The mini-me project. Head swap

[mynameisowen]

wow nick keep us posted mate

[Dodo Bizar]

Very nice Nick! I believe in the UK a company is providing those harnasses btw, but it was for really high prices. Have to look it up, somewere in my hotmail...

[BETEK]

It is possible to swap a head from d16a9 (zc) into d14a3.

[hondaNickx]

It is possible to swap a head from d16a9 (zc) into d14a3.

Yes But ... too much sealing issues and not worth it .The head of the D16a9 has actually bad intake ports.

[antc_uk]

So, if I was to swap a Y8 head onto the D14A4 and get the Y8 Cam reground by Bisi would I need a Z6 Dizzy to make it work with OBD1 - so I would need to change my rocker arm assembly too?

OR.... could I use the Y8 Dizzy?


In my mind at present the Y8 head would be the best option for the D14 given the greater resulting CR and the smaller ports for faster flow as opposed to the Z6 head optimised for greater flow for high lift cams that are most effective in the D16 motors (please correct me if this is crap!)

Failing this how effective would a milled Z6 head be?

[ilya]

I think, "why is everyone so looking connectors OBD1 (2)"? Why not just unsolder from the ECU connectors and do not put any? which is at hand, any car. why should we look for. I think that there are people with straight arms, a clever head and knowing how to work with tools.
TNX for Mini-ME

[Dodo Bizar]

I think error searching is at hand. Especially when I first started out I wanted to be able to re-trace all my doings and un-doings. Just unsoldering everything would have blocked any options of returning to stock. Not that I ever went back to stock, but just in case.

[Law_]

So, if I was to swap a Y8 head onto the D14A4 and get the Y8 Cam reground by Bisi would I need a Z6 Dizzy to make it work with OBD1 - so I would need to change my rocker arm assembly too?

OR.... could I use the Y8 Dizzy?


In my mind at present the Y8 head would be the best option for the D14 given the greater resulting CR and the smaller ports for faster flow as opposed to the Z6 head optimised for greater flow for high lift cams that are most effective in the D16 motors (please correct me if this is crap!)

Failing this how effective would a milled Z6 head be?

you can use Y8 dizzy with y8 head.

[novaksaotome]

this might sound crazy, but i've read the mini -me topics and Joris doesnt mention anything about wiring the vtec solenoid and stuff, forgot maybe, but i dont think it actually works if you don't send any signal to it... let me know if i'm wrong!

[Dodo Bizar]

You are wrong . I re-read all my articles and indeed I forgot to mention it. Thanks for pointing this out, I'll correct it in the coming weeks. I only touch on the subject in the OBD1 pinout article.

But here is the deal:

When no power is supplied to the VTEC solenoid the valve is closed, no oil is passed through the VTEC drums inside the rocker arms and no VTEC is engaged. Meaning the rockers are running on its lower non-VTEC lobes.

Now by connecting the VTS pin from the ECU to the 1-wire connector the ECU can send power to the VTEC solenoid. So to engage VTEC around 4 to 6k rpm depending on your configuration. This is required to have VTEC work. What it does is sent oil to the for mentioned drums, interlocking all rockerarms (so the lost motion arms are locked) and forces the rockers to move with the higher VTEC lobe.

There is a secondary thing going on. On some VTEC solenoids there is a oil pressure sensor as well. This will have a 2-wire connector, green. Those two wires are VTM (or VTPS) on the ECU and a ground signal originating from SG2 if you want to do it properly.

Now there are 4 options:
1: Your solenoid has the pressure switch, the ECU expects a pressure switch. Normal for most OBD1 cars, just connect as above.

2: Your solenoid has no pressure switch, the ECU does not expect it. Normal for most OBD2 cars, no connections possible or needed.

3: Hybrid setup: your solenoid has de pressure switch, but the ECU does not expect it. No connections possible, leave the pressure switch unconnected.

4: Hybrid setup which is very common: your solenoid has no pressure switch, but the ECU expects it! Happens when you have D16Y8 head combined with P28 ECU as in my setup. In this case we can't connect the pressure switch since it is not there. To fool the ECU you connect a split from the properly connected VTS signal towards the VTM (or VTPS) on the ECU. This setup only once triggered an error code in my case, but is 99.9% failsafe. Right after engagement the ECU puts 12V on VTS. then it starts measuring for the oil pressure signal... hey what do you know, it sees 12V! So it is ok it thinks. There is a nicer solution: which is switching of the VTEC pressure switch error code in the ECU which most ECU software is able to do.

I'll append my articles with this soon, thanks for noting!