I have a '99 Miata automatic trans. I bought it not running and it needs a head. Im having trouble finding a head and cams. Can I use a protege head? If so, what years? what mods if any are needed to make this work? Also what performance will be lost? I just want to get the car running for the wife, so just want reliability. Thanks, Rob
You can put a BP4W head on a 94-97 BPZE block, so the head/blocks of the two motors are PHYSICALLY compatible. I would assume that using a non-99 head would throw the ECU into a fit, so you'd need an aftermarket ECU. At that point you could've just bought a BP4W head for less money. Look for them up for sale on craigslist (guamlist?)and from forum sponsors.
it will work but you will lose a lot of performance. talk to the guys at project G they can hook u up for around $450-500 for a used BP4W head. i bought one from them its nearly flawless
You wouldn't loose much performance. The 99 motor doesn't make much more power than a 97. Any 1.8 head mechanically fits on any 1.8 block. With a non-99 head, you'll need a NA ECU to control it properly. IDK if an NA ECU is plug and play with the 99 harness, sensors, etc. My guess would be, no, so you would probably need an aftermarket ECU, which means you'd need to tune it. Check the miata.net/miataturbo.net classifieds.
Again, using a non-BP4W head will probably be more trouble and money.
I emailed an they dont have any, as well as a handful of other places. I didnt realize how hard it is to find that particular head. Just bought the car and now I may just sell if I cant get it the parts to get it running.
The guy on ebay said he has one but his feedback doesnt look too good, just dont want to get another bad head. Thanks though and the search continues....
By the time you bought all the parts needed to make this work, you could have paid for the bp4w head. The intake manifold, modify a fwd valve cover for rwd orientation, throttle body, VICS delete, egr differences, cross over tube, throttle cable, loss of power, etc would make the downgrade probably as expensive as finding another bp4w head with zero benefit.
Guess I will keep searching. I wonder why that head is so hard to find? The demand seems to be there. No auto parts stores sell them? Nopi.com has it listed but when I called they said its not available.
It's not a part that is produced and sold separately. If anyone has one it was taken off a wreck. I suppose one could buy a crate engine, but those are atleast $4,000.
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