Oct 20. FREE Shipping. SIOUX VALVE SEAT GRINDING PINK STONES SET 24 PCS 80 GRIT SIOUX HOLDER DRIVE BALL. 5.0 out of 5 stars 1. Save 7%. $69.85 $ 69. 85 $74.99 $74.99. Lowest price in ...Grinding valve seats. The procedure for grinding a valve seat is as follows: 1. Clean the valve guides thoroughly so that the pilot will centre correctly in the guide. This ensures that the valve seat is ground concentric with its guide. 2. Select a stone to suit the diameter and the angle of the valve seat.The Valve Seat Grinding Stone Resurfacer . No. 1716 in very good condition. There are 24 stones with only two or three that show wear. Most are in very good condition. The set has 15 pilots in great condition and 5 reamers all clean with no chipping. The two stone holders are clean and look great.7 PCS GREY SIOUX VALVE SEAT GRINDING STONES 1-1/4" To 2" India's Best Quality. $46.99. $46. . 99. FREE Shipping. Only 3 left in stock - order soon.30 degree stone will lower/narrow seat contact on valve. 60 will raise/narrow the seat from the bottom. Other basic stones I use are a 15 and a 70 degree stone to smooth some seats. Stones can be dressed to about any angles and some operators have their pet setups.. I like 1/2 degree interference fit so i grind valves accordingly.Valve Seat Grinding Stones + Grinder Holder + Pilots + Drive Ball & Shaft . Sizes & Variations : ( for other combos please contact the seller ) (A) 11/16" Holder SIOUX,