Filed under: Chicago Auto Show
Ford's supercharged Mod motors
Readers of Autoblog know that I'm not a huge fan of the naturally-aspirated Ford modular V8s that are available here in the US, but stick a supercharger on these motors and my opinion changes substantially. Let's take a closer look at the two forced-induction versions; the lame-duck 5.4L DOHC engine used in the Ford GT, and its closely-related sibling that will soon see use in the Mustang Shelby GT500.
Due to this engine's similarities to Cadillac's supercharged Northstar, it's tempting to make comparisons between the two engines, and so I'll do exactly that.
A look at the camshaft chain drive shows that one large chain drives the exhaust cams off the crankshaft, while a short intermediate chain then transfers rotation to the intake cams. This strategy allows the use of a smaller sprocket on the intake cam, and the subsequent reduction of bulk at the upper corners of the head (compare this to the Northstar, which uses two equally-sized sprockets on each cam). The downside is an increase in length, complexity, and noise; this is a huge "small block" engine, despite its modest displacement.
See that log-style cast-iron exhaust manifold? To the eye, it sure doesn't look very efficient. It'll be interesting to see how much room is left in the S197 engine bay by the time this tall-deck DOHC monster is shoehorned into place, but hopefully there's enough space to squeeze in a pair of proper headers.
The serpentine belt is also used to drive the supercharger. It'll be interesting to see how the aftermarket modifies that to allow the use of a cogged belt to drive the blower.
That fuel rail appears much larger than what we'd typically find (the Northstar's rail looks tiny in comparison), and it feeds one injector per cylinder.
This is a lovely-looking Roots blower, but how long until someone mounts a twin-screw unit? It'll be interesting to see what Whipple and Kenne Bell offer for those sickos who just can't be satisfied with smaller blower pulleys. Note that the blower discharges downward into the intercooler, which is a bit more typical than Cadillac's upside-down airflow path.
There's the oil cap, and just above and behind it is the crankcase breather. Follow that tube up to the blower housing, and you can see the vacuum actuator for the supercharger bypass valve right behind it. When the throttle is closed enough to draw a vacuum, this system bypasses the compressor for additional efficiency.
Is that a reduced-diameter multi-plate clutch that we see? Yummy - hopefully it's enough to hold up to the sort of abuse that this engine will be capable of doling out at the dragstrip. The skeletonized flywheel looks to be much lighter than what we'd normally see in a production application. I'm thinking that this engine will provide the definition for "throttle response".
Note the relatively deep sump - hopefully that's sufficient to maintain oiling during high-g cornering, as I suspect that many owners will want to do more than just quarter-mile straight-line blasts.
That's one beefy bottom end, but we can see just how small the pistons are in relation to the exterior dimensions of the engine. That 3.66" bore limits the engine's ability to breathe, even with four valves, but this becomes much less of an issue once that supercharger starts to work its magic. Regardless, note that Ford isn't really keen on showing off the intake and exhaust ports in its cutaway displays.
The dish in these pistons is larger in diameter and not as deep as those found in the Northstar's pistons. That lends itself to a bit less desirable combustion chamber shape, but likely also allows for a higher pin position and more thickness in the piston crown (the latter is especially important to those who will be pushing this engine to the limit). This is a fine example of the tradeoffs and compromises that must be made when designing an engine.
Now, on to the Ford GT engine:
See that big cogged belt, mounted low on the engine? That drives the pump for the dry-sump oiling system, which is employed to reduce the packaging height of the engine. The sump that we pointed out on the Shelby's engine is eliminated, allowing the engine to sit lower in the chassis. It brings with it some oiling improvements as well, especially under high lateral loadings. 'Tis not inexpensive or simple, however.
Methinks there are more than a few horsepower to be found by replacing those exhaust manifolds with a proper header.
