olds 307 and 403

I had a few more back off again. This time I used blue loctite, I did my setting with the lock loose then tightened with the nut.

oddball

Loctite?!?!

Keep the set screw loose. Set the preload/lash. Turn down the set screw. Give the wrench a good tug while tightening the set screw. The wrench will turn another 1/16 of a turn or something, but it'll be good and locked down.

If you just try to tighten with the set screw, then yeah, it'll spin right off.

olds 307 and 403

Thanks, that is how I tightened them the last time, they are much quieter now. I still haven't revved it up to see if they stay put.

TripDeuces

This can also happen if inexpensive studs are used. The ends need to be perfectly flat and square. The set screw can back off if not contacting the flat squarely. Makes it easier to back off. I tossed my first set of rocker studs for this very reason and got ARP's.

olds 307 and 403

They are the Comp Olds conversion studs. They look well made but may have enough wear to cause this.

coppercutlass

Clean the threads and do some green Loctite let it sit and you will be fine. I have never had em back off but have only used the ARP 5/16 3/8 studs with PRW's poly locks that come with their rocker arms.

cjsdad

DOOD! Green Locktite? That stuff is forever! I saw a tractor mechanic install axle bearings with that stuff because the bearings were loose in the housing. That tractor never came back either. If you must use it, yellow or blue Locktite would be best on an adjustable item. Red and Green require lots of heat to loosen once they set up.

coppercutlass

I thought the green was the light still ?? I though the forever was the red ? I know the blue is med//. On loctites website it says it can be removed with heat and hand tools. They strictly say to use heat on the red.

coppercutlass

seems like a great use according to specs. http://na.henkel-adhesives.com/indus...king-13227.htm

olds 307 and 403

I may put blue loctite, have a tube of the paste, on them all and make sure I really lock the poly locks tight, another one has backed off.

cjsdad

Maybe the guy used green on the tractor bearings because of the wicking properties. I never researched it so I just assumed (yeah, that word) that it was a permanent solution like the red. Mah Bad.

olds 307 and 403

Not sure I would use Loctite again, at least on the smaller lock threads. I could barely back one off with a 3/8" ratchet. I bought a replacement socket to fit the lock and readjusted any loose ones and really tightened them good with the ratchet, the Allen key wasn't enough. I pushed against the governor, 4700 RPM for 1-2, which isn't bad, 2 -3 is 5000+ but I let off. No more tick at all even after pushing it, sounds good.

coppercutlass

I usually bump em with a 1/4 in impact and socket allen. You really need em crancked. You can use a heat in to heat the Loctite upoo to help break em loose after its been used. Or a heat inductor. Those are nice but not cheap lol.

olds 307 and 403

Good to know, the tighter lash dropped the idle some. I plan an oil change, trans fluid change and put a new lock up solenoid in along with a locking dipstick, I need it for the track.

coppercutlass

How much lash you running . I would have ran 0 if I didn't sell the engine and was to hit the track again. I went from .040 to .020. Made a huge difference. .

FWIW I hold the wrench while I hit the allen set screw with the impact to not mess with the preload too much.

VinMichael

coppercutlass

The idle cleaned up. It always had a little roughness . The lope was still there but super smooth. Also up top on the rpm range it love it.

olds 307 and 403

I would say close to 0, curious to see what this motor runs in the 1/8 on Sunday. My idle may be slightly smoother but this cam has more loop than my old Performer cam.

OLDSter Ralph

So, you went from being able to put a .040" feeler gauge between the rocker and valve stem to a .020" feeler gauge ? ie. .040 to .020 clearance ?

coppercutlass

Preload not lash. I think the term lash was thrown out there by us as a generic term for pre load. but we are talking hyd. Cams so preload.

OLDSter Ralph

Lash and preload are very different. "Back in the day", we backed off the (aftermarket)adjusters to get " valve clatter" and tightened down to remove "valve clatter" ("0" lash). This was with hydraulic lifters.
"Back in the day", Oldsmobile recommended "shimming the rocker arm stands, with no greater than .015" difference within each rocker stand.
I would think this would increase actual valve duration to "advertised specs" and power ? Now your high RPM limitation becomes the valve springs.
If we exaggerate this a bit and preload .120", would it also keep valves open at TDC on the compression stroke ?
Ok, Joe, what do you think ?

coppercutlass

Well noted on the difference between the 2. I still use lash as a laymans term though as its.commonly used by many as such. I did my preload based off of what old stock racers did. Some would use .020 shims.under the rocker arms. The problem is most lifters at 0 lash will spit out the rataining clip unless its a 0 load lifter like lunati uses on the voodoo line.

