Professional porting

Wireman, I appreciate the offer but you are too far away from NC. Anyway I am over budget now as it is. My head has good valves and guides, no stripped threads, etc. I am just going to cam clearance, port it, and lap the valves. I should not be giving away much hp. This is a street bike (I have to keep reminding myself). My porting is starting to look good. In spite of what Jay said about the smog holes in the exhaust port not being of any consequence I could not stand them. I tapped the holes 10mm and threaded some aluminum rod on the lathe. Screwed it in and took a punch and peened the rod to fit the shape of the bowl, then took the grinder to it for final shaping and polishing. Even if it does not make more power I feel better about it.

www.mototuneusa.com/

Exitpupil wrote:

www.mototuneusa.com/

cool i signed up for his updates,motoman kinda looks like wireman,we even dress alike!:S just like plumbing the bigger pipe will flow more water but the pressure will drop at the other end for same amount of water.

Post edited by: wireman, at: 2006/10/07 19:39

Obviously there is a difference with 4V heads, the ports are so much bigger close to the valve. I wonder how much of his gains are size vs port SHAPE. I have always wanted to try the D shape upside down so the area lost is where the valve guide hangs in the way. I e-mailed him about another different, more radical, idea I've had for years. Interesting to see if he answers and what he will think of it. I would like to build a vacuum cleaner flow bench just so I could test my ideas. I really like how he uses clay to find and eliminate dead area in the ports.

WITH BIGGER VAVLES WHAT SIZE CARBS would you like to see.
solomrus wrote:

i didn't see where anyone mentioned the small valves?

increase the valve diameter, get some more flow. won't matter how big your cams are, or how much you hog the ports if you don't get some more valve area.

ask yourself this: do you wanna wind the engine out, make your power at high rpms? or do you wanna have a fun torque engine that has a broad flat power band?

you can do either, and a decent blend of both, just put some thought into it.

my .02 is that you clean up the ports a bit, match up to your carbs, have new guides and seals installed, and go with larger valves.

i also think your carbs are too big for a 1075, but that's my opinion.

--r<br><br>Post edited by: solomrus, at: 2006/10/05 12:00

Post edited by: mark1122, at: 2006/10/08 16:52

29s!

Are you saying my 28s would be better than the 34s?
I could probably bore out my 28 to 29.
I'm new at this two wheel game, what is so great about the 29s?
I have experienced what happens when a car is over carbed.

Probably refering to 29 smoothbores.

Jay

28s and 29 smoothbores are both great carbs for streetbikes in my personal experiance.very responsive at lower to mid rpms where most bikes spend time at.ive got 33s on one of my old 1170s,they work good at higher rpms but they are a pain to work on and in my experiance the smaller carbs will outgun them at lower rpms.once again just my experiance.

1075/cams/porting/larger valves with vm29's is a very viable combo.

the 29's will give you plenty of fuel, and still maintain some of velocity for great tq. they will give up a little top end to 34's, but i'll take the 29's throttle response and fuel delivery capabilities over the top-end power.

i've never personally dyno'd this combo. joe's machine used to run it in their street bike, and tagged 104hp to the rear with with it.

--r

Post edited by: solomrus, at: 2006/10/09 11:32

now i remembered what i was supposed to do today,go bug joe!:evil: ill grab that block and head to stick on that set of cases,thatll get ya motivated to do some welding!:evil:

Interesting thread.....Here's some info to help you.

First...Mototune's method....works on some multi valve heads where port velocities are already low from the factory. Not for all heads...

If your intended carb size is 29mm smoothbores, then most of your porting shold be focused on the bowl area of the intake ports. There's absolutely no reason to open up KZ port runners to 33mm if you're running smaller carbs.

If you have a J head, the runners are already opened up. The bowl is once again the area where flow is gained.

Your pissing in the wind if you only open up the KZ runners and don't work on the bowl of the intake ports. It's not going to flow any more air than it did before you hogged the runners out.

This isn't a V8 Pushrod motor. You're not dealing with pushrod pinch restrictions where the MCSA is way back at the beginning of the port. The porting approach on Kawasaki 2 valve Z and J heads is not exactly the same as it would be on a 350 Chevy.

