Katit's 1978 KZ650 project

Reading up on valve guide installs. Amazon even sells 7mm "drivers". Basically thingy that attaches to air hammer. Is it really safe/good way? Just hammer them in with air hammer?

I tend to try dry ice. I have extra head to experiment. I can install old ones there by super-cooling guides and warming head to 400F or so?

You only need to heat the head when removing or installing cast iron guides but you don't need to heat the head or cool the guides when installing bronze guides.
The bronze has a similar expansion rate to aluminium so the cold heads fit of bronze is similar to the hot heads fit of the cast iron.
You will also need to HONE the aluminium bronze APE guides for the correct clearance once they are installed.
I made this tool to draw the guides into the head.
The guides follow the bore in the head when being drawn in rather than drifted and leads to closer concentricity with the valve seat and less cutting if any to true the seats to the new guide..

Far right is the draw bar. Middle is the insertion guide for the bucket bore and left is the glorified nut which has a 45 degree taper to centralise it on the valve seat . 
 
Insertion guide slips in the bucket bore and the valve guide on the draw bar.
 
Threaded 'nut' sits on the valve seat. Main body is aluminium to prevent seat damage. 
Threaded center portion is steel and you hold the handle to prevent it from turning when tightening the drawbar. 
Use a bit of lube on the threads and the valve guide.
 
 

What hone type and size needed?

You need a 7mm ball hone like in the link.
Kibblewhite Valve Guide Ball Hone 7mm #GH-2755 | eBay
 

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You need a 7mm ball hone like in the link.
Kibblewhite Valve Guide Ball Hone 7mm #GH-2755 | eBay

 

I don't know much about cylinder head work, but I'm surprised that a ball hone is the preferred tool.  

Why would someone use a ball hone over a reamer?  The reamer seems like it would make a much more precisely sized and more round hole.

shop.kpmivalvetrain.com/c/tools-componen...-speed-steel-reamers
www.amazon.com/Kibblewhite-Precision-Rea...Bronze/dp/B00HXJ9QOC

 

wrote:

wrote:

You need a 7mm ball hone like in the link.
Kibblewhite Valve Guide Ball Hone 7mm #GH-2755 | eBay




 

I don't know much about cylinder head work, but I'm surprised that a ball hone is the preferred tool.  

Why would someone use a ball hone over a reamer?  The reamer seems like it would make a much more precisely sized and more round hole.

shop.kpmivalvetrain.com/c/tools-componen...-speed-steel-reamers
www.amazon.com/Kibblewhite-Precision-Rea...Bronze/dp/B00HXJ9QOC




 

The APE guides are C630 Nickle aluminium bronze .
You can't use a reamer on them, it will just gall and jam.
The reamers in the Kibblewhite/KMPI links are for manganese bronze which can be reamed.
Kibblewhite supply both Aluminium and Manganese alloyed guides and you will note that their reamers are only for use on the manganese ones.

My understanding that APE guides already machined precisely. Honing maybe only needed for better oil retention? Similar to cylinders?

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My understanding that APE guides already machined precisely. Honing maybe only needed for better oil retention? Similar to cylinders?

APE's claim to the precision fit only applies to the outside diameter size for installation in the head, not the bore for valve stem clearance ( which will tighten once the guide is pressed in situ )
The guides still need honing after fitment to obtain correct valve to guide clearance.
Too tight and the valves will bind and stick resulting in bent valves ( been there, done that ) .
It is possible but not recommended to ream the C630 guides with a carbide reamer and bronze oil lubricant but it is tricky and the expensive carbide reamer will quickly dull ( done that too )
Honing will provide an accurate parallel bore for the valve stem .
Clearance for the valve is usually accounted for on the stem so a true 7mm bore in the guide will result in the correct stem clearance.
If you don't possess a small bore gauge or pin gauges etc then some accurately ground 7mm bar stock or silver steel etc can be used as a go/no go tool when reaming the guide.
 

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I am confused. New valves go into new guides and not sticking. Maybe ID of guide will go down after install? Anyways, what better go/no go tool that existing new valve?

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Far right is the draw bar. Middle is the insertion guide for the bucket bore and left is the glorified nut which has a 45 degree taper to centralise it on the valve seat . 
 

Quick question. I am thinking on maybe replicating your tool. Is that m6 thread on it? Is it strong enough to draw insert in?
I really like idea of using aluminum bush to center guide in place. I may just do that and use my press instead of dealing with threads, nuts, etc

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I am confused. New valves go into new guides and not sticking. Maybe ID of guide will go down after install? 

Yes! once the guides are fitted the clearance will reduce.
The new valve 'may' still slide in the guide but the clearance will be too small.
Measure the valve stem, add the clearance required and that will tell you the bore size of the guide that is needed.
As mentioned, the valve stem is usually undersized by the amount of clearance required ( but this must be checked as some aftermarket valves aren't ) so a true 7mm guide bore should result in the correct clearance.

 

wrote:

wrote:

Far right is the draw bar. Middle is the insertion guide for the bucket bore and left is the glorified nut which has a 45 degree taper to centralise it on the valve seat . 

 

Quick question. I am thinking on maybe replicating your tool. Is that m6 thread on it? Is it strong enough to draw insert in?
I really like idea of using aluminum bush to center guide in place. I may just do that and use my press instead of dealing with threads, nuts, etc

Yes! it's a 6mm thread. Couldn't go any bigger, well maybe 1/4" imperial.
Was wary it may not be up to the job when i made it but it works fine and has done many, many guides.
The draw bar is made from a spare swingarm spindle so good tensile steel.