Flow Test Results for 83 GPz11 with 34's

Test conducted on 3" bore @ 28" Test Pressure - OEM intake boot installed - Port#1 - Stock w/ guide milled down 1/4".

.050 - 28.0
.100 - 50.5
.150 - 75.5
.200 - 99.9
.250 - 120.2
.300 - 129.9
.350 - 134.0
.400 - 137.3
.450 - 139.5
.500 - 140.1
.550 - 140.8

@.400 w/ 34mm Mikuni Flat Slides mounted
132.4

Same as above but with K&N filter installed
129.9 [filter could have used cleaning but was acceptable]

Port local velocities ranged from 250FPS at the port entrance to 385 at SSR. Roof to floor variance ranged up to 100FPS. Port was relatively quiet.


Will follow up with runner volumes and calculated average velocity tomorrow if I get time.

Could you give us some pictures of the proceedings?

What does it convert to at 10 inches.

Jay

Jay,

What flowbench are you guys using?

If you're using a SF110 bench, page 26 in your manual has the conversion chart. Or you can use this formula.

To convert from 28" to 10" use the formula:

SQRT(P2/P1)= multiplier

[Flow * multiplier] = new flow

Where P2= [new pressure] and P1= [tested pressure]

Then apply your bench correction value from your calibrated pressure to the converted pressure. Generally, whatever pressure your bench is calibrated at is the pressure you will test at.

I calibrate and work @28" because higher test pressures will reveal things that low pressures won't. I spot check at 10" for comparison of values I obtained on SF110 bench...way back when..

Flowed @10" on my computerized bench[no converting applied] the results are"

.050 - 15.7
.100 - 27.4
.150 - 43.1
.200 - 54.1
.250 - 65.7
.300 - 73.0
.400 - 76.9
.450 - 79.1
.500 - 82.3
.550 - 82.3

Pretty close to the values I obtained on a SF110 bench @10" back in 1984...[has it really been that long:S]

.100 - 28
.200 - 58
.300 - 77
.400 - 82
.500 - 82

Post edited by: larrycavan, at: 2006/12/16 08:24

Larry,post some flow numbers on that great KZ 1000 head you did up for me.Thanks mark

1980 KZ1000 Street Porting - 83GPZ11 Stock

Test pressure = 28"
Bore Size = 75mm
No weather corrections applied for ACFM / SCFM

Lift KZ-CFM GPZ-CFM
0.050 28.4 28.0 [-0.4]
0.100 53.5 50.5 [-3.0]
0.150 78.2 75.5 [-2.7]
0.200 96.2 99.9 [+3.7]
0.250 117.0 120.2 [+3.2]
0.300 136.7 129.9 [-7.8]
0.350 143.5 134.0 [-9.5]
0.400 145.4 137.3 [-8.1]
0.450 145.9 139.5 [-6.4]
0.500 146.6 140.1 [-6.5]
0.550 147.1 140.8 [-6.3]

80KZ - smaller port runners 37.5mm Intake
83GPz - large port runners 38mm Intake

Velocity Profile comparison = .....c'mon now....I
can't give everything away....:silly:

Post edited by: larrycavan, at: 2006/12/19 18:16

Post edited by: larrycavan, at: 2007/02/09 15:27

Very nice. The KZ1000's flow is very good at .400", so much so that you don't have to use cams with lift much beyond .400". I see high port velocity ...

Looks like this is a sweet head for a KZ1000 street application.

BohicaBob wrote:

Very nice. The KZ1000's flow is very good at .400", so much so that you don't have to use cams with lift much beyond .400". I see high port velocity ...

Looks like this is a sweet head for a KZ1000 street application.

Thanks Bob....it's going on a 1200cc motor with .417" lift cams and 34 Mikuni flat slides....should make a nice street motor for the owner...and I guarantee you'll be able to eat off any part of the bike...the guy is 1000% meticulous with his motorcycles...

Larry: How about adding to your great comparison the stock KZ1000 head flow figures to give folks:

1) a baseline look how Z1/KZ heads flow compare to GPz heads; and,
2) an even better picture of what's possible with street porting of their Z1/KZ heads?

I certainly appreciate your contributions. Am sure other Z1/KZ afficionados do to!

How about some vintage 84 Kawasaki stuff, 2V vs 4V flowed at 10" pressure.

84 GPz 11 Stock

.100 - 28
.200 - 58
.300 - 77
.400 - 82 [peak]
.500 - 82

ZX900A1 Stock

.050 - 19.4
.100 - 39.6
.150 - 61.5
.200 - 78.0
.250 - 90.3
.300 - 94.5 [peak]

Larry can you help explain this to us newbee's.From what i see the kz flows higher #'s than the gpz?How is that?I thought bigger was suposed to be better?At least thats what the girls say.:lol:

thats a 16 valve zx900 head,not an 8 valve z motor head.i thought the same thing when i saw it!