ENGINE BASICS

"Charles Vincent" wrote in message news
Torn Lawence wrote:
The British made some WWII engines with rotating cylinder sleeves that
had in and out ports cut into them - rotary valves! No poppets. Good
performance, but burned oil and left conspicuous smoke trails, not a
good thing for a warbird to do.

That's what I remember from an engine class, unless I'm hallucinating
again.

That was a sleeve valve engine, Harry Ricardo's magnum opus. The
Bristol Hercules and Centaurus. Wear was an issue they never did tackle.

Charles

They still live today, but in a different form?

http://www.rcvengines.com/corporate/rcv_technology.htm

On Fri, 12 Jun 2009 14:55:48 -0700, Torn Lawence
wrote:

Tom Wait wrote:
"cmyr" wrote in message
...
On Jun 11, 8:06?pm, wrote:
On Thu, 11 Jun 2009 07:40:10 -0700 (PDT), cmyr

wrote:
? Going back to some hot rodding roots,I believe V.E. was increased
in the late '60's-70's thru the use of a specially designed double
cone affair placed in the collector pipe of a tuned exhaust
system,which created a stronger vacuum effect , creating stronger
scavenging of exhaust, and to some extent , helping draw more fuel/air
mix into the cylinder.
The anti reversion cone was a dirty fix for a crappy header design.
Better than a manifold, but not as good as a proper "tuned" header.

As I recall, this system was on the cover of Hot Rod magazine, on a
high end test vehicle,and was "scientifically" researched. In this
instance the reference to a crappy header design would be wrong.

All the previous 6 or7 posters have come up with methods of increasing VE
w/o superchargers. I want to add 4 or more valves per cylinder which would
probably increase the mass of the valve train. Certainly the complexity. I
don't see how a massive rocker arm or longer fatter pushrod could decrease
VE. Certainly a larger valve head would increase mass but would also
increase VE. A thicker valve stem would increase mass and decrease VE but I
think only marginally. I think the only way more mass would decrease VE
would be if the push rods were rubber.
Tom

The British made some WWII engines with rotating cylinder sleeves that
had in and out ports cut into them - rotary valves! No poppets. Good
performance, but burned oil and left conspicuous smoke trails, not a
good thing for a warbird to do.

That's what I remember from an engine class, unless I'm hallucinating again.
the Knight sleeve valve engine, perchance?

Dan D wrote:


"Charles Vincent" wrote in message
news
Torn Lawence wrote:
The British made some WWII engines with rotating cylinder sleeves that
had in and out ports cut into them - rotary valves! No poppets. Good
performance, but burned oil and left conspicuous smoke trails, not a
good thing for a warbird to do.

That's what I remember from an engine class, unless I'm hallucinating
again.

That was a sleeve valve engine, Harry Ricardo's magnum opus. The
Bristol Hercules and Centaurus. Wear was an issue they never did tackle.

Charles

They still live today, but in a different form?

http://www.rcvengines.com/corporate/rcv_technology.htm

Now THAT'S interesting. They have some with the prop shaft as part of
the rotating cylinder head, instead of the crank.
http://www.rcvengines.com/rcv120sp.htm

"Charles Vincent" wrote in message news
Torn Lawence wrote:
The British made some WWII engines with rotating cylinder sleeves that
had in and out ports cut into them - rotary valves! No poppets. Good
performance, but burned oil and left conspicuous smoke trails, not a
good thing for a warbird to do.

That's what I remember from an engine class, unless I'm hallucinating
again.

That was a sleeve valve engine, Harry Ricardo's magnum opus. The
Bristol Hercules and Centaurus. Wear was an issue they never did tackle.

Charles

They still live today, but in a different form?

http://www.rcvengines.com/corporate/rcv_technology.htm

Dan wrote:

... Weir knows what he's talking about ...

As long as it's Electronics or Aviation that he's talking about :-)

- J.O.-

[quote='Veeduber[_2_];695919']To All:

For example ALL engines have some degree of overlap
in their cam timing. If you have a text book that says otherwise, it
is in error.


No Not all engines have overlap, not early rotary radials with one pull/push rod operating the single rocker between the valves, opening one valve at the time, the valve clearence make it impossible to open both at the same time.

Jan

On Tue, 16 Jun 2009 19:54:20 +0100, Jan Carlsson
wrote:


'Veeduber[_2_ Wrote:
;695919']To All:

For example ALL engines have some degree of overlap
in their cam timing. If you have a text book that says otherwise, it
is in error.


No Not all engines have overlap, not early rotary radials with one
pull/push rod operating the single rocker between the valves, opening
one valve at the time, the valve clearence make it impossible to open
both at the same time.

Jan
And then there is the "atmospheric" intake valve.

Jan
And then there is the "atmospheric" intake valve.

AKA "Wheeze valve" really worked great in 200 rpm
Vaughn Garden Tractors.

Knight sleeve valve engines suffered from carbon
build-up in the sleeve's ports. Oil and fire took their
toll.

60 years back, Ford flatheads didn't need headers.
just dispense with exhaust manifolds. (neighbors
withstanding)

Old Chief Lynn