4.0 Engine (V8) Swap...

[Mustang504]

Hello gentlemen,

I am in a very sticky situation and I need your help and expertise!!!

I have recently purchased a 2001 Cobra motor, T-45 Manual transmission, engine harness and computer for $1600. I've had the block rebuilt with Forged everything! 5.0 Stroker crank, 8:5 Dome top pistons, ported heads, the works! I've even went as far as converting it over to a full 2003 cobra motor. As of now im about $3800-$4000 in the hole. My budget is $8500 with going from a running V6 to a Fully running V8.

The car has been prepped with an upgraded suspension, Steeda X5 Balljoints, 3.73 rear gears, Driveshaft, Steeda Panhard Rod, Brakes, and I have a manual pedal assembly from a Shelby GT500. Majority of what I've acquired over the years except the pedal assembly.

The motor is fully rebuilt from Eaton supercharger on down to the oil pan with all the trimmings. A friend and I had made plans to do the swap here in Montgomery, Ala., BUT after doing some extensive research, I see that the electrical portion can make this a real PITA. Ive also heard about the clutch and gas line being cable oriented and not hydraulic.

SO MY QUESTION IS... with a $4000 dollar budget, and with a friend and I actually doing the swap, is the wiring something I can do myself? Because after a few quotes from people... I got to thinking... If an installer were to charge $100 an hour, and quote me 5-7 thousand for computer installation then wiring the car must be a 2-3 day kind of job but spanned out over the course of a few weeks.

If its just removing the dash and interior console and redoing the dash wiring and gauges then I dont mind, but if its literally every wire in the car from headlight to taillight then F**K That.... youll see this motor for sale!

I plan to buy an auction car to bump around in until i get my girl (05 Mustang) back up and running. Then I plan to sale the auction car slightly marked above value and that will be my Whipple money


And being that its a stroked 281 DOHC, could I use the 07 GT500 computer and harnesses to make everything plug and play so that I wont lose that auto-window feature?

Also is it possible to "Jailbreak" the computer system on my 4.0 computer system (Or 01 Cobra system) and reload a tweaked tune that will run the motor but still retain the 05 features?

Or could I buy the Fast XFI computer system and just start from scratch?

What would make this V6 to V8 swap the easiest? IM CLUELESS as to where to go from here so i'm open to exploring all ideas. all INFO is needed and appreciated, so please steer me in the right direction and if you know of anyone who has completed this swap please forward a link or contact info. Im located in Alabama but Im willing to travel all over the south for solid help at a decent price.

THANKS

 

[NUTCASE]

I have never done this before, nor seen it done on a newer car, but I would say your best bet is to run a stand alone and just leave the factory computer there for guages, ignition, ect. Then to stop every light on your dash from going off go into the factory ECU with a tuner and just turn every code off.

EXACTLY how to do this.........I dunno.

 

[BruceH]

I'd sell what you have and pick up a 3v motor, transmission, harness, and computer. Even better yet would be to sell your car and buy a GT. There is a GT in the classifieds for $8k.

 

[danbev07]

Is it possible? Of course. With that budget? I wouldn't think so.

You'll have to spend a lot of time diagnosing and addressing all electrical features you're looking to retain. The SmartJunction box in these cars communicates with the stock ECU, so that'd probably have to be bypassed in order to retain your electrical accessories.

I agree, the most seamless v6 to v8 swap for a 2005-2010 chassis is to buy a same year v8 with the harness and matching computer for your chassis.

I have done two v8 swaps without any issue from the electrical side (and both are still running!), once you have everything laid out it should only be a 2 day project!

 

[Mustang504]

Thank You Nutcase, How exactly do I go about running a stand alone system?

BruceH, Thanks for the input but this is actually my first car that I purchased cash with my own money so its very near and dear to me. I'd always keep it and pass it to my son someday if im fortunate to have one. And yes thats what im thinking but I hate to quit on something im so driven to complete. But that would free up time and money for a blower. I jus wanted to keep those DOHC's.

Danbev07, How could I go about obtaining a 5.4? I hear the 00-04 Navigators have a really strong block to build off. Im trying to push my car into the 600-700hp range

 

[Mustang504]

And if I sold the motor, would 7500 be reasonable for an 03 Cobra motor?

Could I buy the 5.0 Coyote Crate and bolt it up to the T-45?

 

[dre256]

If you need to meet emissions you cant put an engine in to a car thats from a previous year setup in most states. 5-7k for labor to do wiring harness is about right as a push rod 5.0L swap quote to put into my old T-Bird was about 12K and near all labor was for wiring.

