Functional art. Nothing under the hood of a hot rod fits that description better than a vintage manifold. In fact, lots of rodders have cool old-time multi-carb manifolds hanging on their walls, strictly for decoration. That makes them art. Let’s talk about making them functional.
Dimensional Inspection Laboratories (DIL) uses computer-assisted coordinate measuring machines for dimensional inspection on everything from medical equipment and space shuttle components to computer parts and chocolate bar molds. On this day it was Edelbrock manifolds. Blundell doesn’t need dimensions on the entire manifold, just those that relate to building fuel rails—the relation of the manifold to the fuel fittings, locations of fuel inlets, bolt patterns, carb centers, and surface heights, among other coordinates. In the past, Blundell would have inspected the parts manually, which was time-consuming and less precise. Working with Sean Wertens at DIL, he can now build a three-dimensional model in the computer that he will use to build production tooling, confident that everything is squared, aligned, and dead center and that his customers are getting accurate fuel rail systems that assemble easily and operate smoothly.
Vic Edelbrock Sr. was one of hot rodding’s founding fathers. The company he started in the ’30s has been manufacturing modern and vintage performance parts to the hobby ever since—and the product that started it all was the Edelbrock Slingshot manifold for Flatheads, tested on Edelbrock’s own ’32 roadster on SoCal’s dry lakes.
The latest Edelbrock catalog, containing hundreds of products, still includes the legendary Slingshot manifold. In addition, Edelbrock has re-released several other vintage two-barrel multi-carb intakes for Flatheads, Ford small-blocks, Ford Y-blocks, Chevy small-blocks, and other engine applications.
Over at Blundell Speed & Machine, Chad Blundell has been following this closely. Edelbrock offers carburetors and linkages, but not fuel rails and fittings. Blundell has been developing hard line fuel rails and banjo fittings for early two-barrel carbs like Stromberg 97s, Holley 94s, and Rochester 2GC, as well as new early style two-barrels, like the new Stromberg 97, Demon 98, Speedway Motors’ 9Super7, and the Edelbrock 94. When a customer sends a manifold to Blundell Speed for a custom fuel rail, its dimensions are recorded and kept on file. Eventually Blundell will have dimensions on virtually all popular manifolds, and will be able to build precise rails without needing an actual manifold. Chad Blundell already had the critical dimensions for most of the vintage Edelbrock intakes now being reproduced. The question was, were the dimensions on the new versions identical to the old versions? If not, he would need to develop two fuel line systems for each style of manifold—one for the older version and one for the new version. It was time to do some finding out.
The first step was to convince our connections at Edelbrock to let us borrow some of these new manifolds. Technical sales guy Smitty Smith generously let us borrow the manifolds we needed. They even delivered the parts in person directly to Blundell Speed.
In every case, the new Edelbrock manifolds looked practically identical to the original versions; so far, so good. But looks can be deceiving. So the next step was to deliver the manifolds, old and new versions, to Sean Wertens at Dimensional Inspection Laboratories (DIL) in Santa Ana, California. The trip to DIL served two purposes: to get scientifically precise dimensions on each manifold and to find out how close the new manifolds are to the originals.
From underneath, the new 3x2 Flathead manifold is distinguishable from the original SU 359 by the center heat riser passage and a circular notch at the front on the passenger side (lower right in the photo) for the road draft tube in the lifter valley area of the block. When mounted on the engine, it would be hard to tell the new intake from an original.
While waiting for DIL to get back to us with the dimensions on the intakes, we went back to Blundell Speed to do a few more eyeball comparisons between some new and original Edelbrock manifolds.
A couple of days later, Chad Blundell called to share the findings from DIL. It was good news. On all of the new Edelbrock vintage manifolds, the dimensions relevant to creating fuel rails, were identical between the new and old versions.
Fuel rails for all of these manifolds, with corresponding carburetor options, are now in stock at Blundell Speed & Machine. For one-off or more elaborate applications, Blundell can design and produce fuel rail systems to order. A “Build Your Custom Fuel Rail Here” prompt on the Blundell Speed website allows customers to order a custom system by using simple menu prompts for brand of carb, number of carbs, type of manifold, inlet style, and other variables. If you’ve got some rare, never-before-seen manifold, Blundell can build a system for that too, but you’ll have to send the manifold so it can be dimensionally inspected for an absolutely correct system (and those dimensions will be stored by Blundell for the next customer with the same rare application).
The do-it-yourselfers among us can order unassembled components to built their own fuel rails, including fittings, tubing, solder, and flux. The Blundell website features a YouTube video, hosted by Chad Blundell, which provides step-by-step instructions for soldering the fuel delivery components and creating a custom configuration.
