Can I use the newer Mustang 4.6 engine?

Yes, the new FFR kits are designed to fit the 4.6L.

Engine Types

There are 6 different displacements available, 3.9L, 4.6L, 5.0L, 5.4L, and 6.8L. The 4.6L, 5.4L are available in single and double overhead cam versions. The 3.9L DOHC engine is installed in the 2002 up Thunderbird. The 5.0L is also a DOHC engine but is only available through Ford Racing as a crate engine sometime in 2004, it has never been installed in a production vehicle. The 6.8L is a V-10. The vehicles these engines can be found in are as follows:

4.6L Single Overhead Cam

5.4L Single Overhead Cam

6.8L Single Overhead Cam V-10

4.6L Double Overhead Cam

5.4L Double Overhead Cam

VIN Y for the Mustang Roadster refers to the 2003 DOHC supercharged model.
VIN 3 for the Ford trucks refers to the supercharged SOHC Lightning engine.
VIN 6 refers to 4.6L SOHC Windsor produced engines.
VIN W refers to 4.6L SOHC Romeo produced engines.
VIN X refers to 4.6L SOHC Windsor produced Mustang engines.

The numbers & letters above are the 8th digit of the VIN

There are a lot of questions regarding the differences between the Windsor and Romeo. Either engine will work well for a performance application. If you have the choice pick the Windsor. Rather than try and tell you the differences we will point you to a link that has a great in-depth analysis of these 2 engines. http://www.babcox.com/editorial/ar/eb40228.htm

Mustangs have come with both Romeo and Windsor engines. The 1996 thru 1998 Mustangs came with Romeo based engines. The 1999 thru 2000 Mustangs came with Windsor engines. Then just for fun, Ford went back to Romeo engines in the 2001 thru 2003 Mustangs. Be sure to check the engine no matter what year it is. It seems that Ford carried over some engines into the following model year.

4.6L DOHC engines have come with blocks cast in both iron and aluminum. You can find the aluminum blocks in Mustang Roadster's up to year 2002, Lincoln Continental, Lincoln Mark Series and the Lincoln Aviator. These blocks are cast by Teksid in Italy for Ford. All of the aluminum engines are assembled at the Romeo plant. No SOHC engines have ever been cast in aluminum, although the blocks are generally interchangeable between the DOHC and SOHC. The only exception to this is the Continental engine which is front wheel drive. This block will not work in rear wheel drive vehicles. One of the motor mounts is not drilled, the bell housing is different to allow mating up to the transaxel, the oil filter is located on the opposite side of the block, the front cover and accessories are different. The oil pan has a front sump so this may help with some swaps that require a front sump. If you get stuck with one of these engines, you can still use all of the internal parts, cylinder heads and intake. These parts will bolt up to an iron or aluminum rear wheel drive block. Be sure to evaluate the time and expense associated with this kind of swap, all of the necessary parts needed to complete this conversion will add up quick.

The Lincoln Mark series are probably the most popular 4.6L DOHC engines, due to the relatively low price compared to the Roadster engines. What are the differences between these two engine's? Following are some, but not all of the differences.

The Roadster comes with a forged steel crank using 8 flywheel bolts, the Lincoln comes with a nodular cast iron crank with 6 flywheel bolts.
The Lincoln uses a different oil pan with a reservoir on the side.
The oil filter/water outlet castings are different.
The Intake cams on the Lincoln are a slightly different profile.
The Intake on the Lincoln is different from the one used on the Roadster, although they do use the same cylinder heads and a Roadster intake will bolt on.

The 6.8L V-10 has never been cast in aluminum except for a limited number that Ford did for a Mustang concept vehicle. The 5.4L DOHC has been cast aluminum but has, up to now, only been available in the supercharged GT40. We will have to wait and see if Ford offers this block through it's performance parts division. Just a guess, but you probably won't find many of these at your local pick-a-part yards.

What's a Triton? This refers to Ford truck engines.

What's an Intech? This refers to Lincoln engines.

