Porting 101

Mon Mar 16 15:13:58 GMT 1998

Bruce, 

Please turn you HTML off -- this is impossable to read.

Thanks

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Subject: Porting 101
Author:  diy_efi-owner at esl.eng.ohio-state.edu at dell_unix
Date:    3/12/1998 9:19 PM

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<DIV><FONT color=#000000 size=2>In the mid 70's I spent a bunch of time play 
trying to</FONT></DIV>
<DIV><FONT color=#000000 size=2>&quot;improve&quot; combustion chambers in the 
SOHC Ford 2000cc</FONT></DIV>
<DIV><FONT color=#000000 size=2>pinto motor, and with some Mopar 340/360 
stuff.&nbsp; As poor </FONT></DIV>
<DIV><FONT color=#000000 size=2>as they appear, unless you have alot of past 
experience the</FONT></DIV>
<DIV><FONT color=#000000 size=2>results can be disappointing.&nbsp; I ground up

a few </FONT><FONT color=#000000 size=2>pinto heads</FONT><FONT color=#000000 
size=2>,</FONT></DIV>
<DIV><FONT color=#000000 size=2>and a few pairs of 340s.&nbsp; And I'll 
</FONT><FONT color=#000000 size=2>honestly </FONT><FONT color=#000000 size=2>say

</FONT><FONT color=#000000 size=2>the results </FONT></DIV> 
<DIV><FONT color=#000000 size=2>were never very noticeable.&nbsp;
May</FONT><FONT color=#000000 size=2>be a couple </FONT><FONT color=#000000 
size=2>hundredths,</FONT></DIV>
<DIV><FONT color=#000000 size=2>maybe .5 mph..&nbsp; If you think you 
</FONT><FONT color=#000000 size=2>have to do </FONT><FONT color=#000000 
size=2>something, </FONT></DIV>
<DIV><FONT color=#000000 size=2>maybe a dremel, and smooth out </FONT><FONT 
color=#000000 size=2>some of the </FONT><FONT color=#000000 
size=2>casting</FONT></DIV>
<DIV><FONT color=#000000 size=2>(ie 3 mins/chamber).&nbsp; There was some gains

to be made</FONT></DIV>
<DIV><FONT color=#000000 size=2></FONT><FONT size=2>in porting.</FONT></DIV> 
<DIV><FONT color=#000000 size=2>&nbsp; Porting on a SBC working around the valve

guide, and </FONT></DIV>
<DIV><FONT color=#000000 size=2>short side radius, OK.&nbsp; But, unless you've

done it before</FONT></DIV>
<DIV><FONT color=#000000 size=2>I wouldn't start on a good motor.&nbsp; 
Volunteer to help</FONT></DIV>
<DIV><FONT color=#000000 size=2>someone else, that has a good base line, and 
document</FONT></DIV>
<DIV><FONT color=#000000 size=2>what works.&nbsp; Work slowly, and get the knack

for what</FONT></DIV>
<DIV><FONT color=#000000 size=2>works.&nbsp;&nbsp; Better yet build a flow 
bench, and do it right.</FONT></DIV>
<DIV><FONT color=#000000 size=2></FONT><FONT size=2>Or be honest with yourself,

and say I really don't know </FONT></DIV>
<DIV><FONT size=2>much about what I'm doing here, and just gonna 
polish/</FONT>&nbsp;</DIV>
<DIV><FONT size=2>make em look pretty.&nbsp;</FONT>&nbsp;</DIV>
<DIV><FONT size=2>&nbsp; One of the places I worked at we cast, and machined 
</FONT></DIV>
<DIV><FONT size=2>our own cylinder heads.&nbsp; Did alot of dyno/porting 
R+D</FONT></DIV>
<DIV><FONT size=2>and looks don't mean much.&nbsp; Granted it sells parts, 
but</FONT></DIV>
<DIV><FONT size=2>has nothing to do with performance.</FONT></DIV> 
<DIV><FONT size=2>&nbsp; As I understand the original poster this is for a 
boosted</FONT></DIV>
<DIV><FONT size=2>engine.&nbsp; In that application, I'd start with a stock 
head</FONT></DIV>
<DIV><FONT size=2>so there is a much mass for thermal loading as 
possible.</FONT></DIV>
<DIV><FONT size=2>Start with a base line and work up from there.</FONT></DIV> 
<DIV><FONT size=2>&nbsp; HTH&nbsp; Bruce&nbsp; Happiness is a tailored Cone 
Shaped Hat</FONT></DIV></BODY></HTML>