5.0 Mustang & Super FordsHow To Engine
400 HP 4.6L Three Valve Stroker Build
Three-Valve’s Full - The making of L&R’s big-steam stroker for pre-Coyote S197s
12. With the bottom end coming along, Derek then gaps the rings to 0.016 (top) and 0.014 (second.) Notice the cross-hatching of the bore surface.
13. The piston/rod combos are then slid in down through the bores and torqued to specs. This shot also shows the Three-Valve’s main-cap cross bolting. With beefy caps each secured by a half-dozen fasteners, this is a solid bottom end structure.
14. Here, Derek is pre-lubing our new Melling M340 oil pump, which will spend its life protecting the forged internals. Could we have gotten by with the original? Maybe, but for $98, why risk it?
15. There’s nothing quite like the length of these head studs to remind us of the sheer size of modular cylinder heads.
16. L&R performed its Stage 2 bowl porting on our castings, cut in a three-angle valve job, and fitted a new set of SI valves. At 35 mm (intake) and 38.5 mm (exhaust), these are 1mm larger than their factory counterparts. The SI valves are crafted of EV8 stainless, with hard chrome stems and stellite tips.
17. Never cheap out on head gaskets. Derek laid down a set of Fel-Pro’s PermaTorque multi-layer steel (MLS) gaskets in preparation for our slightly massaged heads.
18. We’re using a set of Lunati’s Voodoo hydraulic roller cams (PN 21270716). With 112-degree lobe separation, gross lift of 0.500/0.508, and 233/241 duration at 0.050, these are what Lunati describes as “awesome street cams with rough idle,” even though our stroker’s roughly 20 extra cubic inches of displacement will have something of a calming effect on these bumpsticks.
19. Those cam phasers are necessary because the 4.6L Three-Valve was the first to employ variable cam timing (VCT) to benefit power and efficiency. A solenoid, under electronic command of the PCM, sits at the forward end of each head and slightly retards or advances its cam as commanded by varying engine oil pressure within the cam phasers (which are not installed in this shot).
20. Beneath the black crackle-finish front cover are fresh timing chains and tensioners. It would make no sense to slap on the old ones and risk valvetrain disaster for the saving of a few bucks.
21. For now, we’re finishing by bolting on Ford Racing’s Three-Valve-specific composite intake manifold (PN M-9424-46Three-Valve). This piece was engineered to team with FRPP’s Hot Rod cams, so we think it should work well with our slightly more aggressive Lunati bumpsticks. Stay tuned to find out.
Most Mustang 4.6L Three-Valves were factory rated at 300 hp, though for 2010, this was bumped to 315. By comparison, the final Two-Valve engines came in at just 260 horses for 2004.