So far I have at least 2 bad lifters and 2 broken rocker arm studs.

The broken studs were intake valve on 1 and 8. All other cylinders looked to be running rich (i wonder why).

I am hoping there is no damage to the cylinders or pistons.

The valve springs were spec'd for the cam and 1.6 rockers when I built the engine.

Thanks,
Chris

 

What cam? What springs? What was their installed height? How much clearance between the retainer and guide?

 

i don't remember all the specs. was built about 15 years ago.

tpis zz9 cam, L31 vortec heads, proform 1.6 self aligning rockers.

The heads were done by a reputable race shop. They did all of my machine work and recommended the springs. Engine build has less than 1000 miles on it and was sitting on a stand since 2005.

It had a dead cylinder after losing oil pressure on the maiden voyage. I blew out the plug in the oil pressure sending unit. I assumed a bad or stuck ring on #8. I felt it when the #1 rocker arm stud broke.

Thanks,
Chris

 

the #8 lifter actually had the piston pop out. could that be caused by too much oil pressure?

 

Piston or lifter plunger ?

 

the smaller piston inside the lifter (probably what you are referring to as the plunger).

Thanks,
Chris

 

MAJOR bummer d00d. I feel your pain.

IIRC that cam had around .520" of lift with 1.5 rockers. Around .550" w/ 1.6.

I've never heard of a 1.25" OD straight spring that will go onto Vortec heads and allow that much lift. Especially not when set up for appropriate seat pressure.

The retainers on Vortec heads smash into the top of the valve guides at around .480" or a little less.

No wonder it exploded. You had something around .060" of pure metal-to-metal going on. Probably coil bind too. That's what destroyed the lifters. I don't guess it went a whole lotta miles before all this happened? Maybe … 5?

Pistons are probably OK... the valve guides protected them.

Everything related to the valve train probably needs to go in the trash now. Cam, lifters, push rods (I bet you'll find bent ones), rockers, springs. When you put it back together it'd be a good idea to do something about the clearance and coil bind issues mentioned above. No idea of course what, if anything, was done to the heads when you built it; but now you know, it needs A BUNCH of massaging to get a combo like that right.

 

they machined the heads for double springs.

i am attaching the pics. also, i didn;t find the retaining clip or washer that goes on the top of the lifter to keep the plunger in.

 

Are these Alex Springs ?

 

 

That's good, as far as it goes; they even got lucky and didn't hit water. Which is a problem kind of between the spring pocket and the head bolt: the "corner" of the spring pocket goes sort of sideways into that "hump", which is thin, and people often scrap a head that way. They must not have cut them very deep.

Any idea what the springs themselves are, or what the installed height is? They look 1.45" OD, like Comp 986 or the like.

Looks also like that one valve that's up close in the 1st photo has a nice divot in the stem.

 

I think they were comp springs. They did crack one of the heads during machining and replaced it with another. I think it was when they were removing the pressed in studs though, if memory serves. They had machined quite a few vortec heads before mine.

That divot is an optical illusion it was just a bit of oil. I went back and checked. Also, no bent push rods.

I rotated the engine and all of the lifters are moving.

How can I check the retainer to guide clearance at max lift.

Is it the exhaust or intake that has the high lift, because I believe both of my problems are on the intake valve.

Thanks,
Chris

 

also, is it possible the rocker arms were too tight causing the failure?

I reused the lifters that came with the block, is that a possible reason for failure.

 

found the box from the springs comp 987-16

 

Wouldn't it have made a lot of noise when idling if the retainers were hitting the guides?

It never made metal to metal noises even after the studs broke.

This engine ran smooth when I first put it together.

Thanks,
Chris

 

can i remove a spring and the valve seal to see if they machined the guides?

 

Yup, that's what I'd do.

Pop a spring off, see how far the valve can go before it hits something. Measure the spring's installed height while it's outta there. Pick one of the valves that self-destructed.

Properly set up, those springs should have been adequate. They are spec'ed to be set at 1.800" IH. If that was not done, i.e. if left at stock height, they might have gone into stack-up.

Who knows about noise. Lack of noise doesn't mean the same as OK.

