in other words..will a b16 and d16 both spool the same turbo the same??at the same time?if not, why not??explain??and if not how much slower will sohc 1.6 spool the same turbo over the dohc 1.6?

 

The heads dont flow anywhere near the same. The b16a will outflow most production heads on 95% of the cars on the market. The d16 head isnt a crappy design, but it doesnt have the capacity to flow as well. Having said that the d16z6 and d16y8 heads have different flow rates. The d16z6 is a better flowing head, due to the intake port shapes. The d16y8 will flow more on the low end, and mid range but die up top. Conversly, the d16z6 doesnt flow much on the low and mid range, but it flows up top very well in comparision. If you are trying to make super high HP levels, the d16z6 is the way to go between the two heads.

Also, the d16 and b16 are essentially different because of the lower redline of the d16. If you move the d16 redline up to 8,000rpm you can move alot more air and run a larger exhaust housing.

A few basic things to open up the d16 head are:

1. Port and polish, deshrouding combustion chamber.
2. Oversized valves.
3. Turbo cam.
4. Optimized intake manifold.
5. B-series throttle body.

All of those things will help the head breath tremendously. With a fully built d16 head will flow close to what a stock untouched b16a head will. Therefore after much modification the d16 can essentially support the same size turbo.

 

yeah there's quite a few differences between the D series and B series 1.6L motors/heads.

just by looking at the port sizes when stock will tell you alot. from the factory the D16Z6 head looks like a piece of crap compared to the B16A head. not to say that the D16 is worthless, just that it needs some work to really be a powerful motor. DOHC B16A head flows much more air than the D16, stock to stock like said above. the D16's can scream up top though and make decent power between 5-7,500 rpm. or higher rpm if the valvetrain is modified and designed to make more high end power. depends on the setup altogether.

 

can i bolt a B series throttle body right onto my ex intake manifold???????? if so which is the best??ITR? will it require any modification plugwise??

 

yes it should bolt right up. i eyed the D and B series TB's up before and the bolt holes and passages all seemed to line up perfectly. so bolting on a 60mm GSR/SI or 62mm ITR TB would be a nice increase over the stock D16 TB. BTW i have a couple extra 60mm B series TB's that i might get rid of if you don't have one yet.

 

I love how people keep saying the B16 flows so much better than a D16 with out showing any flow rates. I have seen charts the B16 does flow better than a Y8. But the Z6 is nice and close to a B16 flow, still not as good though.

 

... a little off topic... but will i still be able to have power steering and air conditioning with a boosted 89 crx with a b16?... if not, how about a d16?...

 

um people say the b16 flows more because...IT DOES!
thats nothing new.. dohc ,4 vlaves per cylinder....

 

What about the ZC....?

Where does it stand up in the D series crowd?

 

Its going to breath a little better due to the dual cams. I havent ever seen a ZC head in person, so I cannot comment on the head's construction.

I am considering using a VX head with the roller rockers, and having a custom cam made. This would be the ultimate head from the factory for the d-series.

 

i personally have not seen the internals of a ZC, but from what i hear the motor is really good for it's time period and makes decent power overall. the ZC is a popular swap for 88-91 Civics and CRX's, and i guess it does a good job of creating power for relatively low cost.

the head ports of the B16A compared to the D16Z6 are still very different in size.
yes the D16Z6 head can flow very well, but the stock ports are little sheist holes compared to a stock B series VTEC head ports like the B16A. and the fact of the twin cams also plays a part.

 

yet another person spouting off more "facts" with no flow charts to prove it. show some proof please. if you would read my post I did agree that the b16 flows better. It flows way better than a y8, but the z6 is near in comparison.

 

It just makes sense that the b16 flows more. It has to if it's making more power. We have no charts to show that the world's strongest man will win an arm wrestling contest with me, but it's pretty safe to make the assumption.


Another thing that will affect turbo spool is the compression. The higher the compression the faster the spool.

Basically, the more power a motor is making the more exhaust it will spit out to spool the turbo. Look at the torque/ horsepower curves of both motors to compare how much exhaust there is to run the turbo.


