Ive seen dynos of b18b and know that the head of a b20 is more restrictive since it isn't matched to the bore. Anybody have any clue on what gains could be achieved with a ported head on a b20? basic setup i/h/e/tp
Do you have a b20? If so, take it to the dyno and see for your self. Honestly every engine is different, just because some one else has a similar setup does not mean that you will produce the same numbers. There are too many variable to take into account. . . the tuner, engine management, the overall condition of the motor . . . etc. The list just goes on and on.
This question is pretty vague. The topic is misleading. Basically you want to know how much power(HP,WHP,TQ) you are gonna gain, with a B20 ported. Like Moe mentioned we honestly don't know because each car is different. Go over the engine building package write up in the articles>performance section by MD and you will see why. Plus you will understand what needs to be done. And how.
you make it sound like there is 1 port job for all heads.
you don't go to a headporter and hand him the head and say: "here, port it" and walk away.
you specify to him what your peak hp goal is and he ports it to size for that stated goal.
so the dynos that you see will reflect what the porter sized the head for.
we don't put threads like this 1 in the common topics for the hell of it to take up space.
it is to teach an idea for understanding.
I'm hoping that you can extrapolate the fact that it's not a b20 head in that thread and get over that.
it's the idea in that thread that you should get: namely that the flowbench shows you the peak hp potential before and after the port job.
This is why in the " I have a Teg. I want more power. Help me." thread, we tell you to know ahead of time and state out loud your peak hp goal...because you then have a clear goal to give the headporter (among other people) to aim for and size for precisely.
You don't walk into a suit shop and say, I want a tuxedo and leave it up to them to throw any tux size at you.
They measure you to a precise fit.
well it's the same idea for headporting. You don't walk into porting shop and say, I want a port job and stop there.
Sometimes I wonder if you people really know the reality of the situation.
this is stock b18b/b20 head on a b20 using crower 62404 cams (max lift 0.445 in. or 11.3 mm).
Sorry but I don't recall whether it was a b20z or b20b here.
the stock Giraffe IM which breathes like crap in the upper rpms (i.e. blunting the top end potential) was not used. A b18b Skunk2 IM was used here.
So most of the flow limit and hence peak hp potential is attributed to the unported stock b18b/b20 head and not the cam or the IM.
what you can glean from this is that with the higher lift
cam, the stock head unported breathes enough at least to meet 160-170 whp (this one topped out at 164).
Porting would do 2 things: it can be sized for a higher peak hp (as long as the porting size doesn't gut the midrange for part throttle lower cam lifts) and it can work on the powerband shape so that the tq doesn't take as much of a nosedive from 6400-7500 rpm.
they shape the port and valve angles to get a certain flow amount at each cam lift point.
Most of my B20 dynos are of B20VTEC's.
that's a clearer example to you of how a head that flows more for a higher peak hp goal can kick up the peak hp.
it's pretty consistent that the stock b18b/b20 head gives up at around 165-170 whp. you see in these 2 dynos that the range is pretty close : 161-164 whp.