Vtec-d15b Engine

[sanjeewatr]

In the mid 1980s, Honda's top engine in the Civic was the DOHC ZC delivering 130ps and redlining at a high 7200rpm. This engine powered the top Honda Civic models; the EF6 & EF7 Civic/CRX Si. In 1989, Honda invented VTEC, implementing it first in the DA6 Integra RSi & XSi in April and followed by the EF8/EF9 CRX/Civic SiR towards the end of that year. Honda continuously refined VTEC and migrated it to other engines and one of the first benefactors was the D15B.

The D15B has always been in the shadow of its larger, more powerful 1.6l brothers. When the DOHC ZC was the top engine, the D15B came in both single and double carb'ed SOHC versions, the dual-carb version delivering as high as 105ps in the CRX 15X. When VTEC became available, two versions of VTEC D15Bs were developed for the EG-series (1991-1995) Civic. One is the well-knowned VTEC-E which delivered an incredible 20+km/l mileage. The other is the VTEC D15B, a power implementation. The VTEC D15B is a very significant engine variant because Honda used VTEC to make it possible to generate as much power as a DOHC design from its SOHC configuration. Thus the VTEC-D15B generates 130ps and redlines at 7200rpm, ably replacing the DOHC ZC design despite having 100cc less displacement and one cam-shaft less !

Also frequently overlooked is the fact that with 130ps from 1.5l, the specific output of the VTEC D15B is 87ps/l which actually compares favourably with the larger capacity DOHC VTEC designs such as the BB1 Prelude's H22A. The specific output of the VTEC D15B is in fact higher than the 190ps version of the H22A used on the previous generation Accord SiR !

For the 1995 EK3 Civic, the evolution of the D15B culminated in the now famous 3-stage VTEC implementation, a merging of the earlier VTEC-E and power-VTEC variants. Thus we now finally get power and economy in one great engine; incredible as it seems, on the 3-stage VTEC D15B, Honda actually delivered the best of both worlds.

[isurujosh]

For the 1995 EK3 Civic, the evolution of the D15B culminated in the now famous 3-stage VTEC implementation, a merging of the earlier VTEC-E and power-VTEC variants. Thus we now finally get power and economy in one great engine; incredible as it seems, on the 3-stage VTEC D15B, Honda actually delivered the best of both worlds.

good to have another Honda informer in the forum! there were some similar articles in the temple of vtec site too