1 Steam Cars : Phorum
General Steam Car topics
La Locomotive a vapeur
Posted by: Mark Stacey (IP Logged)
Date: February 19, 2002 05:45PM
<HTML>This book by Andre Chapelon has been translated into English and reissued.
Has anyone read this book and if so is there enough information about improving piston valve porting to make it a worthwhile buy at 55 English pounds?
The reviews mention that Chapelon researched streamlining the engine passages and ports. This interests me as I've been wondering what effect classic i.c. performance porting, intake and exhaust manifold theory would have applied to a 2 cylinder compound steam car engine.
There should be some improvement on my car as its inlet, receiver and exhaust steam connections are cobbled together from pipe fittings.
Does Chapelon's book give idea / indications of how much improvement could be expected?
Cheers
Mark Stacey</HTML>
Has anyone read this book and if so is there enough information about improving piston valve porting to make it a worthwhile buy at 55 English pounds?
The reviews mention that Chapelon researched streamlining the engine passages and ports. This interests me as I've been wondering what effect classic i.c. performance porting, intake and exhaust manifold theory would have applied to a 2 cylinder compound steam car engine.
There should be some improvement on my car as its inlet, receiver and exhaust steam connections are cobbled together from pipe fittings.
Does Chapelon's book give idea / indications of how much improvement could be expected?
Cheers
Mark Stacey</HTML>
Re: La Locomotive a vapeur
Posted by: Rolly Evans (IP Logged)
Date: February 19, 2002 06:54PM
<HTML>I haven’t read the book, but if you want to see good porting look at Besler’s 3-1/4 X 5-1/2 Four-cylinder 90-degree compound. The piston valve is right up next to the cylinder The ports are .75 Almost no head clearance volume.
Rolly</HTML>
Rolly</HTML>
Re: La Locomotive a vapeur
Posted by: Mark Stacey (IP Logged)
Date: February 20, 2002 06:13AM
<HTML>Ron could you point me to a picture of this engine please.
I've seen a section view of the Besler V2 compound proposed plane engine that ended up in the steam launch. The port layout was very direct with a long piston valve so the valve and cylinder ports line up directly.
The porting in the patterns and spare casting set for my car engine appear
similar. The HP port measurements are 22mm wide by 15mm high fed from an annulus on the 32mm diameter HP piston valve. Cylinder and piston valve walls are 11mm apart where the port runs.
For my 2.5"x4 11/16" x 4.5" stroke engine is this typical or would a port and polish help? ;-)
Seriously I could improve the flow by enlarging the ports and blending in the edges but this will increase the clearance volume. Is there an optimum of some sort or a trade off, rule of thumb? My limited library of steam design books is a bit silent on porting flows apart from repeating minimising clearance volume is a good idea.
Cheers
Mark Stacey</HTML>
I've seen a section view of the Besler V2 compound proposed plane engine that ended up in the steam launch. The port layout was very direct with a long piston valve so the valve and cylinder ports line up directly.
The porting in the patterns and spare casting set for my car engine appear
similar. The HP port measurements are 22mm wide by 15mm high fed from an annulus on the 32mm diameter HP piston valve. Cylinder and piston valve walls are 11mm apart where the port runs.
For my 2.5"x4 11/16" x 4.5" stroke engine is this typical or would a port and polish help? ;-)
Seriously I could improve the flow by enlarging the ports and blending in the edges but this will increase the clearance volume. Is there an optimum of some sort or a trade off, rule of thumb? My limited library of steam design books is a bit silent on porting flows apart from repeating minimising clearance volume is a good idea.
Cheers
Mark Stacey</HTML>
Re: La Locomotive a vapeur
Posted by: Mark Stacey (IP Logged)
Date: February 20, 2002 06:15AM
<HTML>Sorry Rolly not Ron. Shouldn't have had that second glass of wine.
Cheers
Mark Stacey</HTML>
Cheers
Mark Stacey</HTML>
Re: La Locomotive a vapeur
Posted by: Rolly Evans (IP Logged)
Date: February 20, 2002 10:14AM
<HTML>I think the engines have the same design. You have to remember with a long port the valve travel is also longer. The over all design has to have the space for the valve travel. Jim Crank would probably know if the engine designs are the same. I have heard proses and cons on polished port surfaces on a steam engine but I am unfamiliar with the results or benefits.
