We Like RPM II: Edelbrock EFI Top End

Words And Photos: Richard Holdener

Edelbrock pioneered multi-level performance with their Performer, RPM, and Victor Jr. intake manifolds. The three levels of induction catered to the different types of engine builds, ranging from mostly stock through street/strip to full-on race. It was only natural they offer cam profiles to go along with their induction system, and the final step was, of course, to add cylinder heads to complete their top-end package. Edelbrock has taken things even further now by offering complete crate motors, but for this test, we took a look at one of their Power Package Top End kits.

Having already tested the carbureted kit on a 351W (SEE HERE), we decided to give the EFI crowd some love and substitute the RPM Air Gap intake and Holley 750 carburetor with an RPM II EFI intake combo. After all, EFI guys like RPM II!

The 351W test motor came fresh from the wrecking yard, and short of not running at all, it was basically a worst case scenario. The 5.8L was a high-mileage, low-compression Windsor that didn’t deserve the impressive top-end kit from Edelbrock, but if the kit worked well on this motor, imagine the results on a dedicated short block.

The 5.8L was installed on the engine dyno without so much as a bath. All we did was fill the crankcase with a five fresh quarts of Lucas 5W-30 synthetic oil and installed a new K&N oil filter. The accessories were ditched in favor of a Meziere electric water pump, and Hooker supplied the necessary long-tube headers. Run in stock trim, the 5.8L 351W produced peak numbers of 251 hp and 349 lb-ft of torque. As expected of the stock components, the motor produced peak power at just 4,400 rpm, and peak torque occurred even lower at 3,300 rpm. Now, it was time for the top-end kit.

For our 1995 Ford 351W, we chose Part# 2090, which included fully ported, E-CNC 185 heads, an RPM Air gap intake, and healthy hydraulic roller cam. The cam offered a .573/.582 lift split, a 235/239-degree duration split and 112-degree lsa.

Edelbrock also offered a slightly less powerful version of this package for use with the earlier flat-tappet cammed Windsors. Having previously tested the carbureted version, we decided to replace the carburetor and intake and give the EFI guys some love. Since Edelbrock offered an RPM II version of their EFI intake for the 351W, we gave it a try on the modified 5.8L.

After running the motor in stock trim, we replaced the stock heads, cam, and intake with the Edelbrock components. The jump in power was impressive, as the new top end kit with the RPM II Intake offered peak numbers of 436 hp at 5,700 rpm and 430 lb-ft of torque at 4,900 rpm. This represented gains of more than 180 hp and 80 lb-ft of torque. These were pretty impressive numbers considering our humble beginnings, and proof positive the Edelbrock top-end kit works equally well on an EFI application.

Adding an Edelbrock top-end kit makes a huge difference in power, even on a lowly junkyard motor. The 351W produced 251 hp and 349 lb-ft of torque in stock trim, but this jumped to 436 hp and 430 lb-ft of torque after upgrading to the Edelbrock heads, cam, and RPM II EFI intake. Note that the top-end package improved the power output through the entire rev range, from top to bottom — always a good sign. Edelbrock practically invented performance packages, and their new top-end kits continue the tradition.

Sources

Accufab
accufabracing.com

Edelbrock
edelbrock.com

FAST
fuelairspark.com

Holley/Hooker
holley.com

Lucas Oil
lucasoil.com

About the author

Power & Performance News

Power & Performance News is the source for news, tech and products that help you get more performance from your vehicle. If powertrain performance projects and hardcore technical content are your interest, Power & Performance News is the publication designed for you. Our acclaimed editorial staff covers all aspects of engine and driveline upgrades with a mission of presenting information that is both interesting and achievable for the “average car guy”.
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