Here's the backstory. Brand new cam, lifers, rocker arms, pushrods in my 68 400. Has a full MSD ignition, ititial timing at 12 degrees. Ran thru the break-in period. The 400 is running around 210 degree's now & has a miss every now & then. On a hunch I pulled the passenger side valve cover off & this is what I found at #4 cylinder. Any ideas? I know there's a problem with the oiling system, I'm guessing at the lifter. Ideas? Thanks guys.
well I pulled the rocker off. the pushrod did have oil in it. i cleaned the pushrod out, cleaned the rocker arm/pivot ball/nut as well. i'll try reinstalling everything & see if there's oil coming thru the pushrod & coating everything. hopefully it was just a blockage in the pushrod.
What does the pivot and the top of the rocker under the pivot ball look like, any scoring or galling of metal? Looks like there was some pretty good heat there. Any sign of heat damage to the top of the push rod?
just some blueing on the inside of the rocker arm & blueing on the tip of the pushrod that joins the rocker arm. i ordered a new rocker from Summit today, I'm replacing the rocker & pivot ball just in case. At least when I pulled the pushrod there was oil coming out down at the end that goes in the lifter.
No blockage in the pushrod now. the lifter spins freely in it's bore. I haven't pulled the intake to check the lifter face, wondering if I should do that next or not.
What cam did you get? I just put my motor (326)back in Saturday. I rebuilt it with a COMP Cam kit 268H and I had to run the car for 30 mins at 2200-2500 RPM with the inner springs out. The reason is that the springs are so tight it will trash the cam they say. Now I have to take the valve covers off and put the inner springs back in. Change the oil and should be good to go.
that's the exact same cam I put in mine. did the exact same break in process as well. I put everything back together today & started it up without the valve covers on to check oil flow. It's not like it's squirting everywhere, thats for sure. The oil squirts out of the intake pushrod of #3 cylinder & sprays the fender but that's the only one that does it. All the others don't really shoot out everywhere. I know my last 302 Ford engine I rebuilt the oil flowed pretty steady out of the pushrods. Is this normal with a Pontiac 400??
Not sure. I was reading the cam install break in and they said 2200 to 2500 RPM to make sure it squirts oil evenly over the cam. It had to run at that RPM to make it happen. I am a novice engine builder. First one with the help of my brother in law.
started it up again & let it warm up & oil flowed evenly thru all the rockers, so I'm thinking i'm in good shape right now. thanks for the info & help, but still at odds what happened with that one rocker. odd...
Yeah. I had my inner springs put in and now trying to work all the kinks out. When driving down the road about 40 and put a load on the motor enough where it does not kick down I have a loud rattle. I am wondering if the timing or the valves are knocking? FRUSTRATING. LOL I am going to make a new post for a couple issues I am having.
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