Lucky's '96 Mustang DOHC Swap

[Lucky]

Let me start by saying I'm not much of a Ford man - but I had some nice rims left over from a dying Infiniti J30 and I was looking for something fun that used a 4.5" bolt circle. I found a deal on a 96 Mustang GT convertible with a 5 speed
http://eagle-mark.com/pictures/albums/userpics/normal_mus1.jpg

It has pretty good street manners for a Mustang, it ran great and scored an excellent E-test. So I pulled the motor out of course.
http://img714.imageshack.us/img714/237/oldv.th.jpg (http://img714.imageshack.us/i/oldv.jpg/)

[Lucky]

The 96 4.6 2-valve engines have performance issues. Not a great head, not a great intake and a very mild cam profile result in a fairly boring engine that doesn't rev to it's potential. The 96 Cobra addressed these issues with a DOHC version of the 4.6 with 4 valves per cylinder helping the power band reach all the way to 7000 RPM.
A slightly milder version of this engine had been used in the Lincolns for a few years. I started searching the classifieds for a likely engine doner. Found a 93 Lincoln Mark VIII with a serious case of floor rot
http://img689.imageshack.us/img689/9776/donerz.jpg

The engine was complete and the compression test was good but the wires and hoses had been mouse food for a while...
http://img135.imageshack.us/img135/8009/theprize.jpg

The motor was gunged up inside, the IMRC plates had stuck open on one side, shut on the other, the IAC was pooched and the poor EEC couldn't figure out all the vacuum leaks and bad sensors. But I believed in it :lol:

[Lucky]

So out she came - these engines are supposed to go in and out the bottom of the car - call me old fashioned ...
http://img834.imageshack.us/img834/1362/pulling.jpg

Pulling the engine apart revealed some good things. The crank was A1 ok and the cylinder walls still had the factory hone marks. I decided to risk putting it back together without sending it to a machine shop for honing, decking, turning, polishing, tanking, aligning, etc etc
http://img155.imageshack.us/img155/7925/blocko.jpg

These engines use an aluminum block with iron cylinder inserts. The block is about 80 lbs lighter than the iron version and very strong by all accounts. The 93-98 blocks were cast in Italy by a company named Teksid - the same guys that do the blocks for Ferrari. It has 6 bolt main bearing caps. The crank is only the cast model but they are supposed to be able to handle 600 hp and they are a little lighter than the forged cranks since they skip the center counterweights. I would think that would be a problem at very high rpm, I'm not spinning it that fast.

[Lucky]

This is the Mark VIII oil pan. Notice the extra capacity added onto the side with the small 'daughter' pan. Very much like the pan that Canton sells for the Cobra. To use this pan in a Mustang with the stock K member you will need to trim about 3/4" off the inside lip of the K member for about 4". These engines are noted for loading up oil in the valve covers at high RPM so I think the extra oil capacity is good insurance. I find it takes 6 liters to fill it when I change the oil. It has lots of oil scrapers and windage features worked into the insides too.
http://img691.imageshack.us/img691/9843/oilpan.jpg

It also makes the engine very difficult to pull out of the top on the Mark VIII :|

[Lucky]

The heads on these engines are the first gen DOHC heads known as "B" heads. Each intake valve has it's own runner. They flow massive air in stock form. So much so that there is no port velocity at low RPM's and this limits swirl and cylinder filling. That means torque suffers.
Ford helped this out by putting throttle plates in 4 of the 8 runners on each head. At low RPM's the engine uses 1 intake valve per cylinder, at 3200 RPM the plates open up so the second intake valve can draw air. These are called IMRC plates (Intake Manifold Runner Control). When I ported the heads I only matched up the intake ports - no point making them bigger
http://img854.imageshack.us/img854/4560/porting.jpg

On the exhaust side I primarily worked the center divider to smooth the flow where the exhaust flows join. There was some casting flash to clean and a gasket match on the outlet.
http://img191.imageshack.us/img191/4962/porting2.jpg

By the time I finished doing all 16 intake runners, 16 IMRC ports, 16 head ports for intake and 16 head ports for exhaust - I was tired of porting

[Lucky]

The stock rods and pistons in the MARK VIII engine are pretty high tech - but on the weak side. Going over 400 HP is a matter of 'when' they will fail not 'if' they will fail. Since some form of boost is planned for the future I figured it was prudent to insert some forged pieces.
http://img153.imageshack.us/img153/4255/forged.jpg
The rods are 608 grams and the pistons about 340 grams - all matched to +/- 1.5 grams - rated to 700 HP
They are supposed to have a 6cc dish in the piston (it looks bigger to me) which should produce a comp ratio of about 9.4:1
Unfortunately the dish is shaped for a 3 valve head which means that one of the 2 quench pads isn't being used :cry:

