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Ford 302/351 W Roller Cam

In 1994, Ford started using a roller cam in the 351W. It’s a p/n F4TZ-6250-A that can be identified by the "TE" stamped in a repeating pattern on the barrel just behind the distributor gear.

Rebuilder’s survival tip: This cam is unique to the 351W and the 1994 and up 302 truck motors. It is not interchangeable with the 302 H.O. cam (p/n F1ZZ-6250-A), even though it has the Windsor firing order, because the specs are quite different. In fact, the 351W cam has twice as much overlap as the H.O. cam along with differences in timing, lift and duration.

This cam must be used in all the 1994 and later 302 truck motors instead of the F1AZ-6250-C that was used in the earlier 302 roller motors. The firing order for the ‘94 has the 1-3-7-2-6-5-4-8 sequence instead of the 1-5-4-2-6-3-7-8 sequence that was used in prior years.

Ford 2.3L/140 Ford OHC
The 140 Ford OHC engine came with either a steel or aluminum pan, depending on the application. The cars always used the steel version, but the Ranger pickups switched to a structural aluminum pan in mid-’85. In order to clear the reinforcing ribs on the inside of the aluminum pan, the pressure relief valve was moved from the upper outside edge of the pump to the bottom of the casting.

Rebuilder’s survival tip: You must use the correct oil pump for the application, depending on which oil pan is on the engine. The aluminum pan can be installed on the engine with the early pump for the steel pan (M-86C or equivalent) with the help of an impact wrench, but the ribs on the inside of the pan will put pressure on the outside of the pump housing causing the relief valve to stick in the bore. When this happens, the engine will build excessive oil pressure and blow the oil filter off. Be sure to use the M127 pump or an equivalent with an aluminum pan to avoid this problem.

181/3.OL Ford Roller Cams
Ford has used seven different roller cams for the 3.OL Ford V6. Based on the cam specs we have reviewed, we believe that they can be combined into two applications. See the applications and combinations provided in Chart 1.

The "A" and "C" cams can be interchanged but should never be used in a Tempo/Topaz with an automatic transmission. The "B" cams can only be used in the Tempo/Topaz with an automatic transmission.

Ford 183/3.0L Gaskets
Ford has made several changes to the gaskets on its 3.0L V6 engines since 1989. Ford has changed the head gaskets, intake gaskets, rocker cover gaskets and oil pan gaskets on both the FWD and RWD applications. Unfortunately, some of them were mid-year changes, so it can get real confusing for the rebuilder. Here’s the "big picture."

•The intake gaskets are held in place during assembly by two tabs on the intake gasket that interlock with two corresponding tabs on the inner side of the head gaskets. These tabs were originally located in the center of the head gasket from 1989 through 1991 but they were moved closer to the ends of the gaskets in 1992 (see photo above).

So, the rebuilder must make sure the head gaskets match the intake gaskets, especially when selling a long block with the heads already installed. The simplest way out of the problem right now is to use Fel-Pro gaskets for these applications because all of their head gaskets and intakes have all four tabs so they will always fit, no matter which combination is installed on the engine.

•The pan gasket was shortened to accommodate the shorter front covers that were used in the later years. It gets confusing, though, because this change was made on different dates for different applications; some of them were mid-year changes, (before and after 3/27/90), so the rebuilder must either watch the application very carefully or include both pan gaskets with all the ’90 and up engines to be sure the customer gets the right one.

•In 1991, the rocker cover gaskets were changed from the flat style to the thin rope version that lays in a groove in the rocker cover...except for some Aerostars that continued to use the flat version into mid-’91.

Be sure to watch applications carefully and catalog your engines accordingly, or include both sets of rocker gaskets to ensure the customer always gets the right ones.

Ford 3.0L Probe Differences
The 183/3.0L Ford V6 was used in the Probe in ’91 and ’92. There are two differences that rebuilders should know about:

•The 1991 Probe FWD engine is the same as the one used in the ’91 FWD car except that it doesn’t have studded mains.

