5.0 vs 4.6

[trojansouthpaw05]

Greetings everybody,

I know this is a timeless question for a lot of folks, but I am desperately in need of help in trying to decide between one or the other.

A little background on myself and my journey is as follows. I am 22 and still in college but have been obsessed with Factory Five for 3 or so years now. I am graduating soon and am planning on ordering an MK4 kit within the next 12 to 18 months. I am planning on a donor build, which is the reason for my question regarding the 5.0 mustang vs. a 4.6. Although I won't be building for a while, I figured that I might buy the donor early (god bless parents with extra garage space) and tear-down and clean up the engine a bit, maybe even cause some mayhem with it before tear-down!

My plans for the build are rather simple. I am planning a pretty basic(if you can call an MK4 basic) setup. Somewhere in the neighborhood of 275 to 325 HP would be more than sufficient for me. Obviously, some engine mods would be necessary to achieve those type of numbers, but I was wondering if some people could weigh in on which engine they think would be the best fit for my needs. I am spending about as much time reading books on engine building as I am reading for my classes, but have very little actual hands-on experience with engine modification.

Any information/opinion regarding this comparison would be much appreciated.

Thanks!

Mikey

[riptide motorsport]

5.0.....these cars need a carb to look right in my opinion.

[skullandbones]

Personally, I like the looks of the little pushrod engine. It fits visually better in the roadster engine bay. If it was a supercharged 4.6 (435 hp), that would be worth the extra space taken up but the 5.0 is really the engine of choice. I guess the carb version does look more traditional but the EFI manifolds look pretty crazy. Mine is a Holley and it's pretty impressive looking on that small block. It's a lot easier to work on and is real easy to make the horspower level you are targeting even on a pretty tight budget. Keep reading and checking out the different combinations. I still love to check out the various engine setups. I'm sure you will find your favorite when the time comes. Best of luck! WEK.

[CapeCoralCobra]

5.0 X3. They and their performance parts are very plentiful and inexpensive. While you can spend big bucks on aftermarket parts, the top end of your envisioned HP range is easily attainable with readily available Ford parts. Carb or EFI, you can't go wrong. As said above, carb looks more correct, but EFI is more dependable. Your choice.

[MPTech]

My original plan was to run a 4.6 mod motor, but after further research I decided that a push-rod 302 was better for me.
The mod motor is larger (looks cool and really fills up the engine bay) but also cuts into you Footboxes a little (which are not huge to begin with), it will be more expensive to upgrade for increased horsepower, more complicated (more hoses and wires), more expensive to repair, and the wiring is more expensive (I was seeing around $1,200 - $1,500 for a dieted wiring harness). Your research may vary, but this was my findings. You can also find and rebuild a push-rod much cheaper and the donor parts from a 94-95 GT are pretty much ideal for a Donor Roadster. (correct front spindles and rear axle / disc brakes / 5 lug and will also provide a nice tranny and Power Steering and Power Brakes solution!). Selecting a different year will create compromises in the previously mentioned items (too wide or 4-lug / drum brakes).

I'm not an expert, so if anyone has contradicting information, please correct & enlighten me. If you want a good, inexpensive donor project, that is my suggestions.


Good luck! This would be a great car to have in you 20's!! (just BE CAREFUL!)

[AC Bill]

A 302 donor engine will likely have some pretty high mileage already, vs a newer 4.6. You may get lucky after some extensive searching, and find a lower mileage 5.0, or allow for some engine overhaul in your budget.

Fortunately parts are plentiful for the 5.0 still, and usually less expensive. The 302 looks darn good in the Roadster, in my opinion.

[edwardb]

All good comments. I can think of a couple more:

1. Since you're talking about getting the donor now and maybe driving for awhile, there will be more mod motors out there than the older pushrod SBF. It's been a while since Ford was putting SBF's in cars, so the donors are aging. Not impossible, but something to consider.

2. What emissions requirements will you have to meet? Typically driven by local and/or state requirements. Mod motor with all the emissions parts, injection, cats, etc. may be easier. A pushrod SBF can be made to pass inspection, but may take more effort and experience, and you said you weren't very experienced.

