Typical 1940’s racing fuel components

The following technical information is dated 16^th May 1946 and is provided in Jimmie Simpson's  little black book.

Components	Specific gravity @ 60°F	Boiling Range	Chemically correct mixture air /fuel by weight	Latent Heat, B.Th.U.S/Lb	Latent heat per pound of air in a chemically correct mixture (see note 2) B.Th.U.S	Lower calorific value B.Th.U.S/Gall
Petrol (aviation) base stock	0.720	50-150°C (50% below 100°C)	15.0:1	145	9.7	138.000
Benzole (high quality)	0.878	78-120°C (90% below 100°C)	13.4:1	165	12.3	152.000
Methyl alcohol (Methanol)	0.797	65°C	6.5:1	437	73	68.000
Ethyl alcohol (Ethanol)	0.794	78°C	9.1:1	368	41	92.000
Acetone	0.798	56°C	9.5:1	239	25	98.500
Ether	0.714	34.5°C	11.2:1	150	13.4	107.000
Water	1.000	100°C	-	972	-	Nil

 

Petrol (aviation base stock) - Petrols vary widely in boiling range and anti-knock value. Octane number if typical aviation stock is about 75.

Benzole (high quality) – Benzoles subject to variation. Anti-knock value indeterminate (see note 3)

Methyl Alcohol (Methanol) - Anti-knock value indeterminate (see note 3)

Ethyl Alcohol (Ethanol) - Anti-knock value indeterminate (see note 3)

Acetone – Anti-knock value about 100 Octane

Ether – Very poor anti-knock value. Can only be used sparingly. Used to improve volatility.

Water – Used with alcohol fuels to increase the latent heat still further

 

 Notes:

1)      The question of solubility of one component in another is rarely an involved one. Although it requires careful consideration it is not normally a serious difficulty

2)      In tables such as this, it is usual to give the latent heat of the fuel alone. However, it is considered that the latent heat per lb of air in a “correct” mixture is more significant in practice

3)      The anti-knock values of benzole, methanol and ethanol are normally quoted as being 90-100 Octane. In most racing motor-cycle and car engines, however, the effective anti-knock values of these fuels are very much higher indeed.