How many versions of the 13B are there and how do they differ? (RE/T/BRE/BREW) Thanks

Don't forget the '74-'75, '76-'78, and '84-'85 US spec 13Bs. There were some JDM-only engines. They have three little aluminum out-croppings around the spark plugs, or a full shroud like FB 12A rotor housings do.

i'm actually working on that, ive got 9 different ones right now, and i have 74-83 all lumped in together



mike

What is the difference between them? (or are you working on it j9fd3s?)

well basically as time goes on the rotors get lighter, the ports get small and then bigger, they add turbos etc. i have a basic spreadsheet right now i can post if you want



mike

please do!

ok the abbrivations are

nm = newton meters its metric torque



i used the mazda # for each engine so thats the far left #

nf01 = 20b

n3a1 = fd

n390 = 13b cosmo

n370 = 89-91 t2

n318 = 86-88 t2

n350 = 89-91 na

n326 = 86-88 na

n304 = 83-85 13b 6 port

1757 = 74-82 carby 4 port



hmm it wont let me upload the spread sheet

mike

post it in your album then link it here

I know a little about the older styles. '74-'75 had different housings which were sort of a go-between from '71-'73 to the later style and say 13B up near the threaded things that stick up for emissions devices/rat's nests. '76 had more modern housings which resemble pretty much any later housings untill the GSL-SE. Then there are the later ones from possibly '78-'82 with carbs that have either three bits of aluminum, or a complete shroud which requires a thin walled socket or NGK BR8EQ-14 plugs. These also have a single tube in the exhaust ports that can be cut away fairly easily when porting. https://www.nopistons.com/forums/pub...IR#>/smile.png ('74-'76 are a little more involved when porting)

ya, i'm still looking for info on some things. like hp ratings between a 74 13b and a 76. the port timing IS different, but i dont know if they have a hp rating difference?



mike