ryanevansoh

ok first to start off. just picked up this 90 hatch for my little bro last month for $400. he just turned 16 and we are making it his first car. has a little front end damage but thats it. the d15b1 has 116,000 miles on it as of now. we have now replaced te damaged parts and are starting to look for some power. i am looking into the mini me idea because we are on a small budget and he wants a bit of power. we will be replacing the b1 head with a perfect condition z6 head. i know what wiring and parts i need for the head swap, but my question is about the b1 bottom end. i have heard that rods are very weak and we need this motor to be very reliable. so should i get different rods? and if so, which rods would work? thanks guys, and here is the one crappy pic i have of it haha

Jarrat

Don't worry about the rods, the rods will hold up to twice the HP from stock.

The only thing you'd be in issues with, with running a Z6 head, is that you can't bolt up a dizzy to it without ghetto fabing it. Plus would you convert to obd1 and MPFI for vtec, or get a rpm switch for the vtec and stay with DPFI, or convert to MPFI and chip and run a 90-91 ecu. All are alot of work for 20 more hp IMO.

I'd just keep it as it, if there isn't any issues and when he's older and has a bit more experience, then maybe look into it brake upgrades, rims and tires, ect... plus who knows, he might smash it up in a couple months and then it would have all been a waste of time.

ryanevansoh

ok would i have to convert the car to obd1, or can i just get a jumper harness for the dizzy and ecu? i would be using a p28 ecu

ryanevansoh

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4drEF

Sounds like a good project!

To go OBD1 for this you will also be converting to MPFI. It's not that hard to do (just follow the directions properly.) I think this is a great idea if your little bro is out there doing most of the work with you - then he can learn what parts do and such.

Anyway, MPFI to get the 4 injectors working on the Z6 head, ODB1 to get the vtec and distributor of the Z6 working,

One thing - I don't think you need to do the resistor box for the MPFI since you will be most likely using the 5th gen injectors of the Z6 intake manifold.

Radim

iTrader: (4)

Don't worry about the rods unless you're boosting or going for high HP, i think the rods can hold up almost 200HP.
There are many different ways you can wire up the VTEC, of course one is converting to OBD1 but if you want to keep it simple/cheap while staying OBD-0
I'll give you a couple of options you can go with if you'd like.

1. Buy a used VAFC Field's/Spoon VTEC Controller
2. Be really cheap and buy an RPM activated switch.
3. Buy a PS9 ECU and run a 1-Wire VTEC these ECUs are rare and still OBD0.. (90-91 EX Sedan ECU)
3. Chip your PM6 and run a 1-wire vtec with that as well.

ryanevansoh

ok thanks for the info guys

SlammedSix821

Just a quick question about this swap.

Keeping the D15b1 block with a Vtec head and using an RPM switch to activate Vtec, are you still using the OEM Non-Vtec ECU? If so, how does the car react when Vtec engages without having the Vtec fuel/Timing maps that normaly engage with a Vtec ECU.

Thank you

YaheemED6

How much power will this swap produce

24TEN

iTrader: (2)

Impossible to say because there are many variables that apply. Also in the future you should avoid bumping up old threads.