Crankshafts

DOHC & SOHC Cranks will interchange. Some blocks may require minor block modifications for counter weight clearance when installing a forged crank in a block that previously contained a cast crank. The most common cranks for 4.6L engines are the nodular cast iron units. They come in both 6 & 8 bolt flywheel configurations. Note that just because a crank has 8 bolts does not mean that it is forged. The 2-valve Windsor engines use both a 6 & 8 bolt flywheel, the Romeo engines use 6. The only factory forged cranks available for the 4.6L DOHC engines are installed in the Roadster. These cranks are manufactured by Gertach in Germany for Ford. Ford Racing Performance Parts (FRPP) offers these cranks for sale under part # M-6303-D46 for 425.00. The correct 8-bolt flywheel for this crank is sold under part # M-6375-G46 for 250.00. This is a billet steel flywheel. The cranks in the 5.4L DOHC and SOHC engines are also available in cast or forged. Most of the cranks are forged, but not all. The only way to know for certain is to look at the parting line. Thick line for forged, thin line for cast. All 6.8L V10 engines have forged crankshafts.

Connecting Rods

With the exception of the 2000 Roadster R (Carillo) and the 2003-2004 Roadster's (Manley H-beam), all modular engines have come with sinter forged powdered metal connecting rods. There has been a lot written about these much maligned rods. The truth is, they are fine for use in mild performance applications. If a blower, nitrous or turbo is in your future, you would be doing yourself a favor by upgrading your rods to forged steel like Manley's H-beam rods. There are several versions of the factory rods. The Windsor engines use full floating pins where the Romeo based engines use pressed pins. The 4.6L SOHC passenger car engines have the weakest rods, the Windsor (or Triton) engines use a larger connecting rod that is stronger than the passenger car engines. The 4.6L DOHC engines use the same rods as are used in the Windsor's. The strongest factory style rods to date are the rods used in the supercharged 5.4L lightning. These rods have a larger big end than the standard modular rods.
4.6L Rod length = 5.93"
5.4L Rod length = 6.65"

Pistons

The pistons used in modular engines are all of the hypereutectic style, with a few exceptions. These exceptions are the supercharged Lightning and Roadster. This should tell you something about the durability of the factory pistons. If Ford decided (at considerable expense) that it was necessary to upgrade to forged pistons for forced induction maybe you should heed their advice. We have seen forced induction cars run on factory pistons and produce good horsepower, the question is, for how long? If you are building a forced induction engine you need to understand that the factory pistons do have their limitations and when you reach these limitations, it's not pretty. When building a modular engine for mild performance applications, the stock pistons will hold up fine. Most of the pistons used in modular engines are dished. Pistons are interchangeable between the DOHC and SOHC, 6.8L, 5.4L & 4.6L engines. Obviously, you will need to check piston to valve clearance. Following are the dish volumes used in these engines:

SOHC 4.6L, 5.4L,and 6.8L
1991 thru 1998 ------- 10.49cc dish
1999 thru 2000 ------- 18.10cc dish
2001 thru 2004 ------- 15.80cc dish

DOHC 4.6L
1993 thru 1998 ------- 2.66cc dish
1999 thru 2002 ------- 4.54cc dish

DOHC 5.4L
1998 thru 2004 ------ Flattop

Cylinder Heads

SOHC

The most in depth evaluation of sohc cylinder heads can be found at the previously mentioned link http://www.babcox.com/editorial/ar/eb40228.htm
For performance applications the choice is more clear. These heads can be separated into pre-1999 non-performance improved (NPI) and post 1999 performance improved (PI). If you have a set of pre-1999 heads and want to use them, understand that a fully ported set of these heads will perform a little better than a set of PI heads out of the box. There are good reasons for using the early heads, mainly cost. To convert to the PI heads on a non PI head engine will require not only new heads but intake and associated hardware as well. If your willing and capable of doing your own porting work you can build a strong SOHC engine with these heads, just understand that these heads will never perform as well as a set of ported PI heads. Be very careful when porting these heads. There is not much material to play with. This applies to all castings.

The post 1999 heads (PI) are excellent castings. These heads work well as is, but really respond to a good port & polish job. After porting these heads can flow as well as the FRPP heads listed below. For supercharged applications or hi-performance engines these heads are a good starting point. The moral of the story is: if you are looking to buy an engine, buy a 1999 or newer. There is one other option, the FRPP hi-performance heads for the early (1996-1998) engines. These are probably the best heads available for the SOHC 4.6L engines. They also respond well to a good port & polish job. These heads have never been offered on a production vehicle but they can be ordered through FRPP under part # M-6049-D46. Be sure to shop around before purchasing these heads. Prices vary from vendor to vendor but expect to pay about 800.00 each without cams. Ouch!

The numbers listed below are for reference only. Your results will vary depending on who does your cylinder heads and whether or not they were drinking beer at the time. These are not our flow numbers
so take them with a grain of salt.

