The oil pump can't be removed...
The oil pump can't be removed until it's disconnected from the pickup and the bolt holding the pickup to the pump can't be removed until the oil pan is dropped. In LS-series engines, the oil pan is a structural component and a few bellhousing bolts thread into it. These have to be removed so the pan can be dropped sufficiently to access the pickup-to-pump bolt.
In addition to differing in flow rate, the injectors used in various LS engines also differ in overall length and connector style. Depending on the engine and year of manufacture, LS injectors can be the "long-style" with EV1 connectors, "short-style" with EV6 connectors, "short-style" with Delphi connectors or "extra-short-style" with EV6 connectors. Most 4.8- and 5.3L truck engines are equipped with "short-style" injectors that accept either Delphi or EV6 connectors. That being the case, injectors from an LS2 Corvette engine can be installed with no modifications-except for the connectors on trucks originally equipped with Delphi connectors. The LS2 injectors are a good choice because take-out sets are available at relatively low cost from companies like Cody Motorsports.
Now for the results of the second dyno test session-which didn't provide the data we anticipated. In retrospect, we really should have expected relatively little increase in midrange torque, considering that with the stock cam, (which has a paltry 190 degrees of duration at 0.050 inch lift) the engine's torque peak of 308 lb-ft was at 4,000 rpm (which is both the factory specification as well as the actual test results logged at Atlanta Chassis Dyno). That being the case, even with 112 degrees of lobe separation, a duration of less than 200 degrees will probably be required to substantially increase torque between 3,000 and 4,000 rpm.
On the horsepower side of the ledger, improvements were much more dramatic. The power curve jumped by 34, hitting a peak of 302 at 5,300 rpm. And although the engine's torque peak moved to 4,600 rpm, the reading at 4,000 rpm was identical to that recorded by the stock engine.
In spite of the torque readings recorded on the dyno, at part throttle, the truck seems noticeably more powerful, both in normal driving, and when towing. As might be expected, once rpm pushes past 4,000, the difference in performance is dramatic.
We have a few more modifications in mind to pump up midrange torque. Depending on how they work out, you may see "Tow Story 3" in a future issue.
With the cylinder head removed,...
With the cylinder head removed, the lifters are accessible. Note that the front lifter tray and the front four lifters have been removed, but the rear tray (and consequently rear four lifters) are still in place. A single bolt retains each lifter tray in the block.
Performance camshafts for...
Performance camshafts for LS-series engines tend to have very aggressive lobes. This, combined with a 1.7:1 rocker arm ratio translates to cams with relatively short duration and extremely high lift.
Ported throttle bodies are...
Ported throttle bodies are available from a variety of sources, but performance and consistency can vary significantly. The CNC-modifications performed by Vmax Motorsports eliminate those issues and deliver maximum airflow capacity combined with reliable performance.
Comp Cams' adjustable timing...
Comp Cams' adjustable timing set for LS-series engines features a cam sprocket with an eccentric bushing that allows cam position to be easily advanced or retarded. The crank sprocket incorporates multiple keyways and is separate from the oil-pump drive gear. (The factory uses a one-piece sprocket/pump gear.)
Notice that the dots on the...
Notice that the dots on the cam and crank sprockets aren't lined up. That's because this photo is intended to show the eccentric in the cam sprocket. We advance cam timing two degrees to compensate for timing chain stretch/wear.
Cody Motorsports specializes...
Cody Motorsports specializes in cleaning, flow checking and reconditioning electronic fuel injectors. Whether a set of injectors is new or used, it never hurts to have them checked; there can be surprising variations in flow from one injector to another.