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Re: Nitrogen Enbrittlement (acid manifold porting)

To: RMEbstein@aol.com, "Tiger's Den" <tigers@Autox.Team.Net>
Subject: Re: Nitrogen Enbrittlement (acid manifold porting)
From: Steve Laifman <SLaifman@socal.rr.com>
Date: Thu, 21 Oct 2004 15:34:50 -0700
Rodney,

Here is something to ponder. 

Electrohone is a fine process for smoothing out hard to reach places, 
and even achieving a high polish at a reasonable (compared to mechanical 
methods) costs.

However, a nice smooth surface creates the perfect condition for 
stagnate flow along the surface, as the stream "sticks" well to it's 
shiny partner.  This narrows the active diameter of the passageway, but 
probably increases the flow rate profile across the stream, making it 
faster in the middle.  I know that enlarging ports also increases their 
local velocity capability, but with valve and port sizes fixed may 
reduce actual mass flow.  (Ports too big, valves too small - for instance).

Whether the entire mass flow is helped, or hindered by this process is 
something to ponder.  I know great things are claimed in flow bench 
tests.  Those tests are simulations of the real thing.  Turbulent flow 
can actually pass more mass per time unit than laminar flow.

It would be interesting for our good fluid mechanics experts to come 
forward with their views on this.

NOT presuming to know the answer, only the question,

Steve


RMEbstein@aol.com wrote:

>I had a stock aluminum GM big block intake manifold done by Extrude Hone. The 
>cost was $425 and it took somewhere around 6 weeks to get it done. I had my 
>engine dyno'ed and it helped a lot.
>
>However, I probably will never do it again, since the price/HP ratio is very 
>small and the port sizes remained about the same.
>
>Rodney
>B382001478LRXFE
>  
>

-- 
-----

Steve Laifman
Editor
http://www.TigersUnited.com





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