Miss at idle & at cruise speed

409gang

Well Known Member
Supporting Member 1
Did you pull the rocker yet, I have seen the bottom cup of the rocker split before where the pivot ball sits.
 

409gang

Well Known Member
Supporting Member 1
OK did you check the lift on both int. & ex. on #5 with a dial indicator compared to another cylinder, you could have a flat cam.
 

ragtp66

Well Known Member
I had the exact same thing happen on a small block the clip was gone. Had an old lifter took the clip out of it tightened the locknut to compress but not collapse the lifter put the clip around the pushrod and was able to work it in the lifter with two long skinny flat head screwdrivers. fired it up and readjust the rocker arm and buttoned it back up.
 

dualquadpete

Well Known Member
OK did you check the lift on both int. & ex. on #5 with a dial indicator compared to another cylinder, you could have a flat cam.
Yes I did check lift on # 5 lifters when manifold off the 1st. time, & then checked others thinking the same thing, " bad cam" but lift was the same. Thanks, guys we are all thinking down the same path & I'm 99% sure this is a lifter problem, as this "miss" has been there since I bought this, Previous owner didn't drive it very much and says he "never noticed it" mostly sat in garage for 17 years!!!!!
 

dualquadpete

Well Known Member
Intake off, pulled # 5 lifters, exhaust is "pumped to top & seized solid!!!! Put a round punch in it & whacked it with 5 lb hammer, NOTHING solid!!!! No wear at all on bottoms, all the rest look good & ones that have open valves are down in lifter as they should be. SOOO do I just replace the " F'd" one with likely a Chinese replacement or do them all with Chinese junk????? Definitely have found the problem
 

409gang

Well Known Member
Supporting Member 1
No take them all out and soak them, take them apart, clean them and put them back together. Make SURE you put the lifters back in the same hole (wear pattern) or you could have a problem latter. I wouldn't change the lifters unless you were putting a new cam in, that old cam might not like new lifters.
 

IMBVSUR?

Well Known Member
Supporting Member 2
Speaking just for myself, if it was mine, that would be a complete lifters, and cam replacement.
 

dualquadpete

Well Known Member
I was thinking that a cam swap would be good but on reading my motors manual, says 62-64 409 " only, remove engine & trans from vehicle as a unit,then remove oil pan to get timing cover off??? That's not happening!!! Going to try & take bad lifter apart & see what's hanging it up,just out of curiosity.
 

blkblk63ss

Well Seasoned Member
Supporting Member 5
Intake off, pulled # 5 lifters, exhaust is "pumped to top & seized solid!!!! Put a round punch in it & whacked it with 5 lb hammer, NOTHING solid!!!! No wear at all on bottoms, all the rest look good & ones that have open valves are down in lifter as they should be. SOOO do I just replace the " F'd" one with likely a Chinese replacement or do them all with Chinese junk????? Definitely have found the problem
Phil,,,,,,Read......:laugh4
 

boxerdog

Well Known Member
Supporting Member 5
Intake off, pulled # 5 lifters, exhaust is "pumped to top & seized solid!!!! Put a round punch in it & whacked it with 5 lb hammer, NOTHING solid!!!! No wear at all on bottoms, all the rest look good & ones that have open valves are down in lifter as they should be. SOOO do I just replace the " F'd" one with likely a Chinese replacement or do them all with Chinese junk????? Definitely have found the problem
I usually wouldn't stop short of doing the cam and lifters, but it is a real job, regardless of how you do it. So being a bit lazy, and only if the lifter wear surface looks perfect with a little crown and the cam lobe is normal, I'd try to fix the original lifter, or replace it with the best quality piece I could find. You might get by. No warranty on this one.
 
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