351W Engine Roller Cam Conversion - Cam Up, Fire Up

10. With the throttle, fuel, and cooling connections dismantled, the aluminum intake manifold comes away from the engine.

11. The water pump is removed. This very early 351 Windsor has the 289-style front dress. We keep our water-pump bolts in place in the pump to ensure correct assembly.

12. If you don’t have a harmonic-balancer puller in your toolbox, you’ll just have to rent one like we did. It’s a safe bet to use an installation tool when the time comes to install the balancer onto the crank. We also removed the Comp roller rockers and stock pushrods.

13. With the balancer gone, the timing cover was the next component to be removed.

14. We removed the cam-sprocket attachment bolt and fuel-pump eccentric. Here, the old timing set is removed from the engine. This single-row setup was new from a complete rebuild less than 2,000 miles ago. It had a small amount of slack when on the engine.

15. The old flat-tappet cam is being carefully removed from the engine. Try to support the cam as much as possible, and avoid knocking up against the cam bearings. You don’t want to knock any loose.

16. This is as far apart as we are going to go this time. From here on out, everything is “go together.”

17. You can’t over-lubricate the new cam, so Jack liberally coats the journals, lobes, and distributor drive gear with engine assembly lube.

18. Supporting the new cam as carefully as possible, it is installed into the engine. We’ve double-checked part numbers to make sure we got the right cam, and everything checked out. With Comp precision and our new timing chain, we felt confident installing our cam straight up, and didn’t double-check the cam with a degree wheel.

19. With our Comp roller cam in the engine, we double-checked top dead center, lined up the dots on the new timing set, and installed it into place. When the longer of the two included cam sprocket drive pins wasn’t long enough to drive the fuel-pump eccentric, we realized we neglected to tell Comp ours was an early 351W engine. Our choice now was either to eliminate the fuel-pump eccentric and use an electric fuel pump or put the engine back together using our old timing set. With our story on deadline, there was no time to call Comp and get the correct part, and the old timing set went back onto the engine. Bummer. Comp instructions say that degreeing the cam isn’t absolutely necessary for the engine to run efficiently. However, the company recommends it if you suspect the cam or crank gear may be marked incorrectly. Improper machining of the cam or crank, mis-indexed keyways, or accumulation of machining tolerances are other reasons to go through the degreeing process.

20. Our Comp roller lifters had been soaking in a valve cover full of fresh oil. Now it’s time for them to be installed into the bores with the flat sides on the upper portion of the lifters parallel to the centerline of the engine.

21. Our lifter tie bars or “dog bones” are placed in position between each intake and exhaust lifter. These parts ensure the roller on the bottom of each lifter stays in the correct orientation with respect to the cam lobe. The bones must be placed with the dimpled side up.

22. To install the roller spider onto the block, we were going to have to drill two 15⁄64-inch holes, each 3⁄8-inch deep. Going deeper could damage the cam so we marked our drill bit with masking tape for the correct depth as shown here.

23. After carefully plugging the oil drain-back holes, we drilled the two needed holes for the roller lifter-retaining spider, being careful to stop at the tape marker.

24. With our holes at the desired depth, we then tapped the correct thread size into the openings. When all was complete, the metal shavings were removed with a shop vacuum.

25. The spring-steel spider was installed into place using the supplied fasteners. Loctite was used on the fasteners as an added precaution.

26. The special-length Comp roller-conversion pushrods were dropped into place, and the Comp Magnum rockers were then put into place on the studs.

27. The valves were adjusted, according to the Comp instructions. A zero-lash condition was followed by a half turn down of the rocker nut. The nuts were then locked to hold the correct adjustment.

28. With the valves in adjustment, the intake manifold and carb were reinstalled onto the engine. Antiseize compound was used on any fastener going into aluminum.

29. At this time, the engine was checked once again for top dead center prior to the distributor installation. We didn’t want to play any “one tooth off” games during fire-up. Our distributor went in without difficulty.

30. This tool was included with the MSD wires. Once separated into the two halves, they fit together as shown to make a nifty wire-crimping tool.

31. We began the process of making plug wires by trimming each wire to the desired length and exposing the core as shown. Next, each boot for the distributor end was slipped over the wire end. All wires were ready to go at the spark-plug end.

32. After each wire was equipped with the correct terminal end, it was next placed into the crimping tool. The tool was then installed into a bench vise as shown. When the vise was tightened, the crimp was complete.

33. It’s easy to see that the MSD tool does a nice job of completing the connection. We only needed to slide the rubber boot into position over the terminal end and the wire was ready to go.

34. Here’s the completed engine ready for new oil and coolant. The job took two people a whole day. Your install should go quicker because you won’t need to worry about shooting photos for a magazine feature. We were gratified at fire-up, as the engine came to life immediately and ran smoothly. The idle had quite a bit more lope than with our stock cam. Timing was checked with a light, and we went for an exciting testdrive. We were ready for our trip to Superior Automotive Engineering.

35. Out at Superior, the bright yellow Mustang is strapped down onto the dyno jet.

36. The dyno jet tells the tale with a gain of 24.0 hp at the rear wheels. While this is nice improvement, and puts Jack’s car at 268.2 road horsepower, we expected more, and the Superior guys were dismayed to hear we didn’t degree the cam before sealing up the engine.

37. This torque graph shows that something is clearly amiss as we see a torque loss of 10.3 lb-ft. When the Superior guys heard about the reused timing chain, they knew that a degree-wheel session with a new timing set would be needed to realize our best power gains. Check in with us next time, as we’ll venture out to Superior Automotive to do a complete degree-wheel checkup. They’re confident we’ll find more than our lost torque, and some additional horsepower as well.