I've see a lot of home ported KZ heads and most were a complete waste of somoeone's time. The one's where the runners were pretty much left alone were fine to work with because they were not all screwed up.

Many had the runners opened up far too much for the size of the carb chosen for the application. While they still ran OK, they were best suited for full on porting for large carbs, larger cams and big bore.

Most of you would be quite suprised at how little the flow was improved from your porting efforts on a KZ head. I've ported many of them over the past 25 years and flow tested a good many more that came from other shops.

Let's crunch some numbers. If you pay attention, the cross sectional areas and port velocities are here for the taking...



With a 1166 10.25:1 motor .410 APE cams, 29mm smoothbore carbs, stock valves and a stock KZ1000 head, you're looking at about 110 - 120 HP at 8500RPM. That's a 100%Ve [volumetric efficiency]value.

Where this combo washes out is it really would like more valve lift for the Peak HP RPM. It requires more curtain area to fully achieve it's potential.

Here's the data on the combo.

71.173 Cubic Inches @ 8500 RPM with 100.0 % Volumetric Efficiency PerCent
Required Intake Flow between 110.3 CFM and 115.6 CFM at 28 Inches
Required Exhaust Flow between 88.4 CFM and 95.0 CFM at 28 Inches

600 RPM/Sec Dyno Test Lowest Low Average Best
Peak HorsePower 110.6 115.1 117.4 119.7
Peak Torque Lbs-Ft 75.6 78.7 80.3 81.8

HorsePower per CID 1.554 1.617 1.649 1.681
Torque per Cubic Inch 1.062 1.106 1.128 1.150

BMEP in psi 160.2 166.8 170.1 173.4
Carb CFM at 1.5 in Hg. 175 195 205 214

Target EGT= 1371 degrees F at end of 4 second 600 RPM/Sec Dyno accel. test
Octane (R+M)/2 Method = 93.0 to 95.8 Octane required range
Air Standard Efficiency = 61.12717 % for 10.250:1 Compression Ratio

Peak HorsePower calculated from Cylinder Head Flow CFM only
600 RPM/Sec Dyno Test Lowest Average Best Potential
Head Flow Peak HP = 105.0 123.1 141.2

---

Engine Design Specifications

---

Engine Size CID = 71.173 Intake Valve Net Area = 1.517
CID per Cylinder = 17.793 Intake Valve Dia. Area = 1.577
Rod/Stroke Ratio = 1.788 Intake Valve Stem Area = 0.060
Bore/Stroke Ratio = 1.137 Exhaust Valve Net Area = 1.109
Int Valve/Bore Ratio = 0.480 Exhaust Valve Dia. Area = 1.169
Exh Valve/Bore Ratio = 0.413 Exhaust Valve Stem Area = 0.060
Exh/Int Valve Ratio = 0.861 Exh/Int Valve Area Ratio = 0.741

Intake Valve L/D Ratio= .289 Exhaust Valve L/D Ratio= .336
CFM/Sq.Inch = 70.0 to 73.3 CFM/Sq.Inch =75.6 to 81.3

Curtain Area -to- Valve Area Convergence Intake Valve Lift = .354
Curtain Area -to- Valve Area Convergence Exhaust Valve Lift = .305

---

Current Camshaft Specs @ .050

---

IntOpen= 23.00 IntClose= 59.00 ExhOpen= 59.00 ExhClose= 23.00
Intake Duration @ .050 = 262.00 Exhaust Duration @ .050 = 262.00
Intake CenterLine = 108.00 Exhaust CenterLine = 108.00
Compression Duration= 121.00 Power Duration = 121.00
OverLap Duration = 46.00 Lobe Center Angle (LCA)= 108.00
Camshaft installed Straight Up = 0.00 degrees




-Recommended Camshaft Valve Lift- - Induction System Tuned Lengths -
Minimum Normal Maximum Best Length= 10.651 2nd= 8.383
Intake = 0.428 0.461 0.507 3rd Best= 6.802 4th Best= 5.723
Exhaust = 0.421 0.453 0.498 Plenum Runner Max Entry Area = 1.845
Max-effort Intake Lift = 0.531 Minimum Plenum Volume CC = 231.3
Max-effort Exhaust Lift = 0.522 Minimum Plenum Volume CID= 14.1