•The ’92 Probe engine was unique because it had the F2DE block that was designed for roller lifters, but it still had the old flat tappet cam instead of the new roller cam that was used for all of the other FWD applications. And, it didn’t have studded mains.

Ford 140/2.3L - All New In ‘95
Ford made several major revisions to the 140/2.3L Ranger engine in 1995 to reduce "NVH," improve performance and reduce emissions. Here’s a quick overview of the big pieces:

Crank: The earlier E88E/E89E crank is still used.

Rods: There’s a new, longer rod with a F57E-AA casting number.

Pistons: The piston is a new, lightweight design with narrow rings that are closer to the crown. The pin was moved up to accommodate the longer rod, too.

Front housing: The front housing was revised, too. It incorporates a boss for a crank position sensor.

Head F57E: It’s still a dual plug head, but it has smaller intake ports and replaceable guides. The valves have 7mm stems and small springs that have only 60# on the seat.

Stamped steel cam followers are used along with narrow cam lobes instead of the cast followers and wider lobes that were used previously.

All in all, the Ford 140/2.3L engine is completely different except for the crankshaft.

Ford 2.3L/Chrysler 2.2L Timing Belt
Every so often we get a timing belt returned to us as defective that has about a third of the belt worn away with the cords showing on the ragged edge of what’s left. The customer always thinks that it’s a defective belt and expects it to be covered by our warranty, but it really wasn’t a bad belt that caused the problem.

The belt was ruined because the mechanic used the wrong bolt where the oil pan bolts onto the front seal retainer. When a long pan bolt is installed instead of a short one, it sticks up too far, rubs against the belt, and chews on it until it wears it out.

Ford 2.9L With Noisy Lifters
The 177/2.9L Ford has hydraulic lifters with adjustable rockers that can cause the following problems:

• The adjusting nuts won’t lock in place if they have been adjusted too often, so it’s best to replace them when the engine is rebuilt or you will end up with a noisy lifter if one of the rockers backs off out in the field.

• There are some adjusting nuts that have not been properly hardened that are being sold in the aftermarket. They feel okay during assembly and seem to hold their adjustment, but the ball wears quickly and opens up enough clearance to cause lifter noise, especially when the engine is started up. Readjusting the valves quiets them down for a little while, but the lifters start getting noisy again soon after they are adjusted. Consequently, the installer ends up readjusting the valves again or replacing the lifters.

Eventually the wear on the rockers becomes obvious and the installer replaces the adjusting nuts, (hopefully with good ones this time). This solves the problem, but it can get real expensive before the engine finally gets fixed.

Rebuilder’s survival tip: Replace all of the adjusting nuts in these rockers with either genuine Ford parts or aftermarket replacements that have been checked for hardness with a file. Don’t take any chances.

Ford 4.6L Modular:
The 4.6L SOHC modular engine has assembled cams running directly in the aluminum heads without any bearings, so if there is an oiling problem, the cam bores in the head get torn up along with the cam.

Rebuilder’s survival tip: Dura-Bond offers insert bearings that can be used to salvage these heads and cams. They are available with an oversize O.D. and a standard I.D. along with both a .010˝ and .020˝ undersize I.D. so the cam journals can be ground undersize if they are worn.

It takes six of the upper and six of the lower bearings with the correct I.D. for the cam, along with some time and tooling to repair one head, but it’s well worth it given the cost of new heads and cams.

Ford 244/4.0L:
Ford made a number of changes to the 4.0L engine in 1995. The block is now a 95TM-AB casting. It has two extra bolt bosses on the right (passenger) side and two more on the left (driver’s) side. The pictures shown on page 34 indicate where they are on both sides.

The piston has a bigger diameter dish (3.60’") because the head has a smaller combustion chamber. The crankshaft is either a 90TM-AA or a 96TM-AA. It appears that the 90TM-AA was originally used in ’95 and replaced by the 96TM-AA in late ’95 or early ’96, but the date of the change isn’t certain. The keyway and timing gear on the later crank were changed, too, according to those who have seen it.

