ripleydale Posted June 19, 2012 Share Posted June 19, 2012 I rebuilt a 454 and started it tonight. Ran ok and broke in the camshaft. I used a Comp Cams XR276HR Complete Kit and I got the Magnum roller rockers. After the break in when we went to set things up better, you could hear a tick and the vaccuum would fluctuate at the same time. It seemed to come from the drivers side so I took off the valve cover to see what I could find. What I found was that #5 intake seemed very loose. The amount of thread showing on the rocker stud looked about the same as all the rest. I pulled off the rocker arm and tried to push on the lifter and it didn't move. Not sure if it would be pumped up from the recent run (motor still hot) or if it should have give. Put it back on and set it up per the instructions (exhaust just starting to open, get zero lash on intake and 1/2 turn more). Seemed to be moving the valve so backed off a little. Noticeably more thread on the rocker stud. Bumped the starter a bit and heard a little crack. Not sure if something bottomed out or the intake hit the piston. Not a good sound anyway. Wondering if the lifter is collapsed or broken? I'm thinking if it was loose like that, the valve wouldn't open or open as much, which you wouldn't think would drop the vacuum for that little blip on the vaccuum gauge. Any thoughts or advice would be appreciated. Thanks. Quote Link to comment Share on other sites More sharing options...
72 LS5 Posted June 19, 2012 Share Posted June 19, 2012 Man, what a let down! I'll try to chime in although I have never had a collapsed lifter, it sure sounds like it. Did you prime the motor before you started it until you got oil at every rocker? Did you soak the lifters in oil before installation? After that crack sound, have you tried to rotate the motor by hand to see if there is any binding? I'm curious about what you mean by breaking in the cam. The rollers don't need a traditional break-in, although I ran mine off idle for a while to get sufficient oil at start up. Quote Link to comment Share on other sites More sharing options...
ripleydale Posted June 20, 2012 Author Share Posted June 20, 2012 Haven't tried to rotate the motor since the episode last night. I don't really want to use the starter to do it anymore, so I'll need to pull the rad and shroud to get a socket on the crank. I did soak the lifters before assembly, and primed the pump and saw oil flowing from all the pushrods. My buddy suggested the cam didn't really need to break in either, but after starting I kept the revs up at 2000 for a while and then moved it up and down 500 rpm for a little while. Probably ran it about 25 minutes in total before shutting it down. Let it cool down for 30 minutes and then started it up to tune things up a bit. That's when we noticed the vaccuum and the ticking at the same time as the vaccuum hit. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted June 20, 2012 Share Posted June 20, 2012 I have not seen a hydraulic roller collapse yet. The rockers that you are running are they the magnum with the roller tip and rocker ball? I have found that they are tight on the socket when adjusting. Did you prelube the engine before start up? I like to run the drill during prelube until I see oil at all rockers. I rotate the crank a 1/4 turn at at atime it takes a while but it is worth it. Quote Link to comment Share on other sites More sharing options...
ripleydale Posted June 20, 2012 Author Share Posted June 20, 2012 Yes, roller tip and rocker ball. I did prelube. Quote Link to comment Share on other sites More sharing options...
Monteman1971 Posted June 20, 2012 Share Posted June 20, 2012 Is that a flat tapped cam or a roller cam? Sounds like you just have roller tip rockers. Therefore break in is necessary on a flat tapped cam...... If it's a flat tapped cam and the rocker doesn't have as much movement as the others, you may have flatten a lobe on the cam which is not uncommon on flat tapped cams and the lack of Zinc in the new oils.... I'm not even going to say what I think of Comp Cams stuff..... Steve Quote Link to comment Share on other sites More sharing options...
ripleydale Posted June 20, 2012 Author Share Posted June 20, 2012 XR276HR Hydraulic Roller cam. Quote Link to comment Share on other sites More sharing options...
72 LS5 Posted June 20, 2012 Share Posted June 20, 2012 Did you get a chance to turn it over by hand and see if it binds? The crack sound has some concerns. I'm thinking either a lifter plunger issue or maybe even the rocker ball. There is an outside chance the rocker ball did not break in correctly and wore out, but you probably would have noticed it when you removed the rocker. Quote Link to comment Share on other sites More sharing options...
Monteman1971 Posted June 20, 2012 Share Posted June 20, 2012 I think you need to take the manifold off to see whats going on in there...... Quote Link to comment Share on other sites More sharing options...
ripleydale Posted June 21, 2012 Author Share Posted June 21, 2012 I think you're right. Quote Link to comment Share on other sites More sharing options...
ripleydale Posted June 23, 2012 Author Share Posted June 23, 2012 Pulled the intake. Funny how glaring some errors seem when you look at them. The pair of lifters are connected by a little bar, and there is an Up arrow. Several of mine were not pointing up. The lifter wheels are cockeyed when you don't have it in the right direction, hence some nice scars on the camshaft. Glad it wasn't run too long and I took it apart before it really exploded. Thanks for your help guys. Quote Link to comment Share on other sites More sharing options...
cudax Posted June 23, 2012 Share Posted June 23, 2012 Man, good catch hopefully you can salvage everything. How are the push rods? Quote Link to comment Share on other sites More sharing options...
ripleydale Posted June 23, 2012 Author Share Posted June 23, 2012 Push rods look good but haven't rolled them on a mirror or piece of glass yet. The #5 intake lifter was collapsed. The other lifters actually all look ok as I think the cam took the brunt of the pain. I'll save the ones that I put in correctly. There is no hope of recovery for the camshaft and I'll replace the lifters. An expensive lesson. Quote Link to comment Share on other sites More sharing options...
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