Two-Valve 4.6 Head, Cam, and Intake Upgrade - Twisted Deuce

Here's the mandatory before photo. Other than a cold-air kit, short-tube headers, and an underdrive pulley kit, everything is still stock (and dirty).

To make the process easier, Custom Performance drops the entire engine and K-member out of the car. It's only a little more than an hour's worth of work to get to this point (and from our standpoint, it makes photography a lot better), but if you don't have the luxury of a lift, you can do everything you see here with the engine still in the car.

After dropping the engine onto four jackstands, mechanic Jon Wilburn begins by removing the accessory drive system, intake manifold, and everything else that will get in the way of pulling the heads.

With the cam covers out of the way, Wilburn does a quick check to make sure everything has been running correctly without damage before removing the cam and followers. This is especially important if you will be reusing any of these components.

Before pulling the heads it's a good idea to remove the followers, and this is one instance where having the correct tool will definitely make your life easier. You can get by with a big screwdriver, but you're far more likely to end up gouging either a follower or a cam lobe or even hurting yourself. This is a valvespring compressor tool from Ford that makes the job a breeze.

Here's another look at getting the followers out. Once the tool has the valvespring compressed, the follower drops right out.

The next step to getting the heads off is to pull the front cover, but before you can do that, you will have to get the harmonic damper off. This is one area where it's definitely nice to have the engine out of the car.

Jon pulls the tensioners and timing chains. If your engine is still relatively fresh, set these components aside for reinstallation later. But if they've already seen their share of miles, now is a good time to install new ones for peace of mind.

If you are going to reuse your camshafts, go ahead and pop the cam caps off and pull the cams. We're using all new valvetrain components, so Jon leaves the cams in place while removing both heads.

Here's a look at the combustion chamber for the stock two-valve cylinder heads. Notice how the intake and exhaust valves are in line and the chamber is relatively open.

Now compare that to the Twisted Wedge combustion chamber. The intake valve has been moved to the opposite side of the chamber and is now oriented so that air flowing through the intake port has a straighter path into the cylinder. The new chamber design also allows for a large 1.840-inch intake valve without requiring a new piston or boring the cylinders. The exhaust valve is 1.450 inches. Finally, Trick Flow offers this head with two different combustion chamber sizes. This is the smaller 38 cc chamber, but if you plan to add a turbo or supercharger, you may want to consider the 44cc chambers.

If you purchase the cylinder head assembled, it arrives with stainless steel valves and retainers. The springs are 0.940 of an inch in diameter for the intakes and 1.050 for the exhausts, and can handle up to 0.600-inch lift.

Trick Flow sends two identical cylinder heads. Here, Jon marks them for the left and right side of the engine. The recessed side of the head points forward on the left side, while the flat end of the head points forward on the right. Which side of the engine the head will wind up on determines where certain plugs need to be installed.

You can see the NPT plug that has already been installed in the upper lefthand corner of the deck. The heads also have an oil gallery to feed pressurized oil to the cam journals and requires the installation of six plugs to seal off.

This one isn't a necessity, but Jon has found it is easier to install headers on the cylinder heads before bolting them to the block because of the tight fit between the sides of the block and the upper K-member.

Here, you can see that tight fit as Wilburn lowers the head into place. We're using BBK 1-5/8-inch longtube headers for this project. The headers will slide into place with the cylinder heads already bolted onto the block. Once they are there, it's really difficult to access and tighten the bolts on the header flange.

The head gasket is a multi-layer steel unit chosen for its superior sealing ability. We sourced this one directly from Ford Racing Performance Parts.

The stock head bolts are torque-to-yield and cannot be reused. You can get stock replacement head bolts from Ford Racing Performance Parts or your local dealership, just make sure to follow the directions carefully. Usually the process is to torque all the bolts to 35 lb/ft, turn all the bolts 90 degrees, and then turn all the bolts 90 degrees again. If you plan to make more modifications to the engine and might be taking the heads off in the future, it's usually worthwhile to invest in a set of reusable head bolts from ARP.

New lash adjusters are soaked in oil before being dropped into place. The Trick Flow heads maintain all the standard dimensions, so stock components work as they should without modification.

The two-piece cam towers are made of powdered metal. The caps are numbered so when removing and reinstalling them, make sure they always go back on the correct lower section. The cam cap sections are machined in matched sets, so switching them can affect cam clearance. Before installing the cams, coat the housing bores with assembly lube.

We went to Comp Cams for a recommendation on the best cam profile to Match the Trick Flow heads, and this is what the company sent us. These cams feature 0.545 inches of total valve lift, 242/246 degrees of duration at 0.050-inch lift, and a 109-degree intake centerline.

Starting at the center of the head and working out, the cam caps bolt back in place by torquing the fasteners to 150 in-lb. After the caps are torqued in place, the cams should still rotate freely.

Again, since you have the motor opened up, it's probably a good idea to go ahead and replace a few select components if your engine has some miles on it. Wilburn takes advantage of the opportunity to replace the timing set with new components from Cloyes, including the timing chain guides and tensioners.

Setting the timing on a Two-Valve motor is relatively easy. The timing chain has two black links; when you line them up with the dots on the sprockets on the camshaft and crank, you know the cam is timed correctly. In this photo, the dot on the crank sprocket is pointed to the 6 o'clock position, while the cam sprocket is at 12.

Here's the completed timing set with all the new pieces in place.

Installing the followers is a lot easier than removing them. Just place the follower underneath the cam lobe and use a large-bladed screwdriver to pull it into position.

With the followers in place, the valvetrain is complete.

Now that the valvetrain is finished, Jon dropped the valve covers back into place. To make life easier, Trick Flow taps extra holes in these heads so that they will work with the valve covers from either Windsor- or Romeo-style modular engines.

This customer chose to swap out the stock intake for a cast-aluminum intake from Professional Products. We had hoped to compare both intakes on the dyno but ran out of time before it was time to deliver the finished car.

Here's the completed engine back in the engine bay. One final change is the addition of a cold-air intake. Also, sharp eyes may notice the Zex nitrous kit. Don't worry-we didn't cheat. The bottle wasn't attached for these dyno pulls.