engine block compataibliity?
 

Will an NB 1.8 bock fit into an NA 1.8 head?

Thanks

yes.

welcome.

All the 1.8 heads are interchangeable with all the 1.8 blocks. Each have their own characteristics, but the will all physically bolt up.

94-97 1.8L was 9.0:1 compression
99-00 1.8L was 9.5:1 compression
01+ was 10:1compression
04-05 Mazdaspeed was 9.0:1 compression

All blocks are interchangeable. 94-97 can also run a 99-00 head. 01+ Have VVT on the heads, hard to make work on other years. Mazdaspeed Miata engine/head was almost identical to the 99-00 Miata.

Im running a 96 block in my 99. If you can, try to get a 99 head, its better then the 94-97 heads.

you are kind of doing it the other way around, like stated before, you should be looking to use NB head, but im sure you have your reasons
GL

aren't the oil feed ports in different locations too?

Pretty sure there is only one year of 1.8s that had a dedicated oil feed port. Otherwise the rest of the 1.8s have to use a sandwich plate or oil sender adapter.

If I am not mistaken, it was '94

Yeah but i think only the earliest of the 94s had it.

I am not really sure of this, since a friend of mine with an NA8 is burning oil. THought it may be good to replace the block only. Just so we came by an NB engine. Since the NA8 head had machine work to it port and polished, didn't want to let that wasted.

What's your susggestion? Replace the whole NB engine or keep the Moditify NA8 head with an NB block?

THanks you all again. :bigtu:

i would keet the whole NB engine as assembled, and take the NA motor and throw some internals in there in the mean time...and then just drop it back in
BTW-thats kind of what im doing, except both my motors are from NA's, one blew and i replaced it and i will be building it while having fun with newer motor

The NB head flows better then the NA head to begin with. Depending on what kind of headwork was completed you'll probably not see much in terms of loss.

Not to mention the 99 eliminates the HLA's, has better cams... and never ticks.


Has your friend confirmed the source of burning oil? There is more then jsut bad rings that can cause oil to burn. Bad PCV and valve seals are oil burners too. Do a compression check on the old motor. If he had headwork, then the valve seals have been messed with and could be the cause.

But if he would rather replace everything, just get some good internals for the NB block, then swap it in and sell the NA block and head to recover some cost. Assuming he kept the paperwork from the headwork, he could get some extra $$$ for it over a regular head.

Would a 1.8L 94' valve cover fit a 2002 1.8 engine?

I was under the impression that the 94 block had lower compression pistons than the 95-97 1.8l. Is this not true?