Having said that, my plan from the start was a pushrod SBF, and that's what I have. It's an easy fit in the Roadster, has room to work around it, love the old school carb look, simple wiring, relatively cheap parts and easy to upgrade, etc. Although I wasn't planning to, had to do a complete overhaul. I had a machine shop do the rotating assembly, but I did the rest. I too had limited experience, but I did my homework and took it slow. It was great fun and (so far!) runs really great. The mod motors have a much higher parts count.

So I would recommend a pushrod SBF, but gather all the facts and make the decision that's best for you. BTW, many make a strong case for starting with a 351 based SBF. Good power with very minimal upgrades, and a bigger power upside than a 302. Something else to consider.

[trojansouthpaw05]

Greetings everybody,

I want to thank everybody for the quantity and quality of the posts that have been received in less than 24 hours. It seems pretty overwhelming so far that people prefer the 5.0 to the 4.6. Keep the opinions coming, I really appreciate them.

I am trying to do this on a pretty tight budget, hoping to build a car at or around the $20,000 mark. Does anybody have any websites where I may be able to find mustangs at a discount price. I have been looking at places like erepairables.com and ridesafely.com searching for some crashed mustangs, but very few of the vehicles on there are from before 2000. Ideally, I would be looking for a 94 or 95 Mustang with a 5.0 and rear disc brakes. If anybody has any websites to try then please send them along to me!

[skullandbones]

I just wanted to add that going with a donor is not all bad as the pallet donor I got had 60K and when I took the heads off there was no ring wear on the cylinders and I took one bearing off and it is perfect. So if I had just cleaned it up, I would have been miles and many hours ahead of the game. I decided to get a "cheap" crate engine anyway for $2495 (300 hp) before gofast stuff. It was balanced and blue printed. I guess I just wanted the peace of mind of a new engine. The point is, you can find a good donor and if you drive it, you're even better off. You just have to be patient. I am speaking of a 302 still. WEK.

[3yearplan]

You might be able to find engine/trans combinations through a trusted auto dismantle yard. I went through LKQ Automotive and found a 2004 Mach 1 DOHC 4.6 with the Tremec 3650 transmission with 78,000 miles. Came complete from intake to oil pan, computer, sensors, wiring harness, all the front accessories, etc. Finding a 302 from such a yard would be difficult, but the 4.6 route can be achieved for a little more money. In my case the 2004 Mach 1 4.6 makes about 320 hp from the factory. I paid $3600 for the engine/trans combo and shipping from South Carolina to Michigan. Like the others have said, you just have to find out what works for you, and your budget, and abilities.

[AC Bill]

If anybody has any websites to try then please send them along to me!

Place a donor wanted advert, or check on here from time to time, to see what may be available.
http://www.ffcars.com/forums/20-donor-cars-sale-wanted/

Palleted donor parts have worked for many people, so maybe put out some feelers with wreckers in your area.

The parts needed may come from a couple of different Mustang wrecks, but make sure you get the correct ECM for the engine supplied. The Mass Air EFI are preferred over the Speed Density system if your going EFI, so keep that in mind.

If you buy a complete kit you may not need this, but Pre-dieted donor wire harness's are often available, specific to your set up, at a very reasonable price. Chuck Fields (Mustang Medic on the FFR Cars forum), put together a turn key harness set for my set up. It was all well labeled, cut to length, easy to install and to finish wiring up. He even allowed for my need for daytime running lights, (mandatory here), and had extra circuits for, wipers, heater, dash power outlet, etc. It comes with all needed relays in place, and even came with several switches such as the hazard, dash instrument dimmer, etc. For the time it would have taken me to do the wiring myself, (and possible screw ups) it was worth every cent to have him do it.

As far as wanting disc brakes for the rear, you should keep in mind the 87-88 Thunderbird turbo-coupes had them, along with the added bonus of the 3.55 rear gearing. That gearing can wake up a basically stock 302 pretty nicely. A wrecker may be able to provide you with one of these rears, if the donor car is a drum brake model.

Certain year Explorer engines can also be used for your build..not sure exactly which ones are the preferred years..maybe someone in the know could chime in..

Food for thought anyway..