I have pulled the valve covers and have one rocker that is loose enough to wiggle back and forth noticeably. The rest have a very slight wiggle that you can sorta feel, but cannot see. This one wiggles much worse and is a source of tap on #3 cylinder. Basically, I am trying to set the preload on it and the fulcrum bottoms out while there is still a bit of gap between the pushrod and the rocker. Why would this happen and what would have caused this? Do I need a longer pushrod on this one cylinder? The pushrod is straight, and I have swapped pushrods and rocker arms from other cylinders and this one stays floppy. This is about a .050 gap between the pushrod and the rocker.
These are P heads with Crane roller rockers, They screw into the head through a fulcrum. I think the issue is more with maybe a collapsed lifter (not that I am that knowledgeable in this stuff, buy I might be by tomorrow afternoon).
Did you check the push rod to see if its bent??? Look at the valve tip,see if its mushroomed over.Check the rocker at the push rod contact point see if its worn excessively.Check the lift on that lobe with a dial indicator,see if its wiped out.You can do all that with out yanking the intake to pop the lifter out.If it all checks out then you have a bad lifter.Oh check the height of the valve on the suspect cyl make sure its at the same height as the others.
The pushrod(s) was the culprit for me recently. I thought I had flattened a cam lobe when I found out that the "SUPPOSEDLY" hardened pushrods were not! I broke three tips off. I would look there first.
pushrods are good, top of valve looks same as the others, no metal in the oil, looking more and more like a collapsed lifter. About halfway to taking off the intake, then dinner. Want to try my non-ported Torker 289 anyway...good a time as any to put it in. Might solve my high-speed hesitation too.
Top of cam lobe is no longer flat, but sorta rounded and higher in the middle. Looks like the car is done for the season because I don't have any spare cash laying around for a new cam right now... Guess I will go see if the wife has any wine left. I am done for the day
Has it tapped since you put it together originally??? or is this something that happend much later????Stout valve springs/too much pre-load(over adjusted)Poor lubrication/not enough assy-lube at install??Poorly ground lifter/cam lobe/bad metallurgy/heat treat on components?? I feel your pain man,that stinks.Nice glass of wine sounds good.Looks like it wasnt rotating.Check that lifter bore for nicks/burrs too.
Ran fine until I fired it up today. Been running this cam since April '05 with no problems. Today I go out to fix the header leak and I hear it tapping on the other side at #3 or #4 lifter. Sounded like it was hitting the baffle, but never did this before today. Drove it about 20 miles, and it was tapping so loud people were turning their heads at the intersections. Brought it home early, popped off the valve covers and started to check my preload. #3 intake just wouldn't adjust correctly, having a good .050" space no matter how I tried to adjust it. Figured it was then time to pop off the intake. Now in the market for a GOOD cam, not just a performer plus mid-low range cam.
Hmm, I have a rather grumpy solid cam. I could give you details if you'd like. I pulled it when I thought I had flattened a lobe. Turned out to be the pushrod issue I discussed above. It is a nice Crane cam. (Courier11sec runs the same one)
Dont forget,all that metal went somewhere.You may want to do a good visual inspection of cam bearings/oil gallerys.Hate to say it but you may need to do a complete teardown/inspection before you run it again.(pull the pan )at the very least.
When I dropped the oil, it was dark brown, but had no metal chunks in it. So the metal ended up as a dust or fine powder as opposed to breaking off in chunks. I will DEFINITELY be inspecting everything as I tear it all down.