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Technical 390 FE Very loud valve noise

Discussion in 'The Hokey Ass Message Board' started by tartar_sammich, May 27, 2015.

  1. We just built a 390 for the truck and have been chasing noisy valves since the first time we started it.
    It has a Comp 292H flat tappet cam. The cam was broken in properly. We have tried just about every kind of pushrod we could and the noise keeps moving around, but this one is a little worse than what we've been hearing. I realize there is an oiling issue with rockers in the video, we are working that out as well.
    Listen closely, it's more of a knock than a tick. Much louder in person.
     
  2. 1949SilverStreak
    Joined: Feb 25, 2013
    Posts: 21

    1949SilverStreak
    Member
    from Canada

    Sounds to me like its at crank speed. Full rebuild?

    I've heard that sound in one of these FEs when the clip for the wrist pin fell out and the pin started knocking in the groove it wore in the cylinder sidewall.

    Hard to tell from a vid
     
  3. I don't believe that's it, the noise is aggravated by different pushrod lengths
     
  4. 33skippy
    Joined: Feb 27, 2015
    Posts: 28

    33skippy

    have you checked the valve to piston clearance try loosing the rockers to see if you end up with tappit noise instead
     
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  5. We checked the clearances when we built the engine and they were all good. The noise is accompanied by an obnoxious squeaking.
     
  6. 33skippy
    Joined: Feb 27, 2015
    Posts: 28

    33skippy

    did you fit new cam bearings if so do the oilways line up ? if you have had it running all the time with no oil up to the top the valve train will be dry by now and thaty is what the squeaking is. the 292h has hydrolic lifters and if there has been no oil then they will be dry now too that may be the noise. i would get an oil pump primer and pump oil round with a drill (this wont work if the cam bearings are fitted wrong) but i would get oil to the top before you run it any more. hope this helps
     
    loudbang likes this.
  7. Without the rockers on the oil flows very well out of the hole. We have the rocker assembly off messing around with it right now. And yes that's probably what the squeaking is.
     
  8. seb fontana
    Joined: Sep 1, 2005
    Posts: 6,384

    seb fontana
    Member
    from ct

    Solve the oil issue first. bet squeak will go away and maybe other noise too....From memory the rockers get oil through one of the middle rocker shaft stands, either the stand has a square hole or bolt is necked down for oil flow, not sure if all the stands/bolts are the same maybe wrong stand in right place..After shutting engine off for a while see if you can compress lifter fully and note how much rocker-valve stem clearance there is, should be between .110 and .220...Adjustable rockers would sure be nice but I don't know if any one makes a stock replacement [427] adjustable..
     
    loudbang likes this.
  9. There is oil getting into the shaft. With a single bolt loosened on the shaft and the engine turned over, oil comes out of the top of the rocker stands. There's just no oil coming out of the rockers, kind of weird.
     
  10. tommyd
    Joined: Dec 10, 2010
    Posts: 11,395

    tommyd
    Member
    from South Indy

    You know that one rocker stand bolt on each side is different from all the others, right? The skinny ones line up with the oil hole in the head.
     
    falcongeorge likes this.
  11. barstowpo
    Joined: Jun 27, 2012
    Posts: 232

    barstowpo
    Member

    Make sure you have the correct tapered bolt for the oiling pedestal. If it has been replaced with a standard bolt or a non tapered stud, oil will flow with the shaft off but not when installed. These things usually over oil the valvetrain so check for restrictions in the head. I always jammed a Holley 80 jet in my heads to restrict flow. The cam bearings are also a problem area as mentioned earlier. Also galley plugs under the intake can leak or come out and cause a problem. Lastly, are you sure this in a hydraulic lifter block?
     
  12. flux capacitor
    Joined: Sep 18, 2014
    Posts: 661

    flux capacitor
    Member

    this reminds me of a past FE encounter, I also believe you are on to something here, I recall 20 plus years ago an OCD mechanic destroking a FE block to run at salt flats & no provision for oil on a hyd lifter block was an issue he had to overcome for his solid cam grind. Not sure what had to be opened up if at all? Also if needed I can get the old perfect circle adjustable shaft conversion kit part # if you'd like. I do remember an option to fix cracked galleries in blocks was sleeve in gallerie crack area & it was a common fix. Seems like FE's n pushrod related noises go together like 61 impala s n rotted lower front fenders. But thankfully can be chased away. Good luck ! :D. Flux
     
  13. Yes the bolt is in the correct hole.
     
  14. The bolt is in the correct hole. Oil is making it into the shaft as it comes out of each stand at the top when each bolt is loosened, it is just not coming out of the rockers. Yes it is a hydraulic lifter block, we tore down the old one ourselves, it was completely stock before we did anything to it.
     
  15. 64gal
    Joined: Jan 18, 2007
    Posts: 145

    64gal
    Member

    The oil holes in the rocker shaft should be pointing down.
    Make sure the holes aren't galled shut.
    How much oil pressure?
    Use a drill to drive the oil pump and listen for gushing sounds,
    you may have an internal leak.
    goodluck.
     