 

[Mustang504]

If you need to meet emissions you cant put an engine in to a car thats from a previous year setup in most states. 5-7k for labor to do wiring harness is about right as a push rod 5.0L swap quote to put into my old T-Bird was about 12K and near all labor was for wiring.

No emissions inspection so im good with that, but thanks for the heads up

 

[BruceH]

And if I sold the motor, would 7500 be reasonable for an 03 Cobra motor?

Could I buy the 5.0 Coyote Crate and bolt it up to the T-45?

You would want a stronger transmission imo. In order to work with a s197 in your year you would need a 3650 or 6060. Not sure about a T-45. A 3650 or 6060 would plug right in to the harness and would work with the computer.

IDK about the motor value. It's worth what someone will pay and $7500 is a lot of money for a motor. Especially with the older style of heads. You would be better off asking on another site since this forum deals with s197 Mustangs.

If I understand correctly you have rebuilt the motor with a stroker crank. Are the rods and pistons forged? If so what brands were used and who did the machining and assembly work? Are the heads ported to flow the same as the 03/04 heads?

The swap you want to do has been done on here before but it was a 3v into a v6. The example I'm thinking of was done by a member who passed away a few years ago. He went by Tre something iirc. A search should turn up at least his thread if not others.

I'm still convinced that you would be better off sticking with a 3v for your chassis. That way you keep a/c and p/s. Along with having zero headaches when it comes to wiring.

 

[TexasBlownV8]

Whew.
Let's start with the motor and related wiring.

You have a couple options. The easiest (other than using a complete 4.6L 3v motor) is to use a 2005 engine wiring harness and a 2005 or 2006 manual PCM. They both will plug right into your existing car and interact with the rest of your systems. There are some changes you'd need to make on the engine, mainly due to the 2005+ having VCT and the earlier engines do not. You can opt to lock-out VCT altogether and not use any of the variable cam timing; a custom tune would need to handle that in the PCM. For any other connectors that dont fit (or dont exist), you'll have to either splice in the proper connectors or not use the setup. You mentioned the fuel system: you'd need to use a return-style system, or attempt to use a stock 3V fuel rail (I have one for sale if you need one) with the fuel rail pressure sensor (you can re-use the sensor on your fuel rail). Transmission connectors for reverse lights detection and speedometer also need to be handled, unless you use a 3650 or 6060 transmission, which will bolt up to your block.
For what it's worth, a lot of people use this same block and internals, with 3v heads though, and then all the rest simple 2005-2010 4.6L bolt-ons, and have a complete normal v8. IN this regard, grabbing a set of 3v heads, with all the vct and stuff, it would make the overall swap much much much easier; then sell the heads on the motor you have now.

Regarding instrument cluster and 'wiring', you'll be surprised to see how the gauges are 'controlled': all through the CAN network (ie, 2 wires), from the PCM and SJB. Not like the older cars. A such, using a S197 pcm is the preferred way to go if you intend to use the same gauge cluster or even a GT (or gt500) cluster. Your V6 cluster works just fine with a v8 motor and PCM.

You mentioned 373 gears: if that's in the stock 7.5" rear end, you wasted a little money. You need to upgrade to a 8.8 rear end, unless you dont plan to do any hard launches, in which case the 7.5" rear end might hold up.

If you havent seen it already, it might help for you to look over my how-to do a v6 to v8 swap thread http://www.mustangcollective.com/showthread.php?t=38141
That's for a engine meant to go into a 2005+, which you essentially, mostly, have. Plus, using a 3v setup with the 2005 pcm, you already have the fuel system in place, other than the hose that connects from the hard-line at the fender to the fuel rail, so no need to spend more on the pump setup nor lines.

With the built bottom end like you mentioned, you're on your way to a great overall engine, but I would try to make it a 3v for ease of installation and then overall total cost.

 

[Mustang504]

Whew.
Let's start with the motor and related wiring.

