Hey I’ve been looking for this answer for weeks but can’t find anything on it. I have a jdm d15b with a head that says p2j but it has a dual solenoid vtec system. I’ve heard that the 3 stage vtec system head is just a y8 head with a 3stage dual solenoid vtec system put on it. The head codes match so that would make sense but my question is if it’s a y8 head is it possible to put a single solenoid vtec on the y8 head since that’s how they originally are? It’s obd2 right now so swapping it electrically wouldn’t be a problem I was just not sure if everything would match up or cause any problems with idling or anything like that. Please help cause I’m confused on this. I’ve included pics so you can understand more about what I’m talking about. I just want the single stage vtec as I’ve heard it’s more aggressive and it’s better for performance wise then the 3stage. Thanks and have a great day!

 

If it would work since it’s the same head casting between the d15z7 and y8 head would I just need to swap the solenoid or also the cam and rocker set for it to work? Just confused on the whole thing.

 

Turn the two solenoids over and compare the BACK side... also, compare the passageways in the cylinder heads. If all looks the same, I would say run the Y8 solenoid. I have never made this comparison (I wouldn't put a three-stage VTEC engine on my scooter), so I cannot tell you for sure whether the castings are the same or different regardless of the fact that both are P2J castings... my suspicion is that in fact they are different because there must be separate passages for the different stages of operation whereas the Y8 would only need a single oil passage for VTEC operation.