The 4.6L SOHC and the 5.4L SOHC use the same basic heads. The difference in these heads is not whether they were installed on a 5.4L or 4.6L, but whether the engine was built in the Windsor plant or the Romeo plant. The Windsor heads use 14 bolts for the valve covers while the Romeo engines use 11. That is the easiest way to tell them apart but there are a lot of other differences. The two heads share the same basic architecture but that's about it. Chambers and port dimensions are the same for these 2 heads. Valve sizes and combustion chamber volumes are as follows:

Everything stated above regarding the 4.6L cylinder heads applies to the 5.4L and 6.8L V-10. The difference being, the 5.4L and 6.8L V-10 did not receive the PI heads until year 2000.

After looking at the cylinder head combustion chamber volume and the varying amount of dish in the factory pistons it's easy to see that changing heads and pistons from different years will result in a compression increase or decrease. The following chart will give you a guide when scrounging the junk yards for engines. Your compression ratio will vary depending on combustion chamber work, head gasket thickness, decking of the block, & milling of the heads.

Cylinder Heads

4.6L DOHC
There are several different castings available for the DOHC heads. 4.6L & 5.4L heads will physically interchange, but the ports on the 5.4L heads are much bigger than the 4.6L heads. Neither the Roadster or Lincoln intake manifolds will work with this swap. If you were able to get the intake to bolt on, there still is not enough material around the ports to enable port matching to the larger navigator heads. Our single plane 4.6L intakes were designed with enough material to allow for this swap. The Navigator heads ports are too big for a naturally aspirated 4.6L street car but may make for some impressive horsepower on forced induction cars.

These heads can be divided into 2 basic designs pre-1999 twin port heads (also known as the "B" head) and post-1999 tumble port heads (also known as the "C" head). These 2 heads are interchangeable on any of the 4.6L blocks although it is usually not financially feasible to do this swap because it entails swapping intake manifolds as well. Both heads are very good castings with the tumble port heads getting the nod for making more high end horsepower. The heads on the Lincoln are the same castings as are used on the Roadster.

If you are building your DOHC engine for use in a truck or heavy car, you will probably be happier with the twin port heads. These heads with their IMRC plates, create better torque and at a lower RPM than the tumble port heads without severely limiting hi-end horsepower. These heads respond well to a port and polish job. You can also pick up extra horsepower if your engine is a Lincoln, by swapping the intake manifold for an early Mustang Roadster intake.

The tumble port heads have been available since 1999. These heads were never offered on the Lincoln Mark series due to the cancellation of this model in 1998. These heads can be found on the front wheel drive Lincoln Continental. Maybe if you come across a cheap Continental engine it's not such a bad deal after all. Obviously these heads are also available on the Mustang Roadster. The Roadster heads were modified for 2003. They are supposed to flow better on the intake and exhaust than the early castings.
The best heads offered to date have never been installed on a production vehicle. These are available on the FR500 crate engine. The heads on the FR500 are available from FRPP under part #'s M-6049-T46 and M-6050-T46. These heads are bare, but FRPP does sell a hi-lift (12mm) camshaft kit that includes cams, valves, springs, retainers, and rockers under part # M-6550-T46. The heads sell for about 800.00 each and the cam kit is 1495.00

All of the tumble port heads respond well to a port and polish job. Unless you have money to burn, justifying the additional expense of the FR500 heads may be difficult. The standard heads can be made to provide all the flow necessary for even the highest horsepower applications.

5.4L DOHC
Twin port heads have never been offered for the 5.4L engines. You are limited to the Navigator heads unless you come across a set of Roadster R heads (you might have a better shot at hitting the lottery). Being limited to the Navigator heads is not a bad thing as these heads flow a large amount of air. Port and polish these heads and you will see port flow in excess 325 cfm. There is no horsepower to be gained by trying to run Roadster heads, the Navigator heads with their large ports allows the use of much larger intake runners. Below is an outline of the commonly available DOHC heads.

Twin Port Head Dimensions (Intake) Square Port 32mm x 40mm Oval Port 36mm x 44mm

1999 & Later 4.6L Tumble Port (Intake) 50mm x 39mm

1998 & Later 5.4L Tumble Port (Intake) 59mm x 39mm

All DOHC Exhaust Ports 48mm x 25mm

Cooling System

The 4.6L, 5.4L & 6.8L cast iron blocks use a cooling system that is different from the one that is used on the aluminum blocks. The aluminum blocks use a bypass hose (this is the hose that runs in front of the engine to the thermostat housing) to keep flow constant through the block to help eliminate hot spots. This is due to aluminum being more susceptible to hot spots than is cast iron. If you are running an aluminum block do not eliminate this hose. The cast iron blocks utilize a conventional cooling system (no bypass hose).
 

