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Last Updated:
22 December 2006
| | The Buick 90-degree V6 - 225 CID, or The Story of the
Little Engine
that Could
a.k.a. "The
odd-fire "Nailhead"
In 1966, Evinrude and OMC offered a choice of three engines in the
Sportsman. All were Inboard-Outboards using the OMC
electric-shift "stringer" stern drive. The outboard versions
(Sweet '16 and Sport '16) were discontinued
for the 1966 Evinrude boat model lineup, after a two-year run. OMC
was years ahead of the marine-industry in offering turn-key,
ready-to-run boat-trailer-power packages, that required no dealer
rigging or setup.
- The OMC-outboard-derived, two-stroke, 90 hp - 90 CID - V4
(est. wet power-head
weight: 120 lbs., est. outdrive weight: 170 lbs)
- The GM-built, four-stroke, Chevy II-based, twin-carb, 120 hp - 153
CID - I4
(est. wet power-head weight: 375 lbs.,
estimated HD outdrive weight: 215 lbs)
- The four-stroke, Buick-designed/Kaiser-built "Dauntless"
Jeep, 150 hp - 225 CID - V6
(est wet power-head weight: 442 lbs.,
estimated HD outdrive weight: 215 lbs))
Complete 225-V6 engine specifications here.
Note the classic
Buick "nailhead" overhead valve covers in our Sportsman. OMC pioneered the use of V6 marine
engines, an engine format that continues to be popular some forty
years later. Ward's Automotive has rated the Buick V6 as one of "The
10 Best Engines of the 20th Century."
"General Motors Corp. Buick V-6 (1962): Buick's 90-degree
V-6 is the poster child of a bad idea turned good through fastidious
refinement. In 1962, this engine was rudely chopped from a V-8 to supplant a
troublesome all-aluminum (Fireball 198) V-6. Unequal firing intervals caused so much idle
shake that Buick soon dumped its V-6 and tooling was sold to Kaiser-Jeep in
1966. When the first energy crisis prompted a rethink, Buick's V-6 returned
home. A continuous refinement program began with a split-throw, even-firing
crankshaft in 1978 and culminated with a top-to-bottom overhaul for 1995.
In spite of GM's hidebound adherence to a pushrod valve train and cast-iron
construction, Series II 3800s' still excel in packaging efficiency, fuel
economy, smoothness and reliability."
In fact, the current EFI Series II 3800 Buick V6's (L67 --
supercharged) & (L36 -- normally aspirated) have been
successfully adapted for marine applications by Wasp
Marine, Ltd., of New Zealand. Wasp Marine offers complete
supercharged marine Buick V6's or conversion
kits (manifolds, cooling, drive adaptors, etc.) for the
current Series II (even-fire) Buick V6 engine.
Improving performance and reliability of the Odd-Fire Buick V6
Holley
four-barrel carburetor and Offenhauser
Intake Manifold
Our Sportsman (as shown above) has been retro-fitted with an aftermarket Holley
Marine 4160, four-barrel carburetor, rated for 450 cfm on an Offenhauser
360-degree manifold. Setup features an electric choke and vacuum-actuated secondary barrels. Estimated
brake horsepower is now 175 - 180 horsepower @ 4400 RPM, roughly a 20 percent increase over
the stock Rochester 2-barrel carb and original points-coil-distributor ignition system. Torque was originally specified as: 225 ft-lbs @
2400 RPM.
GM HEI "High Energy
Ignition" (electronic) System
The original 1966 (2-amp), coil-points and distributor ignition can only output
about 20-kilo Volts to the spark
plugs. General Motors introduced the (4-amp), 30-kilo Volts, HEI
electronic ignition system in 1974-75.
GM engineers designed the original HEI system to replace the coil-points ignition that had been around for decades.
By the mid-’70s, leaner mixtures for tighter emissions demanded greater voltage and more spark energy to initiate combustion. An HEI distributor is still an inductive-discharge ignition, but it exchanges the points for a
solid-state electronic switching device called a module. Since this system produces more
HT voltage and draws a higher amperage current, it demands a larger-diameter
distributor cap to minimize arcing and cross-firing between adjacent spark plug
terminals inside the distributor cap.
This larger cap also offers space to position the coil internally, making the HEI
"system" a self-contained (coil/distributor) unit. All you have to do to run this system is
to apply 12 volts from the ignition switch via 10 or 12 gauge wire, directly to the distributor and you’re ready to run,
bypassing the original coil and ballast resistor. The hotter and
fatter spark
results in faster, more reliable starting (something I like in
my boat), increased horsepower, torque, and
improved fuel economy as well as leaner and cleaner emissions, especially at
higher altitudes (we typically run at 6000' Above Sea Level).
Remember to
increase spark spark gap from .035" to .045", but you CAN
thankfully forget about ever setting the distributor points again. The firing
order is 1-6-5-4-3-2. The even-numbered cylinders are starboard, while the
odd-numbered cylinders are port-side. The heads feature an unusual valve
arrangement: E-I-E-I-I-E (port bank, stated from front to rear, or starboard
bank, stated from rear to front.)