If you're an oxygen molecule that was unfortunate enough to enter the GT's intake track, this is one of the last things you see before you die:
After a trip through the dual 70mm throttle body (I'd estimate its rated airflow somewhere well north of 1250 CFM), the intake charge is compressed in a twin-screw supercharger:
There, it's discharged downward through an intercooler. Note the use of two fuel injectors for each cylinder. Only one is used at idle and low throttle openings, which allows for fine metering of the injected fuel. Get into the loud pedal far enough, and the second injector comes online to ensure that sufficient fuel is available to keep up with the supercharger's cylinder-filling efforts.
At the upper edge of this photo, we find the four black coil-on-plug (COP) assemblies. Once again, note the relatively small size of the cylinders relative to the overall bulk of the complete package.
To no one's surprise, we find the same cam drive arrangement.
The transaxle is seriously gorgeous - it seems a shame that it likely won't see use in other Ford products.
As we can see, there are indeed differences between these two engines, but they're not huge. The Ford GT puts down well over 500 HP to the rear wheels despite its 550 HP rating; will the Shelby prove its 475 HP rating to be equally pessimistic? We're anxious to find out, and it should be interesting to see how much work is required to bring the Shelby's output up to the same level as its much more expensive cousin. We're betting that it won't take much.
Reader Comments (Page 1 of 2)
mike 5:20PM (2/20/2006)
The size of this thing is ridiculous for its displacement. I'll take a northstar anyday. Ford modular V8's have an terrible reputation. Look at those crown vic taxi cabs. They all smoke (if they live that long!!)
Reply
jonathan 5:50PM (2/20/2006)
Of course a mod motor will smoke after taxi duty, any motor would.. I have first hand experience owning and tuning ford's mod motors... It's balls above anything that GM can muster...
Older they get the better they become..
Reply
md 6:03PM (2/20/2006)
An awful reputation? are you kidding? I can't even imagine how many miles taxi's travel per year. It is probably something north of 50,000 miles a year. After several years of that, it is a testament to the engineers that those motors are even still running. These motors also power Americas best selling vehicle. You don't sell 900,000 full size pickups a year by fitting it with a bad engine.
Reply
Christopher 6:52PM (2/20/2006)
Great review and fantastic pics too, thanks!
Chris
http://amateureconblog.blogspot.com/
Reply
mike 7:23PM (2/20/2006)
I own a auto machine shop and the modular V8 by Ford is a big peice of crap!!! The head is a horrible design. Spark plugs blow out. Many locked cams in the head. Weak bottom end. Smokes because rings loose tension. Bad design. Makes me lots of money. For my money i will take a chevy small block. Piston slap is something I can live with if I have to.
Reply
Ford Mustang 7:37PM (2/20/2006)
Bad reputation? You've got to be kidding. Ford's mod motors have a great reputation because they go forever, and rarely break under normal driving conditions. Have you ever seen how many miles those taxi modulars have on them? 300K is the norm.
Reply
Gardiner Westbound 7:45PM (2/20/2006)
The Center for Automotive Safety reports serious oil leaks with this engine. Ford has been less than helpful.
Reply
Chris 11:21PM (2/20/2006)
We could compare Ford vs. GM engines in taxi duty if GM had any!
Reply
Christian J 12:32AM (2/21/2006)
Lame duck? Are you high? The 5.4L DOHC (all aluminum)in normally aspirated form makes 385 horsepower, and makes it at low revs. The top end is strong too because of the 4 valves. Puts those stupid pushrods to shame. HAHA. Compare that to GM who needs 5.7L to make 350-85 hp(LS1), or 6.0L to make just 400hp(LS2). Sad. They have lots of lame ducks once you get away from the LS6 and LS7 (7 friggin litres). And no there's nothing wrong with supercharging.
Reply
Den in IN 8:15AM (2/21/2006)
I do not have a supercharged Mod, but a 32v NA in a Mustang Cobra. I can truly say it's huge for the displacement. Compared to the Hemi in my Magnum its huge (external size),complex and doesn't make power in the same league. I think it is a cool design and sounds amazing at full steam, but the simpler more efficent Hemi is so much better.
