Technical SBC Valve Lifter Question?

Recently installed a Lunati 220/268 Voodoo series camshaft and lifter set in the 350 Chevy in my 32...NOT my first cam install in a Chevy engine....I have properly adjusted the valves to what the cam maker specified as 0 lash plus 1/2 turn....I re-adjusted to 0 plus 3/4 turn...Anytime the engine sits for a period of time such as several hours or overnight....They chatter until oil pressure reaches the bled down units...I usually run Valvoline 20W50....I changed to a thinner 10W40 and with No improvement..I called the Lunati tech line and was told this is normal...In the numerous SBC cams I've installed over the years..I have never had this issue.. .Your thoughts are appreciated..Thanks

 

you could install a different brand of cam and lifters, from a company that realizes that Lunati's version of "normal" isn't what it should be

 

Why does a Tom Jones song come to mind?

The thinner the oil, the more likely it is to happen. Lifters that are up on the ramp bleed down over time, some just faster than others.

Or as Tom sang, "It's not unusual".

 

I understand being at full lift on multiple valves...But I've never experienced this issue to include the Comp Cams 280H that I removed (Too much cam for the rest of my driving and combo)

 

I just installed a new set of Morel 5372 hydraulic roller lifters in my SBC. The instructions said not to use any oil heavier than 15w40. For high rpm lifter nothing heavier than 5w30. I use 10w30 and at least one of them will leak down if it sits longer than 2 days. I think it is the "new" normal.

 

I'm pretty sure Lunati's lifters are Morel's. Howards also. Made in the USA. Lippy

 

I guess my question is...Would you guys go to the trouble to replace with another brand or live with it?

 

I've lived with it in my wife's slightly OT car for a few decades...

 

I would not run a hydraulic in a hotrod anyway. Solid runs better, sounds better, Nuthin sounds better than an engine with properly adjusted solids.JMO.

 

If you like the cam -
Seems the mostly obvious experiment would be...install a different brand of lifters...

Mike

 

What kind of oil pressure do you run? If you don't mind me asking. Lippy

 

My rebuilt SBC 283 60 over has one noisy lifter that "tics" when it wants to. A frustrating noise but I'm just going to leave it alone. I had a T Bird 390 always "all lifter" chatter until they saw oil........

 

Oil pressure Cold around 60 PSI and Hot 45-50 PSI

 

I don't know what seat and over the nose pressure you have spring wise. Excessive like 30-50 lbs more seat pressure than stock can aggravate a hydraulic lifter. But most of the time it's trash in a lifter that causes it not to seal internally and bleed off. The internal clearances in a hydraulic lifter are very precise (In a good lifter) when it gets debris in it, Not so much.

 

I would adjust them to 0 lash or 0 plus about a 1/4 turn. Make sure you have a good oil filter that is not draining back.


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Kevin, do you run an oil filter with a checkvalve? Can you please explain to me how the filter, (other than being dirty) would affect the lifters bleeding down? Lippy

 

This is a new problem for me with a Chevrolet...I am using an AC filter...I hate hearing it clack...But not crazy about doing the job over or the cost of another set of tappets/gaskets etc

 

Asking seriously , not being condescending , are you positive its a lifter & not an exhaust leak ?

 

Def not an exhaust leak...I had hopes that is was..Also this seems to be consistent to the right bank of the engine only....Which makes me think there are defective lifters Its a standard bore 350 with flat tops and 462 heads with so called Z28 springs..Screw in studs and guide plates

 

Can't compare oil viscosity needs for a roller lifter with a flat tappet lifter. I ran into trouble recently with all sorts of weird valve train lifter/rocker noise on my first SBC roller camshaft. I called Howards cams and their tech told me roller lifters have tighter tolerances, and should never use oil with a rating of over 30 wt.. He suggested a 10-30 or 5-30 wt. oil would be best and solve the lifter issues.
Flat tappets can use much heavier oil wt. and no issues with 50 wt. on them.

 

I bought a set of tall finned valve covers for my sbc. I am running a crate motor with stock cam and a tri-power.
So after putting the valves cover on I developed a ticking noise. I pulled the covers and checked every thing and put it back together. Again, valve train noise. Pulled them off and started it up, noise went away. Turns out the intake was rubbing the valve cover just enough to push into the valve train. I put some clearance in the cover and reinstalled. No more noise.

I have put in a fair amount of cams over the years and never had lifters bleed down in a couple days. If that is the new normal, something is wrong with our industry.

 

Another thought, so called Z28 valve springs, did they come with retainers? Check to make sure the rocker is not hitting the retainer. Change push rods? If so check the length.

 

Eric, what springs did Lunati recommend? Lippy

 

Not a check valve. A drain back valve.

Most filters these days have check valves in them, and the primary one is an anti-drain back valve. That anti-drain back valve prevents the oil from being syphoned out of the filter when the engine is shut off.


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If you want to know which ones are bleeding down, let it set overnight and pull the covers off. Then press on the pushrod end of the rockers and see which ones you can push down. Just a thought. Funny it would be just one bank. Lippy

 

Thanks Kevin. Lippy

 

The springs were the existing ones that came on the heads. They were refurbished a few years ago. I wasn’t really having any problems so to speak with the engine before I changed cams. I just felt it was over cammed with the Comp 280 Mag. I think the compression is around 9.3-1 with the rest of the engine combo. Anytime there is a cold start it’s clack clack for about 2 seconds until it gets oil. Annoying on a new Cam and lifters when the old one didn’t do it.

 

Isn't something impeding the oil flow to the lifters on that bank?

 

kevin may be on to something . Didn't the O/T 5.3 gm engines have a problem with noisy lifters on start up until they went to a different # filter. Not saying this is the problem but... Gotta go back to work. I'll tune in later.

 

The ‘142 spring is 100# on the seat and the same diameter as a stock spring so it takes the standard retainer. Should be no problem there.