Adjusting valves on SBC after cam install

tnman · #1 (**permalink**) 02-03-2005, 08:20 AM

I just installed a new cam a little bigger than stock in my 350. I used a method I read somewhere to adjust the valves. Basically get TDC on a cyl then adjust another cyl, rotate engine and continue until you've adjusted all valves. I know I got this part right.

My question is, I adjusted the valve by tightening the rocker arms until I could barely turn the pushrod, then went 1/2 turn more. Is this too much? My brother-in-law said I should have stopped at the point I could barely turn the pushrod, then started the engine and adjusted from there. I really don't want to mess this up. What are your thoughts?

wally · #2 (**permalink**) 02-03-2005, 08:29 AM

Loose is better than too tight...may I suggest you get it running and adjust them running. That always works for me but many use the other static method successfully. Bit of personnel preference I think...also more mess with adjusting while running.

bracketeer · #3 (**permalink**) 02-03-2005, 10:27 AM

I reciprocate the push rod up and down until there is about 10 thou clearance. The I spin it between my fingers until it just starts to drag. Then 1/2 turn. Never touch them again.

**Siggy_Freud** · #4 (**permalink**) 02-03-2005, 10:29 AM

Assuming you are using flat tappet hydrualic lifters you should be okay. There is a bit of leeway in preload. I usually go 1/2-3/4 turn after up and down play is gone.

wally · #5 (**permalink**) 02-03-2005, 10:43 AM

nice thing about when its running and you adjust you got no worry about them being primed/pumped up....static adjustments depend that they are all primed/pumped. And me thinks 'tight' by feel is a personel thing..some risk is involved.

Matts99Sierra · #6 (**permalink**) 02-03-2005, 11:03 AM

i just start the engine, loosen up the rockers till they knock then tighten them down thill they stop then you can either go 1/4 or 1/2 turn more. i usually go 1/2 turn just to ba safe. doin it that way is pretty messy because you have oil splatter but thats the easiest way i've found.

bracketeer · #7 (**permalink**) 02-03-2005, 11:38 AM

Quote:

And me thinks 'tight' by feel is a personel thing..some risk is involved.

Most Harleys, if not all, have the valves adjusted with the engine off. You cannot adjust the valves with the motor running because the valves are adjusted by lengthening the push rods. And it is done by rotating the push rods between your fingers until they drag.

NXS · #8 (**permalink**) 02-03-2005, 12:39 PM

Quote:

Originally posted by wally
And me thinks 'tight' by feel is a personel thing..some risk is involved.

http://hotrodders.com/showthread.php?s=&threadid=52681

wally · #9 (**permalink**) 02-03-2005, 12:59 PM

Glad I aint got a Harley. On my Goldwing they were adjustable on the bike.

JohnyR17 · #10 (**permalink**) 02-03-2005, 01:24 PM

Adjusting hydraulic lifters while an engine is running doesnt have to be messy.
Get an old pair of valve covers and cut a 1 inch wide strip out of the entire length of them.
Now the rockers can be adjusted without spilling oil everywhere!

**Siggy_Freud** · #11 (**permalink**) 02-03-2005, 01:29 PM

If you take your time and do it right by adjust when the lifters are on the back of the lobe you wont have to adjust them while its running. I adjust them with the engine off and havent had to touch them since. No mess involved.

Matts99Sierra · #12 (**permalink**) 02-03-2005, 01:39 PM

JohnyR17.... thats a good idea. i never would have thought of that.

bracketeer · #13 (**permalink**) 02-03-2005, 02:39 PM

Quote:

Get an old pair of valve covers and cut a 1 inch wide strip out of the entire length of them.

I don't think that's the way GM does it but I have used that method before. I still have the covers on the wall collecting dust.

Siggy_Freud and I use the same method and never come back for readjusting. I was taught this method by a race engine builder.

I know one engine builder who set his by watching the lifter plunger drop.

Troadster · #14 (**permalink**) 02-03-2005, 03:09 PM

bracketeer I was taught like the engine builder you know.If you look in Comp Cams book you are looking for .020 to .040 off the retaining clip. This must be done with out oil in the lifter. All was pre oil after this is done. Chevy is easy at leas you have not tried to adjust a 351 Ford Cleavland. Don't know if you all have done one but it will drive you crazy. Also the valve cover thing is old school(Which I still have mine in the barn) they make a cool clip that goes on the rocker to do this job, you can git them even at your local auto parts(you know the zone/vance).

RAYFIN · #15 (**permalink**) 11-15-2010, 11:38 PM

I reciprocate the push rod up and down until there is about 10 thou clearance. The I spin it between my fingers until it just starts to drag. Then 1/2 turn. Never touch them again.

AGREE... with hydraulic lifters.

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