Reply
Jim Ketzlow 11:58AM (2/21/2006)
Den in IN, I'd say it's a bit of an apples to oranges comparo when you are matching an older 32V NA cobra engine to the latest and greatest HEMI from dodge. If you remember correctly, the original HEMI engines were anemic, too. This article is about supercharged modulars (as you know) which in a Cobra would hand your Magnum its ass (and thats also and older mod motor).
I don't know about you guys, but since Im a gearhead and an auto enthusiast, I like to ask people's real world experience with their cars. Especially people that severely beat on their cars like police officers and taxi drivers and such. The response I've gotten is overwhelmingly positive to the Fords. Cops arent crazy that the mod motor they get isnt that ballsy, but they do appreciate the fact that its smooth and "bulletproof". Most of them will straight up tell you that the Caprices were faster, but the motors would not last and the car.. forget about the car.
The taxi drivers say the same thing. Next time you go to Vegas take a poll of the cab drivers out there (most in lincolns and crown vics and explorers) and they will tell you how reliable their Fords are.
Reply
Art Baker 12:59PM (2/21/2006)
>>but how long until someone mounts a twin-screw unit? It'll be interesting to see what Whipple and Kenne Bell offer for those sickos who just can't be satisfied with smaller blower pulleys.
Reply
Eric Bryant 1:28PM (2/21/2006)
"Lame duck? Are you high?"
I used the term "lame duck" as the GT is soon leaving production, and that particular engine goes away with it. Other than that fact, there's nothing lame about it.
Reply
samuel 1:35PM (2/21/2006)
Mike, you are absolutely talking nonsense. There are many of them running 3-400K in taxi's (and they have a pretty good reputation). Northstars will NOT do that.
As far as comparing them to GM pushrod small blocks , well, I would rate GM higher. Physically smaller, simpler, and they make more power without using more fuel.
Reply
RayRay 3:00PM (2/21/2006)
For #9, those LS engines are pushrods. On paper, the numbers look pretty massive, but once you see the actual design, it is pretty compact for its displacement figure. This is why the Corvette can kill the Mustang any day of the year. As for Dodge, I'm not too sure what type of engine their Viper has, but I think it's an 8.3L, correct me if I'm wrong. But that car is heavier than the Corvette, kills a lot more gas, and handling characteristics worth laughing at.
Nothing wrong with supercharging engines, but supercharging crap engines are still crap engines. I believe both GM and Ford have their own collection of crap engines, and that is why both companies are doing so horribly. Ford... pickup truck's all you've got; GM... Cadillacs and Corvettes... ok, that's all I can think of; Daimler-Chrysler... their infamous HEMI and their boosted SRT-4cyl engines ... but most other engines aren't much to talk about. The Big 3 needs to seriously work on designing more refined and efficient engines, and most definitely improve the quality and design of their interiors.
Reply
Christian J 7:23PM (2/21/2006)
Corvette can kill the mustang? ITS SUPPOSED TO, dummy. It also costs a frig of alot more. HAHAH. It must be that plastic red cover they put on it, adding 20hp. Unfortunately the LS motors do not always win even in Vettes. There have been a few mustangs recently that could give the Vette a good run on a track, road course, for a lotta bux less. Compare the 2002 (C5) Z06 with the 2003 Cobra available from Spring 2002. I'll take mine in mystichrome please. Whatever happened to the Vette motor that was DOHC? It had big valve covers too. There is nore valve gear in a DOHC up top, small price to pay for excellent breathing.
Reply
Poe 8:07PM (2/21/2006)
I also had a 32v DOHC N/A mod motored Cobra (1996) - and it was the best engine I've owned to date. Over 100k miles without a hint of a problem. Not one. Ever. It was still running flawlessly (and NOT smoking) when I sold it. We're talking HARD miles too - including about a dozen quarter-mile track passes and a track day at Road Atlanta - in addition to the regular daily thrashing I gave it on my 70-mile round-trip commute. I still regret selling it. If I could afford it, I'd buy a GT or a new Shelby in a heartbeat.
