Tom’s Corner – Castor Oil in Racing


Those of you who have followed the #52 Fiero may have noticed a distinctive exhaust smell coming from those four big megaphones. This is the result of burnt castor oil which I add to the premium gas and an octane booster (to achieve 100 octane) in the summer months. I use ½ oz. to a gallon of premium gas for the desired result. This may sound like an exotic fuel blend and it is and I get very good mileage with this mixture. At this point I will attempt to explain why I do this. I first noticed this ‘fragrance’ at Elkhart Lake’s Road America sports car course in 1958 while watching sports cars such as Ferrari and Maserati on the track. Flash forward…in 1972 I attended a pro outboard race in Depue Illinois and asked where I could obtain this oil as it was the same fragrance I remember from the Road America days. I could use it in my unlimited outboard hydroplane and was told that Blendzall made a very high quality de-gummed castor oil for cars and boats so I bought a case of it and have been using it ever since.

Now I will digress for a moment and give you a little history on this amazing product. Castor oil is made from the castor bean plant and has been used medicinally for about 4000 years and was given to children to ‘keep their systems clear’. In the medicine field, it is strongly laxative and purgative. It has a myriad of uses in industry and here is where it comes into motor racing. Ever since the internal combustion engine was invented there was a need to properly lubricate it. In February 1899, Charles Cheers Wakefield resigned from the Vacuum Oil Company and the firm he started would go on to become the Wakefield Oil Company. In 1909 the company began production of a new automotive lubricant named ‘Castrol’ a contraction of castor oil from which it is made. The original 3 grades were CW for cars for motorcycles, and R for aircraft and racing engines…the castor oil being responsible for the noticeable odor of early race cars. Castor oil maintains its viscosity from -30 to 500 degrees Fahrenheit and is extremely clean burning. It bonds to metal surfaces, prevents rust, lubricates upper valve guides and upper cylinders and goes where the source of heat is. De-gummed castor oil has been used in engines whose revs can go as high as 21,500 RPM’s! There are several manufacturers of racing castor oil. To name a few are: Castrol ‘R’, Blendzall 460, Klotz BeNol-B-175, Maxima 927, VP RC-3, Burris LC-003. Castrol has sponsorship in all forms of motorsport such as Formula One, World Rally Championship, Sports car racing, NASCAR, and NHRA drag racing and power boat racing, karting, motorcycle racing and airplane racing. Even in the 1950’s there were other racing castor oils such as Pratts Castor, Essolube 60 Racer, Notwen Castor, BP Energol Racing, and Vigzol Golden Race. But the fact is when racing sounds and scents are recalled, all castor oils are thought of as the famous Castrol ‘R’. Today you can achieve this scent of burnt castor oil by using it as I have prescribed at the beginning of this article.

Castro oil is not cheap and you can only purchase it at race shops that carry a specific castor oil brand. Or you can order it on-line using Google to find your preference…My experience with using Blendzall Racing Castor in the #52 car has given me very satisfying results. I also used it in my hydroplane in 1974 for the first time and the boat was clocked at 101.664 MPH in Canada. I can be reached at my e-mail address ( On a much lighter note, wouldn’t it be really neat for someone to make a man’s cologne with this fragrance? I would make someone very wealthy!!

Tom’s Corner – The Technology Behind Smokey Yunick’s Hot Vapor Fiero


After having presented an article on Smokey Yunick’s ‘ hot vapor engine’, I will attempt to explain how this technology works. Normally different parts of a standard non=homogeneous air/fuel mixture burns at different rates within the same cylinder creating turbulence and colliding flame fronts. Under normal running conditions, cooling the intake charge to create higher mixture density is beneficial to keep some of the fuel molecules from undergoing spontaneous combustion or denotation.

