The WC946-3 is a CNC-ported version of the Stock WC946 Wildcat Non-Hemi Head, using the Stainless Steel 31mm intake and 25mm exhaust.
When we designed the WC946 head, we wanted a single head that could be turned into different variations for different goals, with the WC946-3 version arguably our primary goal. Most build center around stage kits, mainly stock valve train components, such as push rods and rockers with increased spring pressure to handle higher rpms and mild camshafts.
The next step from a stage kit or these milder builds is more airflow from the cylinder head, for which there are a few options: more cam, porting, and bigger valves.
- Bigger camshafts may require dual valve springs, which means you may need to cut spring pockets, chromoly push rods, which have to be cut to length, and billet rockers, which may require a billet valve cover for clearance.
- Porting a stock head offers a good gain in performance, but unless you can do the work yourself, it can be relatively expensive to have someone port a cylinder head, and for the time and money, you’ll most likely want bigger valves to get more from the combinations
- Increasing the valve size would increase the potential of your cylinder head, but you’ll see most of that potential when the head is ported.
In most cases, a minor upgrade becomes very expensive, and you go from a performance engine to nearly a full-blown race engine.
The WC946-3 is made to bridge that gap while offering excellent performance.
Air Flow – At .250 lift, the WC946-3 flows approximately 82cfm, which is arguably more cfm than any ported cast head with a 27mm intake valve can flow at .400. In most cases, at .250 lift, you are doubling the cfm of most stock heads with a 27mm or small valve. Compared to ported 27mm intake valves, we usually see 60-70% more cfm out of the WC946-3.
Compression – Many see compression as the holy grail of making horsepower. Most stock heads range from 22 to 24cc, whereas the WC946 is 18cc, which is an immediate increase in compression without modifying the head or using a thin head gasket. (We recommend the .040-.050” fire ring gasket for most builds)
Valve Train—We use our 26-lb springs and billet retainers, which help keep the weight down. A stock 27mm(5mm Stem) Intake valve, 26-lb springs, and stock steel retainers weigh 38.4g, whereas the 31mm(5mm stem) stainless valve, 26-lb springs, and billet aluminum retainer weigh 40.2g. That’s less than 2-gram difference, so the valve train performance and rpm capabilities will be almost equal.
As you can see, the increases in airflow means we can make more power with less lift. With less lift, we can use lower lift cams, which cost less than most high lift cams, and a stock valve train, which is far less expensive than aftermarket valve train components. Our goal is always to make more power for less.
Recommendations
Camshaft—The TTS-680 .268” Reaper Camshaft(NEW DESIGN) is designed with this head in mind and will offer the best power and torque for most applications. Cams with less than .275” and less than 240 duration will also work in most cases without modifications.
Carburetor—PWK24EC-1K The carburetor flows about 107cfm, which is more than enough flow not to restrict the head. The carburetor’s 24mm bore's cross-sectional area closely matches the port's inlet for good, consistent air speed and good throttle response.
The WC946-3, TTS-680, and PWK24 create a performance trifecta.
Using standard-length valves, the install height is approximately .825 for 26 lbs of seat pressure with our 272 valve springs. The maximum recommended lift is .310; going beyond this limit may result in coil bind or interference. Check with your cam manufacturer for recommended spring pressure for your camshaft and valve train combination to prevent valve float.
This version has the Valves, 26lb Springs, and Retainers installed.
You will need to cut spring pockets to install dual valve springs, and we recommend using longer-length valves.
Important! - The valve seats are designed around our new standard length 31mm Intake and 25mm Exhaust Valves. You must cut new seat angles to run a 32mm intake or 27mm exhaust.
These heads do not come with valve seals; we do not recommend using them.
