War is hell kids, but it’s undeniable that many world-changing technological advances were derived from armed conflict. War-related research brought us the moon landing, jet powered airliners, hemispherical combustion chambers, super glue, synthetic oil, and the cell phones in our pockets.
Way back in WWII, the German Focke-Wulf FW 190 fighter plane needed a horsepower boost to give it an edge during aerial combat against U.S. Air Force P51 Mustangs. The FW190’s 1,677 horsepower, 14-cylinder BMW radial engine was already supercharged so adding a huffer was off the menu. Instead, the so-called MW 50 system was devised. As the name implies, a 50/50 spray of methanol and water was administered for short bursts and output jumped to 1,973. Though the MW 50 units were only used experimentally, the idea took root and has been exploited by horsepower seekers looking for minimal hardware investment ever since.
So what exactly does methanol – water injection do? The core objective is to prevent abnormal combustion. Usually identified with words like detonation, ping, and knock, the audible sounds are caused by a fuel/air mixture that’s started to burn too soon. The resulting “death rattle” is just that. The uneven cylinder pressure hammers the chambers, pistons, rings, ring lands, pins, bearings, and block without mercy. In extreme cases, the vibration can be so extreme as to cause flex plate and header flange bolts to loosen
Beyond its threat to mechanical systems, detonation also kills power. The uneven power pulses, which are clearly visible on a printed dyno curve, disturb intact tract function, ignition system efficiency, and vehicle acceleration. While detonation is a problem with naturally aspirated engines, when you add an exhaust-driven turbo or belt driven supercharger and forcibly cram the air molecules together, even more detonation-making heat is the result. Something must be done.
That something is water-methanol liquid injection, which aims to cool the intake charge before it enters the combustion chambers. Back in the ‘70s when the federal mandate for reduced octane, unleaded fuel first hit, and entire crop of aftermarket water injection kits emerged to help drivers of pre-1971 cars run on the lower-octane gasoline. These cars typically had compression ratios north of the critical 10:1 threshold and rattle-prone iron cylinder heads.
Grab a late seventies copy of Car Craft and you’ll see advertisements for water injection kits from outfits like Spearco and Roto-Master. These early kits generally introduced straight atomized water into the fuel/air charge. Since water doesn’t burn and expand during combustion, the water molecules took up a certain amount of space, so less fuel was present and power wasn’t necessarily enhanced. Rather, these systems simply helped the engine “be all it could be”, to borrow a recruiting phrase from the mighty U.S. Army. However, straight water begins to freeze at 32-deg. F, so makers of those water injection kits told users to add various amounts of windshield washer fluid (which contains alcohol to prevent freezing) to ensure their systems would function in the winter time. As victims of cracked engine blocks can attest, confined water takes up seven percent more volume when it freezes into ice. So following the lead of the Focke-Wulf engineers in 1942, many aftermarket water injection system makers incorporated methanol into the equation. Well whaddaya know, alky is combustible and can add power while the water component curbs detonation; it’s a win – win.
Its’ been over four decades since those first water-methanol injection kits hit the aftermarket, and since the best pump gasoline available is still a mere 91 to 93 octane, detonation remains a problem for naturally aspirated engines with more than 9.9:1 compression. With today’s massive surge toward add-on turbo and supercharger kits, the need for water-methanol injection systems has never been greater.
Lets’ watch as the Buzzell brothers of NextGen Performance install and test a Snow Performance Boost Cooler on a Vortec blown 1965 Mustang 2+2. The entire process took just a few hours but added nearly 41 horsepower and 29 lb/ft of torque while calming all signs of detonation.
Turbo Rocket Fluid: Don’t Leave Home Without It
Way back in 1962 and ’63, the compact Oldsmobile F85 Jetfire added an AiResearch exhaust-driven turbocharger to its 215 cube, aluminum block V8. The turbo was mounted to pull air through a sidedraft 1-barrel carburetor. With Chevrolet’s same-year Corvair Monza turbo, these were America’s first mass-produced, post-war turbo cars.
To solve the persistent turbo lag issue, Olds engineers equipped the little 215 with a sky high 10.25:1 compression ratio. It increased low speed cylinder pressure until the turbo’s 5-psi boost came on strong at 2,200 rpm.
To tame low-rpm / high-load detonation tendencies, Olds resorted to – you guessed it – water-methanol injection. A 50/50 mix of distilled water and methanol, Olds dealers sold the fluid in specially marked metal cans and rigged a sensor to bypass the turbo if the underhood reservoir was empty.
Though a brave effort, the system was hampered by overly conservative tuning to protect against careless users. Under boost, the Jetfire’s Turbo-Rocket 215 delivered 215 horsepower at 4600 rpm and a stout 300 lb/ft at 3200 rpm. For comparison, Corvair’s 164-inch flat six turbo made 150 hp and 210 lb/ft.
Though a 3-speed manual was standard in the 1962 Jetfire (a four-speed became optional in ’63), most got a sloppy three-speed Hydramatic and mild 3.36:1 gears out back. The September 1962 issue of Motor Trend magazine tested an automatic turbo car and recorded 0-60 in 10.2 seconds, only 2.5 seconds quicker than the non-turbo 215 V8 with its single 2 barrel and 155 horsepower rating. The turbo’ed Jetfire cranked the quarter mile in a pretty mild 18.7 seconds and 80 mph.
Sold only in the Jetfire two-door hardtop (a specific model with style code 3147), the complex turbo V8 forced the sticker price over $3,700, only $300 less than a stripped Corvette. Production reached 3,765 in 1962 and 5,842 in 1963 before the idea was dropped. But as a pioneering mini muscle car, the Jetfire deserves recognition.