There are two cams that are used, depending on the application. Both are a little bit different than the previous versions, but they both appear to be interchangeable with the earlier ones when used in the corresponding application.

The cylinder head has a smaller, kidney shaped chamber with a shrouded intake valve. It’s a 95TM-AD casting.

Rebuilder’s survival tip: Don’t use the earlier 4.0L blocks for a ’95 or later application because there aren’t enough bolt holes for all the mounts and brackets. And, don’t put the 95TM-AD heads on the ’90 to ’94 short block with the early pistons that have the smaller dish or you will have way too much compression and serious detonation problems.

Crossfire Problems
There have always been problems with plug wires causing crossfire between cylinders, even back in the days of the old 361 and 391 Fords. Crossfire occurs when the plug wire for one cylinder induces a voltage into the wire for another one that fires within 90 degrees.

This is becoming a serious problem on more and more engines because of the high-powered ignition systems and confined engine compartments found on today’s cars and trucks. The later model 302 Fords and 351 Windsors seem to be having more problems with crossfire lately.

Here’s what happens:

•351W – On the 351W, the firing order is 1-3-7-2-6-5-4-8, so if the wires for #6 and #5 are allowed to run close together and parallel to each other for even a short distance, the #6 wire induces a voltage into the #5 wire and ignites the mixture way too soon. Not good.

302 – The late 302 engines with EFI seem to be having more problems, too. The firing order on these engines is 1-5-4-2-6-3-7-8, so the #4 wire can induce a voltage into the #2 wire and fire it 90 degrees early.

The plug wires on the injected engines are routed through an opening under the upper plenum and down over the rocker cover. They are supposed to be supported and separated by a couple of wire looms that are intended to prevent crossfire, but these are often damaged or missing after a remanufactured engine is installed.

If everything isn’t put back the way it’s supposed to be, there’s a good chance that the #4 wire will crossfire to the #2 wire and cause some serious piston damage. The problem is aggravated by high-mileage plug wires with tired insulation that should have been replaced along with the engine – but weren’t.

In the early stages of this problem, shorting out #4 will quiet the noise in the engine because it stops the crossfire on #2. But once the piston is damaged, it becomes obvious that the problem is actually on #2.

Rebuilder’s survival tip: Crossfire is becoming a serious problem with high-voltage ignitions and cramped engine compartments. Think about it the next time you get an engine back that has had detonation in just one hole.

Ford 4.6L Front Covers:
There have been three front covers used on the 4.6L Modular engine from 1990 through ’98.

The original cover had an F1AE or F2AE casting on it. The belt tensioner was bolted onto the same studded bolts that were used to hold the front cover on. The cover is a p/n F1AZ-6019-A.

The original cover was superseded in mid-’92, apparently at the same time the block was changed from the F1AE to the F2VE casting. The new cover came with an F3AE casting number and had six bolt bosses cast and machined on the top corner of the passenger side for the revised tensioner. This cover is available as a p/n F4AZ-6019-A.

According to the "F3" casting number, the revised cover should have come out in ’93, but every late ’92 engine we have seen that has the F2VE/F4VE block has had the F3AE front cover on it, so we believe that Ford changed the cover when it changed the block.

This same cover was used up through ’95, although it had a different part number in ’95 (F5AZ-6019-A), apparently because of a revision to the tensioner that is included with the cover. It was replaced by another cover in ’96 that has since been superceded to the F8ZZ-6019-CA part number that is used up through ’98.

Ford 122/140 OHC
Oil leaks from the seal on the auxiliary shaft on Ford 122/140 OHC engines may be caused by a bad seal surface on the shaft. Many of them have a seal groove worn into the shaft, just like the ones found on the rear seal surface of many cranks. This groove will cause seepage and leakage if the shaft is installed in a rebuilt engine.

Rebuilder’s survival tip: Inspect all of these auxiliary shafts for wear or damage to the sealing surface and either repair them or throw them away if they are grooved. They can be repaired by welding the surface and grinding it down to size, or by sleeving the seal surface with the MS 349 sleeve from Micro Sleeve in Arlington, TX.