Civic EG

Not a very technical post here but I took off my dual solenoid and cleaned it out real good. I was pretty fascinated with it so I snapped some pics. And what the hell I thought I'd post them up.





This is the VTEC solenoid from the 3 Stage VTEC engine which came out in 1996 in Japan and several other countries in the Civic VTi. In Japan it's stamped "D15B" and in other countries it's stamped "D15Z7". Stage 1 is 12 valve mode like the VX (D15Z1) and HX (D16Y5). Stage 2 it switches to 16 valve operation. And then Stage 3 is your standard SOHC VTEC.

nice post! I love the idea. I wonder if the newer engines (didnt really look into the new ones yet) have something like this.

*Baller status*

You got 2 more VTEC's than me

thats really cool i didnt even know they made such a thing.

Is there any maintenance routine when I should clean it? I ve never done it

york62 wrote:thats really cool i didnt even know they made such a thing.

x 2 first time i see this

Yes i knew this excisted, cuz a friend of mine has a D15B, looks really nice and it is a nice piece of mechanic.

LowTEC-Derbo wrote:nice post! I love the idea. I wonder if the newer engines (didnt really look into the new ones yet) have something like this.

No, the D17's don't have it, but to give them credit they get excellent fuel economy and power w/out it. My wife has an 01 EX. We just took a trip to Vegas and got 38 mpg freeway @ 80mph!

iVTEC also pretty much makes this obsolete as well, but look at the cost/difficulty vs payoff of swapping in a K series...

As far as maintenance schedule I'm not sure. You could look through the Helms. My rule is if you don't know if it's ever been done before then it's time to do it. VTEC engagement felt pretty sketchy. It seems to have solved the problem but I can't pin it down to that for certain. The oil inside was very black and there were a few clumps like the size of salt grains. I really had to blast it out with carb cleaner and compressed air to get it all out. I only use synthetic oil and I change it regularly so clearly just changing the oil doesn't get the job done.

The D15Z7 is identical to the D16Y8 and D16Y5 except for the dual solenoids.


Here it is when I bought it.


Here it is swapped in after converting the ignition and swapping a Y8 intake manifold because it lacks the EGR.

i got a question in regards to the engine spark plugs. is this how the spark plug wires are left? i mean i dont see it connected to the Distributor unless theirs a different set up i am not aware of.. thats the only question as i was wondering if this is how they go or what? plz help

I converted to distributor-less ignition. If I had some money to spend I'd get the AEM EPM and get rid of the distributor altogether. Maybe in the spring...

Never seen anything like this in my life.

question for u suspendedhatch. i found out bout this dual solenoid 3 stage vtec like 2 years ago but have never came accross one nor dealt with one. my guess is that like it a 3 stage the cam must b way different from a regular sohc vtec. my question is , is this specifically just for fuel economy or does it also gives sum extra power? of coarse from you experience since u have the motor on your ride.

My friend had a dual solenoid motor once, dunno what kinda or anything just remember see 2 solenoids.... and it workeds pretty good till u blow it up

It's very similar to the D16Y8 except that power comes on sooner and stays on a slight bit longer. The intake manifold is the same as that on the Y8 and Y5 (has EGR). The oil pump is unfortunately the same as the OBD2 D series (a known problem). It's a more efficient head requiring less ignition timing advance than the D16Z6. It has more quench area so it's more resistant to knock. Also it has a "wideband" knock sensor and a CKF. It does not have the roller rockers of the D16Y5, and the VTEC and VTEC-E crossover points are not the same as the D16Y8 and D16Y5 respectively.

The 5 speed trans is more aggressive than the D16Y7's, but less aggressive than the D16Y8's (though I'm using a JDM D15B LSD trans with the same gearing as the Z6/Y8).

I have more specs here: http://causeforalarm.thecarthing.com/ve ... index.html and here http://www.gassavers.org/showthread.php?t=7011

The tuner said that it's the best torque curve he's seen from a stock D series. He shows off a copy a printout of my dyno graph to his SOHC customers. Part of it has to do with the fact that the non-US engines have more cam duration/overlap. More cam duration/overlap is great for NA power but bad for emissions.

The whp figures in my sig are pretty impressive considering it's essentially stock with bolt-ons. ebay CAI, DC header, 2.25 inch exhaust, AEM EMS. I've sorted some things out since the initial tune so there is no doubt I'm making a little bit more power. The weak stock distributor was causing a random misfire in the high RPM's. That's why I swapped to the AEM Twin Fire and CBR coil packs. One day I'll have to get it re-tuned and take it to the drag strip.