You have a couple options. The easiest (other than using a complete 4.6L 3v motor) is to use a 2005 engine wiring harness and a 2005 or 2006 manual PCM. They both will plug right into your existing car and interact with the rest of your systems. There are some changes you'd need to make on the engine, mainly due to the 2005+ having VCT and the earlier engines do not. You can opt to lock-out VCT altogether and not use any of the variable cam timing; a custom tune would need to handle that in the PCM. For any other connectors that dont fit (or dont exist), you'll have to either splice in the proper connectors or not use the setup. You mentioned the fuel system: you'd need to use a return-style system, or attempt to use a stock 3V fuel rail (I have one for sale if you need one) with the fuel rail pressure sensor (you can re-use the sensor on your fuel rail). Transmission connectors for reverse lights detection and speedometer also need to be handled, unless you use a 3650 or 6060 transmission, which will bolt up to your block.
For what it's worth, a lot of people use this same block and internals, with 3v heads though, and then all the rest simple 2005-2010 4.6L bolt-ons, and have a complete normal v8. IN this regard, grabbing a set of 3v heads, with all the vct and stuff, it would make the overall swap much much much easier; then sell the heads on the motor you have now.

Regarding instrument cluster and 'wiring', you'll be surprised to see how the gauges are 'controlled': all through the CAN network (ie, 2 wires), from the PCM and SJB. Not like the older cars. A such, using a S197 pcm is the preferred way to go if you intend to use the same gauge cluster or even a GT (or gt500) cluster. Your V6 cluster works just fine with a v8 motor and PCM.

You mentioned 373 gears: if that's in the stock 7.5" rear end, you wasted a little money. You need to upgrade to a 8.8 rear end, unless you dont plan to do any hard launches, in which case the 7.5" rear end might hold up.

If you havent seen it already, it might help for you to look over my how-to do a v6 to v8 swap thread http://www.mustangcollective.com/showthread.php?t=38141
That's for a engine meant to go into a 2005+, which you essentially, mostly, have. Plus, using a 3v setup with the 2005 pcm, you already have the fuel system in place, other than the hose that connects from the hard-line at the fender to the fuel rail, so no need to spend more on the pump setup nor lines.

With the built bottom end like you mentioned, you're on your way to a great overall engine, but I would try to make it a 3v for ease of installation and then overall total cost.

Thank you! You've cleared up alot of questions for me. I want to go into this swap with as much knowledge as possible.

Although I think I may sell the bottom half for about 4000 and use that to build a 5.4 Navi motor. I hear that a whole motor sells for under $500 and someone makes a manifold adapter plate for 99-13 lower manifolds roughly $300. Ill forge it, save 1000 bucks and gain more stroke. Swap out all the inter-cooling and eaton and its essentially a GT500 motor... correct?

Now, could I use the ported 01 cobra heads with the 5.4 Navigator motor or would i still need 3v heads?

Could I use the T-45 or would I need to get that 3650 or 6060 you spoke of?

Im really trying to avoid reselling and rebuying but i wouldnt mind going the 5.4 route. actually id prefer it! Budget is 5k. Would wiring that be the same as you stated above? if so then all i would need is a GT or GT500 pcm and engine harness and im done right? Would you recommend upgrading the fuel system or would the V6 tank and lines adapt to the new rail?

Its late so I'll read that link in the A.M. but my mind seems to be running faster than my 4.0 so i may check it tonight lol. THANKS AGAIN

 

[porkipine]

Listen to Bruce and texasblown... They will set you on the right path

 

[ejschmidt]

I kind of feel badly for TexasBlownV8, I feel like he's written this up dozens of times.

He eats breathes and sleeps v8 swaps.

 

[Mustang504]

Thank you guys for all the help and support. I have decided to sell the motor and Im currently on a waiting list for a 3v 5.4 from pull apart. Found a really cheap F150 whipple intercooled for $3500 and the motor will be less than $300 so thats the route I will be going. Also I plan to buy the Tremec 3650 next week. Ordered a 2010 GT harness and hopefully I can just flash my current computer. As for the headers, once i completely rebuild the motor can I buy a set of GT500 Longtubes and have them bolt up to a F-150/Expedition/Navigator block? I think they all use the Windsor 330.

 

[Mustang504]

And TexasBlownV8, I especially thank you for that write up! Very insightful. Its actually the reason I changed my build. i Appreciate you

 

[warpig12354]

That 2010 harness wont plug and play. 05/06 had the same connections.

 

[TexasBlownV8]

+1 and to re-itereate, for your 2005, you MUST USE a 2005 or 2006 PCM; the engine wiring harness must also be 2005 or 2006, although the 2006 is a direct plug-in replacement while the 2005 may have the different C110 connector as shown in the image below, 2005 on the left, 2006+ on the right:

 

[Mustang504]

Ok Thanks. Thats all I needed to know.

 

[JerseyCity07GT]

It can be done however the amount of money it requires will exceed the price of a used 05 to 09 GT... it's all up to you...

 

[Mustang Mark]

Old thread...