Ok, so another noob question. I've been reading thru the threads and have seen where it was written the in the vin code for the 03 gt's that the X in the 8th position means PI. My question is what is the difference between the PI and nonPI engine codes mean? Thanks for the help, and please dont beat up on me too much...lol
ok another noob question
- Thread starter 2003whitegt
- Start date
wmburns
SN Certified Technician
PI non-PI differences
Are you asking what is the VIN code for a non-PI 4.6? ("W"). OBTW, Mustang GT's all got a PI motor starting in 1999.
Are you asking what is the difference between a PI and non-PI engine?
The engines have the same basic external measurments. The heads are different to improve air flow (hence PI). Because the heads have different shaped intake ports, the intake manifold is different.
The PI heads have a smaller combustion chamber. The non-PI has flat top pistons. To keep the CR nearly the same, the PI motor has recessed pistons.
When PI heads are installed on an non-PI motor, you get the air flow improvement and a 1 point increase in CR.
Are you asking what is the VIN code for a non-PI 4.6? ("W"). OBTW, Mustang GT's all got a PI motor starting in 1999.
Are you asking what is the difference between a PI and non-PI engine?
The engines have the same basic external measurments. The heads are different to improve air flow (hence PI). Because the heads have different shaped intake ports, the intake manifold is different.
The PI heads have a smaller combustion chamber. The non-PI has flat top pistons. To keep the CR nearly the same, the PI motor has recessed pistons.
When PI heads are installed on an non-PI motor, you get the air flow improvement and a 1 point increase in CR.
Similar threads
