PI Engines
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PI Engines
Is there any way to tell what heads a person has without tearing into the engine? My early 2000 F250 (Sept. '99 build date, IIRC) appears to have had top-end work done on it, and I'm just curious if one of the previous owners did a PI conversion.
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From: Wayyy NoCal, USA
The easiest way is probably to look at them and see if they have "PI" cast into the side of them. Look up inside the fenderwell and look at all the casting info around the exhaust manifolds. The PI heads have a very noticeable "PI" at the end of one of the numbers....
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Thanks, apparently, I don't have PI heads then because I'm sure I woulda noticed that. Of course, I've been accused of being blind before . . .
ETA: A couple of corrections: It is a August 1999 build date, and I have PI heads! I was looking for larger letters, not the little 1/4" tall letters that are there.
Next question, I know the changeover was 2000. Was that according to build date, or model year? I'm just trying to chase down the history on my 11 year-old, 190k truck.
ETA: A couple of corrections: It is a August 1999 build date, and I have PI heads! I was looking for larger letters, not the little 1/4" tall letters that are there.
Next question, I know the changeover was 2000. Was that according to build date, or model year? I'm just trying to chase down the history on my 11 year-old, 190k truck.
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From: Long Island USA
MODEL YEAR 2000-2004 is definitely PI heads.
But who knows, there might have been a few early 2000's that squeeked through, you never know, but we've never heard of one (yet).
But who knows, there might have been a few early 2000's that squeeked through, you never know, but we've never heard of one (yet).
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That's where my concern was, being an early 2000 (Aug. '99), and July '99 build on the engine, wasn't sure if there was a "crossover" period.
This leads me to another question. I thought PI engines revved better than non-pi, but mine seems to fall flat on its face between 3000 to 3500 rpm. Below that rpm range, it seems like it has all the power in the world. If I mash the pedal down, it doesn't want to accelerate very well, but if I push the pedal half way down, she'll get up to speed in a big hurry. Is this normal?
It kinda feels like driving a diesel in many ways. I guess I'm used to the 4.6 in my last truck, which was the exact opposite -- it was happiest above 3000 rpm.
This leads me to another question. I thought PI engines revved better than non-pi, but mine seems to fall flat on its face between 3000 to 3500 rpm. Below that rpm range, it seems like it has all the power in the world. If I mash the pedal down, it doesn't want to accelerate very well, but if I push the pedal half way down, she'll get up to speed in a big hurry. Is this normal?
It kinda feels like driving a diesel in many ways. I guess I'm used to the 4.6 in my last truck, which was the exact opposite -- it was happiest above 3000 rpm.
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From: SE Texas
That's where my concern was, being an early 2000 (Aug. '99), and July '99 build on the engine, wasn't sure if there was a "crossover" period.
This leads me to another question. I thought PI engines revved better than non-pi, but mine seems to fall flat on its face between 3000 to 3500 rpm. Below that rpm range, it seems like it has all the power in the world. If I mash the pedal down, it doesn't want to accelerate very well, but if I push the pedal half way down, she'll get up to speed in a big hurry. Is this normal?
It kinda feels like driving a diesel in many ways. I guess I'm used to the 4.6 in my last truck, which was the exact opposite -- it was happiest above 3000 rpm.
This leads me to another question. I thought PI engines revved better than non-pi, but mine seems to fall flat on its face between 3000 to 3500 rpm. Below that rpm range, it seems like it has all the power in the world. If I mash the pedal down, it doesn't want to accelerate very well, but if I push the pedal half way down, she'll get up to speed in a big hurry. Is this normal?
It kinda feels like driving a diesel in many ways. I guess I'm used to the 4.6 in my last truck, which was the exact opposite -- it was happiest above 3000 rpm.
It makes the engine have a strong torque curve in the useable rpm range for a truck,but at the same time,it kills any chance of power production up high. All of the 2V Triton truck engines are absolute pigs above 4500 rpms-the HP curves drop like a rock from the intake manifold tuning.
JL
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Ok, that makes sense now. If I understand this properly, the F150's have tuning closer to that of a car, allowing them to have high-rpm power. It makes sense for how different the 5.4 feels between the F150 and the Super Duty trucks.
Or am I completely off-base?
Or am I completely off-base?
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From: SE Texas
JL
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