[Modified by Lsos, 4:10 PM 3/29/2003]

 

The head HAS to flow better because the motor stock makes 30 more hp? That assumption is wrong. Both heads from stock flow enough to support WAY more horsepower over stock. That's like saying my head would HAVE to flow better somehow to support the extra power from my nitrous. More flow CREATES more horsepower, but isn't NEEDED to support more horsepower (until that heads limits are surpassed).


[Modified by RyanCivic2000, 4:36 PM 3/29/2003]

 

well then, could YOU please provide charts showing how these heads compare in flow since nobody else is and there just spoutin shittalk??

 

Ahhhhhh, all this D-series talk............I love it!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

boosted hybrid ~
... can you explain?... why would you choose the vx head over the z6?... thanks...

sweet ~
do you (or anyone else) know if turbopanda's rod/piston combo will work in a zc?...

any/everyone else (bryson?), feel free to chime in if you can help... thank...


[Modified by 1.8T_EG, 6:00 PM 3/29/2003]

 

Have you ever looked at the ports on a 2JZ Supra head? The exhaust ports are very small, just about the same size as a stock D-series head. Supra heads flow very well. Port size isn't everything...velocity was a major factor in the design of the 2JZ head.

Let's see some flow charts between a B16 and a D16...

 

I know what you're saying and I did consider that. Nevertheless, I think it's a pretty safe assumption that given two heads from the same manufacturer for the same sized engine, the one from the 60% more powerful engine can flow more air. It's not guaranteed, but it would be stupid of Honda to do it otherwise, especially considering that half the time flowing more air means less low end torque.

 

The vx and hx heads have roller rockers from the factory. This improves frictional losses, as well as letting you run extreme amounts of lift on the cam. This inturn will make more power, and let you rev the engine up higher; quicker and safer than the conventional bearing surfaces of honda heads. The vx and hx are vtec heads, they are vtec economy versions but the vtec solenoids are the exact same as what is found on any/all vtec heads from honda. Just get a performance oriented cam made (contacting ef1.com for a regrind), and have a p28 control the vtec solenoid through hondata and you have one bad-*** head. Aftermarket roller rocker design run 1000-2000.00 to convert over for the honda heads.

I have to take a look at the overall design of the head, but I think that would flow very well.


[Modified by boosted hybrid, 9:01 PM 3/29/2003]

 

i'm not sure about turbopanda's rod/piston combo working in a ZC, since i don't even know the ZC specs off hand. i believe that combo is popular for the D16Z6 from what i've heard.

 

no i have not seen the ports up close on a 2JZ Supra head so i don't know how they compare to the D16Z6 head ports. what you stated about the velocity and port size is very true. the D16 and B16 have quite a few differences in design:
bore size, stroke length, R/S ratio, port sizes, DOHC vs. SOHC, CC and valve size, cam profiles, C/R, rpm limits from the factory etc etc.

the smaller size port of the D16 compared to the B16 doesn't mean that it's extremely weak, it just means that the design combonation is different. we can see how the velocity via the ports and the torque curves are possibly linked together on the D16 motor. i've seen and heard of boosted D16's making impressive amounts of TQ, even more than the B16, or the D16 making the TQ sooner than the B16 which can be linked to the different R/S ratio and the port velocity. as was mentioned before, the B16A ports are larger which flows more air in the higher rpm limits than the D16. but the D16 is still a pretty high strung motor and can hold it's own quite often.

alot of factors come into play. i wasn't saying that a modified or boosted D16Z6 couldn't come close to comparing to a B16A because of the port size difference. i was pointing out how much smaller the D16 head ports were compared to the B16 head ports, which in the end can play a major part in overall performance, and HP and TQ figures.

 

ahh good point and brings up another question..why on boosted D series motors are the torque numbers closer, if not sometimes higher then the hp numbers...ie: boosted d might have alot better torque curve then a boosted b series in comparison with the HP

 

hmmmmm........you consider 160hp in the B16 to be 60% more power than a 127hp D16...........by my calculation that is more like 21%. That's not enough really for the engineers to have to worry so much about headflow being perfect. I mean **** they already raised compression, increased redline to 8000rpm, slightly bigger bore, bigger IM and TB, dual cams, vtec on intake AND exhaust, do you really think that the head has to flow so superior to gain 21% power after all that?

 

Yet another person spouting off more "facts" with no flow charts, come on ryan, lets see some proff please. OH wait, you don't have any....