chevy_small_block

Extract from HOTROD magazine, March 1985.

Featured in Wedge Ezine no.6, May 1998. Submitted by Mark Tinker (USA)

See also article of Will Bridges who did this conversion!

Have you priced a Chevy aluminum small-block lately?

Whether procured from factory or aftermarket sources, expect to pay somewhere in the neighborhood of $2500 to $3000. And that merely gets you a bare block. No crank, rods, pistons, camshaft, or valvegear. Not to mention the aluminum cylinder heads, which'll run around $1000, bare. No wonder most of us make do with the old "iron horses."

Well under the purchase that way for Chevy bare block, you can build an affordable aluminum V8 with displacements up to 305 cubic inches. Unbelievable? Not really.

We're speaking of the 1961-'63 Buick/Olds 215 aluminum motor, an often overlooked granddaddy of the Buick V6 that unfortunately was about 15 years ahead of its time. With over 3/4 million built, blocks are relatively easy to locate at the local boneyard. Since the motors had castiron cylinder liners, corrosion is not near by the problem it was on the linerless Vegas. While it's true that parts on the out-of-production motor are not exactly plentiful, many parts from more modern motors can be
substituted with little or no reworking.

Two individuals -

Phil Baker  (Baker's Auto Repair, 19552 40th Pl. NE, Seattle, WA 98155, 206/363-5088)

Dan LaGirou (D&D Fabrications: P.O. Box 55, Rochester, Ml 48063, 313/652-1359)

backyard-build retained on block by extra head strong-running 215-based motors using amalgamated parts from a variety of engines. Both these indivuals also hoard tons of hard-to-find 215 parts. Additionally, D&D offers a completely integrated Vega swap kit that will be covered in detail in a future issue.

What is a 215?

Before there were Buick V6's, there was a lightweight aluminum V8 installed in many Buicks and Olds,  and some Pontiacs. Designed originally as an economy engine, it found its way into several quasi-high-performance applications, including Olds' turbocharger applications. Because the aluminum castings costs too much money to produce, the cast-iron Buick V6's replaced it in the economy role, with the 400/340 Buicks taking over in the moderate performance category. Later, the tooling was sold to Rover, where a descendant powers that company's products to this day.

There were two major 215 variants:

The Buick version and the Olds version. Olds engines may be identified by their angled 5-bolt valve covers; Buicks have flatter 4-bolt covers. (Pontiacs used the Olds versions.) The late British Rover motor is based on the Buick, and except for different accessory mounting bosses on the cylinder  heads, it is considered universally, dimensionally, and functionally interchangeable with the Buick design. However the imported parts are quite expensive.

Olds cylinder heads are bolted to the block using six bolts per cylinder, while Buicks use only five bolts. The extra Olds head bolt also retains the Olds rocker shafts. Valvetrain pieces from the pushrods on up are not interchangeable between the two versions. Buick blocks don't have the extra head bolt hole drilled in them, and the casting has insufficient thickness to add it. For this reason, an Olds head cannot be installed on a Buick block, although a Buick head (and its associated valvetrain components) will bolt on an Olds block using only five bolts per cylinder. (Head bolt holes are blind, so water jacket seepage from the empty hole isn't a problem.)

Combustion chamber design also differs, with the Buick using a slightly more open-type design. The Olds head runs better on low-octane gas, but the Buick has only one type of cylinder head, varying compression by changing piston design. Olds, conversely, uses only one piston, altering compression by varying combustion chamber volume.

Since the Olds had a unique valve-train not shared by later Olds engines, while the Buick version gave birth to later Buick V6's and V8's, parts for the Buicks are much more plentiful than for the Olds. Also helping tilt the scales in the Buick's favor is its greater production numbers, outnumbering the Olds as it did by about a 3:2 ratio.

Next time more . . . . .

Extract from Hot Rod magazine, March 1985.

Thanks to Mark Tinker for scanning the pages.