The obvious start for this...
The obvious start for this phase is to tear down the engine in preparation for our next set of upgrades, and George makes quick work of it.
Our quest to squeeze some extra horsepower and torque improvements out of our pair of V-8 mule motors without breaking the bank continues. This month, we're back at the Vrbancic Brothers Racing digs over in Ontario, California, with George and Bob Vrbancic to direct our attention to our small-block Ford. As you may recall, we pulled our baselines right out of the box and then proceeded to start some easy and affordable tweaks-the first of which was the installation of a set of COMP Cam's Pro Magnum roller The obvious start for this phase is to tear down the engine in preparation for our next set of upgrades, and George makes quick work of it. Our small-block Ford is a great choice for a street rod powerplant right out of the crate (in fact, an identical engine was my choice for my next project), but as we car guys realize, we can't leave well enough alone. Luckily, though, our upgrades are being handled by a pair of the best performance engine builders we know-Bob and George Vrbancic. Plus, they were smart enough not to let me within 5 feet of it while it was apart. from basic to bitchin' rockers that garnered a pretty good bump for the SBF. We next outfitted the Ford with a set of performance Lunati valve springs, lifters, and camshaft to see what we'd gain horsepower and torque wise.
As you'll see, a few affordable and relatively easy modifications have turned a more than respectable street rod engine into a real performer for much less than a king's ransom. So follow along and check out our latest quest for more power and torque.
After setting up and doing a couple of new pulls, we sat back and took a look at the gains produced by both George's efforts and the new components he installed. I was pleasantly surprised at the gains achieved; it looks as though the cam, springs, and rockers garnered quite a nice increase from the premodification results of 358.1 lb-ft @ 3,200 rpm to a post-modification result of 379.9 lb-ft @ 3,200 rpm, and 228.7 hp @ 4,400 rpm and 281.6 hp @ 4,400 rpm, respectively. An increase of nearly 60 hp and 20 lb-ft of torque-pretty impressive for minimal outlay and a few hours of labor! I'm impressed, and can't wait to see what the future holds. So stay tuned, next time we'll check out how the same set of mods affects our SBC mule motor in the near future.
Our small-block Ford is a...
Our small-block Ford is a great choice for a street rod powerplant right out of the crate (in fact, an identical engine was my choice for my next project), but as we car guys realize, we can't leave well enough alone.
It's important to use matching...
It's important to use matching parts with any internal engine upgrade. Price-conscious catalog shopping may garner you the components you need, but there's no guarantee they will work in harmony.
The timing chain and gears...
The timing chain and gears are removed so we can yank the stock camshaft. Be cautious when removing the cam so you don't damage the cam bearings.
A Lunati Voodoo camshaft (PN...
A Lunati Voodoo camshaft (PN 61001)-with a .483 intake lift, a .499 exhaust lift, and 256/262 duration-was chosen as our replacement. It's a good, streetable choice for a responsive street rod engine of this sort.
We also opted to upgrade the...
We also opted to upgrade the factory timing gear/chain setup with a matching Lunati set. Here, George tests the fit of the new cam gear.
George carefully slides the...
George carefully slides the new Voodoo cam into place after lubing it up.
Next, the new timing set is...
Next, the new timing set is installed, taking care to align the timing marks as needed.
Preparing to degree the cam...
Preparing to degree the cam is the next step in the process. The degree wheel is attached to the crank snout and a pointer fashioned from a length of mechanics wire. The crank is then rotated to top dead center (TDC) and the pointer aligned with the TDC mark on the wheel.
Next, a lifter is placed in...
Next, a lifter is placed in the number one intake bore and a dial indicator positioned securely above the lifter. The engine needs to be rotated clockwise until the lifter is on the "heel" or base circle of the cam lobe, and then zero the indicator.
Rotate the engine in a clockwise...
Rotate the engine in a clockwise direction until you get a reading of .050 on the dial indicator and take a look at the degree wheel. This point is .050 degrees of lift on the opening side of the intake lobe BTDC.
With the cam installed and...
With the cam installed and degreed, the next step is to install the new Lunati hydraulic lifters (PN 71900). With the lifters lubed and in place, George then sets his sights on the new performance valve springs, retainers, and locks (Lunati PNs 3084, 75702LUN, and 77034, respectively).
George tries his best to explain...
George tries his best to explain the process to me in terms a simple mind such as mine can understand-I think I get it. ...
The pushrod and roller rocker...
The pushrod and roller rocker installations come after the springs are installed and their height is checked, set, and shimmed as needed.
The roller rockers are installed...
The roller rockers are installed and adjusted according to spec.
With the internal mods completed,...
With the internal mods completed, George makes quick work of reinstalling the engine's external components and sets up the newly equipped engine for another round on the dyno to see the horsepower and torque improvements we've gained.