MazdaEngines

89-91 BG 1.8 - 140hp

91-94 BG 1.8 - 126hp

94-98 BA 1.8 - 118 hp

:D

Cheers Andy

Do you know something about the comp ratio in these engines?

ph3n1x wrote:Do you know something about the comp ratio in these engines?

hi guys im a new member lookin for some help!!!!
first thing im from barbados!!!!!
and im lookin for the work shop manaul for the bp 18 N/A
have to get a wirin diagram asap!!
my email address is shaneworrell@hotmail.com

ph3n1x wrote:Do you know something about the comp ratio in these engines?

I've heard it's really low, like about 8.6:1. Hence the massive reliability ...

now I can safely say that the 94 -96 bp has a original compretion ratio of 8.8-1, and the 96 - 98 has a cr of 9.0-1

not too sure on this, but to what i believe.
The 140 hp strong BP (89 - 91) should have more agressive camshafts and a "better" mapping from stock. I however don't know if they also had more cr than 9.0-1. (in Belgium this is know as the GRSi edetion.)

the 126 hp version has 9.0 cr and some more agressive camshafts, but not as agressive as the "GRSi"
With any luck Barelyhuman (Matt) can sort this out even better.