  16. seb fontana
    Joined: Sep 1, 2005
    Posts: 6,384

    seb fontana
    Member
    from ct

    Ok, remove rocker shaft bolts and rotate the rocker shafts 180° and rebolt..Maybe the oil holes in the shafts have to line up with a partial groove in the rocker to come out the oil hole on rocker arms? per above post, slow typing
     
  17. We didn't check the position of the oil holes on the shaft. 25 psi idle about 55 cold. Oil gushes out of the oiling hole when there is no bolt in it, so the problem has to be in the shaft.
     
  18. barstowpo
    Joined: Jun 27, 2012
    Posts: 232

    barstowpo
    Member

    There are 2 types of factory shafts. 390 ones have holes in the top and bottom. 427 ones have holes in the bottom only.
     
    loudbang likes this.
  19. hvywrench
    Joined: Sep 29, 2011
    Posts: 158

    hvywrench
    Member
    from N.W. Conn.

    Many, many years ago, on the very first 390 I helped to rebuild, we installed a new timing gear set with the spacer formed as part of the cam gear, and we also installed the stock spacer/washer behind the gear. We didn't know any better, and it moved the cam back too far or forward too far (can't remember exactly) so that some of the lifters banged off of the wrong lobes, chipping several cam lobes and several lifters. It made a knocking noise and a 'squeaking/squealing' noise as well. An expensive and lasting lesson. Do you have the timing gear/cam spacer correct?
     
  20. It should be correct. The squeaking only developed after we rebuilt the rockers again. As somebody said above, it could be due to the rockers being bone dry. Hopefully it's not the scenario you described!
     
  21. flux capacitor
    Joined: Sep 18, 2014
    Posts: 661

    flux capacitor
    Member

    I would pull distributor & run a 1/2 drive "arm breaker" drill priming until the oil flowed freely out rocker shafts, it can take a crazy amount of time on some builds, this would eliminate any more dangerous "dry run" damage to contact surfaces & possibly flush out any "black moly" cam lube possibly clogging up oil passages which could be logged in oil holes if engine is still in early stages of cam break in. Cut the oil filter open immediately & look for Metallic debris. I don't know, but on FE motors could any distributor passageway "housing" problems affect oil pressure? I know I've even seen a few guys racing FE's drill out A few oil passages , especially in main saddles. I finally, this could very well be it , I remembered this one .... 20 ish years ago A fellow co worker spent loads of dollars on a 75 390 & it developed a crack in a common oil gallery I think in distributor area & the CURE was a SBC pushrod drove in to the hole provided the perfect block saving "sleeve effect" fix & pardon my loss of memory" on weather it had to be drilled or not & but after that the oil pressure returned to the lifters! It had pc adjustable shaft kit . Hope this helps! Ounce of prevention = pound of cure theory. Truly time for an oil system "CSI" investigation. Flux
     
    Last edited: May 27, 2015
  22. slickhale
    Joined: Dec 19, 2010
    Posts: 756

    slickhale
    Member
    from Phoenix

    There are oil galley plugs in the end of the rocker shafts, pull them out and I bet the shaft is packed with shit. Had it happen many times.
     
    falcongeorge and loudbang like this.
  23. We pulled them out and it's clean as a whistle. We blew it out and put it back together and same problem. Anything else it could be? There has to be a problem with the way we put it together because there is definitely oil getting in the shaft.
     
  24. Mike Moreau
    Joined: Sep 16, 2011
    Posts: 289

    Mike Moreau
    ALLIANCE MEMBER

    I am reluctant to even bring this up because you have indicated (and are probably correct) that the noise is valve train related. Decades ago, I had a friend who went through a similar deal. Drove him nuts. Finally put a stethoscope on the fuel pump. That was it.
     
  25. Non adjustable rockers and a non stock cam shaft? Am I missing something here?
     
  26. Correct. I've spoken to several people who have done the same with FEs. They have worked fine for us before but we are having trouble with this particular engine. Also, adjustable rockers for the 390 are pretty expensive, just like everything else.
     
  27. I know what adjustable valve train runs for an FE.

    Sometimes you get lucky, doesn't sound like this is one of those times.
     
  28. Probably isn't. Not questioning anything you have said, but what would be the use in shelling out that money for adjustable (let's say roller rockers) when it has hydraulic lifters? They are supposed to "self-adjust" aren't they? Or in our case they did but not enough so we need additional adjustment?
     
  29. Nope they don't self adjust. With a stock cam shaft they are close enough without a stock cam shaft you are just hoping that it will be OK.

    The use in shelling out additional money would be having less vale train noise. Aside from that valve train noise is an indication of a rocker that it too loose, as in too much valve lash or not enough preload. That being the case you also get the added benefit of it running properly.
     
  30. I understand, I'm just reluctant to spend the money until we find out exactly what it is, because it just started making this loud clack a couple of days ago. It has always been a little clicky, but not like this. It runs fine but I hate to drive it when it sounds like there's a dwarf in the engine compartment beating on the valve cover with a hammer. We're going to swap the rockers and see if the noise moves, but I doubt it does. When we can pinpoint the problem we will look into a different set of rockers if need be.
     

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