Best 4 Valve Cylinder Heads - Car Craft Magazine

The MMR 4V build
MMR's Rick Antonette told us that building a four-valve engine out of a two-valve engine is really no big deal. "Any cylinder head will go on any block. You just need to match the rest of the components to the block and head combination you choose." This is because some of the cam gears, chain tensioners, and timing covers are different from engine to engine. So pick your short-block (MMR recommends a stroker if you're building a 4.6) and add a set of heads.

The DOHC and SOHC engines use the same main timing chain. The secondary cams are driven by a smaller chain off the exhaust cam sprocket.
The DOHC and SOHC engines use the same main timing chain. The secondary cams are driven by
The best 4V cylinder heads are on the '00 Cobra R and Ford GT, but don't expect to find those cheap. The Mark VIII heads are good, though. They are known as the B heads, and you will be able to find lots of them for not a lot of cash. Incidentally, you can see why a four-valve-per-cylinder arrangement will always move more air than two valves. There's much more valve area. Antonette tells us about the best you can get out of a 2V engine is 500 hp, and you'll need forced induction to make that. Customers who want more than 500 hp are steered toward building 4V engines.
The best 4V cylinder heads are on the '00 Cobra R and Ford GT, but don't expect to find th
The B heads ('93 to '96 MK VIII and '96 to '98 Mustang Cobra) had unique intake manifolds with a split-runner system. Called the IMRC (intake manifold runner control), the engine breathed just through the squared-off ports under light-load conditions. At heavy loads or full-throttle, butterfly valves in the intake runners would open up the circular ports, too. On paper it works well, but in reality, the butterfly valves would get stuck over time and not open fully. MMR sells an adapter plate that eliminates the IMRC, allowing you to take full advantage of the B head's potential.
The B heads ('93 to '96 MK VIII and '96 to '98 Mustang Cobra) had unique intake manifolds

You can also opt for MMR's new sheetmetal intake. It weighs less than half the Cobra intake to the right of it, has better flow, and deletes the IMRC. The throttle body mounts in the stock location, and it fits under the hood without any modifications.
You can also opt for MMR's new sheetmetal intake. It weighs less than half the Cobra intak
The biggest problem with a 4V build is that the cost adds up much more quickly than with a 2V engine. "There are twice as many cams, twice as many valves, springs, seals, retainers-it gets expensive pretty quickly," Antonette says. Still, if huge power is what you're after, you need the extra valves. Five hundred horsepower is easily achievable with a 4V engine, and racers are making well over 1,000 with a power-adder and a forged bottom end inside a stock block.
The biggest problem with a 4V build is that the cost adds up much more quickly than with a

Build It
We hope this article has given you a better look at the potential lurking within the relatively tiny 281 ci of Ford's modular V-8. We only scratched the surface, though, so we recommend readers hungry for more mod motor information read How To Build Max Performance 4.6-Liter Ford Engines by Sean Hyland and Building 4.6/5.4L Ford Horsepower on the Dyno by Richard Holdener. Both books are published by SA Design and provide a lot of excellent information that we couldn't fit in the space allotted this month. Also, go online to modularfords.com and search the forums. There's a lot of good info there, too.

Just because we are fans of this engine doesn't mean anything if our readers don't care. What do you think? Are we out of our OHC minds? Do you want to see a build? Or will you cancel your subscription if the words mod and motor appear next to each other again? Let us know at CarCraft.com.

SOURCES
Trick Flow Specialties 1248 Southeast Avenue Tallmadge OH 44278 330-630-1555 www.trickflow.com	Bullet Cams 8785 Old Craft Road Olive Branch MS 38654 662-893-5670 www.bulletcams.com
Ford Racing Performance Parts 15021 Commerce Drive S Suite 200 Dearborn MI 48120 800-FOR-D788 www.fordracingparts.com	Modular Head Shop Cassleberry FL 321-262-1132 www.modularheadshop.com
Motorbooks International 729 Prospect Ave P.O. Box 1 Osceola WI 54020 715-294-3345 www.motorbooks.com	Modular Mustang Racing Ventura CA 805-650-1853 www.modularmustangracing.com
CarTech Books 39966 Grand Avenue North Branch MN 55056 651-277-1200 www.cartechbooks.com