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Learn How to be a Survivor When Problems Arise: Chevy Small Block Oil Pans

It’s not uncommon to end up with dirt in a small block Chevy after it’s been installed, even if all the tin appears to be perfectly clean. This problem may be caused by the sludge and debris that gets trapped under the baffle that’s welded in the bottom of the pan. Most installers don’t even realize that there’s a cavity under there, so they don’t spend the extra time required to clean it out. See Figure 1.

Rebuilders’ Survival Tip:
Make sure your customers know that the oil pan isn’t really clean until it’s clean under the baffle. Some installers drill some holes in the baffle so they can clean under it and make sure there’s no sludge left behind. Remind your customers that cleaning the pan with glass bead is deadly, too, because the media will end up embedded in any sludge that is trapped under the baffle and cause an immediate bearing failure when the hot oil flushes it back out.

Chevy 454 Vortech Splash Shield
The 1996 and later Chevy 454 roller cam Vortech engines all came with sequential port injection instead of a carburetor, so GM completely redesigned the intake manifold. The bottom of the new manifold is protected from the hot engine oil by a stamped steel tray that fits down in the valley in between the two intake gaskets. See Figure 2. It’s designed to be reusable, so it’s not included in any of the OEM or aftermarket gasket sets, but it’s possible that an installer may damage it or throw it away and end up needing a new one. If he does, have him call GM and order the "intake manifold oil splash shield" that’s available as a p/n 12555320.

Ford 3.8L/4.2L Main Caps
Beginning in 1996, all of the 3.8L and 4.2L Ford V6 engines started coming with heavy duty main caps that stick down about .400˝ further below the bottom of the block. They are very similar to the caps that were originally found on the supercharged blocks, and they present the same problem: They are so deep that they will not fit in the cradles used for some boring bars and cylinder hones. See Figure 3.

Rebuilders’ Survival Tip:
Take a couple of the shorter caps – along with the bolts – off an early block and put them on the later block while you bore and hone it. We paint them bright red so everybody knows they don’t belong on the block and stamp the serial number of the engine on the original caps to make sure they end up back where they belong.

Buick 3800 VIN "K" Hydrolock
One of the more notable features found on the 1995 and later Buick 3800 VIN "K" engines is the plastic upper intake manifold. It’s cheaper to make, it’s quieter than an aluminum manifold and it makes more power – but there’s a problem caused by the EGR port that passes through the intake manifold directly behind the throttle body. (See Figure 4 below.)

This passage is partially protected by a metal sleeve that sticks up from the lower manifold, but that doesn’t keep the heat from the hot exhaust gas from damaging the upper manifold over the long term. When the plastic deteriorates, it exposes the coolant passages used to preheat the throttle body that are located on both sides of the EGR passage. Then, when the engine is shut off, the pressurized coolant runs down through the manifold, past an open intake valve and ends up hydrolocking one of the cylinders.

Rebuilders’ Survival Tip:
Know the symptoms when a customer calls so you can diagnose the problem before, or after, he installs the remanufactured engine. If one of these engines is hydrolocked, remove the throttle body and check the area around the EGR port for deterioration and coolant leaks.

Ford 3.8L/4.2L Plugs
Ford has used four different plugs to plug the big hole on the passenger side of these blocks. There are:

• Large hex plugs with no internal threads;

• Large hex plugs with internal threads for a detonation sensor. There have been two different holes and threads used for two different sensors; and

• Round shouldered plugs with a recessed internal hex for removal and replacement.

There is no easy way to predict exactly which one the customer needs, so the odds are that the remanufactured engine will end up with the wrong one no matter which one you install in it. See Figure 5.

We tried leaving the plug out completely but discovered that some installers couldn’t get the old one with the inside hex out of the core, so they didn’t have one to put back in the remanufactured engine.

Rebuilders’ Survival Tip:
Install the large hex plug without the internal threads in the block and tell the customer to remove it and use his if it has internal threads for a detonation sensor. This will fix the problem every time.

Chevy 454 Vortech Timing Sets
Chevy has used two different timing sets on its roller cam, Vortech engines. The location of the teeth relative to mounting surface varies by about .130˝, so the matching cam and crank gears must be used together. Here are the combinations:

1996 through ’99, First design:
Cam gear p/n 12551401
Crank gear p/n 12551637

1999 through 2000, Second design:
Cam gear p/n 12560176
Crank gear p/n 12560178

You can easily tell the difference by laying the gears on a flat surface and measuring to the front face of both sprockets. The 1996-’99 first design cam gear measures .405" and the 1999 second design cam gear measures .4185". See Figure 6.

Rebuilders’ Survival Tip:
Both timing sets are interchangeable as sets, but the matching gears must be used together to provide proper alignment for the chain.

Ford 3.8L Cranks and Rod Bearings

When Ford updated the 3.8L engine for the Windstar with the dual port heads in 1996, the company switched from a ground radius to a rolled radius on the rod journals. Some rebuilders who tried to use one of the earlier E8AE/E9AE castings instead of the later F68E crank discovered that the engine locked up when the rods were installed. This happens because the late rod bearings are .120" wider, so they ride up on the edge of the cut radius.

Using the early rod bearings with the late rods and early crank sounds like a good way to create some late model cores, but it doesn’t work because the cracked rods found in these engines can’t be reconditioned by cutting the cap and honing them back to size. They have to be honed out for a special bearing that has an oversize O.D., and it’s only available in the wider version.

Rebuilders’ Survival Tip:
Building the late engines with the F68E crank, the late rods and the right bearings will eliminate the possibility of edge loading a bearing and a comeback.