I hear there is a 3 stage vtec engine made in Japan that was called D15B. It was basically a hybrid of our vtec-e (like in the D15Z1) and the vtec that is found in the D16Z6. Are these engines just the Japanese D15Z1?

the 3.stage resembles more the usdm d16y8/y5 motors
it doesn't have the small intake and head chambers or deep dish pistons.
it also doesn't get the same gas mileage as the d15z1
and it has a much higher total output power
there are very few similarities...
actually i think there is only one identical part used on the whole motor.
the p07 rods

What kind of mpg differences would you see in one of the JDM motors as opposed to a D15Z1?

If I'm understanding correctly... they have lean burn at lower/cruising RPMs, vtec for top-end power, but the lean burn mode isn't as efficient as a D15Z1. Sounds like an interesting compromise, if the losses in mpg aren't too great.

Can some parts be swapped from the 'Z1 to make it more VX-like?

Ok, 3rd question. Is the D15Z1 also available as a low-mileage import?

The d15z1 is called a d15b in japan (which is the same name as the normal vtec model as well) but the vtec-e model is the same as our d15z1.

I've never dropped a motor in myself. Can anyone give me a ball park number to how much it would cost me to have a mechanic install it.

Hey I would love to get my hands on one, I live in Long Beach and just moved from San Diego. How much for an a D15z1 (is that what it is or is the 3 stage vtec, I only want the regular vtec-E D15z1)? What comes with? flywheel, ecu, tranny, A/C??? anything I could buy extra?

https://www.nippon-motors.com/honda.htm your in luck! they deliver FREE to socal from what I know this is a very reputable site.

Guys beware!! If your from the USA don't even bother buying this motor from Canada. I friend of mine bought a Supra 2JZ Twin Turbo motor from them on eBay and it turns out when he got the motor it was bad. He called them and told them they sent him a bad motor and they said too bad. He tried filing a dispute for the charge with his credit card but lost the dispute since they are from Canada.

So buyers if your buying from this vendor beware.

I bought one of the D15B engine/manual trans from JDMSource, and have been very happy with it.

Some side notes:
1. DOES NOT get same FE as the D15z1...I get 40-45mpg if I'm careful.
2. Rated @130HP, 7K redline, great fun when the VTEC kicks in!
3. I replaced my ECU with the PO8.
4. Need to replace the 5wire O2 sensor with a 4wire...haven't got to it yet.
5. All the sensor wires were cut on the engine I received. Would be nice if they'd unplugged them and left the harness intact.

40-45 is still pretty good, with a cx or vx trans i wouldnt be suprised if you saw closer to 50