(I want to preface this with I'm new to working on old mopars/cars in general, any knowledge or assumptions are just things I have read online, mainly here)
So I have been noticing some intermittent valve noise that always seems to be coming from the pass side valve cover. Pulled the cover yesterday to inspect and I could rock some of the rockers with my hand though they had some resistance, some moved more than others. Not knowing exactly what lifters I have I backed off one adjuster on a rocker (valve was fully closed) and it seemed like the preload was about 3/4 of a turn. Screws are 20TPI so thats about .0375 preload I believe. I backed it off a bit more to get the pushrod fully loose, tightened it to zero and went 3/4 in and locked the nut down. Cranked the motor over a bunch and it was tight, after a few minutes I could move it maybe .005", after 90 mins I could move it .030" and the next day (about 18hrs later) I could move it about .100". Is this lifter dead or is that a normal bleed down rate? A few others on that bank are doing the same thing but this one is for sure the worst. This was all done with the engine cold, my guess is when it's hot and the oil is thinner it would be worse and that is what is causing my valve train noise? If they are dead should I just replace the bad ones? I have read quite a bit on the issues with FT cams/lifters going flat lately and feel nervous about replacing them, I do want to go to a smaller cam eventually so maybe just swap the cam and get all new lifters?
EDIT: Not sure if this could be related but I have never gotten a steady vac signal from the manifold, the needle will shake rapidly +/- 1", best I could get at about 900rpm idle is 6-7". A friend told me the fluttering/shaking was probably the cam, but now I am wondering if it could be a lifter/valve issue
Motor is a 440 with TF240 heads, 440 source roller rockers and according the previous owner a magnum 253 hydraulic flat tappet cam. Running 20w50 VR1 per previous owners recommendation, oil pressure is around 75 when cruising and about 45 at idle when hot.
Video of my "test"
So I have been noticing some intermittent valve noise that always seems to be coming from the pass side valve cover. Pulled the cover yesterday to inspect and I could rock some of the rockers with my hand though they had some resistance, some moved more than others. Not knowing exactly what lifters I have I backed off one adjuster on a rocker (valve was fully closed) and it seemed like the preload was about 3/4 of a turn. Screws are 20TPI so thats about .0375 preload I believe. I backed it off a bit more to get the pushrod fully loose, tightened it to zero and went 3/4 in and locked the nut down. Cranked the motor over a bunch and it was tight, after a few minutes I could move it maybe .005", after 90 mins I could move it .030" and the next day (about 18hrs later) I could move it about .100". Is this lifter dead or is that a normal bleed down rate? A few others on that bank are doing the same thing but this one is for sure the worst. This was all done with the engine cold, my guess is when it's hot and the oil is thinner it would be worse and that is what is causing my valve train noise? If they are dead should I just replace the bad ones? I have read quite a bit on the issues with FT cams/lifters going flat lately and feel nervous about replacing them, I do want to go to a smaller cam eventually so maybe just swap the cam and get all new lifters?
EDIT: Not sure if this could be related but I have never gotten a steady vac signal from the manifold, the needle will shake rapidly +/- 1", best I could get at about 900rpm idle is 6-7". A friend told me the fluttering/shaking was probably the cam, but now I am wondering if it could be a lifter/valve issue
Motor is a 440 with TF240 heads, 440 source roller rockers and according the previous owner a magnum 253 hydraulic flat tappet cam. Running 20w50 VR1 per previous owners recommendation, oil pressure is around 75 when cruising and about 45 at idle when hot.
Video of my "test"
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