No it is not possible that the rocker arms being too tight would cause this failure.

No re-using the old lifters didn't cause the failure.

 

after re-examining my valves, they all appear to have excessive wear from the rockers.

I pulled an exhaust valve spring since that is the .540 side and there doesn't appear to be any signs of contact between the guide and retainer.

I am really thinking this may just be bad lifters. If the lifters are not working properly, can they cause the hammering of the valve?

Thanks,
Chris

 

also, some the valves appear to be shorter from the spring retainer to the tip. Is this because some of the valves have been ground?

 

Yes, possibly, but ground tips should have only about.005" taken off. You would not be able to "see" that. Intake valves and exhaust valves sometimes have different stem lengths.

 

Installed the springs look to be close to 1.75" from seat to retainer.

valve seal retainer clearance looks to be about .75" when the valve is seated, if I measured correctly.

with the cylinder at top dead center the valve contacts the piston at about .25"

I am not sure if any of this is helpful.

Thanks,
Chris

 

NO it is not bad lifters. At least they didn't used to be. They're destroyed now. Whatever damage you see to them, they are the VICTIMS, not the cause. Something has hit something and there's carnage.

Probably not anything to do with the pistons; although if it is, it'll leave a mark on the pistons. You can look in there with your borescope and see.

Put your dial indicator on the valve stem; see how far it moves from all the way up to contacting … anything.

Put your valve spring mic under the retainer. Measure the valve spring installed height. 987 wants 1.800". Stock SBC height is 1.700". If you have 987s set up at 1.700", you're into coil bind. Especially on the exh side.

Until you do THOSE 2 THINGS, all else is just guessing in the dark. MEASURE MEASURE MEASURE MEASURE MEASURE MEASURE. Nothing else matters. If you're not going to MEASURE, there's no way we can help you achieve a GUARANTEED successful repair. Anything less is going to be a "maybe it's this maybe it's that" and you'll get to buy and build it back however many times it takes until you guess right.

 

ok i am going to see about getting the tools to make the correct measurements.

My rough measurement for installed spring height is only 1.75" so that is most likely contributing to the failure.

I will have to get a dial indicator to measure how far the valve moves before there is interference.

I do not currently have these tools.

Thanks for your help. I appreciate it.

Chris

 

Yeah, it's not much fun when you pay somebody to do something and it doesn't turn out right, and you have to go back in and debug it yourself.

When you say "my valves, they all appear to have excessive wear from the rockers", exactly what sort of wear is it? What rockers? How did you set up your rocker geometry? What length push rods did you end up with? What valves are they, exactly? Stock? Aftermarket but still stock length?

You can probably pick up a cheeeeeep dial indicator for around $30 - 40. A very useful tool to have around anyway. A valve spring mic unfortunately costs a little more than that, but isn't as universally useful as a dial indicator; and the cheeeeeeper ones have a 1.800" upper or lower limit, but the ones that have this value in the middle of their range, tend to cost more for some reason. You may also end up needing an adjustable push rod; probably a Comp 7702 would be the best one.

 

ordered a magnetic dial indicator and digital caliper with depth rod, so I can take some measurements next weekend.

Yeah the shop that did all my machine work was very reputable, but I guess I should have double checked things myself.

The valve stems look like the rockers were applying a lot of force and have some light grooves from the rocker arm roller contacting the stem. If It was binding that makes sense to me. They were stock valves.

The marks are all right in the middle of the valve, so the push rod length is probably good. The are stock length oem roller cam push rods, but I will measure them to be sure.

OK, so let's assume that the valve pockets are not deep enough to get 1.8 installed spring height. Can I just install a set of alex springs and retainers and shim them .05 to the proper install height? What are my other options to fix the springs?

I am attaching some images that show the valve tips and spring pockets. The spring pockets show that the surface is not smooth from what I assume is the valve binding and pressing into the head.

Thanks,
Chris

 

 

"Mark in the middle of the valve" is not the indicator of correct geometry. Mark as narrow as possible, no matter where it falls on the stem, is what you're looking for.