Rolly</HTML>
Rolly</HTML>
Re: La Locomotive a vapeur
Posted by: George K. Nutz (IP Logged)
Date: February 20, 2002 11:07AM
<HTML>Mark,
It appears form all of Abner Dobles notes that he spent a great deal of time making the passages and pass areas as short and as streamlined as possible, no quick changes of areas that would result in turbulence and shock losses. That had a lot to do with his 5" stroke engines running well(from the dyno plots) to 1680 rpm and the 4" stroke to 2100 rpm. The 4 cylinder engine Rolly mentioned was a proposal and never built,
George</HTML>
It appears form all of Abner Dobles notes that he spent a great deal of time making the passages and pass areas as short and as streamlined as possible, no quick changes of areas that would result in turbulence and shock losses. That had a lot to do with his 5" stroke engines running well(from the dyno plots) to 1680 rpm and the 4" stroke to 2100 rpm. The 4 cylinder engine Rolly mentioned was a proposal and never built,
George</HTML>
Re: La Locomotive a vapeur
Posted by: Rolly Evans (IP Logged)
Date: February 20, 2002 11:58AM
<HTML>George
the engine I was referring to is the one Besler used in the 85 foot boat. It looks very much like the one used in the Plane. I think the Piston and valve design are similer.
Rolly</HTML>
the engine I was referring to is the one Besler used in the 85 foot boat. It looks very much like the one used in the Plane. I think the Piston and valve design are similer.
Rolly</HTML>
Re: La Locomotive a vapeur
Posted by: Jim Crank (IP Logged)
Date: February 20, 2002 01:19PM
<HTML>Gentlemen,
If you are talking about the 150 HP engines in the "COLLENE", Bill's steam yacht and the second airplane engine, then you are right. Both are identical except in size.
That V-4 was a proposal to the Navy and not built. Read what the second stage tubine would have added.
Besler and Stan Whitlock, the designer, always went for the shortest and most direct ports, smooth as possible, and good breathing at top speed.
Look, a steam engine is no different than a racing gas engine. Get the stuff in an out with the least flow losses and the least addition to the clearance volume, in the case of a steam engine.
Yes, Besler's piston valves were probably the largest used in relationship to the cylinder volume. Big valves, very short stroke and straight in and out ports.
Even the Kaiser engine had its one traverse piston valve right on top of the HP cylinders with the shortest ports possible, and I ran that on the dyno several times at 3,600 rpm.
Jim</HTML>
If you are talking about the 150 HP engines in the "COLLENE", Bill's steam yacht and the second airplane engine, then you are right. Both are identical except in size.
That V-4 was a proposal to the Navy and not built. Read what the second stage tubine would have added.
Besler and Stan Whitlock, the designer, always went for the shortest and most direct ports, smooth as possible, and good breathing at top speed.
Look, a steam engine is no different than a racing gas engine. Get the stuff in an out with the least flow losses and the least addition to the clearance volume, in the case of a steam engine.
Yes, Besler's piston valves were probably the largest used in relationship to the cylinder volume. Big valves, very short stroke and straight in and out ports.
Even the Kaiser engine had its one traverse piston valve right on top of the HP cylinders with the shortest ports possible, and I ran that on the dyno several times at 3,600 rpm.
Jim</HTML>
Re: La Locomotive a vapeur
Posted by: Rolly Evans (IP Logged)
Date: February 20, 2002 04:32PM
<HTML>Jim
If my memory serves me as I am not at home, the Besler proposed landing craft was to have the V4 compound with an exhaust low pressure turbine belted to the same out put shaft, with a combined HP of 775 some where over 2000RPM and 1200PSI rings a bell.
Am I close? And the proposed boilers were of the Lamont type. For some reason I seem to remember they were in units of four?
I take it the twin engines in the Collene were two cylinder compounds.
Rolly</HTML>
If my memory serves me as I am not at home, the Besler proposed landing craft was to have the V4 compound with an exhaust low pressure turbine belted to the same out put shaft, with a combined HP of 775 some where over 2000RPM and 1200PSI rings a bell.
Am I close? And the proposed boilers were of the Lamont type. For some reason I seem to remember they were in units of four?
