This is basically mainly because of the improved VTEC technology as well as the enhanced compression ratio with the B16A2 engine. The SiR was made for a 4th gen chassis. It really works great with an '89-'ninety one Civic. Having said that, try putting this motor in a very '92+ https://b16-motor-for-sale10864.affiliatblogger.com/84247167/5-essential-elements-for-honda-b16b-engine-for-sale