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how to tell if it's a 1.8?
Posted: Sun Apr 05, 2009 2:17 pm
by SKYHI
Hey Guys,
Never having seen a 1.6 engine, is there an easy way to tell the difference between the 1.6 and 1.8?
Thanks, Paul.
how to tell if it's a 1.8?
Posted: Sun Apr 05, 2009 2:44 pm
by StanTheMan
The cam cover is a little different. On the pic below you can see Mazda & twin cam. recesses into the Cam cover.
1.8's are the other direction. rather raised instead of recessed. Clear as mud?

Also to the right you will see the Grey thingy. Just after ( or just before) the Mania CAI. This is the 1.6 AFM. The BP one is black & a lot smaller.
If you are only looknig at the engine only. At the back of the head or somewhere you will see big B6 or BP letters.
how to tell if it's a 1.8?
Posted: Sun Apr 05, 2009 2:55 pm
by SuperMazdaKart
1.6 left, 1.8 right

CAS on the intake cam for 1.6, CAS on exhaust cam for 1.8,
1.6 has the vane type AFM, 1.8 has an MAF,
1.6 cam cover has recessed writing, 1.8 doesn't,
1.6 engine number will start with a B6 & 1.8 starts with a BP
how to tell if it's a 1.8?
Posted: Mon Apr 06, 2009 8:51 pm
by mr_rotary
1.6 has coils on the right with a shroud.
1.8 has coils on the left
Opposite to the CAS

how to tell if it's a 1.8?
Posted: Thu Apr 09, 2009 12:14 pm
by whoa_dang_96
not all 1.6 have the coil and CAS in the config shown - maybe the 90-92 model could be this specific
you can get a 1.6 with raised writing on the rocker cover (or a rocker cover off a different model Mazda does fit), CAS on the exhaust CAM etc you just need to look at the "market" that the mx5 was was sold in and the engine cofigurations available.
I have seen it before .... and yes you can get 1.6 BP's
how to tell if it's a 1.8?
Posted: Thu Apr 09, 2009 6:45 pm
by mx52nv
whoa_dang_96 wrote:not all 1.6 have the coil and CAS in the config shown - maybe the 90-92 model could be this specific
you can get a 1.6 with raised writing on the rocker cover (or a rocker cover off a different model Mazda does fit), CAS on the exhaust CAM etc you just need to look at the "market" that the mx5 was was sold in and the engine cofigurations available.
I have seen it before .... and yes you can get 1.6 BP's
Hmmm I have never seen a MX5 B6 1.6 with the CAS on the exhaust side or a '1.6' BP before??? After all, BP is the designated name for the 1.8 engine from Mazda that powered all the Familias/Astinas/MX5s.
I have seen a NB8 with a B6 though, as sold in Singapore and a few other markets. But definitely not a '1.6' BP.

how to tell if it's a 1.8?
Posted: Thu Apr 09, 2009 10:02 pm
by project.r.racing
just look on the block, it'll either have B6 or BP on it...
or look at the engine number, 1.6s start with B6, 1.8s start with BP...