Stick with the 4.6 or coyote swap?

[Paladin27]

So, my 98 GT has about 243,000 miles on it. It still runs strong but I want to be proactive and think about replacing the engine. I narrowed it down to either rebuilding the bottom end and dropping on some twisted wedge heads or doing a coyote swap. I'm not looking to reach a certain horsepower number. This will be a NA setup and know the coyote swap will be more expensive. I'm just looking for some tips and some insight as to which setup would be more fun to drive. Thanks.

 

[Blkkbgt]

The coyote swap will obviously get you more power. You really need to ask yourself how much money and time are your honestly willing to put into this build. The last time I looked into 5.0 swaps they seemed to be a time consuming pain in the ass. I know a few people were having issues getting the cars to actually run correctly.

If it were me I'd would rebuild the 4.6. I however would skip the tfs heads, add pi heads and find a used vortech and call it a day. Sorry but I am not a fan of N/A 2v 4.6s. If you keep the 4.6 you'll save yourself a lot of time and money.

 

[DHG1078]

I agree, the coyote motor swaps are expensive, difficult, and not 100% problem free. The biggest advantage to a coyote swap is increased mpg for the same power levels, but not enough to make up for the huge initial costs.

I would rebuild your motor, do a PI head swap, and find a used supercharger kit (which needs a lightly upgraded fuel system). You will have a safe/fun 400+ hp. 400 hp would be easy and relatively cheap to do. If you want 500+ it starts getting really expensive as you really need to upgrade the whole fuel system and spend a bit more cash on your rotating assembly.

It's not worth doing a NA 4.6 build. You will struggle to get much more than 320rwhp for the same/more cost than just throwing a supercharger at it and having 400+hp.

 

[Paladin27]

Ok, so say I rebuild and do a PI swap. Do I need to go forged if I'm just going to run 7-9 psi on a supercharger? Or should I just forge it for peace of mind? Its not a racer, just a fun weekend driver.

 

[DHG1078]

I'm not sure exactly on the 98 motors, but the 99-04 PI motors are safe at 9-10 psi and up to around 420 hp with a good conservative tune. You can always buy a "cheap" forged bottom end for peace of mind, like an 03 cobra crank and rods and find a new set of aftermarket pistons. Just be careful of what compression ratio you end up at.

 

[Blkkbgt]

I'm not sure exactly on the 98 motors, but the 99-04 PI motors are safe at 9-10 psi and up to around 420 hp with a good conservative tune. You can always buy a "cheap" forged bottom end for peace of mind, like an 03 cobra crank and rods and find a new set of aftermarket pistons. Just be careful of what compression ratio you end up at.

Sorry but there is absolutely zero need for a forged crank for his application let alone anything under 600hp. The cast crank is stronger then people think. A simple search will tell you that people run them at elevated power levels without problem or failure. Some people are pushing them well above 600hp without issue for extended periods of time. Corral is an excellent place to research on this subject.

OP I would add some decent I beam rods like those offered by modmax, probe or MMR for piece of mind and additional potential if you desire it later on. The other side of this is the fact that a few of your rods may be out of round at that milage and you can't resize powdered metal rods. You can also get a slightly upgraded hyper piston as apposed to forged to keep the budget in check but some lower end manley pistons without coated skirts are not all that much more.

The above upgrades are highly recommended but not a requirement if you keep the power in check. Most people want more once they taste boost for a while so keep that in mind. If it were me I'd do H-beams and forged pistons with a stainless ring package and call it a day.

 

[Paladin27]

Cool, thanks guys. I think I'll just pick up a new forged shortblock and get some used PI heads off ebay and call it good. I did some research and found that according to multiple searches, there isnt a real big cost benefit to rebuilding the bottom end vs. buying a new short block.

 

[Blkkbgt]

I understand the cost with regards to rebuilding vs buying a forged short block. I like the idea of know exactly what is in my engine. I have read about enough mistakes by various builders to keep me from going that route.

 

[bobby_0081]

I agree, the coyote motor swaps are expensive, difficult, and not 100% problem free. The biggest advantage to a coyote swap is increased mpg for the same power levels, but not enough to make up for the huge initial costs.

I would rebuild your motor, do a PI head swap, and find a used supercharger kit (which needs a lightly upgraded fuel system). You will have a safe/fun 400+ hp. 400 hp would be easy and relatively cheap to do. If you want 500+ it starts getting really expensive as you really need to upgrade the whole fuel system and spend a bit more cash on your rotating assembly.

It's not worth doing a NA 4.6 build. You will struggle to get much more than 320rwhp for the same/more cost than just throwing a supercharger at it and having 400+hp.

