[NSRCA-discussion] OS Shadel piston/liner

Mon Mar 6 17:27:46 AKST 2006

To answer this question as to why they are different. Die cast aluminum is blended with other materials to keep it from cracking. It is not as dense as bar stock and as such cannot transfer heat as efficiently as metal that has the molecules closer together. (Bar stock). Try going to this link. They have a simple explanation that most would understand. 

http://www.efunda.com/processes/metal_processing/die_casting.cfm

Dennis Cone  

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org [mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Dave Burton
Sent: Monday, March 06, 2006 4:23 PM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] OS Shadel piston/liner

I don't know why the density of a certain aluminum alloy (6061, etc) would be different if die cast or extruded. It's the same material.
But then again, I'm old and so is my metallurgy knowledge
Dave Burton
-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org [mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Ed Miller
Sent: Monday, March 06, 2006 7:14 PM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] OS Shadel piston/liner
I could be wrong but it is my understanding the machined type heads are made from bar stock, not die cast material.  The greater density of the bar stock material should transfer heat more efficiently than a die cast piece. It is true in racing applications one used to polish the piston tops and combustion chamber to aid in maintaining heat in the combustion chamber ( now there are coating for this ) as well as ward off carbon deposit build up.  I think the difference is the ability for a given material to absorb and transfer heat versus the way a surface finish radiates heat. 
Ed M.
----- Original Message ----- 
From: Dave Burton <mailto:burtona at bellsouth.net>  

To: NSRCA Mailing List <mailto:nsrca-discussion at lists.nsrca.org>  
Sent: Monday, March 06, 2006 5:49 PM
Subject: Re: [NSRCA-discussion] OS Shadel piston/liner

I'm curious too Bill. Then same material should have the same heat characteristics. Surface irregularities from casting should have more effective surface area for greater heat loss.
Of course my thermo and metallurgy courses were a long time ago.
Dave Burton
-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org <mailto:nsrca-discussion-bounces at lists.nsrca.org>  [mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Bill Glaze
Sent: Monday, March 06, 2006 4:42 PM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] OS Shadel piston/liner
Ed:
Just wondered why the machined head would show better heat dissipation.  We were always taught that an as-cast surface showed better heat dissipation because of the greater developed surface area.  In fact, the "bad example" was the buffed and polished surface.  It showed terrible heat characteristics.  (Unless, of course, you were looking for heat retention.)  The above assumes, of course, that the materials involved were similar or exactly the same.  Not quarreling, just curious. 
Bill Glaze
----- Original Message ----- 
From: Ed Miller <mailto:edbon85 at charter.net>  

To: NSRCA Mailing List <mailto:nsrca-discussion at lists.nsrca.org>  
Sent: Monday, March 06, 2006 4:14 PM
Subject: Re: [NSRCA-discussion] OS Shadel piston/liner

I'm not sure how one plug going out would cause the engine to go lean.  At best having 2 plugs would cause the point of combustion to be a bit earlier OR ( what I believe ) would cause a slightly more efficient burn of the compressed air fuel mixture. Having 2 plugs also may ward off a sudden engine failure due to a blown glow plug.  The real advantage in my book of the Mintor head is it is made from bar stock, not cast and therefore has a better thermal efficiency, it sheds the head of combustion quicker and better than the cast head.  The lighter weight and second plug which may improve mid range are just a bonus.  If I look back at older OS and YS engines, the more "high performance" versions of the same engine had machined bar stock heads. For example the YS61AR and the YS 61R, the AR having besides other improvements a machined bar stock head versus the 61R die cast head. 
Ed M.
----- Original Message ----- 
From: Grow Pattern <mailto:pattern4u at comcast.net>  

To: NSRCA Mailing List <mailto:nsrca-discussion at lists.nsrca.org>  
Sent: Monday, March 06, 2006 10:42 AM
Subject: Re: [NSRCA-discussion] OS Shadel piston/liner

Randy,
             Said another way, if you lose a plug on a twin head, the engine goes lean and usually get very hot :-(  

Learned that one the hard way. Using two plugs to fix a rich spot transition on a pipe IMHO is at best a band-aid. Try it and see for yourself :-)

Eric.
----- Original Message ----- 
From: Dean Pappas <mailto:d.pappas at kodeos.com>  

To: randy10926 at comtekmail.com <mailto:randy10926 at comtekmail.com>  ; NSRCA Mailing List <mailto:nsrca-discussion at lists.nsrca.org>  
Sent: Monday, March 06, 2006 10:31 AM
Subject: Re: [NSRCA-discussion] OS Shadel piston/liner

Hi Randy,
Mintor parts are available from Aeroslave. 
I find that the twin plug head is not absolutely necessary, but it widens the nneedle valve sweet-spot: in the rich direction.
Dean

Dean Pappas 
Sr. Design Engineer 
Kodeos Communications 
111 Corporate Blvd. 
South Plainfield, N.J. 07080 
(908) 222-7817 phone 
(908) 222-2392 fax 
d.pappas at kodeos.com <mailto:d.pappas at kodeos.com>  
-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org <mailto:nsrca-discussion-bounces at lists.nsrca.org>  [mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Glenn Hatfield
Sent: Monday, March 06, 2006 9:23 AM
To: nsrca-discussion at lists.nsrca.org
Subject: Re: [NSRCA-discussion] OS Shadel piston/liner
Where do you get the mintor head?

Does the dual plug really help any?

Randy

--- ronlock at comcast.net wrote:

From: "Ron Lockhart" <ronlock at comcast.net>
To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
Subject: Re: [NSRCA-discussion] OS Shadel piston/liner
Date: Fri, 3 Mar 2006 17:37:30 -0500
http://www.pspec.com/

Ron Lockhart
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