[Lucky]

With everything cleaned, inspected, replaced, gauged and blessed it was time for some paint and assembly. I'd been watching EBAY closely and badgering the local speed shops for deals. The hardware store got a lot of business too ...
http://img62.imageshack.us/img62/3433/readyb.jpg

Notice the coolant crossover mod to the driver's side head - this tends to run too hot on the Stangs since there is no flow from the back corner - there is now
Mac long tube headers
Aluminum flywheel
11" stage 2 clutch
and many hours modifying the wiring harness to hide it ...
the long block is ready - now for the car and the intake and the computer and the tuning etc etc

[Lucky]

At some point before then the trusty 2 valve had been photographed, documented and extracted ...
http://img849.imageshack.us/img849/8291/2valve.jpg

The bumper and fenders came off, everything was stripped, sandblasted and painted up front.

In an effort to keep things clean looking under the hood (and to use the Mark VIII intake) I relocated the EGR to a place off the engine. I'm surprised that the EEC is running the EGR and it's sensor like this without throwing a code. :shock:
http://img852.imageshack.us/img852/1055/egr.jpg

Notice the area above the tranny has been BFH massaged for intake clearance

[Lucky]

FINALLY ! The engine went into the car. Let the wiring and plumbing begin. These things are TIGHT. There is only 1 place for everything and it doesn't include your hands or a ratchet :x
It has been said that you cannot use the Mark VIII intake in a mustang - and that is mostly true ....
http://img145.imageshack.us/img145/8563/testfit2.jpg

[Lucky]

Though it is much maligned in the Modular Motor circles I always kind of liked the intake from the early Mark VIII. A common complaint is that the runners are too small - but there are 2 per cylinder and combined those 2 tubes have the same area as a single tube 1.83" in diameter - way big in my book. The length of the tubes helps out in mid RPM and upper RPM cylinder filling and overall it adds some needed velocity to the air charge. The plenum is a bit cramped but it's still better than most of the other intakes available. And I like the look myself - totally tubular :lol:
http://img845.imageshack.us/img845/1681/stripped.jpg

Here you can see what needed to be done to make the intake fit in my Stang. The back of the intake was shaved to within a few mm of being a huge air leak - the EGR boss was threaded and fitted so the valve could be connected with a steel line - the IAC boss on the far side got the same treatment. Then I had to make a stalk to lift the throttle body up above the intake since there was no room behind it where it was on the Lincoln.
http://img714.imageshack.us/img714/4932/intakeng.jpg

Items of note; the big electrical connector at the back has every wire that runs on the intake routed to one connector - all the wires come off with it - that has come in handy :roll:
The plenum extension didn't last - JB weld won't hold against a good backfire :(
I also added a vacuum line to the very bottom of the plenum to draw off the oil that tends to collect there from the PCV

[Lucky]

This is what the inside of the intake looked like;
http://img9.imageshack.us/img9/6563/intake1o.jpg

My research indicates that a tube with a bell mouth will flow at least 30% more air than one without. To their credit Ford had rolled the shoulder a bit at the tube entrances. I opened them up as best I could with the material thickness there was.
http://img34.imageshack.us/img34/1787/intake2.jpg

From what I read, polishing the surfaces is counter productive. Boundary layer air clings to smooth surfaces and actually creates more drag. Rough surfaces cause the air to tumble along the surface and flow better. ie Golf balls have dimples to reduce drag.

[Lucky]

With the intake welded up and the lines connected I could finally bolt it on the engine. Then things started to progress up top on the engine and throughout the engine bay. I never liked the coils using up so much prime real estate in front of the engine so I fabbed up a bracket to relocate them.
http://img858.imageshack.us/img858/8498/tbcoils.jpg
The throttle body was modified to use the Mustang throttle cable.

[Lucky]

I still had to mount the MAF. I never liked the look of a huge tube layed across the engine to feed it air, and I wanted some ram-air effect too. So I started cutting into the hood. Fortunately I had the fiberglass model.
http://img836.imageshack.us/img836/7669/hood1x.jpg

The front of the engine nearly touches the hood so I added the center lump to make room for the MAF and vented it to let some hot air out.
http://img15.imageshack.us/img15/1559/hood2x.jpg
Many sheets of sand paper and cans of filler later I had created the outer shape of the MACH0 hood
http://img846.imageshack.us/img846/5776/mach0.jpg
Now to do the inside ...

