Porting and milling options for GPZ750?

quick story i wanted to remove my valve guides so i heated the oven to 500 degrees f let the head stay in to long and my valve seats fell out . wasted head .so becarefull when heating your head.live and learn

In any manual it says to measure valve to piston clearance when installing high comp. pistons and or radical cams. That piston is coming up as the exhaust valve is closing. The clearance is crazy tight. One problem and the valves are gone. Not much wiggle room there.
Steve

It is the intake valve opening as the piston approaches t.d.c..

are we on topic?

Kawi810 you were asking about what is the best KZ750
that would be the 83-84 ZX750A1-A2 head.

thanks .thats the one that i have in the pics.just thought there might be something better.

hey zukdave,how is your drag bike coming out ?mine will be used for drag racing only.since we are running the same engine keep me posted. john

Nebr_Rex wrote: It is the intake valve opening as the piston approaches t.d.c..

You measure all of them.

Not sure about this need for high octane fuel needed for ANY CR increase. All kawis are suitable for unleaded petrol, the 550's were all 10:1 CR standard.

Interesting tuning info here, note the thinner zephyr 750 head gasket and 0.5mm head skim recommendation. Really need to know what the clearances are here - the wisecos have deeper valve pockets generally.

members.tripod.com/gpz_rider/technical/FAQ2000.htm

Note from megacycle catalouge: GPZ 750 engines made 1983 and 1984 require special 1.070" base circle diameter in some models.
All other 750 and all KZ-650 engines have a stock base circle of 1.110". To be sure, measure your stock cams





...I know 'best' isn't always biggest numbers, the older GPZ550 have slide carbs and smaller inlet tracts and whilst the later CV carb variants have more peak rpm power they don't have the same bottom and end grunt. Whether more peak power for less bottom end is an improvement will depend on riding style and conditions.

Tyrell Corp wrote: Interesting tuning info here, note the thinner zephyr 750 head gasket and 0.5mm head skim recommendation.
members.tripod.com/gpz_rider/technical/FAQ2000.htm

Mill off .020" and you will hit the valve seats on a regular KZ750E head. Does the GPZ head have more spacing between the seats and the deck surface?

Nessism wrote:

Tyrell Corp wrote: Interesting tuning info here, note the thinner zephyr 750 head gasket and 0.5mm head skim recommendation.
members.tripod.com/gpz_rider/technical/FAQ2000.htm

Mill off .020" and you will hit the valve seats on a regular KZ750E head. Does the GPZ head have more spacing between the seats and the deck surface?

First two pics are of a LTD(H), same as an E, silver paint instead of black.
Second two pics are of a Spectre, same as a GPz, again just paint being the difference.












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Nessism wrote:

Tyrell Corp wrote: Interesting tuning info here, note the thinner zephyr 750 head gasket and 0.5mm head skim recommendation.
members.tripod.com/gpz_rider/technical/FAQ2000.htm

Mill off .020" and you will hit the valve seats on a regular KZ750E head. Does the GPZ head have more spacing between the seats and the deck surface?

Do you have a head you can measure:

kzrider.com/forum/2-engine/596833-cylinder-head-skim-markers

would be reallly interested thanks