History

This car and engine grew out of the early '60's gas crunch. 

Up until this time, the American car market had consisted of

 big cars with big motors that used lots of gas. In 1961, Olds

 (and Buick and Pontiac, referred to collectively as "The BOP Cars")

 came out with their new small cars (Olds F-85, Pontiac Tempest,

 Buick Special). Available was a new, all aluminum V-8, displacing

 215 cubic inches. This engine was standard in the Buick and Olds,

 optional in the Pontiac. 

The original motor was aluminum from Buick, it used cast iron sleeves.

 The Olds versions got their compression ratio from the heads, and 

Buick's from the pistons. Rover bought the 215, and it became their 

3.5L V-8. There are some small differences between the Buick 215 

and the Rover 3.5l in many aspects of the design. Buick Special, 

Skylark, Olds Jetfire, F-85, and the '61, '62 Tempest used a version 

of the motor with one extra head bolt. It will still bolt to a later 

Rover block, but with one extra hole. They're rare though. Intakes

 are believed to interchange, though. 

The 215 was powerful despite its small displacement. The strong 

motor in such a light body with independent suspension all around 

made the Special and F85 one of the best cars in the early 1960's.

 The biggest barrier has been the brakes which were inadequate at

 the time, and are even more so today. Examples had 3-speeds, 

4-speeds (Borg-Warner I believe), a type of Powerglide that went 

into the Buick and Pontiac, and the Slim Jim Jetaway type in the 

'62 Jetfire. They also had 2-barrel and 4-barrel carbs (Rochester)

 for them as well as the huge 1-barrel side-draft on the turbo Olds

 version. 

In 1961, the F-85 had a 155 HP version of the 215 ci. engine, and 

the Cutlass had a 185 HP version. The 1961 versions of the motor

 were rated at 155 hp, but later years saw increases - up to 

200 hp normally aspirated for the Buick version and 215 hp in 

turbocharged form from Olds (the 62-63 Jetfire). 

In 1962, Olds, along with Ai Research, introduced a 'turbocharged'

 (called Fluid Injection) version of this engine, which put 

"Turbo Rocket Fluid" (½ distilled water, ½ methyl alcohol) into

 the carb. Along with a 10.25:1 compression ratio, yielded 0-60 

in 8.5 seconds (with the manual tranny). The Olds' turbocharged

 Jetfire was supposedly quicker than the 4V version, but it had

 maintenance problems due to its complex mechanics for that era.

 It attained the magic goal of 1 HP per CID. A power boost on 

the order of 40% was claimed. The automatic Cutlass with 10.75:1 

compression gave 195 HP @ 4800 and 235 lb/ft @ 3200. The Jetfire's

 10.25:1 compression gave 215 HP @ 4800 and 300 lb/ft @ 3200. 

Top speed for a 4V was just over 100 mph, but 0-60 took almost

 11 seconds with automatic, although the stick did better. 

The biggest problem with the Special/F85 was the 3-speed "slushbox"

 transmission. Which, according to a Motor Trend road test,

 "seemed to take forever for the Hydra-Matic to get a good,

 firm lockup into the next gear, and the engine lost 2,000 rpm 

on each shift." Oldsmobile scrapped this system in 1964 due to 

reliability problems. The 'performance Olds' then became the 

442 in '64. 

Not long after the motor was put into production, gas became 

plentiful again. You all remember the late '60's, early '70's, 

"Why build a 215 when you can build a 455?" It was the dawning 

of the age of muscle cars. At this same time, across the pond, 

the British were just beginning to turn away from the famous 

4 cylinders. They were selling off their designs and tooling, 

left and right, to the Japanese. The only new motors that 

British car companies seemed to have produced, though, were 

those HEAVY I-6 motors. They attempted a V-8 with the Triumph

 Stag, but due to poor design, the motor was plagued by mechanical

 failure (a Triumph having mechanical trouble, never!) 

GM, still having fun with the 330, 425, 455, etc. decided that 

it had no use for the 215 design, and therefore, sold the design, 

tooling and manufacturing rights for the motor to the very willing 

British Leyland company (Rover/Jaguar/Triumph). It has evolved 

into the 3.5, 3.9, and 4.2 liter engines in various British cars 

(Land Rover, Rover 3500, TVR, TR8, etc.) The engine is a direct

 fit in the MG, as it was offered in the early 1970s, as the MGC 

(ie, next after the MGB). The full-up engine (carb-to-oil pan)

 weighs about 305 lbs. 

The 215 was redesigned from an investment casting to a sand cast

 aluminum block making it slightly heavier, but it is said to be 

less prone to cracking, and better at vibration dampening. Basic

 dimensions remained the same: bore, stroke, bearing sizes, distance

 between bores, etc. 215 manifolds still fit the 3.5l blocks as do 

all of the original 215 aftermarket upgrades. Buick, having had 

given up the 215, recast the block as a cast iron version: the

 Buick 300. Slightly taller and larger bore, but the same bore 

to bore and bearing placement. This engine was equipped with a 

3.4" stroke crank that had larger bearings and a different rear 

seal assembly. This makes the crank a ½ inch or inch longer out 

the back side and the flywheel bolt pattern different. 

About this time, Buick, wanting smaller and more fuel efficient

 cars, decided that they needed a new powerplant. They wanted 

something light, so they went back to those same 215 bore dimensions.

 They made it a V-6 in 198 cu in form. This original V-6 was 

optional in the Jetfire. Later, from this original V-6, Buick 

232 was born. The front covers of these motors will still mate 

up with the old 215's and the Rover blocks. 

The Buick 3.8L V-6 is a variant and can supply bell housings, 

water pumps, and various other common block parts for the 215.

 The basic block was fitted with DOHC 4-valve heads and turned 

into an F1 racing engine by Repco of Australia in the early 60s.

 Mickey Thompson also ran one at Indy in the early 60s. Mickey 

Thompson used the 215 block along with his own forged crank and 

aluminum pistons to make an off road race engine. The crank was

 3.5" stroke, quite a bit larger than the 2.8" stock one still 

used to power the Rover 215. This brought the CID up to 250 and 

it had a higher lift, higher rev cam, as well as Mallory Dual

 point ignition. 

Another interesting bit of trivia is that the 1964 Buick 300 is 

actually a cast iron version of this motor with aluminum heads - 

in fact these 1964 heads have larger ports and valves and will bolt

 to a 215. 

Many articles have been written on installing this crank into the

 215 case to get the 215's light package with the increased stroke 

and displacement of the 300's crank. It does, however, require 

engine rear seal machining, crank grinding, and some funny business

 to get a manual tranny to bolt up. 

Just when you thought that nothing else could be done to this poor

 block, Volvo (yes family sedan/wagon people) valves, it was 

discovered, would fit into the 310 (?) aluminum heads to increase

 flow. Also, Chevy Carrera rods (300, 310, 340) were quite a bit

 stronger than any of the others. Stronger than even M. Thompson's

 box welded rods. 

In Britain, some 215s have been bored and stroked to an amazing 4.5

 to 5.0 liters through the use of the factory crank from a diesel 

Rover (known as the Tundra something or other). Now then, does this 

not sound fun to you, an Olds F-85, with the aluminum Rover 3.5 

litre block, bored to 3.8 liters, stroked from 2.8" to 3.5" using a 

Mickey Thompson crank, Big aluminum head via Buick 300 etc. Volvo 

oversize valves, a 3.8 liter front case w/HEI ignition and still 

able to hang a serpentine belt with all accessories on it, and bolted 

up to a Borg/Warner 5 speed tranny? 

Author Unknown