that's odd glad I didn't haven this much trouble with my 270 h10 What weight of oil are you using?

 

Mobil 1 full synthetic 5W30

 

mobil 1 5w30 full synthetic here too...there might be a real small amount of nonsynthetic oil cuz i put some of that on the heads when i was assembling them, like on the valve stems so they slide through the guides easy when installing, etc.

 

any other thoughts on the valves closing/lifters bleeding down?

 

sounds like fautly lifters. you installed them right side up didn't ya?

 

lol Yes they are the right side up.

Just shooting in the dark here, does it even matter that they bleed down really fast? I mean when the engine is turning they are fine, so shouldn't it not affect how the engine runs?

 

I called Comp this morning and they said that definitely shouldn't be happening. They told me to send them the lifters so they could look at them or test them. So now I guess I have to wait to see what they say. Do you guys think I just had defective lifters or did I do something wrong to make them do that (which is more than likely lol)?

 

Only thing I've heard you say was the pumping them up. If that's a common method that I was not aware of, then it just has to be a bad set I would think.....

 

I dunno my shop teacher at school told me to do it that way. He said he's done it that way for years and it's the only way he knew of to pump them up without starting the engine.

 

Dont need to do it at all they come pre oiled. Also when you set lash your pushing all that oil you spent soo much time pumping in the lifter right on out.

 

Ahh thanks SSC.

So should I just buy new lifters and set the lash without trying to pump them up or should I wait to see what Comp Cams tells me when they look at them?

 

I think I figured something out!

When the pushrods got bent for the second time, I pulled off the intake and looked at the lifters to make sure that they were okay. All of the bottoms of them were nice and flat, smooth, just the slightest slightest bit of a wear spot beginning to form on them. So I figured the lifters and the cam were okay. However, I didn't even think of the fact that I probably destroyed the insides of the lifters when the retainers hit the valve seals/guides. Wouldn't the lifter collapse before the pushrods bent or snapped? Let me know if I'm wrong, but wouldn't just a set of new lifters solve the problem?

I believe the CCA-858-16 Comp Cams Magnum Lifters from Summit would be the correct replacement. What do you guys think?

 

I put in new lifters today and it fired right up! It ran muchhh less roughly than it did before. I ran out of time so I didn't time it with a light, but I will first thing tomorrow. At least the timing is close enough now that I opened the throttle a few times to see how it would rev and there wasn't really any backfiring!

Thanks a lot to everyone who helped out here.

 

Is that a 5.0 moter if so you have to install the dots at 12 o clock. If you install it like a 5.7 you will bend #8 valve for sure I made that mistake my first go around with my Z but the only way I found out how the cams went was looking thru an old gmc chevy van book> The hanes said to install it at 6 and 12oclock>