Minimum Intake Valve Lift to prevent Choke = .461 Lift @ 8500 RPM

---

Operating RPM Ranges of various Components

---

Camshaft Intake Lobe RPM = 7061 Exhaust Lobe RPM = 6554
Camshaft's Intake and Exhaust Lobes operating RPM range = 4934 to 6934
Note=> Lobe RPMs are valid only for conventional 2-Valve Pushrod Engines

Current (Intake Valve Curtain Area -VS- Time) Choke RPM = 7567 RPM

Intake Valve Area + Curtain Area operating RPM Range = 5481 to 7481 RPM

Intake Valve Diameter RPM Range = 7922 to 9922

Intake Flow CFM @28in RPM Range = 6339 to 8339
___________________________________________________________________________

Best estimate RPM operating range from all Components = 6194 to 8194

Note=>The BEST Engine Combo will have all Component's RPM Ranges coinciding
___________________________________________________________________________



--- Cross-Sectional Areas at various Intake Port Velocities (@ 28 in.) ---
145 FPS at Intake Valve Curtain Area= 1.825 sq.in. at .410 Lift
168 FPS at Intake Valve OD Area and at Convergence Lift = .354
207 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 1.277 sq.in. at 8500 RPM
350 FPS Velocity CSA= 0.756 sq.in. at 8500 RPM Port Sonic-Choke with HP Loss
330 FPS Velocity CSA= 0.802 sq.in. at 8500 RPM Smallest Useable Port CSA
311 FPS Velocity CSA= 0.851 sq.in. at 8500 RPM Recommended Smallest Port CSA
300 FPS Velocity CSA= 0.883 sq.in. at 8500 RPM Recommended Port CSA
285 FPS Velocity CSA= 0.929 sq.in. at 8500 RPM Recommended Short-Turn CSA
250 FPS Velocity CSA= 1.059 sq.in. at 8500 RPM Recommended Largest Port CSA
225 FPS Velocity CSA= 1.177 sq.in. at 8500 RPM Largest Intake Port Entry CSA
200 FPS Velocity CSA= 1.324 sq.in. at 8500 RPM Torque Loss + Reversion


--- Cross-Sectional Areas at various Exhaust Port Velocities (@ 28 in.) ---
140 FPS at Exhaust Valve Curtain Area= 1.571 sq.in. at .410 Lift
188 FPS at Exhaust Valve OD Area and at Convergence Lift = .305
232 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 0.947 sq.in. at 8500 RPM
435 FPS Velocity CSA= 0.506 sq.in. at 8500 RPM Sonic Choke at Throat Area
350 FPS Velocity CSA= 0.628 sq.in. at 8500 RPM Port Sonic-Choke with HP Loss
330 FPS Velocity CSA= 0.667 sq.in. at 8500 RPM Smallest Useable Port CSA
311 FPS Velocity CSA= 0.708 sq.in. at 8500 RPM Recommended Smallest Port CSA
300 FPS Velocity CSA= 0.733 sq.in. at 8500 RPM Recommended Port CSA
285 FPS Velocity CSA= 0.772 sq.in. at 8500 RPM Recommended Short-Turn CSA
250 FPS Velocity CSA= 0.880 sq.in. at 8500 RPM Recommended Largest Port CSA
225 FPS Velocity CSA= 0.978 sq.in. at 8500 RPM Largest Exhaust Port Exit CSA
200 FPS Velocity CSA= 1.100 sq.in. at 8500 RPM Torque Loss + Reversion





