Ford 144-250 inline 6 high performance building

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(Ignition)
(Cams)
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==Cams==
 
==Cams==
Aftermarket cam grinds are available from Clay Smith, Comp, Isky and Schneider. Be aware that some of the cams offered exceed the lift capability of stock valve springs, which is about 0.450". There are a couple aftermarket spring options from Clay Smith, but they require machining for PC valve seals. Ford 302 intake springs will clear to just over 0.500" lift, but there is no retainer with a 5/16" valve stem size to fit the 302 intake springs.  
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Aftermarket cam grinds are available from Clay Smith, Comp Cams, Isky and Schneider. Be aware that some of the cams offered exceed the lift capability of stock valve springs, which is about 0.450". They also may exceed the lift rate of these cams at the maximum RPM.  However, the good news is that there are a few aftermarket spring options.
  
To cure this, you can start with 12 stock 302 2-piece intake retainers, then take the 11/32" center section out and set them aside. Then take 12 stock 5/16" center sections from the 144-250ci retainers, and use them in the 302 retainers. Now you have a 5/16" retainer to fit the 302 intake springs.
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Clay Smith offers a couple of options, but they may require machining the head for PC valve seals. Another option is Ford 302 intake springs, which will allow just over 0.500" lift and will provide sufficient pressure to prevent "valve float" at high RPM.  These are single springs, which allow the use of stock valve seals.  However, the valve retainers for these springs were designed for 11/32" diameter valve stems.  In order to use them with the 144-250ci valves, which have 5/16" diameter stems, it is necessary to mix the 302 V8 retainer parts and the 6 cylinder retainer parts. 
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Both of the 144-250ci and 302ci retainers have four parts:
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  1. The outer retainer which contacts the spring.
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  2. The inner retainer which fits inside the outer retainer.
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  3 & 4. The two (2) valve lock halves which lock the valve stem to the inner retainer.
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To do this, you start with 12 stock 302 intake outer retainers. Then take 12 stock 144-250ci 5/16" inner retainers, and place them in the 302 outer retainers. Finally, you use the 144-250ci valve locks.  Now you have a 5/16" retainer to mate the 144-250ci valves to the 302 intake springs.
  
 
==Induction==
 
==Induction==

Revision as of 17:40, 16 March 2016

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