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B6T or BPT

Posted: May 5th, 2010, 9:03 pm
by xapruda
Asking mazda guys opinion, which of there engines more reliable/ give more overall hp, b6t or bpt

Posted: May 5th, 2010, 11:41 pm
by MAZTUNE
gosh ahhh I going to like explaining this one :D :D :

1.6 B6T - Came in the 86-89 BFMR(4WD) or BFMP(FWD) 323/Familia. the 86-87 B660 first model came with 145HP with low impedence injectors, a smaller IHI VJ6 (7psi stock) turbo, a larger intake manifold, and a weaker fifth gear in the box. The 88-89 B677 facelift model came with 270cc high impedence injectors, a smaller intake manifold, larger IHI-VJ13(9psi stock) turbo, more efficient exhaust manifold giving out 165HP. Only the GT-Ae rally model came with a bigger IHI-VJ17 and the Infinity model came LSD.

Now both engines internally are the same, but what's nice about the B6T is the stiffened block, oil cooled 7.6 pistons, water cooled oil cooler and most importantly BEEFY connecting rods. This engine will pull a BF 323/ Ford laser nicely, but put it in a heavier BJ or BH and it will suffer. Oh another point to consider, its hard to upgrade, you cannot run any sort of fuel management on the stock airflow because it reads 5V to 0V not the other way around. If you want to seriously modify this engine I suggest an aftermarket ECU if you can find it or go full management like a Microtech LT8.

1.8 BPT, came in the BP26 90-94 BG GTX runs 185HP, comes with a bigger IHI-VJ20 turbo (9psi) and only comes 4WD. if you want it to work FWD you have to mate it to various 323 gearboxes any B series will work, as well as BJ ZL-ZM. It also comes with oil cooled pistons, a water cooled oil cooler, but with an additional aluminium sump. The difference is the GTX model BPT has weak NA connecting rods which will break after 300HP. the injectors are 310cc high. It will pull a BH or BJ easily and also is an easier fit. The BPT responds to upgrades like Apexi SAFC, Greddy E-manage. I have the wiring somewhere here...hmm...

Now the ultimate is to get your hands on the 210HP BPD GT-R spec engine, but its gold. This engine comes with a massive IHI-VJ23 turbo sadly running 7psi stock you have to "wake it up" LOL it comes with a better 8.2 cast pistons, more efficient intake and exhaust manifolds, 330cc low injectors, sodium filled valves, some neat mild cams and serpentine belts all round. oh and the rods are BEEFY like B6T. hmm you can take B6T rods and put them in GTX BPT that's the solve right there.

OK one major problem with the two engines, keyway failure, this means, the key in the crank pulley breaks with added torque so the crankshaft is spinning but your pulley is not. the solve for this is to take the crank from either a B6-DE or BP-ZE from a 95 323F BH and put it in, these cranks have no key to break. (mazda solve the prob)


Soooo.....here is the summary, the B6T is more reliable but harder to modify, the BPT is weaker but it can be modified easily but you have to go inside.

Hope I have helped a little. Oh if you want a B6T i can get one now , PM me nah. :D

Posted: May 6th, 2010, 6:55 am
by ζђίΰД™
Both the b6t & bpt are very reliable.

Which model 323 are you planning to put either engine into?

Re: B6T or BPT

Posted: May 28th, 2010, 9:10 pm
by chip's auto
gearbox is d problem!!

Re: B6T or BPT

Posted: May 28th, 2010, 11:10 pm
by MAZTUNE
chip's auto wrote:gearbox is d problem!!


well we kind of got around that problem by using Redline 75W90/75W90NS gearoil. Mazda gearboxes have brass bearings, also brass parts in the shifter mechanism which actually breaks down with a sulfer based gearoil. Redline is not as sulfer based as it's fully synthetic. The brass bearings break down and shatter, usually causing the gears to go out of alignment, usually 3rd gear is the first to go. Also in the 4WD gearboxes, we use a street and strip clutch with a heavy pressureplate, so the shock does not hit the transfercase directly, but the clutch just slips slightly taking off some of the load. I supposed to have an official document with Mazda and Redline working together to fight gearbox problems in rally. I will look for it and put it up.

oh one other thing, we change gearoil every 6000km. So far the gearboxes holding out pretty well.

Re: B6T or BPT

Posted: June 8th, 2010, 7:12 pm
by chip's auto
cool maztune!! i using mobile1 is dat any good?

Re: B6T or BPT

Posted: June 9th, 2010, 11:04 am
by MAZTUNE
i'm not sure, check the content and the body of the oil

Re: B6T or BPT

Posted: June 10th, 2010, 12:07 am
by sean364
maztune ,
i want to know, the internals from a b6t , can they work in a b6d block.

Re: B6T or BPT

Posted: June 10th, 2010, 7:45 am
by MAZTUNE
sean364 wrote:maztune ,
i want to know, the internals from a B6t , can they work in a B6d block.


as far as I know it should, and surprisingly the B6D actually has a stronger crank (remember the keyway problem in the older model B6. )

Re: B6T or BPT

Posted: June 10th, 2010, 4:17 pm
by sean364
kool,
1. what is the max HP can you get on a stock B6t
2. which block is stronger the B6t or the B6D

Re: B6T or BPT

Posted: June 12th, 2010, 4:30 pm
by MAZTUNE
the B6T block is supposed to be stronger with better oil passages. I have heard of ppl running 400HP on a internally stock B6T with just external mods in Aus.

Re: B6T or BPT

Posted: June 12th, 2010, 11:28 pm
by sean364
u have any b6t or bpt engines for sale?

Re: B6T or BPT

Posted: June 13th, 2010, 12:55 pm
by MAZTUNE
one of my customers from Tobago is selling his B6T that he bought from me a few years ago. PM me for the guy's number.

Re: B6T or BPT

Posted: June 15th, 2010, 6:51 pm
by nareshseep
MAZTUNE wrote:the B6T block is supposed to be stronger with better oil passages. I have heard of ppl running 400HP on a internally stock B6T with just external mods in Aus.


hmm very interesting a 1.6 block with 400 horses

Re: B6T or BPT

Posted: July 2nd, 2010, 11:16 pm
by trinibuggy
I have a bredrin he need a bpt to put into his 96 lantis(323f)can anyone give me a price!!Pm me and let me know cuz he have a sr too too and regretting it!!

Re: B6T or BPT

Posted: July 2nd, 2010, 11:17 pm
by trinibuggy
or a Klze would be nice if available

Re: B6T or BPT

Posted: July 3rd, 2010, 8:37 am
by xtech
nareshseep wrote:
MAZTUNE wrote:the B6T block is supposed to be stronger with better oil passages. I have heard of ppl running 400HP on a internally stock B6T with just external mods in Aus.


hmm very interesting a 1.6 block with 400 horses



You find that hard to believe?
Toyota turbo 4E 1.3 an 5E 1.5 does make about the same with forged internals

Re: B6T or BPT

Posted: July 4th, 2010, 2:20 am
by nareshseep
I didnt say it was hard to believe, it just that damn impressive!
I always like a good 1.6, with a turbo, its not to big not to small jus right.

Re: B6T or BPT

Posted: August 9th, 2011, 8:29 pm
by MAZTUNE
searching on google and came across this post yes lol

Re: B6T or BPT

Posted: September 5th, 2011, 11:53 pm
by justwhatuseeing
what would u guys recommend for a 626 glx fwd drive model

Re: B6T or BPT

Posted: October 5th, 2011, 9:16 pm
by sldwyz
justwhatuseeing wrote:what would u guys recommend for a 626 glx fwd drive model


ild be slaping a f2t into it mate