In the present work, two types of Castor biodiesel were synthesized by using the pyrolysis process. The first was obtained through pyrolysis of raw Castor oil with no-catalyst, while the second was synthesized in the presence of anhydrous sodium sulphate as a catalyst. Such two types were termed as Castor biodiesel number 1 ( BD1) and Castor bio-diesel number 2 ( BD2) with yield of 55% and 52% respectively. The pressure rise ignition delay of these types of Castor bio-diesel was studied, for this purpose, a shock tube test set up was designed and manufacture. It was fully instrumented for ignition delay measurement with two piezo-electric pressure transducers, dual mode charge amplifier, data acquisition card, laptop computer with suitable LabVIEW software. The test variables include the type of fuel ( BD1, BD2, and gas oil), equivalence ratio, ignition temperature, and ignition pressure. It was found that the ignition delay of the gas oil was more than those of both BD1 and BD2; the delay period of BD1 was less than that of BD2. Rich and lean mixtures exhibited long delay whilst the minimum delay occurred near the stoichiometric mixture. Also, it was found that the delay period reduced considerably as the ignition pressures and temperatures reduced. Modifications of the CIEs will not be needed to be suitable for running with these types of biodiesels. The shorter ignition delay observed with BD1 and BD2 can lead to a reduction in compression ratio. That makes the engine less stressed and accept turbo-charging more readily. (c) 2014 Elsevier Ltd. All rights reserved.