Smokey installed a heat exchanger under the carburetor that used hot engine coolant exiting the motor to warm that mixture to around 200 degrees. Then the air/fuel mixture flowed through a second stage generator, an exhaust driven turbine wrapped in exhaust gas ducting. He called this devise a ‘homogenizer’, but it was really a turbocharger underneath that fancy ducting ! Not only did this devise generate boost, it also served as a one way check valve to keep the expanded hot gas from back flowing out of the carburetor. Then from the turbine the mixture flowed through an intake manifold also wrapped by exhaust ducting to reach its final super-hot temperature. Smokey’s engine had all the usual hot rod items of the period such as trick rings, forged pistons, Carillo connecting rods and so forth. One of the key secrets is the exact tune-up or technique used to get the engine past the detonation threshold to the super-hot, super-lean running condition. In short, an engine makes its most power running on the verge of denotation.

The key seems to be getting safely past 2250 degrees so not only is the tune-up critical…some special cam shaft timing is involved as well. Typical small block GM engines run very reliably at 1750 degrees F stabilized exhaust temperature. At 2250 degrees you are definitely in trouble from engine destroying denotation.So if you can get it to 2600 degrees or beyond you can control the burn rate of the hydrogen molecule in the fuel which is the major radical in the gas which causes denotation, you will make more power without denotation. Since the fuel economy standards are to be raised in the next 10 years, the auto makers are getting heavily involved in ‘heat vapor’ technology. Smokey was way ahead of his time and experimenting on a Fiero is another reason why this car is considered a true time capsule by the automotive industry ! I hope you enjoyed this small part of Fiero trivia.

Editors Note: Sorry for the delay in part two of Tom’s series on Smokey Yunik’s Fiero. Entirely my fault as I was busy looking for a new day job. There was lots of debate regarding the Smokey Yunik Fiero when the Tony Allers re-creation was re-discovered. You can read some of that debate at . The car even made an appearance at one of Ed Parks open houses at The Fiero Factory. — Jeff Jones, Editor

Tom’s Corner – Smokey Yunick’s Hot Vapor Fiero

Every year, someone asks about the fate of a potential break through engine technology developed by legendary racing engine builder and high performance tuner, Henry ‘Smokey’ Yunick, with his long time partner, Ralph Johnson. In the June 1984 issue of Hot Rod magazine, there was a report on a ‘hot vapor’ motor that Smokey developed using a 2.5 litre ‘Iron Duke’ 4 cylinder Fiero engine that met all the ‘80’s emission standards, made 250 horsepower and 250 Lbs/foot of torque and went from 0 to 60 in 6.5 seconds and got as high as 51 MPG using premium gas!

The ‘hot vapor’ engine did all of this running unheard of high temperatures at an extremely lean air/fuel fixture ratio, which was seemingly in violation of accepted internal combustion engine physics. Traditional theory was to get rid of or manage heat. Smokey was channeling heat for improved performance, the exact opposite of conventional engineering science. Here is how Smokey did this : A standard four cycle internal combustion engine utilizes only about 25% of its potential energy to make power. The remaining 75% is lost out the exhaust or transferred as heat into the cooling system and radiator. Heat vapor technology attempts to recapture this heat energy using it to super heat the incoming air/fuel mixture to more than 400 degrees F going into the cylinder, thereby achieving a perfectly vaporized condition that it said to prevent denotation while ensuring complete combustion. Smokey was channeling heat from the water in the engine’s cooling system plus exhaust heat to progressively warm the system’s induction flow to the required temperature. He and Ralph Johnson were actually fooling around with this concept for more than 3 decades. Smokey did take out patents on the basic ‘hot vapor’ technology but took much of the knowledge with him to the grave.

As for the fate of the original ‘hot vapor’ engines, his daughter Trish still retains 4 different prototypes in long term storage, one is also in the Smithsonian Institute. A friend of Smokey’s, (Tony Allers) has the only good running engine. He built a Fiero that is identical to the original car, using the original drive train salvaged from the original Hot Rod Fiero by Smokey before Smokey returned it ti Pontiac for crushing. Allers drove his car for 2 and ½ years before donating it to the Don Garlits Museum where it is currently on display. This Fiero can smoke the tires at 60 MPH and passes all Tennesee emission tests. ‘Hot Vapor’ technology will not die. The time will come when engines will be fully adapted as a heat pump.

(editors note: This is the first of a 2 part series on Smokey Yunick’s Hot Vapor Fiero. The next Tom’s Corner will look more into the Hot Vapor technology and some of the debate about the effectiveness)