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What is the difference between the 2 engines re 97 civic si . Thanks..77.

 
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its "vtec"

 
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the vtec e engine I believe only came on the VX model and was more of a gas saver engine.

 
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ya, c Vtec isn't all just for power gains, honda has built probably more vtec engines for efficiency and emisions purposes than for gaining power, that was its origanal purpose ( efficiency ). yes obviously they built vtec in some for nothing but adding power i.e. the type R, GSR, and B16's, ect. but they also made it for better feul eff. and bottom to mid range torque , i.e. F23 in the 98-2000 accords.

( and someone please don't try to talk about the bottom end torque thing, yes the vtec kisks in very low in those motors )

 
Rep Power: 731

Yeah , see we got a 97 si in the shop . seems like the engine has been swapped before . boss in all his wisdom got a 1.6 Vtech from an Acura to put in it . the motor that was in it has a thermal vacuum sensor on one of the heater coolant lines offa the thermostat hosing . From this TVS a vaccum line goes to between the two centre ports on the intake . Like at the flange where the intake bolts to the head. the glange is flat across the top from end to end on the manifold . Usually the top of the flange is kinda sculptured around the ports. If you take the manifold off , there is a small port next to each intake port . Spraying brake clean into a port causes the fluid to come at the injector in adjacent port.
i assumed the tvs drew from , maybe the charcoal cannister. But this car doesnt have any extra ports/lines on it .
Now the wxtra area at the top of the manifold butts up against a horizontal mating surface on the head . The engine we got doesnt have this area on it . And we need to use the manifold , cause the acura one has differences from the Civic one . So to make the civic intake work on the acura head . I taped the holes /ports and put in # 4 machine screws with loctite and ground the heads off the screws . And taped and plugged the port on the flange of the intake .
I just gotta put one axle back in and top up fluids and see how it runs ..77.