cutters ?

[morrisman]

Hi

These cutters came in a box of bits . I think Are they valve seat cutters ? Mike

[Ropetangler]

Hi Mike, they don't look like automotive valve seat cutters as I remember them, but maybe you meant valve as in gate valve or suchlike. The automotive valve seat cutters as I recall them were the product of Warren and Brown, later part of the Repco group I think, and the ones I used came in various diameters, and the angles were 30, 45 and 60°. The cylinder heads that I rebuilt were of my own vehicles, a Renault R10 and perhaps a Peugeot later, (can't recall what I did to the head on the Pug), but on the R10 the valves were ground to 45°, and valve seats were cut at 30 and 60°, and then a small cut at 45° to give a narrow seating area less than 1mm wide. Other people did the valves at 45° say and the seat at 44.5° on their cars, mainly Holdens and Fords, so I 'spose that was the way they did those. The valve seat cutters used pilots down the valve guide for allignment.
I can't offer any ideas as to what your cutters would have been used for, but someone else will I'm sure
Rob

[.RC.]

Are they just not counterbore cutters?

I would guess the slot is to insert a wedge to knock out the pilot you use

[rogerbaker]

Hi Mike
I agree with Robs comments, however they may be valve seat insert cutters. Most valve seats are a hardened steel insert in the cylinder head which is usually cast iron or aluminium neither of which will withstand the heat or the hammering of the valve in operation. I would guess that that those cutters would be suitable for that part of the machining process either in manufacture or repair.

Roger

[morrisman]

Hi Mike
I agree with Robs comments, however they may be valve seat insert cutters. Most valve seats are a hardened steel insert in the cylinder head which is usually cast iron or aluminium neither of which will withstand the heat or the hammering of the valve in operation. I would guess that that those cutters would be suitable for that part of the machining process either in manufacture or repair.

Roger

Hi

Yes your probably correct . My old Land Rover has those hard exhaust seat inserts in the engine block , its a cross flow design with the inlets in the head . I've seen car manuals that refer to cutting the bores for the seat inserts . These cutters pictured are not very large in diam. , maybe 3/4" . Mike