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I tried to search this using a lot of different terms, but I was surprised that I couldn't find the answer, because surely this has been discussed. I'm looking to swap an 04 crown vic police interceptor motor into a 97 thunderbird with the stock 2v. I assume it would be a straightforward swap, but I'm wondering if I can use my existing wiring harness and ecu from the 97? If I can, will I need a new tune? I'm really looking for the largest power increase available and still have a direct swap. maybe I'm barking up the wrong tree. if so, set me straight. Thanks guys.
 

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I tried to search this using a lot of different terms, but I was surprised that I couldn't find the answer, because surely this has been discussed. I'm looking to swap an 04 crown vic police interceptor motor into a 97 thunderbird with the stock 2v. I assume it would be a straightforward swap, but I'm wondering if I can use my existing wiring harness and ecu from the 97? If I can, will I need a new tune? I'm really looking for the largest power increase available and still have a direct swap. maybe I'm barking up the wrong tree. if so, set me straight. Thanks guys.
Yup. Direct swap. Use your 97 fuel rail, front cover, accessories, etc. Wiring will plug right in. You will need a tune though.
 

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It can be done, there are some things you'll need to keep off your existing engine (intake plenum points the other way so spin it around, fuel rails, cables) though. It should run without a tune but the PI spark tables are different than the NPI spark tables, so a tune will be needed to correct that.

That said the CVPI engines aren't particularly desirable... in the same way taxi engines wouldn't be desirable. Tons of high temperature idling, low speed city driving, and they do tend to beat on their cars. From a power output standpoint they're no different than any other 2v PI motor. In terms of the best "direct swap" engine you're best off looking for an 02-04 Explorer motor, they use the aluminum WAP block which will shave ~60 lbs off the nose which will help with handling quite a bit.

Here are a couple of articles (long since buried) and a few quotes from other threads that are worth a short read.

https://www.tccoa.com/articles/overall/polint.html
https://forums.tccoa.com/7-engine-4-6l-5-4l/87492-4-6l-police-interceptor.html

Other than the oil cooler which is an external accessory the basic engine is the same be it a CVPI, a Grand Marquis, Thunderbird, Mustang, etc for the same year (other than it got PI engine, Performance Improved later than most).

People see that it is a Police Interceptor engine and think "wow, they are fast" when they should be thinking "that thing not only has a million miles, but has idled 10 straight hours everyday". If it is a newer one with the built in hour meter, you never know how many times those things have turned over.
 

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It's a straightforward PI swap.

https://forums.tccoa.com/7-engine-4-6l-5-4l/94152-pi-explorer-engine-swap-article.html

There's info here too.

https://forums.tccoa.com/7-engine-4-6l-5-4l/142765-definitive-pi-intake-swap-all-years-1876-1997-a.html

Here's all the questions I asked back in 2011.

https://forums.tccoa.com/7-engine-4-6l-5-4l/128074-pi-swap-question.html

Note: Do not put the Engine in on top of the Tranny dipstick tube, or pull the TC out to meet the flywheel bolts; make sure it's all the way in the tranny before you put the engine in. :)


You might want to check the Tensioners and Chain Guides on the front of the engine; there were some years they changed the material, and it broke off and caused problems.
Also, the tensioners on the newer motors are plastic, and don't have the ratcheting mechanism, so they have more slack at startup. This is not a good thing.

This shows the problem tensioners:
AGCO Automotive Repair Service - Baton Rouge, LA - Detailed Auto Topics - Symptoms of Bad Timing Chain, Ford V8 Engines

Take them off, and clean and use your stock iron ones. Or buy new ones.

https://www.modularheadshop.com/i-24493852-oem-ford-4-6l-5-4l-iron-primary-timing-chain-tensioners.html?ref=category:1268206

These are the Good guides; if your look like the ones in the problem link above, you should replace them.

https://www.modularheadshop.com/i-24493849-oem-ford-4-6l-2v-curved-timing-chain-guides.html?ref=category:1268206

https://www.modularheadshop.com/i-24493848-oem-ford-4-6l-2v-plastic-backed-straight-timing-chain-guides.html?ref=category:1268206


You also want to degree the cams; they will not be perfect, and you can adjust them a bit for better power.

Here's some info on setting cam timing; this uses the adjustable gears:
https://forums.tccoa.com/7-engine-4-6l-5-4l/141599-detailed-look-into-using-tfs-adjustable-crank-gears.html
 

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Discussion Starter #6
Thanks for the information guys. I am in agreement about the undesirability of the PI motors because of the way they are used and abused. I got my info off Wikipedia for hp and tq numbers. According to them, they have slightly better numbers than the civilian 4.6. I thought if it says something on the internet, it must be true, right? Anyway, thanks for giving me the correct info. I may have to look into the explorer alternative some more.
 

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Manufacturer power ratings aren’t reliable. The P71 Police Interceptor had dual exhaust and allegedly a more aggressive tune, but considering the ratings of mechanically identical engines varies by as much as 40 horsepower depending on whether it’s in a Mustang GT, Crown Vic civilian, P71, Explorer or Town car, there’s no way in hell I can envision those producing such a broad difference. The engines aren’t rated on the car, they supposedly get these numbers on an engine dyno with accessories, but every 4.6 regardless of vehicle uses the same basic AC compressor, PS pump, water pump, and alternator. In reality, most people who have put their 4.6 car on a chassis dyno have predictably close numbers to the next on the same dyno. Ford fudged the numbers to make the 02 Mustang GT look “powerful” to its demographic with its 260 rating, and the 02 Crown Vic seem rugged to its demographic with its lazy 220 rating.
 

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The extra 25 HP for the CVPI comes from the true duals (+14HP), and the larger air box/MAF/zip tube (+11HP), to get the 250 HP rating. The Crown Vic Sport has just the true duals, and a 239 HP rating. Standard Vic is 225 HP with single exhaust.

Al
 

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Ah ha. So from the true dual/upgraded intake 250 horsepower P71, where’s the missing 10 horsepower from the seemingly equally equipped 260 horsepower Mustang GT then?

Intake/exhaust mods to stock modulars picking up as much as 20-30 horsepower have long been relegated to fairytaleland on these and other 4.6 related forums, where it’s wisely suggested to spend your money elsewhere if you have that expectation. Not to say these components don’t pick up some power somewhere, but they don’t seem to even break double digits conclusively, and in most cases for someone modifying their car the exhaust is going to be even freer flowing with larger pipes and less restrictive(louder) mufflers to boot. Even the very common swap we do here using the 02 GT airbox/MAF/intake tube assembly is more a matter of convince and having a better resolution MAF for tuning purposes than it is for freeing up the “restriction” of the stock assembly. Intake/exhaust variations are the oldest marketing plays in the book.
 

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It would be interesting to see Real Dyno measurements on these different stock cars.

Marketing is "highly unreliable". :)

The listed differences on the P71 cars were the intake, exhaust and tune.

The claim is adding the 80mm maf and airbox adds 10hp. :grin2:


My calibrated Butt Dyno says that the 2002 intake, maf, and duals added at least 30hp.

>:)
 
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