4.6 motor
11/22/04, 04:02 PM
#1
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if i'm correct thye started putting the 4.6 in mustangs in 96. is the 96 motor any different than mine ? or they kinda the same cuz i never saw under the hood of any mustang older then mine
11/22/04, 04:33 PM
#2
They are the same motor. The 96-98 variants didnt flow as much air through the heads/intake/cams, therefore having alot lower power curve and they seemed to fall on their face at 5000rpm or so. in 1999, ford introduced the PI heads (Performance Improved). This was a better flowing head design, better cams and better intake. This brought the power up quite a bit and made them a much stronger car.
Alot of folks have done the headswap to PI parts on their 96-98 GT and acctually make more power than a 1999+ car. The reason is because the 96-98 cars had flattop pistons, which with the PI heads, had a higher compression ratio than the 99+ cars with the same heads.
Alot of folks have done the headswap to PI parts on their 96-98 GT and acctually make more power than a 1999+ car. The reason is because the 96-98 cars had flattop pistons, which with the PI heads, had a higher compression ratio than the 99+ cars with the same heads.
12/21/04, 07:18 PM
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Originally posted by Scothew@November 22, 2004, 5:36 PM
They are the same motor. The 96-98 variants didnt flow as much air through the heads/intake/cams, therefore having alot lower power curve and they seemed to fall on their face at 5000rpm or so. in 1999, ford introduced the PI heads (Performance Improved). This was a better flowing head design, better cams and better intake. This brought the power up quite a bit and made them a much stronger car.
Alot of folks have done the headswap to PI parts on their 96-98 GT and acctually make more power than a 1999+ car. The reason is because the 96-98 cars had flattop pistons, which with the PI heads, had a higher compression ratio than the 99+ cars with the same heads.
They are the same motor. The 96-98 variants didnt flow as much air through the heads/intake/cams, therefore having alot lower power curve and they seemed to fall on their face at 5000rpm or so. in 1999, ford introduced the PI heads (Performance Improved). This was a better flowing head design, better cams and better intake. This brought the power up quite a bit and made them a much stronger car.
Alot of folks have done the headswap to PI parts on their 96-98 GT and acctually make more power than a 1999+ car. The reason is because the 96-98 cars had flattop pistons, which with the PI heads, had a higher compression ratio than the 99+ cars with the same heads.
12/22/04, 02:56 PM
#8
Originally posted by Fordracing200+December 22, 2004, 3:03 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Fordracing200 @ December 22, 2004, 3:03 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-mr-mstng@December 21, 2004, 9:25 PM
Swap 99+ heads onto 96-98 GTs.
Swap 99+ heads onto 96-98 GTs.
[/b][/quote]yes. The reason being is that 96-98 motors have flat top pistons. BUt they have really bad flowing heads and intake.
99+ cars have dished pistons and much better flowing heads and intake. But the deck clearence on the 99+ heads is shorter than on the 96-98. Therefore when you put the 99+ heads with a smaller deck clearence, on 96-98 motors with flat top pistons, you get a higher compression ratio than a 99+ car, which produces more HP
12/22/04, 11:00 PM
#10
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the intake was the biggest culprit as the PI heads have better bottom end and mid-range flow IIRC while the old 4.6 heads actually outflow the PI heads on the top (for all the good that'll do ya).
12/23/04, 01:49 AM
#11
You are partially right Bob, but the PI heads cams and intake together will make more HP across the board than a non-pi head car with a PI intake and/or cams.
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