I have had a couple experiences where I think I had collapsed lifters. When I was at the strip on some runs I would have a pretty good tick as I pulled around to collect my slip. By the time I was back to the pits the noise was gone. Then we were coming home from a local car show Saturday and running on the highway at about 3000 rpms you could really hear it rattling, sounded like more than one too. I had installed 1/2 Rhoads and half TA lifters. Today I pulled the intake and rocker shafts and pulled the Rhoads out. Nothing looks out of the ordinary, I looked at the TA lifters too and they looked fine. The lobes on the cam look to all still be there and normally there is just a little clatter from what I assumed was the Rhoads. I have a new set coming from TA and I was planning on installing a full new set tomorrow. I have left all of the pushrods where they were and the rockers are all going back where they came from too. Do I have any big worries on break in? I was going to use a bunch of assembly lube and fire it up. All of the valvetrain (cam, cam bearings, lifters, pushrods, springs, retainers, keepers) is new within the last 500 miles. Has anybody had a problem with collapsed lifters? Is there something else I should be looking at? I have ~20 lbs oil pressure at hot idle. I have the intake off. It is a Performer, should I cut the divider out? If so how much should be removed ideally? Anybody have a picture?
Do you relly think it's wise to mix and match lifters and then use new lifters on a cam that's already broken-in. I don't mean no disrespect or nothing but i've heard of cam loebs going flat because this method was practised. Marc
I guess that is the reason for the post Marc, no offense taken. I don't want to create a new problem but, I want to cure the old one. If I am hearing a bunch of valve train noise at 3000 rpms, what was happening on the dragstrip? Valves not being opened all the way would certainly contribute to my car running so slow. What is the cause? Is it possible that the springs are too stiff for the hydraulic lifters? I ordered them from Postons with the cam, there was no mention of the need for solid lifters. I seem to be running plenty of oil pressure. Will a new set of lifters ruin the cam? I still have everything so that I could return it to how it was, but what about the ticking:Brow:
From what I have read.... You should NOT have any problems replacing the lifters as long as you break them in properly. I recall Jim B saying he has done it, and I believe Jim W has also, but you must break um in properly. There should not be any issues with using Rhoads on the intakes, and regular on the exhaust.
I just went through this with my motor. There were three lifters that I found were collapased. I removed one at a time, cleaned them, and replaced them back in the same hole. Two of them did the same thing after a while. I pulled them and put in some new ones, and five months later, had to replace the cam. John Biggs and I were checking the valve lash on each one when we discovered a couple of them were going flat. Needless to say, the cam had to be replaced. With the proper breakin procedure done, sometimes it doesn't work on a used cam. IF you do that, just make sure to take off the valve covers and check to make sure the cam is not going flat. Good luck
Re: From what I have read.... What I said was that I don't like replacing lifters on an already broken in cam. I would only consider it at an absolute last resort., and if you do do it, you need to treat it like a new cam break in. I have seen it done successfully, and I have also seen it kill a cam. Cam and lifter break in is by far the most difficult part of an engine fire up. Jim Burek
I guess the way I look at it, is to look at it. Thanks to some helpful folks on this board that told me to pay attention to any loss of power, and to measure the rockers for any sign of a lobe or lobes going flat. It sure is a lot easier than replacing a cam, but that is what I had to do eventually. Now the car is back in the low 12's in the 80 degree weather with the new cam:grin:
Just outa curiosity...........have you tinkered with the carb at all? I have experienced something similar as I've been tuning my car. Perhaps under hard acceleration, like at the strip, your carb is getting cut short somewhere in the fuel line, causing detonation? Same thing on the highway? I may be way off, but I thought I too had collapsed a lifter in a freshly cammed and liftered motor. The noise would get loud and scary especially when tweaking with the float levels. It's gone, but I can make it come back with the right screw turns. So perhaps under hard acceleration, your carb isn't supplying enough fuel for the increase in air volume. After all, I've been told that 750's can sometimes be too small for a performance oriented 455. Ya never now. If your lifters seem fine and the noise comes from those kinda situations like racing, it might be easier and cheaper to double check the fuel source. It could be a lifter, but sweat and labor sucks if it ends up being a filter.ou: Also, I noticed we have very similar engine combos going. :TU: Good luck! ~Mark :beer