I take it the twin engines in the Collene were two cylinder compounds.
Rolly</HTML>
Re: La Locomotive a vapeur
Posted by: Jim Crank (IP Logged)
Date: February 20, 2002 04:43PM
<HTML>Rolly,
You are right on the landing craft engine.
The steam generators were probably using Bill's favorite spillover cycle. That proposal is not in front of me; but I think that is what he was trying to sell to the Navy. Don't recall him ever making a pure Lamont with the circulating pump, although he sure knew about it.
That turbine added a lot, much smaller and cheaper than compounding. Belt drive is right.
The engines on the COLLENE were compound with the HP cylinders upright and the LP flat pointing inboard. Very roomy engine room.
The steam generator was in the stack of the boat.
Jim</HTML>
You are right on the landing craft engine.
The steam generators were probably using Bill's favorite spillover cycle. That proposal is not in front of me; but I think that is what he was trying to sell to the Navy. Don't recall him ever making a pure Lamont with the circulating pump, although he sure knew about it.
That turbine added a lot, much smaller and cheaper than compounding. Belt drive is right.
The engines on the COLLENE were compound with the HP cylinders upright and the LP flat pointing inboard. Very roomy engine room.
The steam generator was in the stack of the boat.
Jim</HTML>
Re: La Locomotive a vapeur
Posted by: Mark Stacey (IP Logged)
Date: February 21, 2002 12:05AM
<HTML>Thanks Everyone
A little judicious port massaging and matching will be done when I take Black Betty's engine out for some axle modifications.
I have access to a friends flow bench so I'll try to measure and then report back the result of the changes.
Won't be for a while though. Around home and other car projects to finish first.
Cheers
Mark Stacey</HTML>
A little judicious port massaging and matching will be done when I take Black Betty's engine out for some axle modifications.
I have access to a friends flow bench so I'll try to measure and then report back the result of the changes.
Won't be for a while though. Around home and other car projects to finish first.
Cheers
Mark Stacey</HTML>
Re: La Locomotive a vapeur
Posted by: Peter Heid (IP Logged)
Date: February 21, 2002 12:39PM
<HTML>Mark,
If you want to go hog wild you can try extrusion porting. There are companies that port 2 cycle engines by forcing or drawing by vacuum, an abrasive, tooth paste like substance through the ports to replicate the flow while enlarging the ports where needed.
Peter Heid</HTML>
If you want to go hog wild you can try extrusion porting. There are companies that port 2 cycle engines by forcing or drawing by vacuum, an abrasive, tooth paste like substance through the ports to replicate the flow while enlarging the ports where needed.
Peter Heid</HTML>
Re: La Locomotive a vapeur
Posted by: Peter Heid (IP Logged)
Date: February 21, 2002 11:40PM
<HTML>Mark,
Another word about port wall surfaces. For years the highly polished, mirror finish was thought to be the way to provide the best flow, but it has been found that a slightly rough surface promotes the better flow. The fluid pools in the surface voids and the pooled fluid provides a better surface for flow than the port wall. Notice the surface of a golf ball is dimpled, just for this reason. The hulls of racing boats are wet sanded for the least drag in the water. I can only assume the same is true with steam, the slide rule guys out there can confirm this for you.
In an IC engine, the fuel/air flow is brought in under engine vacuum and for high rpms, they must have a high velocity and require a tuned length so opening the port too large has adverse effects. Steam comes in under pressure so the bigger, shorter and most direct would seem to be the rules of the day.
Peter Heid</HTML>
Another word about port wall surfaces. For years the highly polished, mirror finish was thought to be the way to provide the best flow, but it has been found that a slightly rough surface promotes the better flow. The fluid pools in the surface voids and the pooled fluid provides a better surface for flow than the port wall. Notice the surface of a golf ball is dimpled, just for this reason. The hulls of racing boats are wet sanded for the least drag in the water. I can only assume the same is true with steam, the slide rule guys out there can confirm this for you.
In an IC engine, the fuel/air flow is brought in under engine vacuum and for high rpms, they must have a high velocity and require a tuned length so opening the port too large has adverse effects. Steam comes in under pressure so the bigger, shorter and most direct would seem to be the rules of the day.
Peter Heid</HTML>
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