BP Exhaust manifold...

Nomad_69er · Post by **Nomad_69er** » September 22nd, 2005, 11:30 am

I was wondering if the exhaust manifold off of the B6T (US spec) will fit onto the BP? I have the exhaust manifold and I know someone who is selling the engine for 150 bucks! So I thought I could put 2 and 2 together! Thanks for the help!

atlantamx3 · Post by **atlantamx3** » September 22nd, 2005, 12:24 pm

Mazda_Power · Post by **Mazda_Power** » September 26th, 2005, 1:13 am

Any reason in particular?

JWMotorsports · Post by **JWMotorsports** » September 26th, 2005, 9:48 am

The BP block and head are longer than the B6T's. That is how they raised the displacement from 1.6L on the B6T to 1.8L on the BP. They increased the size of the bore considerably and used a longer stroke on the crank shaft but used the same rods as the 1.6L B6T. The deck height and head height remain the same however. The ports on the BP are not only larger than the B6T but also, like the bore spacing, are spaced further apart w/ a different bolt pattern than the B6T.

Nomad_69er · Post by **Nomad_69er** » September 26th, 2005, 4:51 pm

thank you for the reasoning! I never realized that!!

Mazda_Power · Post by **Mazda_Power** » September 26th, 2005, 9:25 pm

... me neither, thanks X2.

JWMotorsports · Post by **JWMotorsports** » September 27th, 2005, 8:29 am

No problem, thats what the board is hear for.

D323 · Post by **D323** » September 27th, 2005, 2:52 pm

JWMotorsports wrote:The BP block and head are longer than the B6T's. That is how they raised the displacement from 1.6L on the B6T to 1.8L on the BP. They increased the size of the bore considerably and used a longer stroke on the crank shaft but used the same rods as the 1.6L B6T. The deck height and head height remain the same however. The ports on the BP are not only larger than the B6T but also, like the bore spacing, are spaced further apart w/ a different bolt pattern than the B6T.

something like 22mm longer if memory serves.

Oh and b6t rods are not like the BP ones. B6t rods are much beefier than the BP ones.

Order of strength would be:

BP/GTX < B6t < GTR

all of which are cast. (GTR's being squeeze cast, none of the rods listed above are forged despite what you will read/hear most places.)

JWMotorsports · Post by **JWMotorsports** » September 29th, 2005, 7:32 am

Only the early B6T's had the large rods. I think Mazda stoped using them around 89 in the B6T and no longer offer them new as replacement parts from what I've heard. The newer B6T's use the same rods as the BP with the exception of the BP-GTR engine which I believe used the early B6T beefy rods which are comparable in size to the 6-Bolt 4G63 DSM rods (which can hold around 450WHP). I've got 3 B6T engines for my drag car, one 88 323 j-Spec B6T, and 2 early 90's Capri B6T's. Only my 88 323 j-spec engine had the beefy rods. We have 2 BP motors for our sleeper car as well, both from early 90's Escort GT. Also I'm in the process of building up my brother's 92 Talon TSi (automatic w/ 6-bolt 4G63). I'll have t lay all 3 rods side by side and take some pics for you all so you can see the differences.