Aluminum vs Cast Iron Noise Levels

[Drew Pojedinec]

I guess you should be happy a valve lock didn't pop out.  I dunno if they hit the edge that hard.
For picture reference, typical double springs vs beehives:

[unclewill]

Mine looks just like the first photo.  Something is still not right, even after clearancing.  Quieter for sure but still noisey.  Several lifters were soft when I pulled the rockers, but I tried running it anyway.  Small coughs and spitting at heavy throttle, 3000+ rpm.  Idle just not right, almost like a miss, vacuum fluctuates in rhythm by 1-2psi.  I'll try running it sans valve cover to see what's happening.  Seems like some valve(s) somewhere are having problems?

[Drew Pojedinec]

Geez would the *experts* show up already.... I hate for you to be taking info from someone like me....  here goes tho.

Order of operations for me if I was you:

-run engine and either use IR gun (or at the track we use a bottle of water to drip on each header tube to see if a cylinder is dead or weak).  Don't expect exact temps between cylinders, that only really happens with diesels, you are just making sure it's hot.

-put air to each cylinder to make sure there is no major valve leakage

-check each plug wire.  checking plugs may help you find which cylinders are being problematic.  Recheck timing, make sure nothing has changed

-prelube and while doing that, check on those soft lifters

-make sure all the pushrods are straight and none are bent a lil, also make 100% certain nothing else is touching what it ought not touch.



You speak of vacuum.  What size cam are we talking about here in this 482?  What kinda vacuum readings are you getting?  Have you tried capping every vacuum line and rechecking the numbers?

For an engine like this to not want to run easily at 3000rpms, there is something pretty wrong.  Hope it shows it's head.

[unclewill]

Thanks Drew,
The way I figure it, the only adjustment I have left is valve lash/lifter preload, so I will reset that next.  I am meticulous when setting up valvetrains so this whole thing is making me nuts, and I hesitate to make wholesale or multiple changes all at once.  Compression tests were OK, plugs looked like everyone is burning OK, timing is good, plug wires good.  I'll certainly check EGTs, good idea, and comp test again.  I'm also going to recheck cam timing on the chance the chain is off a tooth.  I can't imagine a brand new set of lifters would be toast after less than 3 hours run time unless there is a serious oiling issue.  Oil pressure in this engine is high - 60-90psi @ 3000rpm.  I attribute that to the Precision oil pump, but maybe there is a blockage?  All rocker pedestals use standard Grade 8 bolts - none are "slimmed down" style - could this be a problem?
BTW, I was rereading Barry Rs book and he clearly calls out potential interference issues, including the spring/rockers issue I experienced, as things to double check when assembling the engine.  My bad for not paying close enough attention!

[Drew Pojedinec]

I have a HV pump from Doug.
Cold start is indeed 80-90psi, 100psi with some rpms.  Mine drops to 25-30psi hot idle.  Mine isn't shimmed for high pressure, it's just how I wanted it.  Even hot the pressure rises quickly with some rpms.
So that seems normal.

Since you mention the grade 8's, I'd run the engine with cut up valve covers and see what that looks like.  Or pull a valve cover and prelube, it won't take long to see a good bit of oil oozing from the rocker arms/shafts.  It won't take long to overflow since the oil is so cold it drains back slowly.
I have no experience using standard bolts, I use either the stock bolts or studs that are specific for FE rockers, but that seems a good place to look.  Should be pretty obvious if there is an issue.

Have you cut open an oil filter yet?

[jayb]

Drew, I think you are giving the same advice that I would.  For what it's worth, I had an FE on my dyno a couple months ago that toasted 3 lifters in about half an hour of running.  Too much spring pressure for break-in, or not enough break-in lube, wrong oil, who knows?  Wasn't my engine, so I'm not sure what the problem was.  With flat tappet lifters sometimes this happens.  You could go as far as checking the lift on each valve with a dial indicator setup, to see if any of them are showing lower than expected lift.  If they are, either the lifter is not filling with oil, or the cam lobe is wearing away...

[unclewill]

Thanks for the advice, I'll try everything you suggest this time - I really don't want to take this apart again!  I also don't want to drain the coolant if I can avoid it.

[unclewill]

It's the lifters.  Ran it today without valve covers and at idle four of the pushrods can be pushed down by hand - #1 and #2 cylinder.  I didn't even bother checking the other side since the intake is coming off anyway.  But why?  Could it have been from wonky geometry from the rocker interference?  Is it something else?  Pray for my cam.

[jayb]

No oil to the lifters, maybe?  Sometimes people will run solids and block off the oil passages to the lifter bores...

[unclewill]

Ossly, #3 and 4 cylinders are pumped up, I will check the passages though.  Where would the plug be?

[cattleFEeder]

On my 351c build last year 10 out of the 16 lifters would not stay pumped up. Switched over to morel no more problems.

[Drew Pojedinec]

No one here can really answer as to why other than 'parts failure'

What I would do.

-remove intake
-reinstall rockers and pushrods
-take off rockers, and switch lifters around, reinstall rockers/pushrods, see if the problem follows the lifters or if it is the hole (just prelube, no need for the intake or running the engine).  I can't imagine it being anything other than failed lifters.... but you never know till you prove everything else impossible.

Obviously you can do whatcha want, but if I was changing 2 or 3 lifters, I think my faith would be shaken in that particular brand/type of lifter and I'd be wanting to swap the whole lot of them.

[unclewill]

It is a Comp Cams 292h kit with lifters, valvesprings, cam, etc.  I'm planning to open her up and pull/inspect the lifters, verify cam lift, check all oil passages (the rockers were getting oil when I ran it), replace all lifters and the cam if necessary.  At least I don't have to pull the heads.

[jayb]

Ossly, #3 and 4 cylinders are pumped up, I will check the passages though.  Where would the plug be?

pipe plug

In the engine valley, towards the back, is a raised area of the block casting with two plugs in it.  If they are screw in plugs, you can unscrew them and look down the hole.  If there is a second plug towards the bottom of the hole, it is there to block oil to the lifters.  Usually it is a 1/8" pipe plug, but could be just a drop-in plug or bar.  Just pull the plugs out and oil to the lifter passages is restored.

[unclewill]

Thank you Jay!