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lifters won't pump up after rebuild, #2 exhaust is the worst offender, any ideas?


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10:01 PM
Feb 1, 2013
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Fort Worth, TX
Working on a 66 block, 383, 906 heads. Block had the usual cam bearing and freeze plugs swapped along with getting cleaned. New pistons, new rings, new bearings, balanced rotating assembly, full head job. The heads were treated to new valve guides, hardened exhaust seats, a valve job, and a clean up of the surface for good sealing. All the stem heights and spring pressures were checked prior to assembly. Cam is a mild comp with new lifters. Standard push-rods and factory rockers. The machine shop assembled the long block. Unfortunately the motor was broken in with open headers. I didn't want to do this but I had no choice, long story. I primed the engine prior to the cam break in and used Joe Gibbs break in oil. I had one strange set back before starting the motor. The high volume oil pump would not build pressure at first. Once I finally got a prime on the pump, the pressure spiked the pressure gauge and maxed it out. Soon there after I heard a ping and the pressure dropped. I figured the relief valve was stuck and came unstuck with pressure. Oil pressure while priming thereafter was good. We started the motor and 30 seconds in to the cam break in, lost oil pressure. Assuming it was the pump, I swapped the oil pump and re-fired the motor. Oil pressure was back and was good. Finished the cam break in, 25 minutes of elevated rpm, varying slightly. I took the first pump apart and found the pressure relief valve seized in its bore. Brand new parts can be bad right out of the box, who knew. I got exhaust put on the car shortly there after.

Once I have exhaust on the car, I can hear a lifter/rocker noise coming from the right bank. Left bank is silent. I threw the car up on the trailer and drove it to my machine shop. They were afraid a cam lobe had been wiped during break in. We pulled the valve cover and checked lift across the whole bank. Exhaust all measured the same, as well as the intake for lift so no wiped cam lobe. We did notice the #2 exhaust seemed very loose. Since the rockers are not adjustable, we started to suspect incorrect push-rod length. After trying to rock all the rocker on the bank, we noticed the lifters on pretty much the whole bank were not pumped up.

So we found the problem, lifters are not pumping up. I still have the break in oil in the engine so the machine shop suggests changing the oil to 30 weight and letting the car idle for an extended period of time to get the lifter to pump up. I'm not so convinced this will fix the problem. I am also not convinced because the left bank seems silent. Granted, it only sounds like and appears to be one rocker making noise. Hughes performance thinks the oil holes in the lifters are clogged with trash and needs to be pulled and cleaned.

What do you guys think I should do? Can you pull a lifter to clean without pulling the intake, I have never tried but maybe with a magnet it could be done? Are the lifters bad? Did the huge spike in oil pressure from the initial prime damaged the lifters? I would love to hear ideas before I tear into it.
spring inside the one lifter could have collapsed,or have trash in it.depends on how clean the machine shop was.you can pull lifters without intake removal,but it aint easy.much simpler to pull the intake and get new gaskets.i would call comp and see what they recomend,since it is there lifters and cam.
I would definitely pull the intake, inspect the cam, and check your lifters. You may be able to pull a lifter using a magnet without removing the manifold, but just do it anyway. Look at your cam. Check all the lifters.

My first 440 rebuild break-in sounded great! In my lack of experience, I went back to check my rockers (hydraulic lifters) with the motor hot, and found one very loose. It never occurred to me to check the lifter. This was a mistake that cost me an entire motor. The cam ate the lifter, scored my cylinder walls, destroyed my bearings, etc. It's a pain, but do the right thing now and save yourself some time and money.

By the way, when building that motor, I had two suspect lifters: one that stuck a little when compressed, one that didn't seem to prime. I will never, ever put a suspect lifter in a car again (yes, I know better now).
Pull them out, keep them in order, let the soak in oil. Ask the machine shop if they let them soak in oil or did something else to pump them up first. COMP says not to now, IDK why but it seems like BS.
i'd just take the tappets apart and clean them. kinda messy but no big deal. just reassemble the parts in the correct order.
Pull them out, keep them in order, let the soak in oil. Ask the machine shop if they let them soak in oil or did something else to pump them up first. COMP says not to now, IDK why but it seems like BS.

.....hmmmm, my comp cam lifter install instructions say no priming......now I'm worried.

i'd just take the tappets apart and clean them. kinda messy but no big deal. just reassemble the parts in the correct order.

Lifters need to be bled prior to installation I would remove the ones that are not pumping up and try to bleed them this can be done by using an oil can that pumps with a trigger put the nozzle in the hole where the pushrod goes and pump in the oil until it comes out the oil hole on the side how ever I am skeptical about using the collapsed ones over I don't like doing things twice but you can try once you pump them up you should not be able to collapse them by hand hope this helps
Is there any chance that in the block prep they did not put the oil galley plugs back in. I ask because this exact same thing happened to me on a Pontiac 389 and it was the missing oil galley plug in the back of the block causing a lack of oil to the lifters so they wouldn't pump up. Replaced the plug and all was fine after that.
pumping tappets up before installation is not recommended.
66 440 is a 1 year only block and takes special cam bearings. Sorry bro.
Lifters of today are known to be bad occasionally. The left side lifter bank is oiled after (thru) the right bank. This being said, if the left is silent, then you have not left any pipe plugs out. As far as the oil, what break-in oil did you use, BR or BR-30? BR is a 50 weight oil, and the BR-30 is obviously a 30 weight oil. Also, the break-in oil can be used up to 400 miles according to Joe Gibbs. It is unlikely you harmed a lifter by the high pressure during pre-lubing the motor, you more than likely just have a bad lifter.

