Proflo Performance-build 526ci big-block Chev combo

This big-block beauty pieced together by ProFlo Performance is expected to make north of 1200hp and is destined for a customer's HK Monaro street/Powercruise car

Photographers: Charlie Sant

Barras are nice and all, but if you really want to make a statement, it’s difficult to go past a big-block Chev with a good old-fashioned belt-driven inlet manifold. This particular example weighs in at 526ci and has been pieced together by the wizards at ProFlo Performance for a customer’s HK Monaro street/Powercruise car.

First published in the February 2023 issue of Street Machine

It runs a Bowtie block that has been outfitted with such goodies as a Callies Magnum crank, Oliver rods and CP pistons. The cylinder heads are 14-degree Big Chief alloy items running titanium Victory 1 valves and Jesel rockers, and the camshaft is a Comp Cams solid-roller sporting .780/.760in valve lift and 274/286 degrees duration at .050in. Crower lifters also got the nod, as did Smith Brothers pushrods.

The noisemaker is a standard-helix 14/71 atop an Indy blower manifold, topped off with a Enderle Bird hat. “We went with E85 over methanol, because the customer was after a tough but driveable engine that could be used occasionally on the street,” ProFlo’s Paul Sant explains. “It hasn’t seen a dyno yet, but it should make somewhere around the 1200-1300hp mark.”

It might seem odd referring to an engine that looks like this and makes north of 1200hp as “driveable”, but such is the modern-day wonder of E85 and electronic fuel injection. Retrofitting old-school mechanical hats such as this with EFI hardware is all the rage at the moment, and it allows gearheads to have the best of both worlds: the fearsome look of an injector hat without the light-switch power delivery that’s commonly associated with such a set-up.

In this instance, ProFlo has decked this Enderle hat out with eight 1500cc injectors mounted internally, allowing it to retain the mechanical EFI look. Once the engine is fitted up to the car, the injectors will be controlled by a FuelTech FT600 ECU, and spent gases will exit the chambers via a set of custom, large-primary headers.

Cover me

A sweet set of rocker covers go a long way towards dressing up an engine, and ProFlo’s go-to covers are custom billet items from Shaun’s Custom Alloy, in this case anodised to match the car and engraved with the ProFlo logo.