Valve adjust on a small block Chevy

[RANDY P]

Originally posted by indigowhale
My friend is trying to get a small block running right and he came accross this procedure. Seemed crazy to me. The rebuilt engine had some of the rockers eaten through by the valve stems only after 2000 miles. Some rockers were way off center without any hope or guide to keep them in place. I'd never would have believed that such a poor design keeps these engines running. One of the lifter rods was bent.

How does he know if he has hydraulic lifters? I think the block came out of a 74, went into an 86 Chevy S10 side step.

I would suspect that something is seriously out of whack with the length of the pushrods or maybe the base circle of the camshaft is the wrong diameter - that would be a new one.

I would assume that the issue with the rocker alignment is that there's binding - the pushrod must be hitting the inside of hte head where it passes through - in this case either -

1) a serious misalignment between the block and head missing dowl pin on block?

2) head or block have been shaved to the point where a standard pushrod is now too long for proper geometry - this would be a rare situation - but if someone shaved the head for more compression it's possible. however that's a hell of a lot of metal removal to get that kind of misalignment. Intake manifold wouldn't seal up properly anymore either unless that's been cut down to match.

If you've gotten broken rocker arms, are you sure the camshaft and crank are sync'd right? If the camshaft is radical it probably pushed the valves into the piston -- and you might have coil binding up top too. Judging by the way this thing sounds this is probably not too far off.

You might have to rip it apart, but fortunately, it's just gaskets and a lot of cussing. Shouldn't be more than a day and $50 or so for all the extra stuff you need.

[Westy]

Forget the messy valve adjusting. Just get an old Chiltons at the flea market and it will explain it. I'm amazed at all of the people that put the clips on a running SBC and try to adjust the valves. Oil on the headers is my favorite breath of fresh air.

My book is at home so I can't quote it, but you bring the motor to TDC (compression) and adjust a couple of valves to where the lifter is tuff to turn, then go 1/4 to 1/2 turn on the nut. Rotate the motor, do a couple of more. Repeat until done. I just can't tell you the order of adjustment without my book. I've done this a dozen times and only once had to readjust one lifter. And that was because I lost track of where I was. I think it was the beer.

Good luck.