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66 440 is a 1 year only block and takes special cam bearings. Sorry bro.

Not sure what your talking about, but ALL big blocks from the lowly 361 up to the last 440, including Hemi's, used the same cam bearings, PD-17 Durabond. If the #4 cam bearing was clocked wrong (impossible), the rockers would be the only thing affected, not the lifters.
I had the same issues. One of the guys mentioned the machine shop may have left the oil galley plug out. If you have the oil pressure gauge mounted at the rear and it's shows pressure then that's not the case (the oil is fed down the passenger side and then over and up the driver side). My Comp lifters also state no priming but once I had the issues I tore them apart cleaned them and primed to make sure they worked before reinstalling them. I had absolutely no problems pulling all of my lifters with only the valve covers removed but it wasn't fun working around the brake booster (make sure you get a strong telescoping magnet). Unfortunately after 2 noisy sets of lifters I had enough and had them send a solid lifter cam and lifters, music to my ears now. Good luck

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Dido on the #4 cam bearing, as stated it feeds the rockers. The lifters are fed by passages down each side connected at the rear where the oil pressure port is located.
pumping tappets up before installation is not recommended.

Never heard of that one before. What are they saying...drop dry tappets in the overhaul?

I've always primed new tappets, simply to get oil into the tappet cavity, before placing them. Also always primed the motor just before firing it off the first time.

On that 440, gotta wonder if the rocker arm tubes were cleaned out good, or were they new? Or oil galleys scrubbed clean? Or cam bearings installed wrong? Lol! Easily could be a bad tappet, too...especially these days.

All kinds of good stuff! Think I'd take a couple steps back, and check things out.
Might even pull ALL your tappets, tear 'em down, and go from there, just like mentioned. Could save your motor.
Not that it makes a difference but the motor is a 383, not a 440. I am 99% confident that the parts were properly cleaned and the machine shop did proper work. The shop has built dozens of similar motors with no problems. I will have to dig out the receipt on the break in oil, the machine shop gave it to me when I picked up my motor. Down below is a diagram of the oil galley passages. Even if 66 had an odd ball cam bearing it would not affect the lifters. I do no believe a lifter galley plug has been left out for three reasons, my engine builder has never left one out, I would have no or low oil pressure, and the driver side bank would be more likely to have issues being the last place to get oil. Here is the plan:

I am going to pull the rocker shaft and try to pull the lifter that is the biggest problem without pulling the intake. If I see any sign of a cam lobe going flat, I will dig in further. I am going to take apart, clean, and try to pump up the lifter to make sure it is good. I will bleed it off before I re-install the lifter and rocker shaft. I will then check to see if I have a bent or bad rocker arm. If the problem goes away, I will throw the valve cover back on with the same gasket and fire it up. If the rocker stays quiet, I will change the valve cover gasket. If the problem returns after any period of time, I will be forced to remove the cam and lifters and warranty exchange for a new set. I'm hoping to find trash blocking oil from entering the lifter. If I find nothing wrong, a bad lifter would be my next guess. Since the other lifters are not rock solid but are not as sloppy as #2 exhaust, I am hoping an oil change and some idling will help them pump up. I will report back what I find.

Sounds like a suspect lifter to me. Pull the intake and rocker shaft off the bad side. Passenger side? Inspect the lifter and cam lobe. Replace the lifter.
Yup, again. Besides, just getting some oil inside the lifter doesn't mean that much, besides lubricating the inner moving parts. Oiled tappets will close right up, once mounted in place. Takes oil 'pressure' to pump 'em up.

Hope it's only the one tappet that's guilty. Could be trash in it. One other thing you might check is the tappet bore I.D., and tappet O.D., to make sure all is savvy. Oops...that's two.

Good luck with it!
First off, I hope nobody kills me here because I do not have a Mopar, but I do have a relevant topic and we are all essentially car guys, right? Also, I realize this is an old thread so it may not even get read. I have a 1971 Jaguar E Type with a fuel injected small block 427 (General Motors). A few months ago, I started to notice lifter noise (Howards Roller Cam, hydraulic tie bar roller lifters and Scorpion roller rockers.) Shortly afterwards, the exhaust started sounding like I was hitting on 7 cylinders and felt sluggish. Same issue as in the thread above, rockers started getting loose, even after adjustment, the lifters seemed as though they were losing hydraulic pressure and would get loose right after adjustment. I replaced all the lifters with brand new Howards tie bar roller lifters ($$$) and all seemed well for a short time, but they too fell victim to the same issue as the first. A step back in time, I remember hitting a large cobblestone that fell off a truck and dented my oil pan and busted one of my mufflers. I did notice a drop in low rpm oil pressure afterwards but did not put two and two together until now. My theory is that I had reduced the distance between my oil sump and the bottom of the pan and restricted the oil flow at lower (idling) rpm. That incidentally is where the pressure drop is the most pronounced on my gauge. After I pull out and the revs build, the issue seems to dissipate some and the lifters pump up (or so it seems) but sitting at a traffic light and pulling out it gets worse. This seems to be the most logical issue causing this and I'm going to pull my pan and replace it and a new pump while I'm in there hoping to solve this. Two sets of lifters cannot be bad. Any thoughts? BTW: The cam sheet for Howards cams and lifters states "do not soak the lifters prior to installation."

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