Hemispherical combustion chambers were successfully employed by many factories during the two-valve era and their origins go back to the industry’s very beginnings
Revhead 15-year-olds like me knew all about ‘hot’ engines. Our vast knowledge relied on a few certainties: Ultimate ignition: Scintilla Vertex magneto. Top Carbies: SU (twin or triple) – Euro brands like Dell’Orto, Weber and Solex were ignored at a time when the only spaghetti in our mothers’ pantries was Kia-ora or Heinz (in tins). Holy Grail combustion chamber: Hemi head (of course). If the mighty XK series Jaguar engine wasn’t proof enough, how about Phil Irving’s Repco Hi-Power head, a 12-port aftermarket item that boosted Holden ‘grey’ motor performance to unprecedented levels? Say no more.
Obviously no serious hemi discussion happens without entering Mopar territory and referencing Chrysler’s ‘ownership’ of the concept and its capital H branding of the label. I became aware of Chrysler’s Hemi V8 when legendary US drag-racer Don Garlits visited Melbourne around 1959 – at a time when his blown and injected former truck engines were producing a then-astonishing 1000hp (top dragster outputs have advanced a little since, now claiming 11,000hp!).
Chrysler’s pioneering Hemi V8 launch in 1951 won the first battle in the US power wars, producing 10hp more than GM’s new, equal-displacement, wedge-chamber, Cadillac V8 (Ford wasn’t even in the hunt, then still relying largely on its flathead V8s). No surprise then that Chrysler’s Hemi soon attracted the attention of constructors for circuit racing and particularly for drag-strip action. And the rest is more or less history…
Vince’s Emi Sul powered Vedette
Just in passing I reckon Chrysler Australia took a liberty in using the legendary label for its ‘Hemi-6’ Valiant engines. Traditional (dare I say ‘proper’?) hemi engines, including Chrysler’s Hemi V8s, have cross-flow cylinder heads with pairs of inclined valves forming two lines that straddle the line of the crankshaft. The inclined valves of the so-called Hemi-6 form a single line along the crankshaft. To me, a head with intake and exhaust ports on the same side ain’t a Hemi. They were seriously impressive engines, but IMHO they weren’t real Hemis.
Until recently I reckoned I had Chrysler and its Hemi history pretty much down pat. That was until I became aware of an engine called the Emi Sul (Roughly Portuguese for: Southern Hemi), a unique small V8 developed by Simca do Brazil that was available there from 1966-69. It came on the market around the time that the Simca operation became an official Chrysler subsidiary. This was not one of Chrysler’s typical ‘Big Daddy’ Hemis – it was a ‘junior woodchuck’ 2.4-litre hemi producing 140hp – similar performance to the British Daimler 2.5-litre hemi V8.
It struck me as particularly interesting that the Emi Sul was actually the final upgrade to the side-valve Simca V8 that had once powered the Simca Vedette, an appealing Holden/Zephyr/Vauxhall competitor here from 1959-62. Simca history shows that the French factory inherited the Vedette as a Ford model when it bought Ford’s French operation in 1954. Looking more closely you find that Ford had dug deep into its archives for the Vedette engine template, drawing on the basic design of its V8-60, a 2.2-litre ‘economy’ model flathead V8 that was introduced in the US in 1937. Its inadequate performance by US standards saw it withdrawn by 1940. However it found homes in various British and European Ford models, including the Vedette.
Daimler’s similar Mini Hemi V8
Finding a decent image of an Emi Sul was such a challenge that I never expected to discover an actual Emil Sul in sunny Australia. So I was amazed to learn that local Alfa and Simca enthusiast and motorsport identity Vince Parisi had one. Vince happily confirmed that he had managed to find and import one, before putting some solid work into bringing it up to scratch. Interesting too to learn that it still has a three main-bearing crankshaft like the original V8-60. The Emi Sul now powers his lovely Group Na Simca Vedette historic racer.
You have to wonder whether the Chrysler Head Office ‘All Star’ team of 1967 began having nightmares after finding engines with obvious linkage to arch-rival Ford powering key models from newly acquired foreign car manufacturers. They took over effective control of the British Rootes Group in 1967 only to discover small-block Ford motors under the bonnets of Sunbeam Tigers. Assuming control of the Simca operation at around the same time probably felt easier until someone in the know pointed out that Simca’s lovely little Brazilian Hemi had Ford DNA flowing through its oil galleries.
From Unique Cars #471, Oct/Nov 2022