Clearancing Head for Cams - Photo?

You shouldn't even think about it till you have the cams placed in the head... with every cam it is going to look different. You only clear what is necessary and people have put really big cams in the stock 900 cylinder head casting since it came out.

So I still don't understand why there is such a need to see it... if your really desperate I have an article from Motorcyclist March 1977 called "The Perfect Engine", written about a Z1 buildup done by V&H when they were working at RC Eng - they show the work needed on one page...

BTW - the cam only rotates in one direction so there is no need to clear 360 degrees... some blending on the edges of the cutout makes it look nicer but it is only necessary where the lobe travels.

"cam only rotates in one direction "... Well ya I had that one figured out for myself.... :laugh:

Concern was since the bucket can spin 360, not freely mind you but can rotate just the same...

Is there the possibility where it could possible rotate to the high spot thus the lobe would hit it....?

I guess it truly doesn't matter pending which cam is used for above .410's, you'd be going under bucket shims or do I have that screwed up as well.... :S :laugh:

Injected wrote:

You shouldn't even think about it till you have the cams placed in the head... with every cam it is going to look different. You only clear what is necessary and people have put really big cams in the stock 900 cylinder head casting since it came out.

So I still don't understand why there is such a need to see it... if your really desperate I have an article from Motorcyclist March 1977 called "The Perfect Engine", written about a Z1 buildup done by V&H when they were working at RC Eng - they show the work needed on one page...

BTW - the cam only rotates in one direction so there is no need to clear 360 degrees... some blending on the edges of the cutout makes it look nicer but it is only necessary where the lobe travels.

Actually - that would be really cool. It's mostly curiosity and inquisitiveness. Nothing else.

Advice from an old guy :laugh: .... old music

youtube.com/watch?v=iq2WJ2r0NkM&feature=related

As understood, the relieving is to clear a path for the rotating cam lobe so it won't hit underside of valve cover, or mating surface of head and valve cover, or top of bucket tower. Being both red and blue areas, and "X" areas on underside of valve cover.

Having never done this, the following is speculation.

The buckets themselves (including shim surround) remain untouched, and are probably not even installed during the metal trimming operation.

Would envision extent of metal trimming needed being determined with only cams installed, and cams very gently rotated to determine exact locations and amounts of trimming needed. Then trim valve cover to match head where their mating surfaces meet.

Good Fortune!

DoubleDub wrote:

I'm surprised nobody has a photo of a head that has been prepared for bigger cams....wtf people!

i don't know if you can blow this one up enough to see the work done.
this is my j-head after it was done.



you can see the cam tips but it's hard to see the bucket area.
you can also see the milling for the cam chain adapter.

OMR - I guess I did not understand what you meant about the 360 degrees... my bad, I think your concerned about shim on top of bucket and that retaining notch? spinning...

All of my experience comes from shim under bucket so I can't answer any questions related to shim on top...

When this modification is done there is less support on the bucket in one direction (missing material) but it does not seem to effect them all that much since they are under constant tension.

Yes, bolt down cams in bare head... rotate till it hits - mark area with sharpie... grind - repeat till clear.
For the cover just wait till you do the head and bolt the cams in again... point lobe up and measure from gasket surface... measure cover to see if there's interference (make sure to add gasket thickness) grind till there's clearance.

Take the + right out of the valve cover completely on a KZ 900/1000. They serve no function anyway. Grind them flush.

If you get too deep in the tappet bores you'll get bucket rock and that's not good at all.

The head needs to be completely disassembled & de-greased before you do anything.

After grinding, head needs to be completely flushed with a garden hose, sprayed with a more de-greaser and flushed again.

While you have it apart, spray out all the bolt holes and cam journal oil holes with brake cleaner and hose away all the crap that comes out of them.

CLEAN CLEAN CLEAN CLEAN CLEAN and the CLEAN it again

Blow it out with compressed air and reassemble.

When flushing with garden hose, make sure to flush oil passages as follows.

With your fingers, plug the end stud holes top and bottom.

That's 2 holes on each end. 3 plug points and one opening left for the hose nozzle. Then spray water through the one open spot on the end stud holes. Water will flush through the oil passages and you'll see 4 nice streams come out the cam journal oil holes.

Did I mention CLEAN IT GOOD :laugh:

:laugh:

Thanks guys - very helpful!

get me your email and i will send you a good picture i have a head apart that set up to accept .500in lift cams in. I just do not know how to post a picture on this site.
Barry