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Austinsevenfriends
Valve Seat Cutters - Printable Version

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RE: Valve Seat Cutters - Bob Culver - 15-12-2020

All covered in some detail very recently. Restraint necessary as once metal gone it is gone. Serious grinding with a valve to be used should be avoided but much can be done with an old valve. And not being in a hollow as ohv seats can be narrowed with fine file, scraper etc.

RE: Valve Seat Cutters - Robert Foreman - 15-12-2020

Dave, 
my method is a little more scientific, I had a refaced valve diamond plated. 
A few rotations By HAND with a little paraffin and job done. Then grind in valves in the normal manner.

RE: Valve Seat Cutters - Dave Wortley - 15-12-2020

Reckless, I could have used my dad's old valve hand grinding brace but that's too unsophisticated. Robert hmmmm thoughts about that diamond ring of my missis's.... no perhaps not....!

RE: Valve Seat Cutters - tomcotez - 15-12-2020

Hi Renaud, i just sent you a PM.

RE: Valve Seat Cutters - Barry Townsend - 15-12-2020

I’m impressed with your resourcefulnesso

RE: Valve Seat Cutters - Ray White - 16-12-2020

(15-12-2020, 08:01 PM)Robert Foreman Wrote: Dave, 
my method is a little more scientific, I had a refaced valve diamond plated. 
A few rotations By HAND with a little paraffin and job done. Then grind in valves in the normal manner.

That sounds interesting.  I have heard of liquid diamond paste but not plating.

 Where would one find such a service please?

RE: Valve Seat Cutters - Renaud - 16-12-2020

(15-12-2020, 08:01 PM)Robert Foreman Wrote: Dave, 
my method is a little more scientific, I had a refaced valve diamond plated. 
A few rotations By HAND with a little paraffin and job done. Then grind in valves in the normal manner.
Same with the little Neway:

[Image: dsc_2024.jpg]

which is tungsten carbide.
Some manual turns only are enough. Very good finish and then I also use some paste grinding.
One has to machine the "pilote" which centers the 3/8" mill in the valve guide.

[Image: dsc_1420.jpg]
As can be seen this 30 mm mill can be extended for larger valves.

RE: Valve Seat Cutters - Zetomagneto - 16-12-2020

I have the Neway ones, they are excellent but not cheap. Neway do the mandrels as well to guide the cutter.
Essential that the valve guides are unworn for best results

RE: Valve Seat Cutters - Robert Foreman - 16-12-2020

Hello Ray, 
the plating process is the same for needle files you can buy. 
   Unfortunately the company I used was about twenty years ago and I'm not sure if they are still trading.

RE: Valve Seat Cutters - Renaud - 18-12-2020

My offer about the Neway has got interest from another member here. I'll lend it to him but as I have no mandrel for A7 I will machine one. Mandrel is 3/8" and guide 9/32" (7.144mm)
Hence I would like to know the dimensional tolerances of the valve guides. Maybe also of the valve stem?
And confirmation that the cut angle is really 90 degrees?
Thanks