Oil System

The oil pump used on modular engines is what's referred to as a gerotor pump. It contains two internal gears with the middle one being driven by the crank. The clearance between the sides of the gears and the internal sides of the oil pump are critical. These pumps are not as robust as the pumps used on the older push rod Ford's. If any debris gets into the oil pump it will gall the sides of the aluminum housing, creating a situation where the pump will not prime. If you are reusing an oil pump be sure to pull the cover off the pump for a close inspection of the housing for galling. Replacing this pump after installation of the engine is not a fun job.There have also been failures of the powdered metal gears utilized in these pumps when used in hi-performance applications. There are billet pump gears being offered by some vendors to address this problem, do a search on Google and you will come up with several suppliers. FRPP also offers a high volume oil pump. It is available under part # M-6600-D46 for 59.95. This pump is the same unit as is used in the Roadster's and does not have billet gears.

Engine Weights and Dimensions

Engine Weight 4.6L SOHC 500 lbs. 5.4L SOHC 525 lbs 4.6L DOHC Aluminum Block 425 lbs 5.4L DOHC 540 lbs 6.8L SOHC V-10 640 lbs.

Accurate weights are hard to come by. It seems everyone has their own idea of what constitutes an engine assembly. Was it weighed with all the accessories, was it dry or filled with fluids, etc. Use this as a guide, these numbers are close but will vary from what you see elsewhere.

Dimension A measures from the top of the throttle body pad (if you are running our intake) or top of the factory intake (if stock) to the bottom of the factory oil pan. Dimension B measures from the bell housing face to the front of the water pump pulley. Dimension C measures from the outside edge of each cylinder head.

Engine "A" "B" "C" 4.6L SOHC Mustang Intake * 23 5/8" * 5.4L SOHC F-Series Intake 28 " 23 5/8" * 4.6L DOHC Roadster Intake 27 1/8" 23 5/8" 26 5/8" 4.6L DOHC Sullivan Intake 27 3/4" 23 5/8 26 5/8" 5.4L DOHC Navigator Intake 35 1/2" 23 5/8" 28 1/4" 5.4L DOHC Sullivan Intake 28 1/2" 23 5/8" 28 1/4" 6.8L SOHC V-10 Van Intake 28 1/2" 27 1/8" *

Water Outlet / Oil Filter Mount

According to Babcox there have been at least 6 different castings for the water outlet / oil filter mount. These castings are interchangeable for all of the modular engines. The one you will probably want to use is found on the Roadsters and some Mustangs. You can get it at your Ford dealer under part # F8ZZ6881AA. It retails for about 150.00. This casting accepts a factory oil cooler that also doubles as your water outlet, the water outlet exits above the power steering pump. The factory cooler is also available from Ford under part # F8ZZ6A642BA, it sells for about 150.00. If you are running our 5.4L single plane intake and opted to relocate the alternator with our bracket, you will need the oil cooler housing off the 2003 Roadster. The water outlet on this housing exits below the power steering pump. This cooler is available under part # 2R3Z6A642AA for about 150.00.
 

Engine Mounts

All of the modular engines have the same basic mounting locations on the cylinder block. This means you can take the mounts off a 4.6L Mustang Roadster, bolt them onto a 5.4L Navigator engine and bolt the engine directly onto the factory cross member. This scenario also applies to the 6.8L V-10, 5.4L SOHC, or the 4.6L SOHC. The only exception to this is the Continental blocks previously discussed. For your information the Roadster R model used motor mounts that lowered the engine in the chassis 12mm, It did however, bolt onto the standard Mustang cross member. Something to think about if you are having hood clearance issues. If you are a Mustang owner and want to go with a tubular cross member we very highly recommend Anthony Jones Engineering. Their cross members fit perfect and the quality is the best on the market. They can be reached at http://www.ajeracing.com

Exhaust

The 4.6L & 5.4L share the same exhaust port configuration. You can use a pair of Roadster shorty headers for your 5.4L DOHC transplant if you wish. None of the long tube headers currently available for the DOHC Roadster will work with the 5.4L swap inside a Mustang without modification. There are no commercially available swap headers at this time. Same thing goes for the 4.6L & 5.4L SOHC. There are several company's making shorty headers for the V-10, do a Google search for "Ford V-10 headers" and several will come up.

Terminator 4.6L (2003-2004 Roadster engine)

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