1966 Mustang New Cam and Lifters but now has Lifter Tap!
As I put out in my last thread, the roller rockers fixed the problem with the engine not firing due to no compression.
Now I have 1 valve that is tapping like a gipsy. The # 1 Intake valve. I have reset the adjustment three times, same thing. Just the one cylinder.
It's a rebuilt 289 with Edelbrock performer cam, lifters, pushrods, Crane Engerizer roller rockers, on Edelbrock ready to run heads.
Runs smooth, but the lifter tap does affect the idle.. when it stops tapping the engine is smoother, and when it is loud the engine seems out of balance. The tap is not consistant... it is very random in fact.
I think the # 1 intake lifter is bad, even new and because it will not pump up it us holding the intake valve open causing blow by in the intake and messing with the engine idle.
Thoughts?
Makes me mad to think of having to pull this intake again...
John
From what you say you've got a bad lifter. I hope you did the cam/lifter break in procedure, if this is a flat tappet set up. If I remember you had a rocker arm problem from the start and I don't really know how you could have done a break in with the rockers that you originally had. You may have wiped out the cam lobe on the cylinder you mention. Worst case you're going to have to replace the cam and lifters. Best case just the lifter with the problem. If break in wasn't properly done, eventually all of the lifters are going to start doing the same thing.---Chuck
Good point on the rockers Chuck, but the engine NEVER started on the old rockers.... Only rolled over with the starter. It never fired because I had no compression because I had all the rockers bottomed out to the bottom of the studs. Could this have caused the lifter to damage and thus fail to pump up?
When the engine was started (After pre priming with a drill) it was run in as per the break in requirements of keeping the idle above 2,000 RPM. The Oil pressure was constant at 50 psi so we had plenty of oil pressure. I have run in flat tappet cams before with way more neglect and had no problems.
Based on bottoming out the rockers, should I just change all the lifters since I will have the intake off anyway? Something tells me to just do it...
Also, is a lifter a lifter? I bought Edelbrock (Cam lifter kit) will any flat tappet hydraulic lifter for a 289 work?
Also Chuck,
It's burning in my mind so I might as well get it out... What if the #1 intake is bent at the valve stem just enough to hang up the valve through the engine cycle. bent and holding in the valve guide.
So the idea is, through the rapid engine cycle, the valve sticks on the guide, holding it open for a nano second and firing into the intake. I really do not want to think about that...
But again, with the rockers bottomed out, I rolled the engine over many times so if the valve was hitting the piston, I would have known. AND, it never fired wirn bottomed out because there was no compression...
I'm thinking I just crushed a lifter... I hope... geeze!
Thanks again,
John
John, did you bend a pushrod in the no. 1 intake? If you did then it is a possibility of a valve stem problem. You can try to manually actuate the rocker arm to see if you can duplicate the valve hanging up and maybe try manually actuating another cyl. intake valve to compare how they feel. I wouldn't think a valve kissed a piston if the pushrods are not bent, but there also may be a faulty valve guide from the start. This is a valid assumption as to what the problem may be. After all, those heads are mass produced and you may have gotten that one in a million (sounds like my luck) that is defective.
I would first pull the lifter on no.1 intake. Take it apart and look to see if there is any scuffing in the internals and also look at the bottom of it to see what it looks like compared to another lifter and also see if you can get a peek at the cam lobe. Does it compare to the other lifters and lobes?
If you are going to change out the lifters, get some that have the same characteristics as the ones you have. There are other designs of flat lifters (anti-pump up, Rhodes for example). Read up on them, you may want to use them. I personally would change all of them (for peace of mind) since you are in there. Be sure to get a name brand lifter because I have heard of bad metalurgy problems with offshore products. They may look good, but as they say, looks can be deceiving. Do another cam break in procedure with the new lifters and hope that the cam will be OK. You may be alright, see if you can look at the cam lobes with a strong light and rotate the engine so you can get a 360 degree look at it before making a decision on just replacing lifters. I wish you good luck and I hope you don't have to replace the cam. -----Chuck
Oh yeah I did forget to mention that I thought the same thing and pulled the # 1 intake pushrod a few days ago. I checked it on a known true surface, just as true as they come... so good point, the rod should be weaker then the valve and take the blow if its smacked. As far as a bad head valve guide.... your killin me.... I hope not...
I'm going to run up to the speed shop today and buy all new lifters and try to get the same Edelbrock performers if I can... I'll check the cam with a good light, I have a borescope that is very intense.
I'll post back after surgury... Thanks again!
John
Well, I finally had time to bust into the engine, found the tapping area was sure enough the #1 intake. What I can't figure out is that when I pulled all the lifters.... #1 Intake was badly damaged. Bottom worn off, actually at an almost 45 degree angle and missing about 1/8-1/4 inch of the bottom material. The rest look perfect....
So what made this one lifter eat itself? Could this be the result of me bottoming out the rockers for the engine roll? I find this hard to believe since the engine never fired, just cranked over a few times on the starter because the valves never closed to make compression.
Thinking.... Maybe the bottomed out lifter was crushed enough to wipe the cam lube off and just so happened to be the one that fired up dry when I fixed the rocker adjustments. OR... maybe the lifter was bad out of the box and had no hydraulic preset such that it floated on the cam loose and beat itself to death... I doubt the second because it was tight evertime I took off the rocker cover to check the pushrods. But maybe it floated some through the cam cycle enough to beat it up???
I bought new lifters, BUT.. I can't see that one lobe very well.. It looks ok with a light, somewhat consistant wit hthe rest of the lobes... and as most of you know, pullong the cam is much more work.
Thinking of just trying the new set of lifters lubed up heavy and adjusting the rockers again and see how it works.
Hydraulic lifters will act like a solid lifter if the internal plunger is bottomed out on its travel limiting snap ring. What you would allow for valve clearance on a solid lifter adjustment is clearanced internally with the hyd. type. The difference being that oil is filling the gap in one type and no oil is present to do this with solids. The slack is taken up by the oil pressure on the plunger, so that they automatically compensate for wear and valve slack adjustment for wear on solids is, of course, done by manual adjustment.
Flat lifters are designed to constantly rotate in the lifter bores. The bottom of the lifter is shaped in a way to promote this rotation as are the cam lobes. By taking all of the clearance out and bottoming the plunger didn't allow for this rotation and the lubrication associated with it.
Once the metal to metal contact without proper lubrication continues, even briefly, the metal starts galling (peeling away). Once this starts a complete resurfaceing of the metal must be done and hopes lie in the fact that the metal's temper is retained. This resurfacing is impractical with the lifter, of course, but the camshaft may be saved if the damage isn't too deep. But about the temper is anyone's guess.
I would definitely take a good look at those cam lobes. If it takes pulling out the cam, do so and chalk it up as a learning lesson. If there is even the slightest bit of wear on the lobes, you're going to experience problems down the line. I know this is a difficult decision. I wish you luck with this and keep us posted. ---Chuck
I bet the lobe is now flat. Modern oil sucks....I'd be breaking in a flat tappet cam with Crane's moly lube, a bottle of GM EOS and Rotella T Diesel oil so it would get lots of zinc and all the other chemicals that aren't in normal oils any more.
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66 coupe 5.0/T5, home-brewed power 4 wheel disc setup, 350hp+, looks like it belongs in 1968
1966 Mustang New Cam and Lifters but now has Lifter Tap! 
