05 Crown Vic 4.6 2V swap into 00 Mustang GT

amazingrandy1 · Mar 20, 2018

Hello All,

I have a 2000 GT that finally needed an engine after 200K miles. I swapped in a 05 P71 and used all of the GT parts in the swap. Since I have swapped in the P71, the GT has been slower (time & speed) at the track. NOthing has been changed on the car, but I am running 3-4 tenths of a second slower than the original set-up. My compression is great (~180) on all cylinders, with no electrical or DTC issues. I know that PI engines supposedly have the same cams from engine to engine, even between Romeo or Windsor. Are there any other variables between a 2000 Windsor GT and a 2005 P71 engine that I am missing. If it helps, it is noticable on the top end that the engine seems to be falling off sooner that the GT did. I starting to wonder if i was sold an LX Vic engine vs. an Interceptor (any way i can tell?).

Any help or info that anyone has would be great. Race season is coming up soon, and would like to get this ironed out before then if possible.

Thank You!!

96blak54 · Mar 20, 2018

Ive measured and mapped a good amount of stock cams. Not all npi cams are the same and not all pi cams are the same. Long story short, the cams from mustangs, npi or pi, are the better performing cams.

Without thumbing thru my notes, iirc, the vic cams were the least performers, directed more towards torque. For instance lower valve lifts and less durations.

amazingrandy1 · Mar 20, 2018

96blak54, i had feeling that it was a cam issue. For the engine to fall on its face at the top end, it was the first thing that I thought of, but wanted to be sure. Im just glad I saved the GT engine, and that the top end is still perfect on it. Looks like ill be swapping out he cams or heads/cams in the next couple weeks.

One more question, are the compression ratios any different from 2V to 2v PI?

Thanks again!

NEURON · Mar 20, 2018

The only difference power wise between the LX and PI engines(2005) was dual exhaust on the PI giving it 239HP vs 224hp. Stock GT has 260 HP.

96blak54 · Mar 20, 2018

amazingrandy1 said:
96blak54, i had feeling that it was a cam issue. For the engine to fall on its face at the top end, it was the first thing that I thought of, but wanted to be sure. Im just glad I saved the GT engine, and that the top end is still perfect on it. Looks like ill be swapping out he cams or heads/cams in the next couple weeks.

One more question, are the compression ratios any different from 2V to 2v PI?

Thanks again!

As much as ive seen, the ratios are the same, now i could be wrong....but i have not see any difference.

I plan to sit down one day and type out all specs of the cams ive measured and what they were from. I just dont have time.

Silver95bird · Mar 20, 2018

My first thought is check the cam gears and timing. 00 would be Windsor pressed on gears, wonder if they were more advanced or more accurate bank to bank than the Romeos.

07GtS197 · Mar 21, 2018

Does the motor have a Ford intake manifold or aftermarket?

BMAC96GT · Mar 21, 2018

96blak54 said:
Ive measured and mapped a good amount of stock cams. Not all npi cams are the same and not all pi cams are the same. Long story short, the cams from mustangs, npi or pi, are the better performing cams.

Without thumbing thru my notes, iirc, the vic cams were the least performers, directed more towards torque. For instance lower valve lifts and less durations.

PI Crown Vic cams are different than PI Mustang GT cams? I had no idea. Any other changes in the heads other than the cams?

amazingrandy1 · Mar 21, 2018

07gts197, the engine has the original 2000 GT intake on it. It also has all of the GT exhaust manifolds, acces., etc. The only thing different is the long block.

96blak54 · Mar 21, 2018

07GtS197 said:
Does the motor have a Ford intake manifold or aftermarket?

Good question! I forget about aftermarket intakes being junk.

07GtS197 · Mar 21, 2018

I guess it is the cams then but I still find that hard to believe. Almost half a second down in the quarter mile would be a decent amount of power loss or am I wrong?

Edit: I used a quarter mile et calculator for reference and it looks like losing 4 tenths of a second would equate to almost 30 hp lost. Would using the cvpi cams cause such a large loss of hp? In that case I wouldnt even bother swapping to stock pi cams and go straight to aftermarket cams for even bigger gains.

Silver95bird · Mar 23, 2018

I still think the cam timings might be different. What are the intake center lines on each bank? If you're thinking of aftermarket cams anyway, it's not wasted time to check.