Naturally we ran long-tube...
Naturally we ran long-tube headers on our 347. These Hooker Super Comp 13/4-inch headers were ideally sized for the stroker small-block Ford. All testing was run with high-quality Lucas Oil, a K&N oil filter, and 91-octane pump gas.
Once we had the baseline numbers, it was time for the head swap. Off came the stockers and on went the aluminum Brodix 195 castings. From a weight standpoint, aluminum heads have it all over their iron counterparts. That the Brodix heads also offered 195cc intake ports that flowed 300 cfm at 0.700-inch lift was icing on the cake. The Brodix heads also feature CNC-porting, the aforementioned 17-degree valve angle, and ductile iron seats for use with unleaded fuel.
Like the stockers, the Brodix heads were drilled for accessories holes so they can be run with A/C and power steering. The CNC-ported Brodix heads also feature 60cc combustion chambers, a 2.02/1.60 stainless steel valve package, and competition valve job. In short, the Brodix heads were everything the stock heads weren't. The only change required for the swap was replacing the stock 6.25-inch pushrods with a slightly longer 6.50-inch set from Comp Cams. We also replaced the self-guided rockers with Ultra Pro Magnum rockers from Comp Cams (retaining the 1.6 ratio).
Run on the dyno with the stock...
Run on the dyno with the stock E7TE heads, the 347 produced peak number of 351 hp and 395 lb-ft of torque. Obviously the factory heads were greatly restricting the stroker.
After installation, the 347 came alive. The Brodix heads were run with the same dual-plane intake and Holley carb employed with the stock heads. No longer did the 347 struggle to produce 400 lb-ft of torque. In fact, the Brodix 195 heads transformed the 347 into a serious street/strip performer.
The power output jumped from 351 hp and 395 lb-ft of torque to 462 hp at 6,200 rpm and 435 lb-ft of torque at 4,400 rpm. The simple head swap improved peak power output by over 110 hp, but the gains were even greater higher in the rev range, where the power curve fell off dramatically with the stock heads.
Next up were the KC LH 17...
Next up were the KC LH 17 195 heads from Brodix. From a weight-savings standpoint alone, the Brodix heads were worth the price of admission.
Whereas torque production with the stock heads failed to reach 400 lb-ft, the 347 exceeded 400 from 3,500 rpm to 6,000 rpm. Don't be tempted to think the stock heads offered better low-speed power, as the Brodix heads improved the power output from as low as 3,000 rpm (our lowest test speed) to 6,800. The Brodix head swap improved the specific output of our test motor from a touch over 1 hp per cubic inch to a more street-worthy 1.33 hp per cubic inch. Add to that the significant reduction in curb weight and you have the reason why performance aluminum head upgrades are so popular on 5.0L motors.
It came as no surprise that the Brodix KC LH17 heads offered huge power gains over the wimpy factory heads, but we weren't finished with our Brodix-headed 347 test mule.
Full CNC-porting applied to...
Full CNC-porting applied to the 195 heads produced impressive flow numbers. The intake port of the KC 17 195 heads flowed right at 300 cfm at 0.700 lift, and 294 cfm at a more relevant (for our cam) 0.600 lift.
Since we had it on the dyno, we decided to swap out the dual-plane for a single-plane design. The funnel-web intake has always proven powerful, and this design is now available from ProComp as well. The only downside is possible hood clearance, as the high-rise intake will not fit under a stock 5.0L hood. Since our motor was not hood-clearance challenged, we opted to install the FunnelWeb intake on our 347.
The intake proved to be every bit as deadly as its eight-legged namesake, as power increased to an even 500 hp at 6,600 rpm. The peak torque was up slightly, to 441 lb-ft, but at a much higher 5,300 rpm. As expected, the single-plane traded a loss in low-rpm torque for all that wonderful top-end power. The dual-plane intake offered more torque and horsepower up to 4,800 rpm, but then it was all FunnelWeb up to our self-imposed ceiling of 6,800 rpm. The extra 40 hp offered by the FunnelWeb is certainly a compelling argument for a cowl hood!
The exhaust flow was equally...
The exhaust flow was equally impressive, as the porting unearthed 214 cfm at 0.700 lift and 213 cfm at 0.600 lift.
The Brodix heads featured...
The Brodix heads featured 17-degree valve angles, 60cc combustion chambers, and a 2.02/1.60 valve combination.
Brodix offers the 195 heads...
Brodix offers the 195 heads with a 987 spring package (135/345) designed for hydraulic-roller cams. To ensure adequate spring pressure for the aggressive ramp rates used on the XFI cam, we further upgraded the valvespring package (180/435 pounds). Since the Brodix heads came equipped with guideplates, we replaced the self-guided roller rockers with a set of Pro Magnum roller rockers from Comp Cams. The rocker swap retain the 1.6 ratio used on the stock heads.
5.0L Head ShootOut
Stock...
5.0L Head ShootOut
Stock vs. Brodix KC LH17 195 (347 Ford)
The true test of any performance upgrade is not whether it adds power, but whether the gains are offset by losses elsewhere in the curve. Any time you increase the power output throughout the rev range, you know you've done something right. Replacing the stock E7TE iron 5.0L heads with the Brodix KV LH17 195 heads resulted in improvements in the power curve from 3,000 rpm to 6,800 rpm. The head swap improved the power output of the 347 by 110 hp and 40 lb-ft of torque. Equipped with the stock heads, the 347 produced 351 hp and 395 lb-ft of torque. This compares to 462 hp and 435 lb-ft of torque with the Brodix heads.
Intake ShootOut
Single vs....
Intake ShootOut
Single vs. Dual Plane (347 Ford)
Looking at the XFI cam specs on our 347, we couldn't help wonder if the combination might benefit from a single-plane intake. We knew there would be a sacrifice in low-speed torque for the gains at the top end, but we were still curious to see just how much power the combination had to offer with the right intake manifold. Replacing the dual-plane intake with a funnel-web resulted in the typical single-plane, dual-plane test results. The dual-plane intake offered better power up to 4,800 rpm, but the FunnelWeb pulled away thereafter. Equipped with the FunnelWeb, the 347 produced 500 hp at 6,600 rpm and 441 lb-ft of torque at 5,300 rpm. Geared more for top end, torque production with the FunnelWeb exceeded 400 lb-ft from 4,000 rpm to 6,500 rpm.
Installation of the Brodix...
Installation of the Brodix heads required longer pushrods. The 6.25-inch pushrods used with the stock heads were replaced by a set from Comp Cams measuring 6.50 inches in length.
After the head swap, the 347...
After the head swap, the 347 stroker really came into its own. The Brodix heads improved the power output by 110 hp, as the 347 produced peak numbers of 462 hp and 435 lb-ft of torque. Torque production exceeded 400 lb-ft from 3,500 rpm to 6,000 rpm.
After running the stock and...
After running the stock and Brodix heads with the ProComp dual-plane intake, we decided the Brodix-headed combination deserved a suitable single-plane manifold. Since ProComp now offers a funnel-web, we decided to give it a try.
Run on the dyno with the funnel-web,...
Run on the dyno with the funnel-web, the 347 produced an even 500 hp and equally impressive 441 lb-ft of torque. As expected, the single-plane FunnelWeb lost out to the dual-plane up to 4,800 rpm, but it is hard to argue with an extra 40 hp or a 347 that produced 500 hp.