D14 /y7 head flow numbers

[hondaNickx]

I just came across this information from a guy that made his own flowbench and it works great.
Since the y7 head is exactly the same casting as the D14 head (P2A-06)

Stock D16y7 cylinder head

Intake
.100 - 75.3 @ 28"
.150 - 111.5 @ 28"
.200 - 137.5 @ 28"
.250 - 144.7 @ 28"
.300 - 163.7 @ 28"
.350 - 165.2 @ 28"
.400 - 166.4 @ 28"
.450 - 167.6 @ 28"

Exhaust
.050 - 28.6 @ 28"
.100 - 61.1 @ 28"
.150 - 91.1 @ 28"
.200 - 111.3 @ 28"
.250 - 122.1 @ 28"
.300 - 125.7 @ 28"
.350 - 127.9 @ 28"
.400 - 128.6 @ 28"
.450 - 129.4 @ 28"

According to some Porting shops around 180Cfm would be enough for 190Bhp.The stock D14 cam has just below .300" lift intake and exhaust And flows around 160Cfm intake and 124Cfm exhaust @ below .300 " lift.
I would guess the stock head could handle 160bhp but the exhaust flow (124Cfm) is really low and would restrict it.With some good porting you could gain 20Cfm and that would make this head flow around 180Cfm.

[saxophonias]

wow. excellent info. Does this fact tell us anything about the exhaust diameters we need and the cam specs for n/a tuning?

[Law_]

Great info indeed. Hope Y8 head flows better !

[hondaNickx]

wow. excellent info. Does this fact tell us anything about the exhaust diameters we need and the cam specs for n/a tuning?

I can tell you just need to increase timing by 10 degrees and 0.8 mm of lift to know the stage 1 specs.Timing of intake and exhaust are roughly the same ,except on the stage 2 cam you can clearly see the exhaust getting more timing then the intake.

My Bisimoto stage 2 cam has lifts around 0.340" , and timing around 250 degrees to give you an idea.This also cleary shows the difference between vtec cams and non vtec cams.Vtec cams have way more lift and less timing , and i think a D14 needs the opposite less lift and more timing.
A D14 engine isn't a D16 so in my opnion you need different cam specs.

@ Law i once asked Larry from Endyn if the difference in hp between a D16y7 and a D16y8 was because of the head flowing better or not.
He said that both Y8 and an y7 head flow roughly the same ,but the y8 has a better cam (vtec) and that was why it made more power.
So the difference in flow between the Y7/D14 head and the y8 would be minimal .I do think the y8 head has better exhaust ports.

[Law_]

And do you reccon the d16z6 head to flow better?
what would be better in a mini me setup like this:

Possible softly milled vtec head
Possible layer from head gasket removed
JapSpeed Exhaust Maniflod
D16 dizzy
Vtec ECU
D16Y8 IM

Can get my hands on a good z6 head, and i can get an y8 one, but i dont know whats the general state. but i would consider to use y8 due to higher compression etc...
Cheers

[hondaNickx]

The D16z6 has slighty bigger ports and it flows slighty better indeed.But on a D14 i'd go with the y8 head for more velocity and a better combustion chamber/more quench area.A stock y8 head with a 3 angle valve job and some aftermarket flat face valves already gives you a good improvement in flow.The valves having a valve stem uncercut that will help in flow.
Most of the gains are gained because of the 3 angle valve job and improving the bowl area around the valve on a sohc D-series head.
I'd also prefer a custom grinded vtec cam for your D14 instead of using a aftermarket sohc vtec one.

[Law_]

Quoting: " When properly designed, the quench areas can have a tremendous effect on the quality of combustion, and allow higher compression ratios, and due to this they are considered "artificial octane" by scientific types.Bottom line is, properly designed, quench is good "

So, y8 all the way. I dont know how to evaluate the heads general state though. I could for instance notice if there is something broken but not a lot more... Any advices?

[hondaNickx]

More quench is always good.You could also weld up the quench pads of the D16z6 head .Bisi does that on all of his heads he uses.
You could get a leak test done to ensure all of your valves seal up properly.

[Law_]

Thats a good idea, thanks =)

[mynameisowen]

Could you explain the baove numbers please, I understand that they are figures for flow rate through the head but not much else. Also im guessing that Cfm means "cubic feet per minute"?