What is the Dumbest SBC Valve Adj Mistake?

...'Cause whatever it is, I'm making it.
I just replaced a rocker and pushrod in my 305. Figured I ought to readjust all the valves, so I did that and it still went clack/clack. So I did it again. And again. Each time I'd run the engine, turn it off, then check the adjustment; it was different than how (I thought) I'd just done it. Always looser than where I'd left it.
So I've now adjusted it several times, and it seems to be getting where it is not "changing"(was it ever really changing?), and the engine is running and not stalling when I step on the gas, but I'm still hearing a click/click that sounds like valve train noise.
I've spent several hours on this and am pretty frustrated.
What stupid thing am I doing wrong (Yes, I'm sure it is the most obvious thing, I just can't see it), and is there anything else I should check that makes a sound like a slappy valve train?

 

just curious, where is the piston in the cylinder who's valve you're adjusting? and is it at the firing position or between exhaust and intake when you're adjusting it?

 

Exhaust leak?

 

the way i like to do it is a bit diffrent then most peoples but it works the first try and ive never had a problem.

First make sure the valve is closed (rocker arm wil be higher) car would be off for this

Second take your 5/8" socket and tighten the jam nut untill you can no longer spin the pushrod with your fingers.

Next u want to back off the nut untill you can spin the pushrod (<edit)

then crank the motor over and do all the ones that "up" this time.

just keep checking them. and it should fire up with out any noise first try and be set.

 

I'm doing this static per my Chiltons:
With #1 at TDC I adjust Exhaust-1,3,4,8
Intake-1,2,5,7
Then rotate the crank 360 degrees and do
Exhaust- 2,5,6,7
Intake- 3,4,6,8

 

It sounds to me like a lifter may be bleeding off or an intake lobe may be down. It's really hard to say without being there to help.

 

the first motor i had ever built, the rockers were adjusted until "i wasnt able to spin the pushrod"... wound up grinding 2 cams.

3rd time i adjusted until there was no vertical play and the pushrod had slight resistance, worked well.

if the motor has been sitting awhile and you have hydraulic lifters, it may take some time for them to fill with oil.. if not, you might have a collapsed lifter or two...

ive had odd ticking/clacking sounds before and traced it to the rockers hitting the valve cover... i had installed some repro stock chrome covers and the cam had a lot more lift than stock... i pounded out the offending areas a bit, modified the oil baffles and added 1 thicker valve cover gasket to the thinner rubber gasket that came with the set... problem fixed.

 

Damnit thanks for pointing that out.. i ment to say Then back it off slightley untill you can spin it damn some help i give

 

yeah, it's bad news to tell someone to do it that way if they don't understand what's going on.

The Chilton method may work, maybe not though if the cam has a lot of duration. I always adjust the two valves on each cylinder as it's in the firing position, at TDC, start with 1 then turn the crank 1/4 turn and do the next, go thru the firing order like this. There are other methods that work.

but there could be other stuff wrong with it to make noises.

 

fyi - tell tale signs of a ground lobe... backfiring through the carb and shitty to no idle.

 

do it while its running, then you know when it stops clicking,

another thing to check, is the locking nut worn where its backing off, ive had this problem

JEFF

 

That's my method also, how long have you been doing it like that?
-ps- I also use poly locks, I think they really help b/c you can run them down by hand until the nut stops them give a 1/4-1/2 turn.

 

I adjust one cylinder at a time.. with a remote starter switch bump it until the intake just starts to close and adjust the exhaust.. bump it again until the exhaust just starts to open and adjust the intake....

CC

 

Don't try that with solids.. not suggesting that you would but I know a guy that just did exactly that & didn't understand why it wouldn't run..

CC

 

? Maybe i don't understand what you're saying? Maybe you mean to disregard the cam card and not use any lash? I would never do nor suggest such a thing,LOL!
But I do take the same method and set the lash like that {place the feeler gauge under the rocker tip and run the poly lock till it stops}.
First I take the balancer and mark it every 90* {ie, 1/6 @ 0* then 8/5 @ 90* and again 4/7 @ 180* and finally 3/2 @ 270*}. You just bring to to TDC on the compression stroke on #1, set it, turn the balancer 90* and #8 is on TDC compression and set it. Continue down the line like that for a sbc. Same thing on any 90* engine, just mark your balance in your engines firing order.
If you don't use poly locks use the thinnest feeler gauge possible and pull it in and out {from between the rocker tip and valve} as you slowly tighten the nut. When it just binds pull it out and give the rocker nut an additional 3/8 turn {or whatever you can card recommends, be it 1/4 turn or 1/2 or 3/4}. I just like a 1/4 to 3/8 turn personally. it seems to free up power to me although I've seen dyno results with a 383 mopar and they continued to increase power until all the lifters avalible preload was used up. Also, if a rocker is set to 1/4 there is less chance of lifter pump-up at high rpm.

