dave blissett
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posted on 26/2/03 at 09:11 PM |
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valve seat cutter
i have access to milling machines at work and i am thinking of putting bigger inlet valves into a pinto head i have no problem with putting in the new
guides bronze
but where can i get a cutter that has the three angles in it i belive these are 30 60 and 45 but the david visard book sugests opening up the last
angle
i want to have a go my self as i am a tight b1111td
i dont care to much if i scrap the head as this is a spare one to experiment on
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paulf
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posted on 26/2/03 at 09:45 PM |
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I have machined a few heads and have used a number of methods. The easiest would be to fit the guides and then get an engine reconditoner to cut the
seats bigger, however if putting in larger valves the valve throats will also need to be enlarged.I would set up on the mill and drill and ream for
the guides first, then open out the valve throat to the dia required to suit larger valves using a boring head. Then make up three form tools of the
requred angles and machine the valve seat angles going slowly and carefully to avoid any chatter marks.
Finally fit the valve guides and finish the seats with a hand type seat cutter locating in the valve guide and then lap in the valves.
If you are fitting valve seat inserts you could turn the angles on them before fitting and then finish as above.
Pinto heads can be a bit difficult to set up as the valves are on two angles therefore you need a turret type mill such as a bridgeport or
similiar.
Paul.
quote: Originally posted by dave blissett
i have access to milling machines at work and i am thinking of putting bigger inlet valves into a pinto head i have no problem with putting in the new
guides bronze
but where can i get a cutter that has the three angles in it i belive these are 30 60 and 45 but the david visard book sugests opening up the last
angle
i want to have a go my self as i am a tight b1111td
i dont care to much if i scrap the head as this is a spare one to experiment on
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