Hey guys, sorry for the long read, seems like my questions always are.
I'm having more issues with my valvetrain on the camaro (SBC 406, hyd. roller). Back when I built this motor I had trouble adjusting the preload on the lifters. I didn't really understand why, but my buddy helped me adjust them with the engine running and all seemed well for the moment.
Fast forward to now, and I have been hearing a funny valvetrain "noise" at 6500 RPM and up. Thought it was valve float, so changed to the proper dual springs (that's another story).
Upon putting valvetrain back together, I again have the issue with adjusting the preload on the lifters. If I set at 0 lash plus 1/4 turn, four of the 16 lifters will not pump any oil, and will be making noise, the fix being to tighten them up several turns to get the plunger in the right dimension.
Here's where it gets weird. If I set 1 of the lifters in question next to one that is "good", you can see the difference in the angle between the two rockers (like the pushrod is .200" longer or something). It's a large difference. I don't know what could cause that to be wrong. I've made sure the pushrods are seated, same length, etc. It's just 4 lifters out of the 16 that do this (and it seems to be the same ones all the time). To set these lifters I have to just "guess" how far to tighten them, cause the 0 lash + 1/4 turn doesn't work.
Cyl. # 7 (which has one of the problem lifters, exhaust side) was making a lot of noise from one lifter (and not pumping any oil through the pushrod either), so I put my windowed valve cover on and adjusted it with it running, and the oil starts to flow as the clacking goes away. Now I notice the motor is running like crap, and when I crank it to start, it sounds like there's a bad cyl. in the motor.
So I get curious and do a compression check, and sure enough #7 has no compression. So I loosen the rocker just a little and the compression comes back, a little looser and it starts clacking again. It acts like a solid lifter. I don't get it.
What is with these lifters? I don't know if I need to replace or what? Lifters are Comp Magnum roller retros.
The motor has 3K miles on it with no problems to speak of (other than devil lifters).
ANyone have any insight on this? I could really use some help, all my car buddies tell me to throw the hyd. roller out and get a solid roller.
I'm having more issues with my valvetrain on the camaro (SBC 406, hyd. roller). Back when I built this motor I had trouble adjusting the preload on the lifters. I didn't really understand why, but my buddy helped me adjust them with the engine running and all seemed well for the moment.
Fast forward to now, and I have been hearing a funny valvetrain "noise" at 6500 RPM and up. Thought it was valve float, so changed to the proper dual springs (that's another story).
Upon putting valvetrain back together, I again have the issue with adjusting the preload on the lifters. If I set at 0 lash plus 1/4 turn, four of the 16 lifters will not pump any oil, and will be making noise, the fix being to tighten them up several turns to get the plunger in the right dimension.
Here's where it gets weird. If I set 1 of the lifters in question next to one that is "good", you can see the difference in the angle between the two rockers (like the pushrod is .200" longer or something). It's a large difference. I don't know what could cause that to be wrong. I've made sure the pushrods are seated, same length, etc. It's just 4 lifters out of the 16 that do this (and it seems to be the same ones all the time). To set these lifters I have to just "guess" how far to tighten them, cause the 0 lash + 1/4 turn doesn't work.
Cyl. # 7 (which has one of the problem lifters, exhaust side) was making a lot of noise from one lifter (and not pumping any oil through the pushrod either), so I put my windowed valve cover on and adjusted it with it running, and the oil starts to flow as the clacking goes away. Now I notice the motor is running like crap, and when I crank it to start, it sounds like there's a bad cyl. in the motor.
So I get curious and do a compression check, and sure enough #7 has no compression. So I loosen the rocker just a little and the compression comes back, a little looser and it starts clacking again. It acts like a solid lifter. I don't get it.
What is with these lifters? I don't know if I need to replace or what? Lifters are Comp Magnum roller retros.
The motor has 3K miles on it with no problems to speak of (other than devil lifters).
ANyone have any insight on this? I could really use some help, all my car buddies tell me to throw the hyd. roller out and get a solid roller.