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Re-inventing the guide wheel

Posted: Tue Nov 24, 2020 2:10 pm
Author: RALPHARAMA
I have just installed a hydraulic press and need to change the guides on one of my A4 heads. My oven is just big enough to take the cylinder head.

I was thinking that if I made a jig to hold the head at the correct angle, I could hydraulically push the hot guides out, which might be more accurate and less risky than beating them out with an arbour and big 'ammer as suggested by Lord Kawasaki in his Zed bible.

Does anyone on here know the valve stem angles and are they the same inlet and exhaust?

Anyone heard of this being done before ?

Re: Re-inventing the guide wheel

Posted: Wed Nov 25, 2020 9:07 am
Author: chrisu
i'd talk to Buzzard about this approach.

Re: Re-inventing the guide wheel

Posted: Wed Nov 25, 2020 10:46 am
Author: Ultim8pc
chrisu wrote:i'd talk to Buzzard about this approach.

For what Buzzard charges I'd just get him to sort it...

Re: Re-inventing the guide wheel

Posted: Wed Nov 25, 2020 11:54 am
Author: zed1015
On all but the GPZ1100A Unitrac /Z1100R and some 1100 Spectres that use bathtub heads the valve angles are all the same at 30 degrees.
The Uni motor has a 1 degree steeper exhaust valve.
I personally wouldn't bother faffing with the press for removing the guides as it won't be any better or quicker then drifting them out.
I would however recommend using a self centering draw bar tool that aligns on the seat for fitting new ones like the one I made in the pic.
Much more refined and accurate than drifting them in as they follow the guide bore and the seats rarely need much re-cutting if any to center the valves.


PICT0452.JPG
PICT0452.JPG (193.84 KiB) Viewed 1424 times

Re: Re-inventing the guide wheel

Posted: Wed Nov 25, 2020 1:44 pm
Author: RALPHARAMA
That seems to be an excellent idea for refitting them. I can see some lathing coming soon. As an aircraft trained fellow, belting the crap out of things with a hammer goes against the grain.... That thought has just spurred another idea - I have bought a genuine Kawasaki arbour, but I could machine up an attachment to use with my air hammer for removing the buggers!

I already have an M7 tap; best I buy and M7 die as I guess the puller wants to have the biggest thread that will fit though the guide :)