norcalz28

iTrader: (13)

I've heard a lot of back and forth about how to properly adjust the valves on a SBC, and I want to know who is doing what, or who's had good luck with their respective method of doing it. I am building a new 350 using the gm zzz crate as a base. I have installed a new cam, heads, and so forth, but I want to know how to properly adjust the valves when the time comes. Any help would be appreciated fellas. Thanks

Will

Guest

Engine running is the best and easiest way.

If there's so much other nonsense noise going on the book method is fine for 99% of us. I have a car I have to do that way, while running I cant hear over all the other noise and I have pretty good hearing.

Book method:
TDC, adjust a bunch of various valves
Turn crank, adjust a bunch more.

I personally wouldnt bother doing them one/two at a time like some recommend.

norcalz28

iTrader: (13)

Yeah, I get the basic premise, just don't know which ones to adjust when/where. And for that matter, how much to adjust them.

Will

SilentNight1647

Alright this is the way I do it, turn the crank until the a few rockers are all the way down and there is no pressure on the valve spring or pushrods. Tighten the nuts down to the desired lash using a feeler gauge or spin the pushrod as you tighten the nut and stop when you feel resistance. Don't do the book method that sys to tighten them another 1/4 turn or so after that, it will have issues. Again this is my personal experience so your results may vary. Good luck with your project.

327_TPI_77_Maro

iTrader: (8)

It really depends on what lifters you are running. For a stock type non fast bleed lifter, you want 20-30 thou preload (1/4 turn gets you close). For a fast bleed type lifter (like the comp pro magnum $600 retro roller lifters I am running), you only want 0.002-0.004" lash. Flat tappet fast bleeds adjust similarly.

jtrescot

I have always hated adjusting hydraulic lifters. My experience is strictly with flat tappets, but I would think rollers are about the same. I am currently assembling a 350 for my truck, and just got done doing the lash (still on stand). I let the lifters soak in motor oil for like 2 weeks before doing it. I tightened the rockers (stock type), while on the base of the cam, until the pushrod could no longer turn freely, and then went another 1/2 turn. The very next day I could turn the pushrods again with my fingers. WTF? I firmly believe the best way is while the engine is running. It may be messy, but it sure is effective. Back off until it clatters and then tighten until it stops, go another 1/4 to 1/2 turn. Button it back up and forget about it. I went with a solid lifter cam in my GTA, and half the reason was because feeler gauges can't lie or mislead you while setting lash with the engine not running.

Guest

With the engine in the #1 firing position
-Exhaust 1, 3, 4, 8
-Intake 1, 2, 5, 7

With the engine in the #6 firing position
-Exhaust 2, 5, 6, 7
-Intake 3, 4, 6, 8

What lifters? If they're normal lifters, car running, tighten down to zero lash (thats when the noise goes away), then 1/2 turn. I wouldnt run less than that, not enough preload. 1/4 turn isnt 20 thou, more like 10. You should set them at .020-.030 if they're normal lifters. If they're not, follow the manufacturers recommendations for preload.

327_TPI_77_Maro

iTrader: (8)

Woops you're right. 3/8-24 gives you around 20 thou at 1/2 turn from clacking. I am usually running the near-zero lash fast bleed high rpm hydraulics.

Pat Hall

iTrader: (31)

[QUOTE=madmax;3502310]With the engine in the #1 firing position
-Exhaust 1, 3, 4, 8
-Intake 1, 2, 5, 7

With the engine in the #6 firing position
-Exhaust 2, 5, 6, 7
-Intake 3, 4, 6, 8

Use this method to get them in the ballpark when you're putting a new engine together. Then once you get it running and warmed up good, adjust them once more with the motor running. Back off the nut until it starts clacking, tighten it until the clacking noise stops, then go 1/4 to 1/2 turn more. When you're doing the cold adjustment, if you have the intake manifold off, it's really easy to set them. Just watch the plunger on the top of the lifter, and tighten the nut until the plunger goes down about 20-30 thousandths. If the intake is on, tighten the nut while rotating the pushrod with your fingers. As soon as you start to feel a little bit of resistance, you're there. Either way, just make sure to do a final adjustment with the motor running.

Guest

No need to do things twice. If you set it with a dial indicator cold, its done.

Pat Hall

iTrader: (31)

Point noted. I hate messing with dial indicators though. For me it's always been easier to just "ballpark" them cold, then do the final adjustment with it hot and running. I dunno, I guess I feel like it's a more "real-world" way to do it anyways, since the lifters are pumped up properly when it's running, so there's zero margin for error as long as you know how to set them properly.

Guest

I prefer engine running adjustment myself, I just happen to have one car I cant do that. Too much other noise. Its a pain using a dial, but it works fine.

Oh while we're on the subject, spinning the pushrod is a horrible way to determine zero lash. Hydraulic lifters can start to collapse under the load and still allow you to spin the pushrod, throwing the preload off.

Pat Hall

iTrader: (31)

Oh while we're on the subject, spinning the pushrod is a horrible way to determine zero lash. Hydraulic lifters can start to collapse under the load and still allow you to spin the pushrod, throwing the preload off.[/QUOTE]

It is pretty hard to tell where zero lash is by spinning the pushrod. But if you pay close attention, you can usually feel just a slight more resistance when you start depressing the plunger. Ideally though, I much prefer to do it with the intake manifold off so you can easily watch the plunger while you tighten the nut down. With the intake on, sometimes it's possible to shine a flashlight down the pushrod slot and see the lifter plunger. In fact, it's pretty easy to see them on the self-aligning rocker type heads since the pushrod slot is big and round.

rgarcia63

I use the same pattern, with 1/2 turn, but cold.

evilemokid94

iTrader: (6)

Is 3/4 turns with the motor running too much?

327_TPI_77_Maro

iTrader: (8)

That's fine. The stock spec in the factory service manual for most SBC is 1 full turn.

Pat Hall

iTrader: (31)

Yeah 3/4 turn is a bit on the tight side, but it will work. I usually go 1/2 turn on mine. 1/4 turn is a bit too loose, and 3/4 is a bit too tight, so I shoot for the middle and go 1/2 turn with the motor running.

evilemokid94

iTrader: (6)

is this with hydraulic roller lifters?

Pat Hall

iTrader: (31)

Yeah, you can use that method with either flat tappet hydraulics or roller hydrualics.