86:, the engine's high-lift VTEC cam lobe is engaged. A higher lift lowers restriction even more, giving the highest airflow. If one built a non-VTEC engine to make the maximum power, the trade-off would be very low efficiency at low RPMs in order to get the most flow possible at high RPMs. A three-stage allows the engine to run in "economy", "standard", and "high power" modes, while a VTEC only gives "standard" and "high power", and a VTEC-E only gives "economy" and "standard".
73:
At about 2500RPM, the engine is able to switch to the 16-valve mode, which is typical of classic engines. The first VTEC solenoid is opened and directs the oil to the sliding pin that connects the rocker arms of the intake valves with the first intake valve's lobe. Thus, all two intake valves move at
60:
ratio and thus enables extra fuel saving. This works similarly to the principle which gave the Buick "Nailhead" V8 its reputation for high torque (in that case, the engine had notably small intake valves, giving good torque, but limiting peak power). In an engine running at lower RPMs, a smaller
31:
and power. VTEC-E (for "Efficiency") is a form of VTEC that closes off one intake valve at low RPMs to give good economy at low power levels, while "VTEC" is a mode that allows for greater power at high RPMs, while giving relatively efficient performance at "normal" operating speeds. "Three-stage
61:
intake valve area forces a given volume of air to flow into the chamber faster; this causes the fuel to atomize better, and therefore burn far more efficiently. An average of 30 km/L (70.6 mpg
40:
VTEC-E (economy) was designed to achieve better fuel economy, at the cost of performance. The engine operates in "12-valve mode", where one
74:
the normal profile of that lobe. The engine's performance is usual to the non-VTEC engines. This mode is suitable for mid-range RPMs.
154:
164:
159:
23:
and VTEC-E (colloquially known as dual VTEC) technology, implemented in some of the company's
49:
65:) can be achieved while in the lean burn at a constant speed of 60 km/h (37 mph).
8:
104:
53:
45:
32:
VTEC" gives both types in one engine, at the cost of greater complexity and expense.
28:
57:
24:
148:
41:
83:
123:
27:
from 1995 to the present day, allowing the engine to achieve both
20:
48:
in the 16-valve engine remains mostly closed to attain
146:
35:
19:is a multi-stage implementation of Honda's
102:
77:
147:
68:
121:
13:
14:
176:
115:
96:
52:. The lean burn mode gets the
1:
89:
7:
82:From ~5200 RPM to the
10:
181:
36:Stage 1 – 12-valve VTEC-E
122:Wong, K. N. (May 2000).
78:Stage 3 – 16-valve VTEC
155:Variable valve timing
124:"D15B 1.5l SOHC VTEC"
69:Stage 2 – 16 valve
165:Engine technology
56:above the 14.7:1
54:air to fuel ratio
172:
139:
138:
136:
134:
119:
113:
112:
103:Kong-Ngai Wong.
100:
25:D series engines
17:Three-stage VTEC
180:
179:
175:
174:
173:
171:
170:
169:
145:
144:
143:
142:
132:
130:
120:
116:
101:
97:
92:
80:
71:
64:
38:
29:fuel efficiency
12:
11:
5:
178:
168:
167:
162:
157:
141:
140:
114:
94:
93:
91:
88:
79:
76:
70:
67:
62:
58:stoichiometric
37:
34:
9:
6:
4:
3:
2:
177:
166:
163:
161:
160:Honda engines
158:
156:
153:
152:
150:
129:
128:asia.vtec.net
125:
118:
110:
109:asia.vtec.net
106:
99:
95:
87:
85:
75:
66:
59:
55:
51:
47:
43:
33:
30:
26:
22:
18:
131:. Retrieved
127:
117:
108:
98:
81:
72:
42:intake valve
39:
16:
15:
84:rev limiter
149:Categories
133:24 January
90:References
63:‑US
50:lean burn
46:cylinder
105:"VTEC"
135:2019
44:per
21:VTEC
151::
126:.
107:.
137:.
111:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.