[Lucky]

The inside got the same treatment - and then some plumbing. I wanted enough air path to separate rain water from the air, but not to add restrictions - and I was getting tired of complex fabrication with fiberglass and filler so I modified some 4" tubing and grafted it on.
http://img220.imageshack.us/img220/9041/hoodtubes.jpg

I like to think the primer makes it look less like drain pipes stuck to a hood lol. The tube ends are the correct size to fit some aftermarket air cleaners.
http://img703.imageshack.us/img703/175/ramair.jpg
And then I grafted on the Mustang MAF housing and connected it up with some rubber and steel
http://img192.imageshack.us/img192/6162/hooddone.jpg
Whew - a lot of work :!:

[Lucky]

Drat. The fresh engine Was all dusty before I even got to drive it. But at least it's testdrive time.
http://img696.imageshack.us/img696/380/roadtest.jpg
Items to note; Overflow bottle from a Beretta
Coolant connector modified so that the hose points down(to clear the air cleaners)
Relocated power steering fluid reservoir
Modified strut brace
A/C lines from a Marquis
A lot of things you don't see were moved to the inner fenders - like electrical and IAC - battery is in the trunk
The MAF is at the top end of the silver tube. I have tried several materials for the air tube, it's hard to find something 4" that will 'accordian' easily but not collapse when it bends or when the engine starts drawing hard. Currently I have a plastic one that has been working fairly well.

[Lucky]

While the MAF adds a whole level of complication, fabrication, wiring and PITA factor - it does let the EEC make a very good guess as to how it should run your engine. For the first tests I used the stock MAF from the Stang with the stock computer. So the EEC was getting real air flow numbers. Even with the larger injectors in the DOHC engine (24lb vs 19lb) it ran fairly well.

I had the IMRC connected to a toggle switch since the stock EEC won't switch it. I was having trouble finding software to tune the Strategy my 96 was running so a trip to the wreckers yielded an EEC from a 97 running the CDAN4 strategy. I found software support with Binary Editor for tuning and EEC Analyzer for datalogging and analysis for this EEC. It took me a while to learn this Ford tuning stuff. For a long time the stock tune ran better than my custom tunes. But eventually I got the hang of it.

A trip to the drag strip produced 6 runs at 97 mph, best time of 14.5 sec. Turns out I hadn't disabled the speed limiter - it starts pulling timing at 90 mph and shuts off fuel at 100 mph. :(

Since then I've gutted the MAF for more flow, put on a Magnaflow cat back exhaust and done a lot of tuning. It pulls a LOT harder above 5000 RPM than it did at the drag strip. EEC Analyzer has some fun tools like virtual drag strip and a dyno calculator. Here is what it calculates
http://img696.imageshack.us/img696/6120/hptq.jpg
Take it with a grain of salt ;) I have been reworking the MAF Transfer table to get rid of that lean spot. Probably the single most helpful tool on EA is the MAF Calculation tool. It calculates MAF comparisons like this
http://img4.imageshack.us/img4/3208/mafw.jpg
The bottom row is volts from the MAF and the side numbers are airflow. The yellow line is the new calculated MAF calibration. Notice the little spike it put in to correct the lean spot. Cool 8-)

[EagleMark]

wow Lucky, that is a SWEET project! That ram air set up was a lot of work but looks awsome!

[Lucky]

Rebuilt a new/used front cover the last few days. Been a long time since I tried to do a real paint job. I'm kinda rusty.
http://img580.imageshack.us/img580/2228/img0199w.jpg
This urethane skin had a couple big rips in it from an accident the previous owner enjoyed. Fixed them up but it's still kinda stretched. Hope it fits ok

[Lucky]

This is dragging on too long - need to get working on the house. But the parts are getting painted and going on the car. I like it :jfj:
http://img94.imageshack.us/img94/9610/img0213cm.jpg
the new top is on too. It's like scarey white. I'll never keep it clean :rolleye:
http://img8.imageshack.us/img8/6136/img0222ma.jpg
This shot really shows the extra shadow I painted in on the door. I think perhaps I need to do the front fender too ...

Note; jury is still out on ricer tail lights :thumbsup: or :nono: ?

[EagleMark]

American Muscle car with Ricer tail lights!
:confused1:

So there's one vote...... FAIL!
just my opinion...

Lucky why don't you put this up in your Ford section?