I recently put a new exhaust and headers on my car. I put some pro-magnum 1.6 rockers on at the same time. After these mods, some header primaries were glowing red in the dark. I did compression tests, leak down tests, swapped plugs, plug wires, and injector wires, but nothing showed a problem. So I started relashing the valves. While relashing, I found that some of the lifters could be compressed by hand. Two of the worst are on the cylinders that who's headers get red the quickest.

I can believe that oil has leaked out of the lifters due to the compression tests and valve lashing, so I'm going to borrow an oil primer tool from Autozone tomorrow (gotta love the loaner tool program). I expect some to compress easily by hand even after re-priming them.

So, how much should you be able to compress a lifter by hand? The wosrt ones will completely compress right now. These are Comp Cams 850 lifters with less than 5000 miles on them, so they should be decent. I call CC, but their tech support guy wasn't too knowledgeable. He did know I can get individual replacement lifters for $14 each. Since these have no good reason for going bad, I don't know if the rest are about to go to crap also. This makes me think I should replace them all.

Any suggestions for a high quality lifter (not fast bleed)? Any ideas what would have killed these lifters? I'll take the bad ones apart when I pull them to see if there's any visible reason for them to fail.


Later.
Joe
http://home.cfl.rr.com/shuhy/chevy.htm

 

You will not be able to prime the lifters with that tool, you will be lucky to get 10psi from it.

Set them with the motor running.

 

When I originally did the cam swap (and lifters, push rods, and heads), I used the tool to get oil flowing up to the rockers. This wouldn't be enough oil to fill the lifters? If a lifter is empty right now, then I'd expect this to at least make some difference. I've never seen a lifter compress this easily, even new ones out of the box.

Any idea why these would be completely bleed off while others aren't? The internals of a lifter seem pretty simple, but I haven't torn one apart myself yet. Though it seems that will happen soon.

As for testing lifters, a guy I work with who used to race and work on dual and quad engine truck pulls said they could feel bad lifters by putting pressure on the back of the rocker with the engine running. Apparently, you can feel a difference between good and bad lifters.

 

If all else fails, just take em apart and clean each part then put em back together with oil of course. My 12 second car has the stock L98 lifters that have over 190,000 miles on them . I just redid them and they work great.

 

A running engine will deliver about 50 times as much oil to the lifters as that tool ever thought of. I wouldn't waste the electricity.

I don't know of any fast bleed hydraulic lifters; but if I did, I'd stay at least as far away from them as I stay from fast bleed flat tappet ones.

Lifters will always bleed down if the engine isn't running. Then once the oil has run out of them, they will easily compress by hand. But I would assume you were lashing the valves in the usual manner, i.e. with the motor running. Can you push the push rods down when the motor is running?

What kind of oil are you running?

 

I lash the valves using the standard EOIC method and tighten them to 0 lash + 1/2 turn. I've done it this way for years on multiple motors and haven't had a problem before. Even if there's no oil in the lifter, the spring will push the plunger to the top of the lifter. I don't find 0 lash by twirling the push rod - which will vary depending on lubricant and pressure from the lifter. I find it by gently lifting the push rod and finding the point where it has contact with both the lifter and rocker - the definition of 0 lash. It's never been a problem before.

I don't want fast bleeds, I want good regular roller hydraulic lifters. Most of the ones currently in the car can't be compressed at all by hand. A couple exhaust lifters, which correspond to the cylinders whose headers turn red, can be compressed easily by hand. They don't act like the others, and those cylinders don't run like the others. Too damning to be a coincidence.

I don't want to run the engine and adjust these two exhaust valves to compensate for bad lifters. If they are bad, I want to know, and I want to replace them. I don't know why they would have gone bad, but they sure appear to be bad. I'd want to know how to figure out which other ones are marginal too.

 

I tossed in set of Crane roller lifters for factory roller blocks when I did my 383, they have been flawless so far.

 

I never could get the lash perfect when doing it with the motor cold and off. The motor running method has worked the best for me.

 

Just an update.

I ran the engine and let the oil throughly circulate. I checked the lifters and they all seemed pretty firm. I guess some just bleed oil off easier than others - I had cranked the engine with the starter and also by hand for compression leak down tests. So I relashed the rockers (still engine off EOIC method) and they headers aren't getting red anymore. I haven't put the valve covers back on (chasing a spark issue first), and all the vacuum lines are plugged, so I'll still need to check the headers again when everything's actually reassembled to make sure there's nothing strange going on.

Thanks for the input guys. I'll make sure the lifters are firm before I set valve lash in the future. Maybe I'll even trying setting lash with the engine running someday.

 

setting valve lash with the motor running is by far the easiest way to do it, loosen till u get chatter, and tighten back up till the chatter goes away, easiest and best way to do it

 

The better flowing exhaust could make the engine run leaner and cause the primary to glow.

 

I don't think it was lean. I use Diacom to monitor the O2 readings and I burn my own chips. The O2 numbers were looking good, even when the headers said there was some problem. I'll probably need to make a new chip since I've relashed and potentially have a better running engine. I also tried adding propane to the intake to richen the mix and that had no effect.

I've ordered a distributor to try to fix my spark problem, so I hope to do some test runs later this week. I'll let you know how it goes.