[modeleng] Re: Tall Tales?
- From: "Phill Smith" <steam@xxxxxxxxxxxxxx>
- To: <modeleng@xxxxxxxxxxxxx>
- Date: Sat, 5 Mar 2005 22:26:33 +0800
Andy,
The shape, of the piston side, on the cylinder covers, is to reduce the
volume of the compression stage of the valve timing and increase the
pressure obtained during compression so as to equal the "designed" boiler
pressure. This cussioning effect is an essential component in extending the
life of the piston rod at high piston speeds, and in the economic use of
steam. The shape of the covers was (in the late engines) designed to allow
better breathing of the ports, though sometimes this created other problems.
Cheers,
Phill.
----- Original Message -----
From: "Andy A" <AndyA@xxxxxxxx>
To: <modeleng@xxxxxxxxxxxxx>
Sent: Saturday, March 05, 2005 6:48 PM
Subject: [modeleng] Re: Tall Tales?
> HI Ron
> I believe the BR standards also had hollow heads but need to check that.
> Most piston heads had some dishing to there shape which would have made it
> difficult to cast them hollow. I hadn't thought about the reciprocating
mass
> idea, I just know they are extremley heavy and certainly not a single man
> lift. Another thought, most cylinder covers were not flat on the rear
face.
> Would that have been done to help steam ditribution across the piston
face?
>
> Andy
> ----- Original Message -----
> From: "Ron Head" <ron.head@xxxxxxxxxxxxx>
> To: <modeleng@xxxxxxxxxxxxx>
> Sent: Saturday, March 05, 2005 10:09 AM
> Subject: [modeleng] Re: Tall Tales?
>
>
> Hi Andy
>
> I've just been looking through some of my technical books and it seems the
> LMS may have been unique in using hollow piston heads - anyone else care
to
> comment?
>
> Presumably this was done to reduce the reciprocating mass.
>
> Regards
> Ron
>
> ----- Original Message -----
> From: "Andy A" <AndyA@xxxxxxxx>
> To: <modeleng@xxxxxxxxxxxxx>
> Sent: Saturday, March 05, 2005 2:17 AM
> Subject: [modeleng] Re: Tall Tales?
>
>
> > Hi Barrie
> > Not all piston heads are hollow, the LNER preferred a one piece forged
> > head
> > and rod.
>
>
>
> --
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>
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