I have a N/A stock bottom end 4.6 that makes 350+ HP to the rear tires. I have TFS heads and cams with Long Tube headers 34lb injectors. I drive my car daily and it has really good street manners. If I want to get over 400 HP then I can buy a 75 shot on the cheap. My heads were $2000 ,the cams were $600, and the injectors $200 from Ford Racing and the Pro Charger runs $5,000+ and the Vortech $4,000+

 

[Blkkbgt]

You can easily do a used S-Trim for what you spent on heads and cams with more power potential down the road.

To each his own.

 

[Massie02GT]

I have a N/A stock bottom end 4.6 that makes 350+ HP to the rear tires. I have TFS heads and cams with Long Tube headers 34lb injectors. I drive my car daily and it has really good street manners. If I want to get over 400 HP then I can buy a 75 shot on the cheap. My heads were $2000 ,the cams were $600, and the injectors $200 from Ford Racing and the Pro Charger runs $5,000+ and the Vortech $4,000+

Malarkey. My Intercooled ProCharger cost me under $3k all said and done, and that includes my $350 dyno tune. That also includes many new/upgraded parts. I now make 400/402 to the tire through my auto trans. Stick would bump that up a little. Deals are out there; you don't have to spend $5k on a centri set up.

 

[CalBoy101]

I have a N/A stock bottom end 4.6 that makes 350+ HP to the rear tires. I have TFS heads and cams with Long Tube headers 34lb injectors. I drive my car daily and it has really good street manners. If I want to get over 400 HP then I can buy a 75 shot on the cheap. My heads were $2000 ,the cams were $600, and the injectors $200 from Ford Racing and the Pro Charger runs $5,000+ and the Vortech $4,000+

bobby, nice numbers for a NA stock block build, which cams are you running?

 

[bobby_0081]

bobby, nice numbers for a NA stock block build, which cams are you running?

Trick Flow stage 2.

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[jaxbusa]

Sell it and buy a newer one.


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[Kornilov]

Bobby,

Can you give more detail on your build? I knew it was theoretically possible to coax 350 rwhp out of an N/A 2V, but to hear it has good street manners is really encouraging. 350 rwhp is about what stock Coyotes put to the wheels. A ~3300 lb SN95 churning 350 to the wheels will run with and better than a stock ~3600 lb S197.

 

[StrayBullitt]

Bobby,
Can you give more detail on your build? I knew it was theoretically possible to coax 350 rwhp out of an N/A 2V, but to hear it has good street manners is really encouraging. .

I need to get back to the dyno, but I'm in the 350 whp ball park as well. The car runs around on the street pretty well. Only thing is It likes to be above 1500 rpm, you can't really cruise at 45-50 in 5th gear, I find myself in 4th a lot. I went for middle of the road cams, MHS stage 3's. They aren't too crazy of a grind.

 

[bobby_0081]

I need to get back to the dyno, but I'm in the 350 whp ball park as well. The car runs around on the street pretty well. Only thing is It likes to be above 1500 rpm, you can't really cruise at 45-50 in 5th gear, I find myself in 4th a lot. I went for middle of the road cams, MHS stage 3's. They aren't too crazy of a grind.

I have the Trick Flow stage two cams.

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[bobby_0081]

Bobby,

Can you give more detail on your build? I knew it was theoretically possible to coax 350 rwhp out of an N/A 2V, but to hear it has good street manners is really encouraging. 350 rwhp is about what stock Coyotes put to the wheels. A ~3300 lb SN95 churning 350 to the wheels will run with and better than a stock ~3600 lb S197.

I have a stock bottom end 4.6 from a 2007 or 2008 Crown Victoria. It had 29,000 miles when I got the engine from a salvage yard. Below are the parts I put with the stock bottom end.

Trick Flow Stage 2 cams
Trick Flow 38cc heads
34lb Ford Racing Injectors
Stock Bullitt Intake from 2001 Bullitt GT
Twin 65mm BBK Throttle body
Meziere electric water pump
March underdrive fluid dampness
Windage tray
BBK MAF
BBK long tube headers
JLT cold air induction
BBK x-pipe with cats
Flowmaster 2.5 inch cat back exhaust
Accel Coil packs
Fidanza Aluminum Flywheel
McCleod Stage 2 clutch
Tremec T56 Magnum
8.8 31 spline moser axles with rebuilt Cobra carrier with 3.73 gears.

That's a list off the top of my head.



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[StrayBullitt]

Nice, that's impressive making that power through the Bullitt intake.. is it ported at all ?

 

[StrayBullitt]

I'm bored.. I'll throw down my mod list too...

Terminator Short Block / rotating assembly
Trick flow 44cc heads. Only around 9.5 compression
Modular head shop stage 3 Cams
Edelbrock intake mani
6061 plenum
Accufab 75mm throttle
JLT Cold air
BBk shorties
SLP X with Cats
SLP LM1
MD Dyno Tuned with SCT x4
4.10's
Stock Terminator clutch and flywheel.