My son and i have a question and are reaching out, we are trying to figure out if a 96 caddy 4.6L northstar motor would be a good swap for our 96 mustang gt? I personally am a chevy guy myself but just trying to help my son out, and don't really know much about fords. So if anybody can help us out we'd greatly appreciate it.
Swap Questions
- Thread starter DonkeyWarrior2018
- Start date
wmburns
SN Certified Technician
Well...............
IMO the GM Northstar is a terrible unreliable motor (IE head bolt problems, weak timing chains, and coking PCV valve covers for starters). So I'm having a hard time figuring out why anyone would go through the expense and hassle to figure out HOW to accomplish this swap and all that it entails. As opposed to spending $600 or so for a salvage yard 4.6 that will "drop in" and "directly bolt up" to your existing car without having to re-engineer the whole car.
If looking a project just for the "cool" factor or because it's something different by all means, "go for it". But if looking for a "cost effective" repair, this isn't it.
IMO the GM Northstar is a terrible unreliable motor (IE head bolt problems, weak timing chains, and coking PCV valve covers for starters). So I'm having a hard time figuring out why anyone would go through the expense and hassle to figure out HOW to accomplish this swap and all that it entails. As opposed to spending $600 or so for a salvage yard 4.6 that will "drop in" and "directly bolt up" to your existing car without having to re-engineer the whole car.
If looking a project just for the "cool" factor or because it's something different by all means, "go for it". But if looking for a "cost effective" repair, this isn't it.
wmburns
SN Certified Technician
FWIIW, for a modern 4.6 there isn't a difference in the LONG blocks between the Romeo SOHC iron block motors put into a Mustang verses what is put into a Police vehicle or "Panther" class car. In fact that is a cost effective swap to use a PI Romeo from a 2001+ Town Car, Crown Vic, or Grand Marquis (aka Panther) to repair a 1996-2004 Mustang GT.
The only real difference between the 4.6 in a Police (or fleet) vehicle is the addition of an external oil cooler (which will have to be removed if used in a Mustang) and a beefier Alternator. Plus maybe a Hobbs meter. All stuff that is "bolted" onto the long block.
My advice is to avoid any 4.6 that came out of a Police car (unless getting very cheap). They spend soooooooooooooo much time idling that mileage is no longer a good measure of wear/age. Stick to Grand Marquis or Town Car as those engines are more likely to not have been abused in their first life.
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Thanks again for your response, again that info was very helpful, needing a good strong block to build on. Going for a good enough build to where we wanna go a couple different routes; turbo, super charger, turbo charger, or NOS. Trying to debate on which route to take. So any and all kinds of info and tips will be useful.
wmburns
SN Certified Technician
Just checking. The original car does have a motor inside it right? Why? Because you are going to need some of the Mustang specific parts from the original motor that will be needed to make the Panther motor "look like" the Mustang motor.
Basically put both motors on an engine stand. Take TONS of pictures of the original motor. Make the donor motor look like the original by swapping the Mustang specific parts that are "bolted on" to the long block.
This includes (but not limited to):
Basically put both motors on an engine stand. Take TONS of pictures of the original motor. Make the donor motor look like the original by swapping the Mustang specific parts that are "bolted on" to the long block.
This includes (but not limited to):
- Ignition
- fuel injectors
- EGR
- Throttle body
- oil pan
- motor electrical wiring harness.
- front belt driven acc.
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wmburns
SN Certified Technician
Well. If changing from an automatic to manual it will be necessary to swap the flex plate for a flywheel. And it will be necessary to install a pilot bearing.
wmburns
SN Certified Technician
Not difficult at all. I usually use of block of wood and a hammer to drive it home.
If you are able to pull and install a new engine this is just a "minor" detail of the whole swap.
wmburns
SN Certified Technician
From the get go this swap has been mentioned as close to a "plug and play" swap. Think about it. It's not a plug and play swap IF Ford were to use a different motor for an automatic verses manual transmission application.
Again. The external dimensions and mounting points of a 4.6 Romeo SOHC LONG BLOCKS are the SAME. There is NO difference between the engine used in an automatic verses manual application EXCEPT:
- Flex plate verses flywheel.
- pilot bearing verses no pilot bearing.
Now that does not mean that a transmission from a V6 will bolt up to a V8 as these are not the same motors.
Of course this assumes that you have the correct flywheel for your intended use. There is a difference between a flywheel for a 10.5" clutch verses an 11" clutch. But this has nothing to do with the base motor's long block itself as the flywheel and clutch is a "bolt on" part. I'm assuming that you will be reusing the flywheel from the old motor.
As already has been mentioned there will be "bolt on" parts that will have to be swapped from the old motor to the donor. Hence the need to put both motors side by side on an engine stand. If you expect a simple straight forward swap, then the donor motor must be made to look electrically the same as the original.
Want further proof? The 4.6 motor that is currently in my 2000 manual transmission Mustang GT came from a 2003 automatic Grand Marquis. I did the swap 7 years ago and 100k miles ago. The Grand Marquis motor has been in use long enough where I'm now on my 2nd clutch.
Once going down this route it's no longer a simple and cheap "plug and play" wrench only project. Good luck.
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