His Follower

This is my first post here and I'm really glad you here. This is specific to my Suburban, but after I lay out my situation, I think general tech is a good place for this.

My 5.7L 1998 Vortec is very much stock. I did pull heads 8 years ago to fix a water leak. Then had headers added. Bought an RV and it struggled pulling it at highway speeds. I read an article about a cheap way to add horsepower by adding a CAM and I went to Summit Racing to get the list of what else I would need. I am smart but not wise you might say. I can learn but I did not understand what I needed to know before attempting this.

Bought the cam, new hydrolic roller lifters and new roller rockers and stiff valve springs. I had a lot of time so I watched youtube every step of the way. When I got to pushrod length and geometry, I started getting nervous. Went through a number of methods and even purchased light springs and an adjustable pushrod for testing. After it was all said and done, i had a push rod that just seemed right based on the wear on the top of the valve by using the dry eraser method. At this time I did not pull the heads. With the headers on and they sounded so perfect, with no leaks, I just didn't want to push my luck. Anyway turns out the pushrod length I ended up with matched my stock existing push rods. I thought, well I guess that makes sense. Saves me some money I guess.

Getting to the point, I got it all together, though uncertain about valve lash adjustment on the hydrolic roller lifters. Did what I thought was what I was hearing in the videos and it seemed like I did not trust what they were saying. It's very hard to know feel when you only have words and no experience. But when it was all said and done, and I finally read the tech document that came with my lifters, it turns out the lifters are short travel and they need zero to 1/8 turn after zero lash. I had set them all to 3/4 turn. Oops. Well when it came to starting the motor, it started immediately but it did sound kind of tappy, noisy. Too much so. I mean, I know what it should sound like and not that.

I am thinking that I set them too loose. Not too tight. And to be honest, its so hard to tell what it should be just by saying the first trace of drag or resistance. But he told me he tightens the rocker arms down until it's hard to turn the pushrod between his fingers and then backs off a little. I could identifty better with that approach thinking for sure I originally had them too loose. So I go through all of them and start the engine and things sounded a lot better. But on the passenger side, one tapping sound and I went on a 15 minute drive, keeping the RPMs under 3000. Just feeling it out. The tapping got really loud and I got paranoid and took it easy getting home.

During all of this, the engine is not missing and it's starting easy and idles smooth. Just the tapping noise.

I have the engine no set up to quickly take off the valve cover and as soon as I take it off, I notice cylinder 6 valve is loose. Very loose. The bolt and nut are tight though. Well did this exercise 3-4 times before I realize the rocker arm stud is pulling out of the head. I thought I'm dead in the water And then there was Youtube...

I find out about all the issues with new CAMs, very stiff springs, and stock pressed in rocker arm studs. I decide in the time frame I have to get this running, to pin it. Well I don't want to pull the head, so I'll do it right on the motor. I used an air hammer and pushed it back in until it stopped traveling.

Used a 3/16 drill bit and drill right through the mount and stud. I could not do it level, so it's kind of a 20 degree downward hole. I used a magnet to pull all the shavings out as I was going. At this point, I'm far beyond trying to get to a blueprint engine. We have camping trip we have planned at the end of next week and now I'm taking short cuts and throwing caution to the wind.

Well I get a pin and it won't go all the way through and I'm a little nervous about hammering it too hard and it cracks the block. So it's hangout out about 1/4 inch, but I'm certain it's through the stud. At least on one side.

So I put the rocker arm back on and tighten down, the way I had done all the rest. It sounded good until I revved the engine and then the tapping would start. I tightened down some more and repeated. It seems to keep loosening, but the nut it tight in the rocker. I'm thinking, what the hell is happening. So I think well maybe it's still moving a little with the pin, but certainly it's going to stop eventually? Right. I start measuring and if it's changing it's not much. But then I must have not been patient enough and I bent a push rod really good. It continued to run. Noisy, but it isn't missing or anything. So I got some more push rods. Exact matches and then I realize the specs on the push rods are 300 lbs, but the springs are around 450lbs. ughhh. So I think well I'm going too tight. I back off and go light, no movement at zero lash and just 1/8 turn. But it's noisy.

Questions are what do I do now? Could it be I crushed the lifter during the pushrod bend?

Again, I can go out and start the car, it just has a noisy lifter. It doesn't miss and I have set up a good diagnostics program on my computer. I can see everything.

Is this safe to drive with a collapsed lifter if that is what is going on? With out pulling the head, is there a fool proof way to troubleshoot the lifter?

Thanks

oilcanhenry

That's quite a lot to consume, but motor modifications can turn out badly. I am an OG now, but I did the same back when I was a younger man. If I were you, assuming you have the funds, I would pull the head and replace the lifters and the head. I know it's a lot of work, but so is putting in a new modified camshaft, lifters and pushrods.

His Follower

Well the engine kept bending push rods on the same cylinder. Turned out to be spring bind. So I pulled the heads and had them done. To get the lifters back to a position where I could be confident with adjusting them, I took all the lifters apart and emptied out the oil so that they would start compressing again. Feel pretty good about it.