts outlay, but they're very well understood and very predictable in terms of performance gains per money spent.

[malbeare]

I think that the twostroke had 6 cylinders volkswagen beetle style opposed cylinders with 3 central intake disk valves and the exhaust is a piston port.
my 2 cents

http://www.sixstroke.com/gallery.htm

[Sayshina]

I think that the twostroke had 6 cylinders volkswagen beetle style opposed cylinders with 3 central intake disk valves and the exhaust is a piston port.
my 2 cents

http://www.sixstroke.com/gallery.htm

The exhausts via piston port regardless. It's been the very rare design over the last 40 years to vary from that. There has been quite a bit of work on making the effective height of the exhaust port variable however.

I don't know anything about the engine in question, but generally reed valves give the best drivability and in a car that would almost certainly be the highest priority. They're also by far the easiest for a small tuner to work with.

It does look to be a flat 6, my comment was that I don't see that being the ideal configuration, as it would seem to force a lot of compromise into your expansion chamber design.

[Formula None]

2 stroke rotary/disc valves for reference:













You didn't mean rotary valves like these (below) did you Sayshina, in regards to the F1 engine? I'm just not sure how a disc valve would be used with a four stroke is all.

[Sayshina]

First off, I keep forgetting to answer one of the OP's questions, so as to what I think the ultimate incarnation of the 3.5 and 3.0 formulae would have been without interference:

3.5: Possibly V10, but most likely V12.
3.0: Possibly V12, but I suspect the V10 would have won out on drivability.

I know, way to go out on a limb. The history of racing is really very conservative, with few big risks being taken and usually punished when dared. Even some big advances like active suspension and semi-auto gearboxes are really quite conservative when looked at closely.

I don't see a W config ever making the cut aerodynamically, a V16 would be silly long and probably very flexible, and somehow a V14 doesn't seem likely.

No to the rotary valves above, I remember reading about them a couple of years ago and I remember their claim that they were ready to take over F1 if only they'd been allowed to compete, but it's easy to make those claims once you no longer have to prove it.

The disk valve head I'm talking about looked a lot like a 2-stroke head, with I think 2 disks inside rotating in the same plane as the piston crown. Details were hard to come by and honestly I wasn't really paying attention because I think the whole thing is rather silly.

It's absolutely correct to continue researching alternatives to everything built by humans, but too often we see pet projects that are "clearly much better" than existing designs but are somehow always held back by nefarious dark forces.

An engine guy in maybe Racecar Engineering a couple years ago wrote an article on why poppet valves dominate. Basically he said poppets are just very tough to beat, and not only because of the huge sealing problems most alternatives have to overcome. From memory, his claim was that poppets are capable of much higher accelerations than alternatives and therefore superior at all partial opening points, and that overall this made them superior.

I was interested in those above rotary valves, but only casually. I just don't buy their claims. They've been banned from F1, they haven't been banned from all motorsport. If they had a valuable contribution to make to the world I can't help but think they'd have found a way to prove it by now.

[elmerfud]

I designed a system 12 years ago, but could not get my head around sealing, heat loss and inertia in the drive mechanism.


blah, blah delete



,,,,,variable geometry turboshaft would be the next big step forward.

[Billzilla]

No to the rotary valves above, I remember reading about them a couple of years ago and I remember their claim that they were ready to take over F1 if only they'd been allowed to compete, but it's easy to make those claims once you no longer have to prove it.

The disk valve head I'm talking about looked a lot like a 2-stroke head, with I think 2 disks inside rotating in the same plane as the piston crown. Details were hard to come by and honestly I wasn't really paying attention because I think the whole thing is rather silly.

It's absolutely correct to continue researching alternatives to everything built by humans, but too often we see pet projects that are "clearly much better" than existing designs but are somehow always held back by nefarious dark forces.

An engine guy in maybe Racecar Engineering a couple years ago wrote an article on why poppet valves dominate. Basically he said poppets are just very tough to beat, and not only because of the huge sealing problems most alternatives have to overcome. From memory, his claim was that poppets are capable of much higher accelerations than alternatives and therefore superior at all partial opening points, and that overall this made them superior.

I was interested in those above rotary valves, but only casually. I just don't buy their claims. They've been banned from F1, they haven't been banned from all motorsport. If they had a valuable contribution to make to the world I can't help but think they'd have found a way to prove it by now.

I have access to one of the people in Bishop Engineering, and he knows quite a bit about their rotary valve test engines. They spent quite a bit of effort on a single-cylinder prototype getting it all working right, making good power, etc. They really did build some V-10 prototypes as well though they were never tested in a car as they were banned before they could do so. They still exist in Ilmor Engineering in Northamptonshire, and the NDA that everyone signed will expire in a couple of years so we should be able to find out about then then.