My friend just aquired a free 1989 Civic STD. We're wondering what gives the DX (D15B2?) engine 22 more hp. I know the STD has a close-coupled cat, but can that be it? Any cam or ECU differences? Don't bother recommending a swap, he's just looking for a bit more power out of a beater. Basically stuff to grab from a junkyard.

 

For some reason, I'm thinking the STD might be an 8 valve.

 

I'm having the same thought.

 

I know the HF was 8 valve so you might be confusing the STD with that. I've never seen any solid evidence to say that STD was 8 valve though.

The "Cylinder Head" pictures on hondaautomotiveparts.com have the same image for the STD and DX engine, so I don't think STD is 8 valve.

Also "Valve-Rocker Arm" both lists the needed amount of valves as 8 intake 8 exhaust for both engines. So once again I don't see it being 8 valve.

The cam shafts are different part numbers also, perhaps different cams.

 

Well, I just broke down and looked in my books. Chilton's lists the D15B1 STD engine as a 16v. Where the 22hp went I have no idea, but the cam and cat would sound reasonable.

 

I started comparing part numbers. The STD, DX and Si all use the same head. The cams and ECUs are all different. We grabbed a DX cam with the rockers, exhaust manifold and ECU from the yard.

 

OMG! Gasoline Fumes! whoa, long time no see?

 

I quickly skim over a few of the forums every day, I'm just not posting much.

 

We made an odd discovery. The "choke" in the throttle body doesn't open up as far on the STD as the DX (looking at my parents' DX Wagon). The STD "choke" hits a stop at around 45 degrees. :wtf:

 

"Choke" as in the throttle body butterfly plate? Weird.