Re: maximum wear for 356 valve stems?

Posted by Owen_Dyneto On 2011/12/4 12:11:17

Just to add a little information, I took some measurements from my KD-815 (11/32) valve guide driver. Very easy to make one if you have access to a metal lathe. Start with about a 6 inch length of steel rod, plus enough length to chuck in the lathe, diameter of 3/4 or 7/8 or even 1 inch inch would be fine. The bottom (first) section which enters the guide should be 11/32 diameter and about 1-1/2 inches in length, exact length not critical, give or take an 1/8th or so. The middle step, that which rests on the top of the guide and forces it down needs to be large enough in OD to cover most of the guide top surface, yet small enough to enter the hole in the block as the guide is driven down. For this, turn the next section to 0.550 inch in diameter and about 2 inches in length (again, not critical as to length). For the top and largest diameter section, you want something to comfortably get your hand around, and tall enough to get your hand and the hammer strikes above the protruding studs. About 2-1/4 or 2-1/2 inches in length will do it, and a diameter of 0.750 is reasonable. Thus if you start with some 3/4 inch steel rod, you only have two steps to machine.

As to breaking off the lower portion of the guide as it emerges into the valve chamber, it may sound scary but they snap off like glass - no problem. But do cover the exposed valve train and especially the oil drain holes to the crankcase just to be sure no debris can drop into the lifter bases or the crankcase.