To the OP, if you can pull the valve covers off and have a buddy crank it over {with the +12v unhooked from the coil/dist} and watch to make sure that all the rockers are moving an even amount. if any are not opening all the way check for a collapsed lifter by pushing on the pushrod real hard. If you can push it down by hand it is weak and may need replaced. If you can't push it down by hand the lifter is probably good and a lobe may be down.
good luck!

 

No, as I said "not suggesting you would" ... there's a lot of people that read these posts.. someone less mechanically inclined might might take that statement literally and adjust their solids that way..just as my friend did..


CC

 

My buddy had a set of heads reworked once and I put his engine back together and set the rockers, drove it to him at work and everything was fine. He called that night and said "I thought you said you knew how to adjust the rockers, these things are clattering like crazy!"

Took awhile to realize all the "press in" rockers studs were pulling out. Guess when they hot tanked the heads they came loose.

 

I'm thinkin' what new2u is thinkin'. Might be a bad lifter or cam. Are we talking about solids or hydraulics? Why did you replace the rocker and pushrod in the first place? I tried to adjust my uncles 307 valves one time that clattered. Turns out the 2 that still clattered after adjusting were worn through on the bottom, had a hole straight through! The Chevy Helms repair manual says to turn to TDC on number one, then half the valves can be adjusted. Turn it over one full revolution and the other half can be adjusted. I've used this method, it works. I can look which ones are in each half if you want to try this.

 

I've had mechanical SBC fuel pumps make a noise that was impossissible to differentiate from valvetrain noise, until I got out my "stethoscope".

Also, to an inexperienced ear, piston slap might be mistaken for valvetrain noise...

 

valve closed, tighten to zero lash and then go a 1/4 to 1/2 turn........works for me.

 

It sounds like your adj method is reasonably correct. However on a new set of lifters that haven't been prelubed it is possible to bottom them out by hand.Also if you are running higher than stock spring pressure oh say 125 or 135 on the seat closed without screw in studs or a cam that has more than 500 lift with the stock springs and some shims under them (can you say coil bind) it might be trying to pill the studs like dukofbluz mentioned.Or you could just be one of the unlucky ones whose cam is going flat.
Word around the campfire is,it seems that there has been a rash of bad lifters floating around in the market in the last year or so.
Intersted to know your outcome,T.OUT

 

WELL....Ya didnt read my post on your other post did ya?
Its butt simple man,for one thing ya didnt need to set but the one you replaced.
But thats past now.Start it up with one valve cover off-[running]- and do as I indicated. loosen each rockers nut till it clicks- Then tighten till the tick stops[in slow deliberate 1/4 turns]......when the tickin stops -TURN ONE MORE HALF TURN and you're done...
Actually you may need a new set of lifters.....especially if any were overtightened in your attempt to adjust them.......

 

I know a guy that put shop towels on the headers so oil wouldn't get on 'em

Somewhere is adjusting them the phone rang and he went into the house to answer it

When he came out the car was BURNING!!!!

Honest!!! Anytime I feel really dumb I think of ALL that

 

Evidently you can read get a book for chevys they sell them at 7-11

 

I also had a problem with worn locknuts on my SBC. Had a set of rebuilt heads, and i'd set the valves, drive it for a few minutes, and they'd start rattling. Only I figured out it was two valves on one head, and one on the other. Luckly, I had some more nuts that size, so I double nutted them. Which isn't as kinky as it sounds. Come to think about it, I think they are still on the motor, so they held up through some high rpm launches. Does adjusting your valves and getting soaked in oil on the side of the road count as hardcore? BTW, it's amazing how a far a moving rocker will knock a socket out of your hand...

 

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This is the EASYEST way to adjust your valves on a half-warn-out ol' Chev engine. If Choprods method don't work, OR LAST AWHILE, your engine is ready for some internal parts replacement, but his way to adjust them is as quick & easy as your going to get..READ his post again, and just do it.

 

I have seen the fuel pump old and slopy make the valve out of adjustment sound also on SBC.Hot rod to hell may be on to something.

 

I might get slammed a bit for this but the way I adjust valves is ... I pay my engine builder

 

Just start the damn thing up .loosen one valve at a time untill it starts to click .tighten it till it doesent then go 1/4 turn more. Thats enuff and they run good . If all the noise goes away but comes back in a bit your cam is junk and after you set the valves it just keeps wearing away cause your in through the hardened case of the cam. If the clicking just cant be adjusted out then the fuckers junk also. or a lifter is collapsed...
Dave
ps: oil is gonna squirt at ya so watch out.

 

Check to see if your timing chain is stretched.