Dart Mercury 525, 600, 700 EFI Aluminum PRO 1 Cylinder Heads - Assembled (Pair)
Dart machinery has just introduced the ultimate Mercury Racing replacement aluminum cylinder heads for the Mercury Racing 525, 600, and 700EFI engines. These are available in three upgraded intake runner sizes 310CC, 325CC or 345cc ports. All heads have a Dart Marine exclusive chromate finish that provides a superior corrosion resistance extending the life of the heads in a harshest of marine environments. These heads are sold as heads w/valves only or completely assemble with inconel exhaust valves & dual valve springs.
Leave it to Dart Machinery to bring a real high performance marine aluminum cylinder head to market. These hard coat anodized marine heads feature a mil-Spec integral surface treatment option which dramatically enhances the corrosion resistance.
These PRO 1’s race-proven cylinder heads include rolled valve angles, improved spark plug location, extra-long severe duty intake valves, raised exhaust ports, fast-burn chambers, an extra lifter valley head bolt feature, 1.550" valve springs, and lastly Inconel exhaust valves and must have in any marine cylinder head. The PRO 1 series of big block cylinder heads can be used with off-the-shelf pistons, valve train components, and performance intake manifolds.
Standard PRO 1 big-block heads are available with a choice of three standard intake port sizes - 310cc, 325cc, and 345cc as well as two new CNC ported race versions. The CNC heads feature the same high quality valves and components but they are NOT hard coated (the coating creates a finish non-conducive to machining). This wide spectrum of options means you don’t have to settle for a one size fits all head. you can match the cylinder head to your engines size and power requirements. Using proprietary "Speed Flow" technology, Dart has produced as-cast ports and chambers which deliver more power and flow than ever before. So if your in the market to add horsepower that only a high quality aluminum head can offer then look no further.
- Premium alloy: Dart aluminum heads are cast from virgin 356-T6 aerospace aluminum alloy for superior strength and integrity.
- Bolt on compatibility: 2° rolled valve angle and standard spacing. Accommodates all stock accessories
- Heart-shaped 119cc chambers improve combustion efficiency.
- Raised spark plug location improves flame travel for a quicker, more complete burn - producing more power.
- Multi-angle intake seats and radiused exhaust seats dramatically increase airflow.
- Hardened exhaust seats are compatible with unleaded gasoline.
- Exhaust ports raised .300" to improve flow (requires 1" longer head bolts next to exhaust ports).
- Spark plug holes are machined and gasketed for 3/4" reach plugs.
- Manganese bronze valve guides extend cylinder head life and reduce stem wear.
- As-cast heads are bowl blended on 5-axis CNC machining centers.
- Head Assemblies include heavy-duty marine stainless steel intake valves and inconel exhaust valves.
- NEW Dielectric hardcoat surface treatment protects aluminum cylinder heads against corrosion from saltwater environments.
