D PORTING KZ HEAD

prostreetkz wrote: I'm truly honored to have you on my discussion, Larry. Now I'm going to get somewhere, lol, That's interesting on the exhaust side, I have read similar info on the exhaust side for porting , really just polishing the exhaust side, maybe a little match porting is sufficient. I want to pick your brain on D porting the intake side. I have read you say it's only needed if the port size is large. First off tapering a port runner, being larger on the carb end and smaller on the valve end will indeed increase velocity is that what the idea is to do? I have a 37.5 intake valve, shouldn't 40mm rs mikunis theoretically work well? Match porting the carb slowly tapering the port to the intended throat size of 89% then blending that to the bowl in turn to the valve seat? I would love to talk to you on the phone , I have also posted this same topic on your forum , again thx larry. I have rs40 mikunis but Have realized I may need 36 or maybe 38s.Cams have 485 at .040, 37.5in 33ex 76mm bore kz 900 crank. I am wanting peak power around 95-10000 but is that to high with heavy stainless valves and steel retainers? about 60% strip 40% street. I think that's all your needing for CSA values Thx Larry

36mm carbs will do the job, 38's really ought to have a J head. 40's are total overkill for the size of the engine IMO

Here's the result. It's heading home to you today Alan...

38.6 APE GPz11 Intakes turned down to 38.
KW exhausts Springs
Cam Motion Z10 Grind Cams .485 lift [101CFM@that lift@10"] Tested with the intake boots it will run.
APE Guides
OEM 650 Retainers

Valve Job setup for 280-285 shims to avoid the tendency of fracture that is so often seen with thin shims being used in a high performance application.

Normally I would have reduced the velocity a bit more to 270ish. Cams, compression ratio and bore size play into the equation.

Should make plenty of torque

It really amazes me how you can get those port walls so even looking without any grinding marks showing. Craftsmanship at its best. Nice job!

Racer that's why I talked to Larry around the first of the
year about doing my GPz750 head.

I just need to finish rounding up part's to send him
with the head.

Yes Larry is the best !!! I can't wait to get the head back !! This bike is going to be an absolute beast!!!!!
THX LARRY

That is bad ass. What's that all worth?

Hollywoodmx wrote: That is bad ass. What's that all worth?

You mean in terms of power?

LarryC wrote:

Hollywoodmx wrote: That is bad ass. What's that all worth?

You mean in terms of power?

No the cost of parts and work but now that you mentioned it power gains too.

prostreetkz wrote: Yes Larry is the best !!! I can't wait to get the head back !! This bike is going to be an absolute beast!!!!!
THX LARRY

You're welcome