Just rebuilt 258 now it's tapping help!

[djdelee421]

I'll check the preload. I'm curious if it's my oil pump making the tap but when I turned it with the drill it sounded smooth I just think the tap sounded somewhere around the oil filter so I'm not sure.

[djdelee421]

Well I don't have anything to measure thousandths of an inch with to check preload but my old pushrods are a 16th inch shorter then my new ones however i can spin my pushrods in there now with ease when the valve is closed. So basically I'm still 100 percent lost and I'm about ready to pull the whole engine again I don't want to get new lifters and push rods and put it all back together again just to find out it's the cam and at the same time I don't want to pull the motor and put a new cam in it just to find out it's a lifter or a pushrod. Thanks again for all the help guys maybe motor building is just not for me 

[mudkicker715]

I know its disheartening. Anyway. Run it for a bit without the valve cover its messy, but cleanup is easier than pulling it. Maybe it will be obvious than? I hope anyway.

[djdelee421]

I took some time to think and I'm pretty sure it's something to do with lifters buddy of mine said he messed up the priming of the oil pump on a rebuilt ford 302 and he said his lifters were all bad due to running dry for a few minutes. And in the video you can kinda see where I put the camera was right behind the oil filter and to me it sounds like is coms from right above the cam but when I turn the motor over by hand with cover off all the valves go down and none of my rods are bent so I'm thinking it's a lifter that is internally stuck? So I'm gonna go ahead and pull the head when I get a chance pull all the lifters and inspect them and look down at the cam lobes and that should give me my answer. I will post on the topic again when I do that and maybe post another video. Thanks guys

[djdelee421]

Here's a link to a new video I have now replaced lifters and went to shorter pushrods and no avail still taps even changed to rotella 15w40 I used the zinc additive too that didn't help I put an OP gauge in and at idle she's 40-50 psi. So thanks for any help guys. Let me know
https://youtu.be/PF0xWPafeVA

[mudkicker715]

Are the rockers tight, meaning if you wiggle them do they move much. Should be tight. Also are the rods tight at all parts of rotation of the motor? I am thinking the noise is louder from below, but maybe its just you getting closer.  I would personally say longer pushrods, not shorter. I also would like to know when the rockers get tight (if at all). Torque spec is low on those ( i could throw a incorrect number out at say 35psi), but technically if they are tight they should not rattle. Is oil coming up the rods?

[djdelee421]

I used a torque wrench on the rocker arms to spec 19 ft pounds they were pretty easy to thread down. It's all new parts on the head rocker arms and bridges. What makes you say longer pushrods? And yes I'm getting oil all the way up on the rocker arms. When I had the head off the valves looked good and I could push each one down.

[mudkicker715]

Is 19lb spec? I forget.       I think longer cause even though thr rocker is torqued how is the pushrod? Is it tight on all cycles of the cam? Meaning does the pushrod ever get to a loose point. Even without hydro push from oil it should be tight. An old motor will spin a pushrod around a bit by hand easily. A new motor should have tight pushrods. Everything on a new motor should be tight, meaning the starter should struggle a bit till its broke in.

[djdelee421]

19 ft lbs is spec everywhere I looked so if I could spin my pushrods even the first set that was in they were too short? Cuz I could turn the ones that were down and I couldn't spin the ones that were up. I also noticed my power is down. I bought a leak down test kit and they don't have threads that reach my spark plug holes  . I've still been working on figuring out how to do the lifter preload.

[amcfool1]

hi, technically there is NO lifter preload spec. You have hydraulic lifters, so if your lifters/pushrods/rockers are factory, all should be well. A couple of thousands shave to straighten head should not alter anything. good luck, gz

[djdelee421]

It's something to do with the head the machine shop sold me I think it's from an 81 jeep cj I don't know if that makes anything different

[mo.eagles]

Have you checked your distributor? Could it be making the noise?

[djdelee421]

Didn't know a dist could make that noise. How would I check it?

[djdelee421]

I just went with a stethoscope and isolated the tap a bit more. It sounds like it's coming from behind the distributor right under #5 and #6 spark plug holes on the block. I also continue to get the noise below the cam on the block but it is quieter

[v0rt3x86]

Sounds like a lifter or rod.

When you put the rockers and whatnot on, you have to check clearances and preload - you can't just assume they'll work, and you need to check all 12 individually when you build.

Rather than risk it, just tear it down and re-check.