Looks like you had roller rockers? (well, roller tip at least, anyway) Aluminum or steel?

The valves are actually supposed to rotate during operation. The rockers are supposed to kind of be off-center a little bit, such that as they swing through their arc, they should roll around the edge of the valve somewhat, rather than straight across. Looks like that wasn't happening; but it might have just been because the rockers were hammering on them so hard and dug a rut.

Your machine shop definitely cut the guides down; those double springs wouldn't have gone down on them, in stock form. Plus, those look like Comp Teflon seals, probably for .530" OD guides, which is good. You can see in the 1st and last photos how cutting the pockets too greedily can easily get out of hand. I don't see any evidence that the retainers hit the guides, since the seal is intact; obviously it would be pounded to mush if it had been getting hit. Looks pretty conclusive to me that the problem is not enough installed height on the springs.

To get extra IH there are several strategies you can use.Longer than stock valves; cut the pockets deeper; or offset keepers if those give you enough extra room. Longer valves is best but that changes other things at the same time. I wouldn't dare cut the pockets deeper on those heads either. You don't want to run it with no shims at all on the bottom like it was, because the cast-iron of the heads is MUCH softer than the spring metal, and will get chewed up; you can see in fact that they already are. So if you put the thinnest shim you can get under them, say a .015" hardened steel one, and then .050" offset keepers give you the extra height you need, you might be good to go. Measuring the height with the hardware you have there will tell you what options you have available to you. You may find you need valves anyway; they may be damaged where the keepers sat in the grooves, or so beat on the tip that they need to be replaced. Don't try to take them out of the heads until you clean up any burrs around the keeper grooves that might have been thrown up by the interference, to avoid gouging the guides out.

 

I believe they are Proform 1.6 aluminum self-aligning roller rockers.

Using the tape measure, because I won't have the proper measuring device till Thursday. I got right at 1.75 mark for installed height. Offset retainer locks look to be good for .050. Adding a hardened shim .015 should put me in the .02 tolerance for installed height.

Lots more measuring to do and some parts to buy.

I am going to inspect all of the roller lifters. What should I check to make sure they are still good. (I may just order a set of lsx lifters)

Thanks,
Chris

 

Thinking about it some more, there's another choice: you could also use LS motor springs and Comp 787 "adapter" retainers. https://www.texas-speed.com/p-6431-p...-pac-1219.aspx

I'd be real hesitant about re-using those lifters, given that at least the one came apart. They all took a pretty good beating. Yes, LS lifters would be fine, they are interchangeable.

Part of this is going to depend on what cam you run. Is your current one damaged?

 

I haven't touched the bottom end yet. I want to keep it together until I get the measurements worked out. It is easier for me to remove the valve springs with the heads mounted

Next weekend, I will pull the heads and cam so that I can look at the pistons, rings, and cam lobes.

I am hoping the cam is not damaged.

Thanks,
Chris

 

Speedway motors has +.100 length valve for about $150 total. If I am gonna need valves anyway.

https://www.speedwaymotors.com/Super...-8,412494.html

https://www.speedwaymotors.com/Super...-8,412476.html

Then I can add the hardened steel shims. I will have to get a push rod length tool so that I can figure out what push rods I need.

I found this deal on new ls7 lifters.

https://www.lsxceleration.com/lsx-ls...fters-5850-16/

I looked for the delphi lifters, but everywhere seems to be sold out.

Thanks,
Chris

 

Just don't buy your "Delphi" lifters from Skip White. They ARE made offshore and do not function correctly.

 

I ordered a set of ac delco lifters.

I will order the valves next week.

Gonna pull the heads and check cam, pistons, rings and bearings this weekend.

Thanks,
Chris

 

I measured the installed spring height of cylinder #1 exhaust 1.80 and intake 1.83

I measured the max lift of .503 exhaust and .509 intake

With these measurements, I am not sure why there would be binding.

The intake is the one of the 2 that snapped the stud.

With 1.5 rockers they would measure about .475/.476, so I am guessing I got taken on my cam or the lobes are damaged.

I think I am going to measure the rest of the spring installed heights and write them all down so that I can figure out what needs to be done.

