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NA8 and NB8A Engine Question
Posted: Sat Apr 25, 2015 11:17 am
by forcedfive
Hi All,
Can anyone confirm if the block and crank from teh Na8 engine are the same as the nb8a block and crank?
Would anyone happen to have a NB8A crank lying around that they would like to sell?
Cheers
Re: NA8 and NB8A Engine Question
Posted: Sat Apr 25, 2015 12:52 pm
by 93_Clubman
Re: NA8 and NB8A Engine Question
Posted: Thu Apr 30, 2015 2:25 pm
by forcedfive
Thanks for the link. Not 100% sure from the info though that i am able to interchange a 1.8 NA short motore with the NB8A, Can anoyone confirm from personal experience.
Re: NA8 and NB8A Engine Question
Posted: Thu Apr 30, 2015 4:46 pm
by slug_dub
Pretty sure you can but you'll be dropping .5 compression ratio... NA B: is 9.0:1 and NB8A is 9.5:1 I thought?
Re: NA8 and NB8A Engine Question
Posted: Thu Apr 30, 2015 5:29 pm
by forcedfive
Thanks Slug. Compression is fortunately not a concern for my needs.
Re: NA8 and NB8A Engine Question
Posted: Thu Apr 30, 2015 5:48 pm
by manga_blue
I dropped an NB8B crank and rods straight into my NA8 block after a longnose failure on the original crank. I had them side by side and measured them up - they were identical. I couldn't imagine the NB8A crank being any different.
Re: NA8 and NB8A Engine Question
Posted: Thu Apr 30, 2015 5:55 pm
by manga_blue
Mazda crank part numbers:
NA8: BP06-11-300C
NB8A: BP06-11-300C up to 0522
NB8A: BP06-11-300D after 0522
NB8B: BP06-11-300D
Re: NA8 and NB8A Engine Question
Posted: Thu Apr 30, 2015 6:55 pm
by forcedfive
Thanks Magna Blue
I have heard there are issues with the NA8 cranks and your expeience seems to support that. Any else know of issues with NA8 cranks?
Re: NA8 and NB8A Engine Question
Posted: Thu Apr 30, 2015 10:49 pm
by manga_blue
It doesn't support that. My experience is that some dodgy mechanic put a crank pulley on badly during a timing belt change job. The crank nose started to fail after that, just as it could with any BP nose. I've never heard of anything inherently wrong with any of the cranks other than that.