Justin Burcham of JPC Racing...
Justin Burcham of JPC Racing jumped right in for this buildup.
Horsepower costs money; no question about it. MM&FF has showcased many engine builds over the years--some reasonably priced, others a bit expensive. During the budget builds, all hope was lost when it came time to add a cylinder head to the package. If we didn't use a set of low-buck iron heads or stock pieces, then we turned to a pair of aluminum heads, increasing the price tag of the build by hundreds of dollars.
Today, the popularity of reasonably priced stroker kits is on the rise. Companies are coming to market with 331 and 347 packages--with the stock block--that won't break the bank. The difference today is that when it comes time to choose a budget-minded set of heads, a fancy pair of aluminum ones can be had from Patriot Performance without breaking the bank.
Patriot released its Freedom cylinder heads earlier this year, with a pair coming in at a terrific price of $895, making these heads cheaper than some iron castings on the market. Low-priced products are sometimes too good to be true, so we ventured to JPC Racing and put the Freedom heads to the test on a fairly common street engine. We wanted to know for ourselves if budget and performance can be used in the same sentence. Patriot has succeeded.
A JPC 331ci short-block sat in a car ready for action, sans heads and intake. The combo is a budget build using a stock block, cast steel crank, steel rods, and off-the-shelf pistons. The cam (PN XE282HR) is a standard item from Comp Cams, too. Valve lift enters this party at 0.564 on the intake, while exhaust is listed as 0.575. Duration is shown to be 232/240 degrees at 0.050 inch lift, and lobe separation is a rather mild 112 degrees. This was the perfect combination for Freedom's 185cc port volume. The heads can be run on top of a stock short-block (with fly-cutting the pistons), but it isn't the ideal combination for such a large intake hole. The 185cc port, however, is more useful on a larger cubic-inch combination, like the one we were testing.
Freedom comes at a price....
Freedom comes at a price. These aluminum cylinder heads will set you back $895, placing them below pricing versus several iron heads on the market.
A little background into our test: The car we flogged on the chassis dyno belongs to Ron Cullember, an NMRA Pure Street racer. He was kind enough to let us use his Mustang for this engine buildup and subsequent chassis dyno testing. Cullember's race engine was out for upgrades at Rich Groh Racing, so we took the opportunity to drop the engine in his chassis. For that, we are grateful and appreciative.
The one thing different from this test vehicle and the car in your garage is that it runs an electric water pump and the alternator, no other engine accessories. However, the transmission is comparable to what is in your Mustang--a Tremec TKO-500 (modified by Hanlon Motorsports) that rests in the trans tunnel.
We turned to a carbureted induction system, partly because of the budget theme. It's also what Cullember runs in NMRA action.
Freedom's price tag is the noteworthy feature on these heads. Many times, uttering the word budget brings the notion that parts don't fit properly. That isn't the case. They fit perfectly, and there were no issues with the valvetrain, intake, or valve covers. We do, however, suggest you take the time to disassemble the heads and blow out the ports. Packing material and debris were found in the set we tested, but that's typical with most mail-order cylinder heads. If you're not capable of disassembling the heads, bring them to the local machine shop--it will be money well spent.
The exhaust ports feature...
The exhaust ports feature 1.60-inch valves (left), while the intake side delivers air and fuel via 2.02-inch valves. Combustion chambers have a standard size of 64 cc, but you can mill the deck of the surface for a smaller combustion-chamber size. Shrinking the combustion chamber will bump compression but at the cost of piston-to-valve clearance, although most aftermarket pistons should have deep enough valve relief cuts to handle it.
Do not expect to see monster flow numbers from these heads since they are budget pieces for a reason. But that's not to say Freedom heads aren't right for your project. Independent flow testing shows these heads will support a good amount of horsepower. The flow tests resulted in 250 cfm through the intake port at 0.600 inch lift while utilizing a 4.030-inch bore on the flow bench. The midrange flow numbers are fairly decent as well, with 194 cfm at 0.300 inch lift and 235 cfm at 0.500 inch lift. Moving to the exhaust side, the most air moved at 0.600 inch lift was 155 cfm. The exhaust port is in the factory location, meaning standard headers will bolt right on.
With these heads on the market, budget buildups will never be the same. The aluminum casting offers lighter weight, better heat dissipa-tion, and makes it easier to port the heads. All that and a reasonable price tag--this sure is the land of opportunity.
On The Bench
|Valve Lift||Intake CFM||Exhaust CFM|
We had Ladd's Porting Service throw the heads on the flow bench. A 4.030-inch bore was used to mimic the one we had in our short-block. Max flow at 0.600 inch lift was 250 cfm on the intake and 155 cfm on the exhaust. Since these are aluminum heads, they'll be much easier to port than iron castings.