Chevrolet Performance 8.0L K5 Update

We have separated the body from the chassis; located a new 1-ton chassis and axle assembly to keep up with the torque from the 8.0L Big Block. This frame has been cleaned, prepped and powder coated. Axle assemblies are going thru inspection and clean-up to be prepared for installation.  As mentioned in an earlier newsletter, we could not wait to get this 8.0L torque monster on the dyno to see where our base line power and torque was for this 4WD K5 project. Let’s review the new GM engine and how we prepared it for a test session in the SDPC Raceshop Chevrolet Performance Dyno Room.

#19328586 – 8.0L BBC Crate Long Block Engine

8.0L Crate Engine Highlights

  • All New Components Built by GM, Long Block
  • 10.200" Tall Deck Block, 4.250” Forged Steel Crank, 4.270” Bore
  • Unique GM Style L29 Vortec Heads with Large Oval Port
  • Gasoline, CNG and LPG Compatible
  • Hardened Valve Seats, Stainless Intake and Exhaust Valves for CNG/LPG Durability
  • Equipped with Sensors and 58X Crank Reluctor and 4X Cam Sprocket for EFI Applications
  • Hydraulic Roller Camshaft Designed for Low RPM High Torque Requirements
  • Hypereutectic Pistons with Hard Anodized Top Ring Land, 9.9:1 CR

SDPC -  Complete the Long Block and Prep for Dyno

This 488ci long block is ready to be completed and run as an EFI application using a controller that will operate an LS engine. We elected to use a Holley Terminator TBI Kit with 4L60/80 transmission controls in the ECU. A perfect match since we will be mating this 8.0L to the GM 19260961 4L70E 4WD transmission in our 1987 Blazer. Lots of questions will be raised because we choose the Dart single plane tall deck oval port intake. First it is the only tall deck oval port intake currently on the market. Second over years of testing on the dyno for both street and marine big block Chevrolet applications at our facility, we discovered that this Dart single plane intake out performed dual plane and low-rise design intakes in almost every area of the power curve. Bottom line, it works! Having 488 cubic inches to feed, plenum volume becomes a factor that effects the power output. Our previous tests with this intake showed as the cubic inches increased, this intake gained more torque and power in the bottom end than its competitors. Our initial results below are proof this intake still works for low RPM applications.

  • Dart Oval Port Tall Deck Intake – Port Matched by the Raceshop
  • Holley Avenger EFI Kit – Use the Holley Controller in “LS Engine Mode”
  • 8 LS Coils
  • Long Tube Truck Headers – 2” Primary Tubes into a 3” Collector

Dyno Results

Adding 8-quarts of Maxim Break-In oil and going thru the Raceshop’s standard protocol for initial start-up, break-in and oil filter inspection, we were ready to make some dyno tests. The Holley Terminator kit is absolutely flawless and easy to use. After tuning on the fuel curve and timing with the 100% stock 8.0L engine we made over 420HP and more than 520FT-LBS of torque. At 3300RPM we had 525FT-LBS of grunt!

RPM

HP

Torq

3300

330

525

3600

363

530

3900

396

534

4200

413

516

4500

426

497

What’s Next

The K5 heavy duty chassis should be going back together in the next few weeks. Our rendering and paint scheme is complete – tell us what you think; Big shout out to KEG Media for their artwork. Time to order some parts and get to work! We are going to put the 8.0L back on the dyno and do a few more tests at lower RPM’s (below 3000) and possibly try a different camshaft and some roller rockers to see where that would land us. The SDPC Team will keep you posted.