This may be something youve all cover many times but im helping a buddy of mine. He has a 99 NB with a blown motor and he also has a complete 95 bp05 . I've read up on putting the bp4w head on bp05s but it seems they are all in 94-97 miatas. So my question is can we put the bp05 block with the bp4w head into his 99 ? I know it will drop in compression and need a knock sensor. But will it work and is it worth it?

Thanks

 

You will need the intake manifold from the 95 as well because they are different.

 

oh ok cool, thanks. i wasnt sure if the bolt pattern for the intake manifold and exhaust manifold were the same as the 99 bp4w or not. will i still be using the harness and ecu for the 99 since ill be using the head off 99 and the block from a 94-97?

 

The exhaust manifold is the same. I think there are some minor differences in the harness configurations for the bottom end, but I'm not sure. I know they were minor. The NB has a smaller and lighter weight starter if you are able to get it, too. Saving a few lbs in our cars makes a difference in ways it doesn't in larger cars.

 

If he's using a 99-00 BP4W head on a 94-97 block in a 99 body he needs either the 99-00 intake (preferable) or the 01+ intake. They'll both work. The 99-00 exhaust manifold will bolt up. He'll also need to swap the front crank pulley. He'll also need to use the 99-00 AC/PS/Alt.