I just thought I would throw in my two cents. I agree that the 5.0 was a great motor. A fox body with a 5.0 had amazing potential. Agreed, they weren't as impressive as they could have been stock with with a few bolt on's there was nothing that could touch it for the same money, however... That 5.0 was based on something that was designed in the early sixties and had a few inherant desgn flaws. It had a very short connecting rod. This places the rod a greater angle at mid point in the stroke, thus loading the cylinder walls unevenly. This created extra friction and caused the bores to elongate after high mileage. Now before people jump down my throat about this, yes I know these engines, if properly cared for would last a very, very long time, but when it came time to rebuild it usually took more machining to clean up the bores than it did with other engines. In most cases you need to go 0.030 over any way so I guess it wasn't much of a problem but the increased friction was. I don't know how many Ford small blocks I took apart to find egg shaped bores. This is a problem the 4.6 does not have. Also with a short connecting rod, the piston has shorter dwell time at top dead center, thus less time for combustion pressure to build against it. You loose torque because of this. A good example is a 350 Chevy compared to a 350 Olds. They are the same displacement but the Chevy has a longer stroke, yet the Olds makes more low end torque even with a shorter stroke. The reason is a longer connecting rod. The same holds true when you compare a 396 Chevy with a 383 Chrysler. The 383 makes more low end torque despite a shorter stroke and comparabile displacement. Again, the reason is a longer connecting rod. The other problem with the old Ford small block is tiny exhaust ports. To get really good performance you had to really go crazy with porting on the exhause side or go to aftermarket heads. A friend of mine has a set of GT40 heads on his 351W in his '69 Stang. I had a good look at them before we put them on. They aren't bad but even these are not as good as some "standard" heads I have seen for other brands of engines. The Ford 4.6 does not have these problems. In addition to this, the 4.6 being overhead cam has fewer moving parts in the valve train. The valve train is much lighter and less subject to valve float at high rpm, bent pushrods, rocker arm problems, ect. The overhead cam design gets the same job done with fewer moving parts. Certainly anything you can do to produce a lighter weight valve train will always increase reliability and efficiency. I don't think anyone could argue that if you were to take a hydrualic lifter, pushrod, rocker arm assembly and wiegh them compared to a cam follower from an OHC engine you would find a huge difference in weight. A lightweight valve train is critical for any sort of high performance application. The other problem you find with underhead cam engines is the fact that in typical mass production, the rocker ratios are very inconsistent. For example, I once took a full set of 16 rockers arms from a 5.0 Ford and checked the ratios. I found that they varied between 1.3 - 1.48. Not one of them was at the design spec of 1.5! Since the amount of lift you get at the valve is multiplied by the rocker ratio, you would be getting a different amount of lift at the valve for every cylinder. I would like to point out that each rocker arm I tested had a lower ratio than the design spec which means that not even one cylinder in that engine could breathe as well as the original designers had intended! I did find this to be corrected with several brands of aftermarket rocker arms that I checked. After discovering this, ALL of my engines received aftermarket rocker arms! Again, because an overhead cam engine does not have a rocker arm (typically), this problem is eliminated. Also, the combution chamber, at least on the 05 3V engine is vastly superior. It is a true hemishperical shape, with a centrally located spark plug for excelent flame propagation. This is the reason Ford can get away with 9.8 - 1 compression on regular gas. Please correct me if I'm wrong but I don't think anyone has been able to get 9.8 - 1 compression with the old 5.0 design without using premium gas. It would also be possible with this better combustion chamber to produce lower emissions and actually increase power when compared with a wedge or any other style of combution chamber. This may not be an issue for some car enthusiats, but it is a BIG issue for anyone mass producing cars. Additionally, the 5.0 shares parts only with the 5.8 so Ford stands to make more money by using the modular design than can share parts with many other engines. All these things considered, I can certainly understand why Ford developed the modular engine. The only downsides I can see to the mod engine is that it's physically larger than the old 5.0. It would not make good engine swap meterial as the 5.0 in small cars like the Mazda Miata. I've seen 5.0 engines in some pretty intersting stuff, like a Triumph. That's a lot of engine for a car like that! The other downside to the mod engine is the same with all overhead cam engines. The valve train is all up top in the head. I'ts not buried in the lifter vallley. They tend be a little noisy but this is true of all overhead cam engines. This is one of the reaspons Ford is using magnesium cam covers. Stamped steel ones would amplify the noise from an overhead cam engine and the public would not accept a noisy engine. The magnesium cam covers tend to dampen the noise and because they are stiffer they also seal better. The same could said of aluminum covers.
So, overall, certainly the 5.0 was a compact package that made some really decent, reliable power, I feel the 4.6 is just a better design. I'm usually of the opinion that bigger is always better but in the case of the 4.6 vs 5.0 debate, I really beleive that the 4.6 / 5.4 is just a better design. The exception being the 5.0 cammer. It again is OHC and has nothing in common with the older 5.0.
OK, I'll shut up now. Feel free to correct me on any of this crap. Hope I didn't piss anybody off. I've been out of the loop for a while.
Posts: 1740
Joined: 8/29/2004 From: New York Status: offline
Normally I would NEVER read a post that long, but you seem to know what your talking about and maybe I could learn something from all that. I totally understand your point, and yes the 4.6 is probly a better design. But you cannot only compare the engines, we are comparing the 5.0 fox body vs the 4.6 96 and up models. I just feel that the 5.0 is more of a hotrod than the new mustangs, in MMFF it was named the hotrod of the 21st century or something to that effect.
You also have to consider, which you did touch on breifly, that to mod a 5.0 is around half the price to mod a 4.6. If you put the same amount of money into a 5.0 and a 4.6 the 5.0 fox would decimate the 4.6 stang.
This is just opinion though, I love ALL MUSTANGS! I just prefer my 5.0 over a 4.6 and this is a good thread.
dang thats a heck of a psot and analysis... thanks man nice info. I would have to say that engine to engine the 4.6 might be superior... but the legacy isnt there and the ability to bolt on massive killer horsepower cheeply as well... plus im poor and 5.0s are still cheaper bodies to get. lol in any case thanks for the post dude
Thanks a lot for your comments. I know I'm waaay to long winded at times. Hell I don't even own a Ford yet. I'll be ordering an 05 GT next week as soon my financing is finalized. At any rate, I'm glad I didn't piss anyone off with my stupidly long post. I'm very pasionate about cars as you can tell. Anyhow, I do agree that the fox body 5.0 is one of the best hotrods you will ever get your hands on. They are light, strong and have an over abundance of reasonably priced performance hardware available. Not bad looking either. OK, I'll shut up now.
The stock 5.0's are overrated IMO... 220 hp's. The foxbody is a good body to build a drag car but the stock motor isnt very quick.
If they kept the 5.0 in the cobra... and a 4.6 with with pp heads in the gt's... not the cardboard ones ford decided to use in mid 90's.... the cobra is going to be slower... doesnt make much sense.
In 1990 225 was HELLA hp. It's not quick by todays standards, but in it's day, so you have to give it credit for that. What's funny is in 2015 You're going to look back and say "260, that's crap."
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RE: 5.0 stang? - 
