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  #91  
Old 06-01-2009, 09:03 AM
fpv_gtho fpv_gtho is offline
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There must be something banning radial valves for F1. Ive read plenty of sources about Ilmor's attempt at using it and the technology getting banned.
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  #92  
Old 06-01-2009, 06:12 PM
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Matra et Alpine Matra et Alpine is offline
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Quote:
Originally Posted by hightower99 View Post
Does an engine only qualify as high revving if its redline is over some arbitrarily chosen number?
Yes. It's defined as 11,432.5 revs
Quote:
As far as I'm concerned I consider bore:stroke ratio and in that case the HP2 Sport's engine is more than short stroke.
Confusing stroke and squareness
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How is that weak?
Coz it was "Made up" to try to climb back out the the hole dug
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As it stands any discussion about the possibility of F1 using a radial valve head is pure conjecture.
Ah, ok, so the last 40 years of F1 engineering don't get to count ?
They wren't used BECAUSE of the valve train issues (sic)
[/quote]Ummm BMW seemed to have a nice solution with conical cams and cam followers that are mounted at the same angle as the valves... the resulting forces are exactly the same as a normal valvetrain...[/quote]
NOT. THe esultant forces AT THE VALVE STEM are similar.
But there are now forces at each of the angular transitions. Forces that promote wear and power loss and maintenance/

Quote:
BTW this is the first time you have mentioned this problem, last time you mentioned that it might be hard to achieve a high compression ratio and that the space for the radial valves was limited...
Rrofl

So in ht world, is an engineering solution only to have ONE problem ?
BOTH are issues and I've never tried to say otherwise.
HOWVER< that is not impoasrtant as my post at 7:17pm the previous day covered it

zing ...... spark.... spark ..... spark
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  #93  
Old 06-01-2009, 06:29 PM
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Matra et Alpine Matra et Alpine is offline
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Quote:
Originally Posted by fpv_gtho View Post
There must be something banning radial valves for F1. Ive read plenty of sources about Ilmor's attempt at using it and the technology getting banned.
hmm, never heard that one. Needs searching
The last I know they tendered to be the "stadnard F1 engine" supplier, but lost out. They offeed the old Mercedes-Ilmor engine. Cosworth won the FIA support. Nothing was about technology as far as O was aware. It was purely commercial. Price and IP.

Their most recent engine design, the MotoGP V4 did not use radial valve setup !
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  #94  
Old 06-01-2009, 08:43 PM
fpv_gtho fpv_gtho is offline
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I think they wanted to use it around the late 90's. This came up from a google search however: Ilmor F1 rotary valve project - 10 Tenths Motorsport Forum
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  #95  
Old 06-02-2009, 04:42 AM
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Quote:
Originally Posted by Matra et Alpine View Post
Yes. It's defined as 11,432.5 revs
Really? Why? <-- thats what I am trying to get to...
Why isn't it 11,432.4RPM?

Quote:
Originally Posted by Matra
Confusing stroke and squareness
I am not confusing them I am equating oversquare to short-stroke... maybe you think that that is another one of my "original" ideas? maybe you should check
Maybe you have a criteria that is better? like some arbitrarily chosen value perhaps?

Quote:
Originally Posted by Matra
NOT. THe esultant forces AT THE VALVE STEM are similar.
But there are now forces at each of the angular transitions. Forces that promote wear and power loss and maintenance
Really? with conical cams, and valves that are angled so that the forces cancel each other out? The biggest issue which I see is the lack of space for the actual cylinder head. Radial valve heads tend to have compact combustion chambers but they need huge heads with room for all the independant airways and the valves and the conical cams.
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  #96  
Old 06-02-2009, 05:06 AM
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Quote:
Originally Posted by fpv_gtho View Post
I think they wanted to use it around the late 90's. This came up from a google search however: Ilmor F1 rotary valve project - 10 Tenths Motorsport Forum
ah, see where the confusion comes from.
Those are rotary valves .. not radial.
So the rotary valve spins to open/close whereas radial is still poppet valves just arrange in a hemispherical position.
AS with many other "innovatison", yes I'd have loved to see this developed as it needs it.
Been tried in bikes for lon long times, but never that succesful on tuned engines as sealing and wear become an issue. The kind of research F1 did woudl have foudn a solution that provided the necessary performance and service intervals. Shame
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  #97  
Old 06-02-2009, 05:11 AM
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Quote:
Originally Posted by hightower99 View Post
Why isn't it 11,432.4RPM?
WHen it was accpeted as an SI standard unit the French demanded it be set at the value they had bene using rather than the rest of us.
Quote:
I am not confusing them I am equating oversquare to short-stroke
That's the point, you were bringing in a second variable.
Quote:
Maybe you have a criteria that is better?
Would have but after the SI standards debacle over the revs (see above) they have not decided on the actual value yet. Sorry, but stadnards bodies ... you gotta love em ... or hate em
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Really? with conical cams, and valves that are angled so that the forces cancel each other out?
FOces cancle out ?
Erm, not without WEAR they don't.
two equal forces measn double the force on the item in question, it just happens to be opposing. That sdoesn't REMOVE the force.
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Radial valve heads tend to have compact combustion chambers but they need huge heads with room for all the independant airways and the valves and the conical cams.
yep as already stated.
They do NOT bring huge advantages in smaller capacity performacne engines
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  #98  
Old 06-02-2009, 07:35 AM
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hightower99 hightower99 is offline
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Quote:
Originally Posted by Matra et Alpine View Post
That's the point, you were bringing in a second variable.
What??? There is no second variable there is only one, the bore:stroke ratio. If it is larger than 1 then the engine is considered oversquare and short-stroke.

If you don't have a serious answer as to when an engine should be considered high reving or short-stroke then your original statement of how the advantages of having a radial valve head couldn't come into play with the bimmer are non-sense...

Quote:
Originally Posted by Matra
FOces cancle out ?
Erm, not without WEAR they don't.
two equal forces measn double the force on the item in question, it just happens to be opposing. That sdoesn't REMOVE the force.
The resulting force is zero so no extra wear compared to a conventional valvetrain. You know, if you push down on the table with 10N force the table pushes back with 10N force and your hand doesn't go through the table Of course the forces are still there but the result is zero.

Quote:
Originally Posted by Matra
They do NOT bring huge advantages in smaller capacity performacne engines
Never said "huge" advantages... Radial valve heads allow: larger valves, better port shape and a compact combustion chamber due to reduced valve-relief size for any given lift.

BTW: Define "smaller capacity"
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