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Discussion Starter · #1 ·
OK, so I've had a misfire above idle for years believe it or not. I've thrown a bunch of stuff at it over those years. Well I decided to finally get into it so I pulled the plugs. This time I could def. see it's #4. So I pull the valve cover off to check the crane rocker arms adjustment. As I'm turning the balancer I notice that #4 intake barely moves. Pull the arm off. Turn the balancer a bunch of times. NADA. The lifter is down there, I see it. Did one of my cam lobes wear off without killing the rest of the motor. It's been like this more or less for probably 7000 miles or more. Have to get the intake off next when I'm in the mood. We shall see....to be continued. Oh, I put the cam in (crane, I forgot the model it's been so long), along with new motorsports lifters together a looooong time ago.
 

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lifter spins, wheel perpendicular to the cam, bad thing with spyder lifters. Even without the lifter turning, break a needle bearing and the wheel quits moving. Not even roller cams are completely trouble free....
 

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Something isn't adding up. If the lobe is worn down enough not to move the intake valve significantly, the rocker should have been ticking loud enough to tell you something was going bad.

It this a hydraulic roller or hydraulic tappet? Either way, there's only so much clearance a hydraulic lifter can take up before it runs out of "adjustment".

If a lobe it worn down, a lot of metal went through the engine. If the engine is worth anything, it's worth taking apart to examine for secondary damage.
 

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Something isn't adding up. If the lobe is worn down enough not to move the intake valve significantly, the rocker should have been ticking loud enough to tell you something was going bad.

It this a hydraulic roller or hydraulic tappet? Either way, there's only so much clearance a hydraulic lifter can take up before it runs out of "adjustment".

If a lobe it worn down, a lot of metal went through the engine. If the engine is worth anything, it's worth taking apart to examine for secondary damage.
Once the cam lobe is gone there isn't enough valvetrain movement to cause much noise. This used to be soooo common before roller cams were mainstream. I remember pulling a Chevy cam with 5 lobes that were basically round.
 

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Something isn't adding up. If the lobe is worn down enough not to move the intake valve significantly, the rocker should have been ticking loud enough to tell you something was going bad.

It this a hydraulic roller or hydraulic tappet? Either way, there's only so much clearance...


You adjust the rocker on the cam base circle, no lobe present, it would simply behave as a closes valve would. With only a slightly measurable lobe left, even then, it would just behave as an incredibly low lift camshaft. No noise.

If it ate away enough lifter material to remove all tension from the rocker, then it would be loose, but without significant lobe lift present, it may not offer enough movement or force to cause a noise.
 

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Squashed a lifter. My '90 did this many years ago. When I pulled the valve cover I could move the pushrod up and down quite a bit. Yanked and replaced all the lifters. The one from the trouble cylinder had all the bearing gone and the roller was just slapping around on there. Not long after that, what was left of said bearings clogged an oil passage and killed my motor :(
 

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Guessing what it is won't matter anyway, because it needs to come apart to find out. However, if you want my guess, the lifter is stuck in the bore because the wheel/axle broke off and spread the base out. If you think about it, having a cam lobe totally disintegrate along with a lifter would send a ton of metal through the motor, to the point there would be obvious amounts visible in the oil.
 

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I had the bottom part of a lifter break off and went sideways right into a water jacket. Brand new custom cam was ruined and hole in the lifter bore. At first I thought it was a head gasket from milk shake oil when I pulled the head and head gasket was fine. I didnt know what was going while pulling the lifters out, and only half of one came out immediately saw what happened. Hopefully your issue isnt as severe.
 

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Pull the lifter and have a look.
 

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Discussion Starter · #12 ·
Hey,
Thanks for all the replies. They are a surprise because for some reason I had email notification off. Well, the time is nearing when I will take it apart and have a look. It's amazing that whatever happened has been that way for years and been through some pretty good abuse/spirited driving. Sounds like if I were to have major metal debris problem it would have showed up by now. Either way, the thing to do is to take off the intake and see what's up, then move on from there. Would like to get away without doing any more than cam/and/or/lifters. They were new motorsports lifters along with the crane cam when I did the install. I installed new early Edelbrock 6037's at the same time. Wondering what else to consider checking while I"m in there. Always had that spring seat issue in the back of my mind with the heads. And springs? Should stick with what came on heads way back then? It's had this dead mis for so long will be nice to see what it can do again when everything's right. Would love to know what caused this so if it was me, I don't repeat. I'm usually pretty meticulous so it's surprising. Lucky it hasn't blown up I guess. Could always be worse. Nice to have the springtime itch again even though the car is in pretty rough shape compared to the old days.
Thanks,
Ken
 

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took a 7 month break from it huh. im gonna step out on a limb and say when you pull the intake and lifter, your problem will show itself.
 

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Discussion Starter · #14 ·
that's what I'm thinkin boost n/m

/
 

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took a 7 month break from it huh. im gonna step out on a limb and say when you pull the intake and lifter, your problem will show itself.
I noticed that too...
 

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i didnt mean anything mean with my post.
 

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Discussion Starter · #17 ·
Hey, I'm lucky to accomplish tying both my shoes at the same time. Doing lots of stuff, getting little done. Plus winter doesn't help. But at least now I made some diagnostic progress. Time for the rest of the work now, (or soon).
 

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Discussion Starter · #19 ·
looks like it might be a couple weeks or so, winter isn't quite over with here yet and I'd be doing it out in the driveway. So stay tuned.
 
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