This is the SOHC VTEC 16V 1.6 used in the Del Sol Si and the old Civic Si (EG, not the EK) for the US market. The cam has a ~5,300rpm switch point (as far as I can remember), and the VTEC swichtover only affects the intake valves. Output is about 125hp at the crank, stock.
What's up man. I have a '92 Si that is the US model, and it has the D16Z6 engine. I am pretty sure that the US Ex also has this engine, which would make it VTEC as well.
Yes, it definitely has VTEC. This is surprisingly often a topic of confusion.
The earliest that VTEC will engage is 4800 rpm. There are several factors that control this: vehicle speed (>13mph), water temp (>140F), and engine load (measured by intake manifold negative pressure).
I am reading my Helm's and it says that the D15Z1 has VTEC-E. The only differnce I can discern is that the high speed rocker is locked in a little earlier (2500 rpm, 3mph, 22.5F). I cannot remember for sure, but I think they put this engine in the CX's. And the DX's got a 100hp non-VTEC, and the VX's got a 70hp non-VTEC with EGR.
The factors controlling VTEC engagement are merely minimums. Therefore, if you turn on your car after it has been sitting overnight and accellerate hard right away, VTEC won't engage, until the temp gets to 140F (at least in the D16Z6).
The Si easily makes up for this higher VTEC engagement point with it's shorter gearing. The maximum speed in the Si in 4th gear is 88mph, while in the CX, it is 102, VX-111mph, DX-92mph.
I have no idea how our models translate to Canadian models, but I do know that they don't have the 70hp engine. What a loss. I have heard that they have a SiR, and that is our Si, but the Helm's manual doesn't say anything about that, so I am not sure.
No, VTEC engages at 4800 on D16Z6. Reread my post. Enano Siniestro was guessing.
Yeah, you can look at any Honda engine to find out if it has VTEC if the valve cover doesn't tell you.
If you are looking under hood at engine compartment from front of car, it is at the same height as the valve cover and sticks out from the head pointing straight up and down. It is about 1.5 cm in diameter and 3 cm in length, and is sorta brass looking. There is one wire going to it that is shielded, but behind the shield, it should be a green wire.
On D-series, it is behind engine, on B-series, it is in front. In both cases, it is on the left. Kinda near distributor, if that helps.
Yeah, you circled the VTEC solenoid. I guess my description worked?
I mentioned VTEC, and VTEC-E in my previous post. Here are the details...
VTEC: There are 3 rocker arms, and 3 cam lobes per cylinder. The low speed cam lobes act on the primary and secondary rockers before VTEC engagement, and the mid rocker arm always follows the high speed cam lobe. When VTEC engages, the solenoid electronically (controlled by ECU) opens a valve that allows oil to flow into rocker assembly. The oil pressure acts on a piston which locks the primary, mid, and secondary rocker arms. Now all 3 rocker arms are following the high speed cam lobe. Yes 3, but there aren't 3 intake valves, the mid rocker arm just locks the two together, and you need the mid rocker arm, because it is following a completely different cam profile. It just doesn't have the other half of a normal rocker arm which attaches to a valve.
VTEC-E: In this case, there are only two cam lobes and two rocker arms. The secondary cam lobe only slightly acts on the secondary rocker arm and the secondary valve just slightly opens (mainly to prevent fuel accumulation). Therefore, before VTEC-E engagement, the engine acts kind of like a 2 valve engine (even though both exhaust ports open, having only one intake port kinda limits your power). After VTEC-E engagement, the timing piston forces the secondary rocker arm to lock with the primary rocker arm and now follows the primary cam lobe movement. There is no high speed cam lobe in VTEC-E engines. It just switches from a 2-valve to 4-valve engine. Very good fuel economy.
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