What is a Predator head?

A Predator head is a symmetrical port cylinder head that is designed to fit on a 4.800 bore spacing block. It features an oval intake port that is deigned for maximum airflow with minimal cross sectional area. Port volume starts @ just over 420 cc’s and can get as big a 480 cc’s max ported. It uses valves that are 6.800” long (almost 2” loner than a stock 440 valve) and has a 2.400 intake and 1.850 exhaust valve. The intake and exhaust valves are both canted. What this means is the valves open on a compound angle. As the valve lift increases the valve actually moves towards the centerline of the bore. This increases the unshrouding of the valve as valve lift increases (more lift/more flow= more power!) Out of the box, with the correct valve job and blending of the seat the heads will flow over 485 cfm on a 4.500 bore. Properly ported the heads are capably of flowing over 530. Combustion chambers come CNC ‘ed and will start life around 85 cc.

The head can be ordered with a Wedge or Hemi head bolt pattern. This allows for “off the shelf” availability of many different choices for gasket thickness and design. The Hemi or Wedge bolt pattern availability allows the user to use a preexisting short block (B1, Indy and Hemi) and this way you can upgrade your engine program to a better flowing cylinder head without have to buy everything from scratch.

The head does not oil the rocker arms thru the head like traditional Mopar so spray bars or pushrod oiling must be used. The rocker arms themselves are made exclusively by T&D and are available in 1.75, 1.8 or 1.9 ratios. The rocker arms are all independent and bolt to a common rocker stand. Because of this design they can be located for optimum rocker am geometry. The rocker arms have no offset and all 16 are identical. Because of the rocker arm location, an engine using Predator heads does not require offset lifters. This design will allow the use a very big pushrod (for valve train stability) with little to no grinding required. Each Predator head features 4 oil drain back holes that return oil from the rocker arms directly back to the valley. No external drain back lines are required.

Predators do have their own intake and exhaust port spacing and require “Predator specific” intake manifolds and headers. Because of the canted valve design they will require a Predator specific piston. They also have a unique valve cover and will require the use of and offset distributor. While the Predator head does not look like a typlical Chrysler head it is a direct bolt on and actually uses a Hemi valve pattern so it uses a Hemi cam core (intake, exhaust, intake, exhaust, etc). This I,E,I,E,I,E,I,E valve layout greatly increases head gasket durability. A typical wedge headed engine with a 4.500 or bigger bore that makes over 1100 HP has gasket durability issues between 3&5 and 4&6. This is because any block that has a 4.500 bore is a Siamesed block and has no water in between the cylinders. That coupled with the issue of having two exhaust valves right next to each other in the middle of the engine makes this specific area of the engine run very hot. Because this area very susceptible to overheating, head gaskets are prone to premature failure. Not having any two exhaust valves next to each other helps maintain a more consistent temperature throughout the cylinder head that in turn greatly improves head gasket durability in high HP applications.

The Predator has be incorrectly called a “Big Chief head for a Mopar”. Big Chief refers to an aftermarket GM cylinder head (and who would want that garbage!) . In all honesty it most resembles an aftermarket Ford cylinder head or a modern day Pro Stock head. All intake and exhaust ports are identical (just like a Hemi) and it really should be referred to as: A cylinder head that features that the latest flow technology that can be directly bolted on to your Mopar short block.

A 4.800 bore spacing refers to the distance in-between cylinders. How far the cylinders are spaced apart will effect how much bore the block design is capable of and the head bolt location. All factory Chrysler big blocks (Wedge and gen 2 Hemi’s) feature a 4.800 bore spacing. This means a Predator head will bolt on to any big block Mopar. You can order the Predator head with either Hemi or wedge head bolt pattern an you must have the correct corresponding bolt pattern head for the block you have. Having said this; I DO NOT recommend attempting to use a “stock” block. Basing on the power potential of these heads (1200+ HP) using a stock block is a receipt for failure.

There are however, quit a few options for a block that will work quite well. You want to use a block that has a large bore potential and very strong bottom end. The main choices are as follows: Mopar Performance Mega block (iron), Mopar Performance World block (iron or aluminum) Indy Maxx block (iron or aluminum), Keith Black (aluminum). The Mega block, the Iron Maxx block and the Keith Black aluminum are no longer in production but good used ones can still be had. There are a few blocks that are new to the market. One is called HP products the other is The Keleno but I have no experience with either one of these blocks. The point of all of this is that there are many choices and you want to make sure you have a secure bottom end that is capable of withstanding a lot of power and is capable of at least a 4.500 bore.

In the fall of 2008 Indy Cylinder head purchased the rights and inventory of Predator heads. Indy’s vast manufacturing capability’s will be a definite improvement for the Predator heads and associated components. Indy has already developed a cast tunnel ram and valve covers. They now have a race single 4 manifold. These improvements will make the heads more cost effective for the end consumer. And with Indy’s reputation for having EVERYTIHNG in stock, the future for Predator cylinder heads looks VERY good.

We here at Muscle Motors have always been and will continue to be a strong proponent of Predator heads. We had the first Predator headed engine I competition back in 2004. We have built literally dozens of different combinations. Small to big cubic inch engines ranging form 468” to 645”, naturally aspirated for drag racing and truck pulling. Nitrous applications ranging from Heads Up street cars to Top Sportsman and Top Dragsters. We have also built supercharged engines ranging from street and tractor pulling. We have built just about every type of engine combination you can with Predator heads. We have our own Predator specific CNC programs that feature a 440 cc & 480 cc intake runners. Whatever you application you have, we have probably build a Predator combo similar to it. Call anytime and ask for Mike to discuss Predator engine combinations.