OLDSter Ralph

"Lash" in your previous posts on different threads did confuse me. Now I know you are referring to "preload". Shimming the rocker arm stands would reduce preload on the lifters. How are you shimming the rockers ? Are you putting shims on top of the rocker arm pivot ? A couple thousanths preload won't hurt anything.

coppercutlass

I run studs and ford rocker arms. I just adjust them based off of the thread formula. Half turn is roughly .040 so 1/4 is .020 etc etc. I have never shimmed stock rocker arms i have no desire to use them in anything i build.

OLDSter Ralph

So, you were going toward .000" preload on the hydraulic lifters.

coppercutlass

Yes. Saw improvements across the board

My442

When setting the hydraulic lifter preload, you have to take the ball end of the pushrod into consideration.

On the Harland Sharp pedestal rockers: The current 50026A rockers use a 3/8-24 thread adjuster. This is equal to .042 per turn. If the adjuster is a 7/16-20 then it’s .050 per turn.

So if you go one full turn, the preload is the .042" to .050" amount plus half of the diameter of the pushrod ball end.

On roller rockers, I only go 1/2 turn past zero for the preload.

And, the only rocker studs that work are from ARP. They have a superior end that locks down the set screw.

The Comp Cams rocker studs were junk.

coppercutlass

Everything i have read regarding a 3/8 24 stud leans towards appx .040 preload with half a turn. But then again the math equation make sense .

OLDSter Ralph

I generally go 1/8 to 1/4 turn after valve clatter stops. .0416" or .042" is correct for 24 threads per inch. .050" is also correct for 20 thread per inch.
Here is some interesting reading from" back in the day".
1. Google "Rich Powers W-31 Oldsmobile". (use quotation marks)
2. Read the BuickV8 thread on wildaboutcars.
3. Also read the untitled .PDF which is a scan from SS FX magazine Feb 1970.
(sorry, I don't know how to add the links)


While they had to use "stock valve train" for stock classes, the concept of setting lifter preload is accurate.


Using Perfect Circle internal snap rings on valve lifters is also explained.


I had the pleasure of talking to Rich Powers "back in the day", since I had the direct number to his phone.

olds 307 and 403

I go by any ability to move the rocket arm side to side, I am probably the 1/4 turn past that. They are Scorpion 1.72 ratio SBF true roller rocker arms.

oddball

?????????????
One has to find zero lash on hydraulic lifters. My preferred way to find that is to twist or jiggle the pushrod. You're at zero lash the instant the pushrod starts to tighten up. The rocker will still be very loose at that point - particularly side to side, but the pushrod end shouldn't be able to move up and down easily. An empty or dry lifter can be compressed with your pinky, so just ham-fisting the rocker will make it move. Your process there would completely collapse an empty, loose or fast-bleed lifter (the internal springs aren't strong).


And, again, loctite on poly locks?!?!?!? Holy cow.

olds 307 and 403

I am basically doing that by removing play in the rocker arms, weak hands and oily pushrods isn't accurate either. I am going maybe a 1/4 turn at a time. Other than ignition issues and a small trans leak, pulling fine past 5000 RPM and much quieter, no more loud clattering. I wouldn't use Loctite again, I just wasn't cranking the locks tight enough.

TripDeuces

Side to side movement of the rocker would be controlled by the push rod guide plates that you need with those rockers. Trying to stop rocker side to side movement with polylocks is not the way to do it.

You're using those, correct?

olds 307 and 403

Yes, Comp 5/16 to 3/8" adapter studs and 5/16" guide plates.

CDNW30

So, did you make it to Yorkton for the test and tune ?

olds 307 and 403

I was on my way there and stopped at the Mall parking lot in Yorkton. I noticed a trans leak, the dipstick tube is leaking. A small leak but I would not have made it through tech. I considered fixing it but also had issues with the Mallory distributor as well, which I think is fixed. I may see if I can scrounge the dollars for a torque converter, I plan on making the August test and tune, torque converter or not.

83hurstguy

Don't confuse a pedestal rocker like My442 described (adjuster directly acts on the pushrod) vs a typical roller rocker with polylock on the stud. The half turn on the polylock results in more lifter preload than the direct-acting pedestal rocker adjuster because of lever ratio. More people fall into the trap with pedestal rockers assuming that half a turn is sufficient...

Last time I had to do this, the cam manufacturer recommended having 0.030" lifter minimum preload if the lifters have the wire retainers and not high quality snap rings. The wire retainers can't handle the abuse of running at zero preload.

coppercutlass

I have never ran pedestal rocker arms . Knowing what I know from running my old set up I will use tru lock lifters or whatever they are from lunati that allow you to run them at zero load. But I did not catch that one. Good call. But if you are running a pedestal rocker arm couldn't you just use a dial indicator on the end of the rocker arm to measure drop or "load" on the lifter since its directly over the lifter ?

83hurstguy

The end of the pedestal rocker doesn't move, only the threaded adjuster does, and trying to fit a dial indicator on the adjuster along with an allen key is almost impossible. So you basically have to know your thread pitch and set accordingly... 3/4 turn for 0.030" preload with the H-S pedestals.