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why is a 99 model head better than others....?

Posted: Tue Sep 19, 2006 10:50 am
by marky210
Ive been hearing and reading alot that the Head off a 99 model mx5 seams to be really good and i was just wondering what makes it so good compared to the other models :?:

Mark :D

Posted: Tue Sep 19, 2006 10:52 am
by StanTheMan
not nececarily better. But had no niggling issues. one of the few rock solid models.

Posted: Tue Sep 19, 2006 10:56 am
by Garry
The NB head flows better than the NA8 head and the 98/99 doesn't need to worry about VVT hardware so it would be easier to retrofit to an NA. Thats my guess.

Posted: Tue Sep 19, 2006 11:02 am
by marky210
Awsome :D

Thanks for that Stan the man
and thanks Garry :D

Just want to learn as much as i can about these awsome cars :P


Mark 8)

Posted: Tue Sep 19, 2006 12:02 pm
by Matty
Apart from the better head flow (which is the main reason it's better than the NA8 head), the NB uses solid lifters (so the cam profile can be more aggressive and rev higher), and the intake has dual runners for better high and low speed power.

more here: http://members.aol.com/solomiata/MX5Engine.html

Posted: Tue Sep 19, 2006 2:30 pm
by CT
Definitely the most important aspect is that the 98+ head has a different angle on the inlet tract which flows better than the earlier head. It has solid lifters as a bonus. The manifolds do not matchup. Exhaust however is mildly different but the bolt pattern is the same.

Posted: Tue Sep 19, 2006 9:23 pm
by sirbob
Does that mean an NB set of extractors will not fit an NA??

Re:

Posted: Fri Sep 22, 2006 9:15 pm
by irwin83r
sirbob wrote:Does that mean an NB set of extractors will not fit an NA??


pretty sure they still will. just where it meets the CAT will be different, still use the same manifold patterns im pretty sure.

Posted: Sun Sep 24, 2006 10:45 am
by Garry
Do they? I thought the ports were slightly different. Maybe I'm getting confused with the intake.