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what are the specs of pi heads? ports, valves, chamber? are these good heads for the street? i am an fe person but i am starting my first 385. also is there a good source for 385 info other than the ford performance book? thanks. jim.
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Alvin
(no login)
24.11.186.48 PI heads
No score for this post September 25 2001, 8:47 PM
PI heads have 92cc chambers. The intake valves are 2.19 and the exhausts are 1.72 . Ports sizes fall about halfway between the CJ and the regular production head. When used with a flat top piston, they yield about 10: 1 compression and make a good street performance head. One bit of advise, throw all of the valves away and buy new ones. They seem to have a habit of loosing their heads.
Alvin
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Bobby A
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209.245.98.156 Untitled
No score for this post September 26 2001, 12:34 AM
I know first hand what you`re talking about,Alvin.Get a good set of valves.
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JIM
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216.96.127.96 PI HEADS
No score for this post September 26 2001, 6:20 AM
do pi heads use the small sparkplugs? other sources have told me that the pi heads used the same combustion chambers as the cj/scj heads in 72 & 73. part number d20eab. i have a set of c8ve heads off an early 460 and wondered if i would be as well off putting 2.19 intake valves in them instead of purchasing pi heads? thanks. jim.
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Alvin
(no login)
24.11.186.48 PI heads
No score for this post September 26 2001, 7:24 AM
Yes, PI heads use small spark plugs. The combustion chamber sizes are definitely around 92ccs, and are much bigger than CJs. If you already own C8VEs, then they can be ported to make plenty HP. The port work is actually more important than the big valves.
Alvin
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jim
(no login)
216.96.127.5 port work
No score for this post September 26 2001, 1:55 PM
where and how do you port them. the intake ports look fairly healthy but the exhaust side looks pretty small. thanks. jim.
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Alvin
(no login)
24.11.186.48 Port work
No score for this post September 27 2001, 7:49 AM
Most of your work will be done on the exhaust side. To start with, the lump in the roof of the exhaust port must be ground flat. While you are working in that area, slim and streamline the valve guide bosses. Don't remove them.
It would take about a thousand words to really tell how it should be done, but maybe a picture would help even more. I've got some, if I could just figure out how to send them.
Alvin
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Alvin
(no login)
24.11.186.48 PI heads
No score for this post September 25 2001, 8:47 PM
PI heads have 92cc chambers. The intake valves are 2.19 and the exhausts are 1.72 . Ports sizes fall about halfway between the CJ and the regular production head. When used with a flat top piston, they yield about 10: 1 compression and make a good street performance head. One bit of advise, throw all of the valves away and buy new ones. They seem to have a habit of loosing their heads.
Alvin
Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message
Bobby A
(no login)
209.245.98.156 Untitled
No score for this post September 26 2001, 12:34 AM
I know first hand what you`re talking about,Alvin.Get a good set of valves.
Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message
JIM
(no login)
216.96.127.96 PI HEADS
No score for this post September 26 2001, 6:20 AM
do pi heads use the small sparkplugs? other sources have told me that the pi heads used the same combustion chambers as the cj/scj heads in 72 & 73. part number d20eab. i have a set of c8ve heads off an early 460 and wondered if i would be as well off putting 2.19 intake valves in them instead of purchasing pi heads? thanks. jim.
Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message
Alvin
(no login)
24.11.186.48 PI heads
No score for this post September 26 2001, 7:24 AM
Yes, PI heads use small spark plugs. The combustion chamber sizes are definitely around 92ccs, and are much bigger than CJs. If you already own C8VEs, then they can be ported to make plenty HP. The port work is actually more important than the big valves.
Alvin
Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message
jim
(no login)
216.96.127.5 port work
No score for this post September 26 2001, 1:55 PM
where and how do you port them. the intake ports look fairly healthy but the exhaust side looks pretty small. thanks. jim.
Score 1 2 3 4 5 (5=Excellent) Edit Message Delete Message Lock Thread Respond to this message
Alvin
(no login)
24.11.186.48 Port work
No score for this post September 27 2001, 7:49 AM
Most of your work will be done on the exhaust side. To start with, the lump in the roof of the exhaust port must be ground flat. While you are working in that area, slim and streamline the valve guide bosses. Don't remove them.
It would take about a thousand words to really tell how it should be done, but maybe a picture would help even more. I've got some, if I could just figure out how to send them.
Alvin
