degreeing cams 750

yeah, I've put the sprockets in the lathe and turned the face down to the depth of the bolt head rebates ( using centre punch to mark the timing marks first)then using a rat tail file elongated the std holes
I rebuilt last night and have now got the right numbers 105 on both cams. I'm looking forward to running the engine as i'm booked for a dyno run next week to fine tune the carbs
I,m riding to Philip Is for the World Super Bikes in 4 weeks, 2500km round trip, that should be a good tester for the engine mods
GPzepher, can i ask wat make gear box you have Re 6 speed?
cheers

6 speed! Well its basically using a 550 gear set, selectors and transmission cover. It all pretty much bolts straight in.
The 550 cover is needed to put the neutral switch in the right place for the selectors. The cover is not an exact fit, it leaves a small gap at the top, but it hasn't proved a problem as the gasket is wide enough to bridge the gap.
The only other thing is that the output sprocket is held on by a different method. But again nothing too serious.

Well worth doing.

jimmybon wrote:

I am at present trying to check the cam degrees on my z650 hybrid
make up-
gpz750 bottom end
zepher zr750 head and barrels
810 pistons
gpz750r1 82 ex cams
gpz750r1 82 or zepher in cam (not shaw, may have got them mixed up but both have the same lobe size 63.3

I'm using the Doug Meyer method of calcuating the lobe centre at 1mm lift. So standard is 60+30+180/2-30=105, and have found @1mm lift the inlet cam at 4* open, 42* close. So 4+42+180/2=113-4*=109 and -4* for chain slack =105
The exhaust measures 31* open, 11* closed. so 31+11+180/2=111-11=100
firstly, are my calcs wright? and if so shouldnt the ex be 105 and could it be 5* out because of zepher head ( I recall a member stating that the zepher head has been allready decked by kawsaki. Is this right? cheers

When using the lobe center method to time cams, lash or checking height has no effect on the lobe center when checking a concentic cam, concentric meaning same radius on the opening and closing side of a cam. Your exhaust cam is what it is regardless of decking or lash or checking height. Pick a number and be consistant but .040"/1mm is fine with or without lash. Your intake cam though is just a guess. -4? Maybe, maybe not? In the past I have cut-up spare valve covers to replicate the center rubbing block on j/gpz motors and later made a fixture to do this. My point is your just guessing on the intake...mod

[/quote]
When using the lobe center method to time cams, lash or checking height has no effect on the lobe center when checking a concentic cam, concentric meaning same radius on the opening and closing side of a cam. Your exhaust cam is what it is regardless of decking or lash or checking height. Pick a number and be consistant but .040"/1mm is fine with or without lash. Your intake cam though is just a guess. -4? Maybe, maybe not? In the past I have cut-up spare valve covers to replicate the center rubbing block on j/gpz motors and later made a fixture to do this. My point is your just guessing on the intake...mod[/quote]

good point, I'm goin to try and measure the -4*
cheers

modprod wrote:

jimmybon wrote:

I am at present trying to check the cam degrees on my z650 hybrid
make up-
gpz750 bottom end
zepher zr750 head and barrels
810 pistons
gpz750r1 82 ex cams
gpz750r1 82 or zepher in cam (not shaw, may have got them mixed up but both have the same lobe size 63.3

I'm using the Doug Meyer method of calcuating the lobe centre at 1mm lift. So standard is 60+30+180/2-30=105, and have found @1mm lift the inlet cam at 4* open, 42* close. So 4+42+180/2=113-4*=109 and -4* for chain slack =105
The exhaust measures 31* open, 11* closed. so 31+11+180/2=111-11=100
firstly, are my calcs wright? and if so shouldnt the ex be 105 and could it be 5* out because of zepher head ( I recall a member stating that the zepher head has been allready decked by kawsaki. Is this right? cheers

When using the lobe center method to time cams, lash or checking height has no effect on the lobe center when checking a concentic cam, concentric meaning same radius on the opening and closing side of a cam. Your exhaust cam is what it is regardless of decking or lash or checking height. Pick a number and be consistant but .040"/1mm is fine with or without lash. Your intake cam though is just a guess. -4? Maybe, maybe not? In the past I have cut-up spare valve covers to replicate the center rubbing block on j/gpz motors and later made a fixture to do this. My point is your just guessing on the intake...mod

Normally checked by putting the valve cover on and then taking off to reveal the slack in the chain.
Then using a degree wheel, wind the engine on slowly until the slack is taken up, reading off how many degrees it takes.