I am thinking I will get the CS XR270HR-10 cam.

Thanks,
Chris

 

well i pulled the heads and apart from looking like they were either burning oil or running extremely rich they look fine.

Is it possible that detonation could have caused the failure. I am wondering if my fuel/compression ratio was part of the issue.

Thanks,
Chris

 

No not really possible.

Check your rockers for binding on the studs; running out of "rock" room. Not usually a problem with roller rockers but who knows. Look carefully at the studs, the nuts, the trunnions, etc. for witness marks. Could have been the inside of the rocker, around the nut, hitting on the nut at full lift. This would especially be a problem if the push rods were too long.

SOMETHING definitely hit SOMETHING. I would not bolt that motor back together until such time as it is found and cured.

 

I just measured the cam lobes

My max lift according to measurements

exhaust: base circle: 1.07, lobe: 1.41, difference: .34, 1.5 ratio: .510, 1.6 ratio: .544
intake: base circle 1.08, Lobe: 1.41, difference .33, 1.5 ratio: .495, 1.6 ratio: .528

here is a pic that shows the cam lobes.

 

 

If all of your heights and clearances check out, then look for this:



You have to verify no interference throughout the entire cycle, not just when the lifter is on the base circle of the cam lobe.
Do you see any witness marks/gouges on the underside of your rocker arms?

 

Your picture. See the yellow line I added?
Install a spring retainer with it's locks and measure from the bottom of the retainer to the top of the valve seal.
Here are your spring specs:
Part # CCA-987-16
1.430 Dual Spring
121 @ 1.800
388 @ 1.200
Coil Bind @ 1.150

 

The only one with any marks is the one that broke the stud. and it looks like the push rod did all that damage.

it looks like the push rod was out of the cup at some point and dimpled all around the cup. It could have happened before the broken stud or after. I have no way of knowing for sure.

There is no contact between the rocker and retainer. I checked that today with a test spring.

I would like some opinions on whether the cam looks ok. You can see where the rockers make contact with the cam, but nothing look gouged to me.

Thanks,
Chris

 

i measured it at .090

 

Typo maybe? I was expecting something like 0.750"

 

I think it was supposed to be .90

I can measure it again.

Thanks,
Chris

 

I did a quick measure and got .88, but I didn't take my time like I did the first time, so there may be a little discrepancy.

The tool was still set to .90 from before.

Thanks,
Chris

 

OK, with those measurements, and an installed height of 1.800", CC-987 springs don't coil bind until 1.150" - so you are safe there.
And your worse case scenario with a valve lift of .544 (1.6 ratio), you are plenty safe with your retainer-to-seal clearance.
And if your rocker arm had clearance to the spring retainer (you said it does), then you are safe there.
If your valvetrain geometry was in the ballpark, then the only thing left that I can think of to cause your broken studs is that the rockers were not properly adjusted (too tight).
That is as long as the lifters themselves were not at fault.
And from what I can see in your picture of the camshaft, the lobes look fine also.

So what went wrong ???

 

I am going to reassemble it and drop it in the car and hope for the best.

Thanks,
Chris

 

The valve stem tips have unusual wear on them that looks like the rocker tip was really hitting it hard. The wear in the spring seat at such low miles of use also indicates heavy pressure. I think coil bottoming could cause a lifter to explode if the bottom was only a little too much and the oil pressure in the lifter would go through the roof every time it tried to overpush a little. The overtravel was just enough so that the lifter was taking the hits and was able to manage for a short time before popping.

My 2 cents, that's probably what its worth.

 

You do know that the proper rocker adjustment is 1/4 to 3/4 additional turn after lash removed - on the base circle of each cam lobe?

 

Yes. I think I used 1/4 turn when I did them before.

I am going to pay careful attention as I re-assemble.

Should i re-hone the cylinders if I re-ring. The cylinders still have visible cross hash. I was thinking of just wiping them down with wd40. Then oiling the new rings. I had at least 1 oil ring that wasn't seated but don't remember which cylinder it was.

I am going to clean the pistons and combustion chambers before reassembly as well.

Thanks,
Chris