Lifter noise

[Leny Mason]

A friend built a 390 for a 1969 Cobra clone, when he starts it up it sounds like bad adjusted solid lifters, it has 50 psi oil pressure at start up as it warms up the oil comes down to 40 psi and the lifters start to quiet down one at a time, then you shut it down wait and minute and it starts all over again noisy lifters and then they get quiet again, any Ideas what causes this ? I have never seen this before. Leny Mason 

[BigBlueIron]

What viscosity of oil?

[shady]

bad filter?

[Falcon67]

50 wt is more than a bit much to have in there.  I would change the filter and oil to 10w-30 VR1 and see what it does.  50wt is neraly engine assembly lube.

[shady]

maybe pushrods are on the slightly short side.

[Leny Mason]

The oil is 10-30 and a remote filter, the filter was my guess I hadn't thought about the pushrods being to short, Thanks Leny Mason

[blykins]

Roller cam?

[Stangman]

Maybe the remote filter is draining out and it takes time for it to fill. should there be a drain back valve. 50 oil pressure cold seems low and 40 hot seems high.

[338Raptor]

I assume they are hydraulic lifters.
Either way, I think the best action is to start my readjusting your lifters making note if anything was out of adjustment. While the valve covers are still off look for signs of proper top end lubrication by pulling the distributor and spinning the oil pump to view the top end oil flow. Doing this will help you eliminate some basic stuff if the noise remains.

[67428GT500]

Don't run 10-30 on flat tappet cams. FE's rarely have any issue with valve train oiling. They are fed direct, not push rod oiling with rare exception.

[blykins]

Don't run 10-30 on flat tappet cams.

Why?

The camshaft type has absolutely nothing to do with the viscosity of oil that’s used.

[Leny Mason]

He said it has all kinds of oil with the valve covers off I am not sure if it is a roller I will ask. Leny Mason

[427LX]

Sounds like it's taking a bit of time for the lifters to get pressurized oil since they quiet down after start up.
Leaky/bad lifters will act up after oil gets hot.

[67428GT500]

Don't run 10-30 on flat tappet cams.

Why?

The camshaft type has absolutely nothing to do with the viscosity of oil that’s used.

Barry and two other builders suggested I stay away from multi-viscosity oil on a flat tappet cam. I run straight Penn Grade 30. I had cold, 35-40 hot idle and 70 at cruise. (3200 @ 65)

                                                                                         -Keith

[blykins]

Hmm, I'd have to get them to clarify because that makes zero sense.

The viscosity has nothing to do with a flat tappet camshaft.   On top of that, the multi-viscosity only means that the oil behaves differently when cold and hot.  So, at hot cruise, a straight 30W oil behaves exactly the same as a 10W-30 oil. 

Break-in is a different scenario and typically the Brad Penn break-in oil only comes in a straight 30W.  However, they (along with Gibbs and a few others) make a 10W-30 for flat tappets that I use on a regular basis.   As a matter of fact, if I had built your engine, I'd be recommending Penn non-synthetic 10W-30 oil, or a Valvoline VR1 non-synthetic 10W-30.