CRT
Performance, of Buzzards Bay, MA, offers rebuilt HEI units, modified
for odd-fire V6's, complete with
HT wire kits, modified and
ready to drop into your 225/V6 Buick-powered boat or Jeep 225/V6. Ask for Glenn, he knows his
stuff. It's a great service, considering how very few odd-fire V6's were
originally built with HEI. The larger HEI distributor is a tight
fit on a marine installation, but with a little work it can be made to fit.
Another electronic ignition upgrade alternative is available from Pertronix,
Inc. Their Ignitor
electronic module replaces the points and fits inside the stock
distributor, retaining stock appearance.
And oh, by the way, at least with this odd-fire V6, there's no bothersome idle
shake.
Buick
V8 HEI Conversion Info --
Buick
V6 and V8 Engine Parts Directory --
History
of the Buick OHV Nailhead
In 1953, in the beautiful Harley
Early-designed Skylark, Buick engineers introduced a unique V8 featuring a vertical
Over Head
Valve (OHV) head that featured a "pent-roof" shaped
combustion chamber. This head design permits excellent low-end torque and
fuel economy characteristics with a free-flowing (45-degree) intake tracks, but
the design does compromise the exhaust ports' ability to breath at
higher RPM's with restrictive 135-degree bends. It earned the nick-name
"Nailhead"
from the unique, vertical orientation of the valve covers, making it easy to identify
Buick 264, 322, 364, 401, 425 CID OHV V8's prior to 1970. See
Buick Engine specifications.
Buick
Introduces the first mass-produced V6 in the 1962 Buick Special
& Skylark
Source: Buick Motor Division,
Copyright © General Motors Corporation,
all rights reserved
The V-6, one of the most popular engine designs
in use today, was first developed by Buick for its 1961 Special.
It was the first use of a V-6 in a mass-produced U.S.-built car. (Note:
the GMC Truck Division had
successfully introduced a 60-degree V6 in 1960.) Joseph D. Turlay, Buick's top engine designer of
the period, responding to Buick's need for an engine for the new
small car, said he could build a 90-degree V-6 quickly by simply
eliminating two cylinders from Buick's 215 aluminum V-8. (Note:
Buick sold the 215 V8 aluminum tooling to Rover in 1967; and the
Buick-designed aluminum-V8 only
recently (2004) ceased production in the Land Rover Discovery.)
"We got it into full production in less
than a year," Turlay said. "It had a new crankcase (and
a cast-iron block instead of aluminum), but the rods, pistons and
valves were nearly the same as those of the V-8."
The new engine resulted in the Special earning
the "Car of the Year" award from Motor Trend magazine
for "pure progress in design, originative engineering
excellence and the power concept for the future expressed in
America's only V-6 automobile engine."
In the muscle-car era of the late 1960s, Buick
phased out the V-6 and sold the tooling to another company (Kaiser
Jeep). But in the fuel crisis of 1974, Buick re-purchased the
tooling, re-introduced the V-6 and began a series of improvements
and design changes which led to the powerful, smooth, responsive
and fuel-efficient power plants of today.
In 1976, Buick's pace car for the Indianapolis
500 was powered by a turbocharged V-6 -- the first V-6 ever used
in any Indy 500 pace car. Buick's first front-wheel drive car, the
1979 Riviera, was offered in two models -- a standard version with
a V-8 and an S Type, with a turbocharged Buick V-6. The S Type won
Motor Trend's "Car of the Year" award.
In 1986, when Buick offered an intercooled
turbo V-6 in the Regal Grand National, auto magazines labeled the
Grand National as America's quickest automobile. The Buick V-6
became a major factor on the race tracks of the country as well as
a mainstay among production power plants.
It all started with the 1961 Buick Special & Skylark.
"If
someone had told me in the sixties that the Buick V6 would be the most common
engine found in all GM cars -- I would have laughed at them." --
www.BuickStreet.com More
Compact B-O-P V6-V8 Engine Development History
-- www.442.com
But
why
an odd-fire V6?
Solving the 90-150-90-150-90-150 mystery
and why this engine sounds so unique. Hear and view
the Buick odd-fire V6 pushing our Sportsman below:
Buick engineers first introduced the 90-degree "Fireball"198 CID V6 for
the Buick Special & Skylark in 1961. In 1964 Buick bumped the V6's
displacement to 225 CID. The 90-degee 225 CID V6 engine was
essentially the 300 CID V8 with two cylinders removed. A 231 CID odd-fire
V6 was offered from '76 - '78. For smoother idling, Buick switched to a
(weaker) split-pin
crankshaft, resulting in an even-firing V6 with the 231 & 252 CID V6's
midway through the 1977 model year. See
Buick Engine specifications.
The
Utah Connection -- Hayes Brothers Jeep; (Read how GM sold the V6 engine to Kaiser-Jeep)
The
Life & Times of the Buick V6 (The Little Engine That Could)
By Ken Mosher
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