Intake Intake Curtain Area 300 FPS Velocity Minimum Head
Valve Choke Square Inches Cross-Sect Area Flow @ 28 In
Lift RPM Intake Exhaust Intake Exhaust Int Exh
.050 923 0.223 0.192 0.096 0.080 12.0 10.0
.075 1384 0.334 0.287 0.144 0.119 18.0 14.9
.100 1846 0.445 0.383 0.192 0.159 24.0 19.9
.125 2307 0.556 0.479 0.240 0.199 29.9 24.9
.150 2768 0.668 0.575 0.287 0.239 35.9 29.9
.175 3230 0.779 0.671 0.335 0.279 41.9 34.8
.200 3691 0.890 0.767 0.383 0.319 47.9 39.8
.225 4152 1.002 0.862 0.431 0.358 53.9 44.8
.250 4614 1.113 0.958 0.479 0.398 59.9 49.8
.275 5075 1.224 1.054 0.527 0.438 65.9 54.7
.300 5537 1.335 1.150 0.575 0.478 71.9 59.7
.325 5998 1.447 1.246 0.623 0.518 77.8 64.7
.350 6459 1.558 1.341 0.671 0.557 83.8 69.7
.375 6921 1.669 1.437 0.719 0.597 89.8 74.7
.400 7382 1.781 1.533 0.767 0.637 95.8 79.6

Intake Intake Curtain Area 300 FPS Velocity Minimum Head
Valve Choke Square Inches Cross-Sect Area Flow @ 28 In
Lift RPM Intake Exhaust Intake Exhaust Int Exh
.425 7843 1.892 1.629 0.814 0.677 101.8 84.6
.450 8305 2.003 1.725 0.862 0.717 107.8 89.6
.475 8766 2.115 1.821 0.910 0.756 113.8 94.6
.500 9228 2.226 1.916 0.958 0.796 119.8 99.5
.525 9689 2.337 2.012 1.006 0.836 125.8 104.5
.550 10150 2.448 2.108 1.054 0.876 131.7 109.5
END Data

Now, let's install 37.5mm intake valves and go with the APE .435 lift cam.

---

Operating RPM Ranges of various Components

---

Camshaft Intake Lobe RPM = 7326 Exhaust Lobe RPM = 6819
Camshaft's Intake and Exhaust Lobes operating RPM range = 5200 to 7200
Note=> Lobe RPMs are valid only for conventional 2-Valve Pushrod Engines

Current (Intake Valve Curtain Area -VS- Time) Choke RPM = 8362 RPM

Intake Valve Area + Curtain Area operating RPM Range = 6058 to 8058 RPM

Intake Valve Diameter RPM Range = 8765 to 10765

Intake Flow CFM @28in RPM Range = 6339 to 8339
___________________________________________________________________________

Best estimate RPM operating range from all Components = 6272 to 8272

Note=>The BEST Engine Combo will have all Component's RPM Ranges coinciding

End Data

Lastly, let's improve Ve 10% [which happens to work out to 10CFM on this head at 28" of water] with the bigger cam and intake valves.

71.173 Cubic Inches @ 8500 RPM with 110.0 % Volumetric Efficiency PerCent
Required Intake Flow between 125.0 CFM and 131.2 CFM at 28 Inches
Required Exhaust Flow between 94.4 CFM and 103.3 CFM at 28 Inches

600 RPM/Sec Dyno Test Lowest Low Average Best
Peak HorsePower 128.3 133.6 136.3 138.9
Peak Torque Lbs-Ft 87.2 90.8 92.6 94.4

HorsePower per CID 1.803 1.877 1.914 1.951
Torque per Cubic Inch 1.225 1.276 1.301 1.326

BMEP in psi 184.8 192.4 196.2 200.0
Carb CFM at 1.5 in Hg. 193 214 225 236

Target EGT= 1327 degrees F at end of 4 second 600 RPM/Sec Dyno accel. test
Octane (R+M)/2 Method = 94.8 to 95.8 Octane required range
Air Standard Efficiency = 61.12717 % for 10.250:1 Compression Ratio

Peak HorsePower calculated from Cylinder Head Flow CFM only
600 RPM/Sec Dyno Test Lowest Average Best Potential
Head Flow Peak HP = 132.6 146.3 160.0

Post edited by: larrycavan, at: 2006/10/09 17:06


Post edited by: larrycavan, at: 2006/10/09 17:14

Post edited by: larrycavan, at: 2006/10/09 17:27