Reply
spear 7:46PM (2/23/2006)
Since when did a MUSTANG ever wander onto a track and finish a lap???
Reply
Cop Car 10:13PM (3/08/2006)
I have been driving my mom's '92 Town Car which has a 4.6 modular motor.
I use this as my company car to service my military foods brokerage business centered out of Louisville. I have to travel as far as Detroit, Nashviile, St Louis and Chicago. Now at 197,000 miles, the car runs very well and averages between 20.5 mpg and 21.7mpg.
The only motor issues have been:
- a small oil leak developed at oil filter housing. fixed by having a new gasket installed,
- intake manifold egr track had to be cleaned by the dealer to clear a check engine light,
- simple electric contact problem where the spade like starter wires plug into starter,
- car will smoke a little only when reving after it has been sitting at an idle for several minutes,
- spark plug wires.
The car has never failed me or left me stranded on the side of the road. Even at almost 200,000 miles I have complete faith in the old girl and just installed new 70,000 mile Bridgestone Turanza LTSs and front wheel alignment.
I am very impressed with the reliability and durability of Mom's old Lincoln Town Car Cartier. the exterior and interior are in remarkable shape! Almost like new! This was my mom's first luxury car that Dad replaced in '97 with a new Town Car. Well Mom is gone now but I think her old car, which I'm sure made her feel proud, may live on for many miles.
Reply
Carmine Galletta 11:28PM (5/06/2006)
I own an 05 GT prchased new and thank goodness I have not found any oil leaks as of yet. However I would like to inform you of my experience, As an all America muscle car collector I purchaesd my GT with great expectations and I really love the car. But with about only 500 miles on the car, I found that the lower passenger side rocker panel began to buldge just below and behind the passanger side door. Concerned I called my dearlership where I purchasd the car, and brought it in for inspection. After 2 days they called me an told me that after a few attempts they could not service the car because their lifts could not accomodate the car. Furstrated and amazed at their excuse, I brought the car home and on my low profile buddy lift that I bought at the Atlantic City Auction I was able to get the car in the air with no problem at all. I proceded to remove rear the under panels and after removing what seemed 1000 screws, I was able gain assess to the oil pan and inside rocker panels. In the passanger side rocker panel I found that all of the piping for the coolent, power steering, and brake lines -- as much as 5 or six lines were jammed into this small area. The large coolent line was pushing outward onto the other lines causing the buldge ans stressing the plastic panel. I re-adjusted the 2 large clamps to reduce the outward pressure on the rocker and also secured the rest of the lines that were rubbing together with nylon tension ties. By preventing the lines from rubbing on eachother, you will in turn prevent friction leaks in these lines in the future this very important! I then contacted the Ford GT hot line and the woman requested that I email the pictures of what I have found so she could forward them to her technical department. About 4 months have passed and still no response, no fix no explination from Ford. The dealership has not even called me to follow up. These lines would have without a doubt broken thorugh the rocker, I have stress cracks in the panel where the lines were pushing outward. Oh yeah I performed my own oil change as well paying just shy of $300 for the oil and filter from Ford. I recently inspcted a new 06 GT on the showroom floor of the dealership where I purchased my car and found that the aluminum lines near the passanger side rocker panel under the rear deck lid were not even in the factory clamping and just floating in the air. What is wrong here? This is a brand new car. I hope this helps someone. So keep an eye on your rocker panel this most likley is inherent in all of these cars. I hope this helps. PS before you buy a GT ask the selling dealer if they have the proper facility and knowledge to service your car. It sad that a Ford dealershi can sell their so called flagship vehicle and not be able to service it. This is my first Ford car and it may be my last. In my opinion there is just not enough respect for these cars when they arrive at the dealership for service. Training is key and there should be criteria that a dealership should be required to meet before a car like this is even allowed to roll into ther showroom. The American way I guess sell it and worry about servicing it later. Talk about putting the cart before the horse. Good Luck and safe drivig to all.
Reply