mefreema

Just got my motor re-built and have a couple hundred miles in it, now I have valve train failure!
The stock pushrod have worn into the guide plates and the worse one failed on me! The guide wore done so much that the roller tip rocker worked its way off the valve stem and I assume started to push on the spring retainer itself and or the retainer lock. It was the exhaust valve, the car started to run like crap and a backfire (not sure if it was through the intake or exhaust) I got it home (2 miles away) once I let it cool down and restarted it I heard a lot of noise coming from the engine (sounded like valve train) so I took off the valve covers. The locks were laying on the head and the spring was no longer retained. As well the rocker was just loose and hanging there. The pushrod was slightly bent. The pushrod guide was severly worn and bent. A lot of the other guides are warn as well and some of the tips are half way off the valve stem for contact. Were my guides crap and not hardened but the push rods were? What do I need to do to make sure this does not happen again? What parts should I get, hardened pushrod and hardend guides? Also how can I check to see if my valve or piston got damaged? I was thinking of getting hardend pushrod and guides, getting the spring reset with new retainer locks and just checking the compression on that cylinder compared to the rest. If it looks good then just button it back up and run it. Does this sound like a good/safe plan? Thanks!!!

tpi_roc

You're supposed to use hardened pushrods with guide plates.

rezinn

You're not using SA rockers, right?

You MUST use hardened pushrods with guideplates.

RB83L69

I don't know where this business about how you "must" use hardened push rods with guide plates got started... lots of motors (all big blocks, for example) come from the factory with guide plates and the same crappy push rods that small blocks come with. That doesn't mean that it isn't a good idea, but it's not a "must" deal. More to the point, that isn't what's causing this failure; his guide plates are wearing, not the push rods.

You have 2 things attempting to guide your rockers. There are 3 possible methods of retaining them in the correct location over the valve stem: guide slots in the heads, guide plates, or "self-aligning" rockers. One, and only one, must (and that is a definite "must") be in effect at any one time.

Replace all the broken stuff. Check your parts choices, and make sure that if you are using guide plates (IMHO the best of the 3 choices) that you are not using SA rockers and that the slots in the heads are enlarged to huge holes.

mefreema

Thanks RB83L69! I would like to keep the head on the car to cut down on my work so I am going to try and get away without clearancing the pushrod holes. I have Crane Roller Tip rocker so the self aligning ones I wont be using. So that leaves guide plates which caused the problem to begin with. Do i just need to make sure I have a hardened ones this time and I should be all set? Also can I just put things back together and check compression for that cylinder, then if it is the same as the others just run it. Or should I take off the head and give everything a visual inspection?

1986redbird

maybe someone else can chime in here, but, how can the locks and retainers come off of a valve and the valve not fall into the engine? either you are the luckiest SOB in the world or there is a problem with the valve guide. I'm no expert but I have seen this happen once and it makes quite a mess of the piston top.

Nordbert

If you put the spring back on the valve and pressure up the
cylinder ( with the rocker arms loose or off ) any pressure lost
through a bent valve should be heard through the intake or
exhaust pipe.

mefreema

On the way home the car was making some *** awful noise sounded like back fireing. As I pulled into the garage I didnt notice alot of engine noise it just sort of stumbled to stop. I let everything cool down and restarted it and it made a ton of noise. I could have failed just then. Anyway the piston is high up in the bore now keeping it from dropping back into the engine so maybe I am a lucky SOB I have a compession checker so I can see how well it holds compression with that too. At the most I ran it for 2 miles like that or 2 seconds from the restart or anything in between. Man I hope I didnt screw my valve or piston up! If I did what better reason to make it a 383

ede

i've saw a few engines drop valves and never saw or heard of one having the keepers, retainer, and spring come off and not drop the valve. if i were you i'd run out and buy some lottery tickets.

Ukraine Train

you also should check your valvetrain geometry, ie. make sure that the rocker is centered over the valve stem and not riding only one side of it, if it is you need to get shorter/longer pushrods depending on which side of center the rocker is. you can use and adjustable pushrod to figure out what length you need and then buy a set of those.

i too would be very surprised if you didn't at least bend your dropped valve or at worse put a hole through the piston, good luck though, let us know what happens

mefreema

The spring and retainer were where they were supposed to be but the locks were on top of the head and the rocker was turned off to the side of the spring and retainer. The valve was dropped from the spring. The heads are brand new so the valve seal holds the valve in position. To get it to drop I would have to physically push it in but the piston as it sits is up to high to let that happen. Hopefull it stayed up in the seat and didnt contact the piston. We shall see

RB83L69

aIf the guide holes in your heads are still slots, then that's your problem. You have 2conflicting systems attempting to align your rockers.

You can put hardened push rods and any other stuff you want on there, it will just continue to eat parts until you take the heads off and enlarge the guide holes.

What kind of a moron for a machine shop would set up a pair of heads for guide plates, and not drill the slots out??? Sounds to me like you need to find a new machinist.

The reason the retainer is still on the spring is that when the whole deal failed, the rocker could get sideways and push on teh retainer, which will eventually hammer the keepers out; but as long as the rocker is still on top of the retainer, the retainer won't be able to come up out of the spring.

Since you'll be removing your heads to get the holes enlarged, you'll get to see if there's any internal damage.

mefreema

The heads are Dart Iron Eagle's and dont have the slots so they do need the guides. I think the problem were the guides were junk and not made from a hardened metal. I hooked the valve back to the spring, replaced all the guides(Comp Cams), and replaced the bad pushrod. After resetting the valve lash I checked compression 60psi then reset valve lash and got 50 psi. Looks like I am **** OUT OF LUCK!!!!! I did two othere cylinders and got 150 & 160 psi. About what compression would that equate out to? So now I have to pull the head and see whats up, bent valve probably but I hope I didnt screw up the piston or that will be even more work. I think I may pull out the motor and put it on the stand to do all this work seeing that I just bought a 2500K stall converter. I might as well put it in while I got everyting torn apart.

RB83L69

Do you have self-aligning rockers?

I can't stress strongly enough: just replacing the wasted parts is probably not going to solve the problem; something is binding somewhere for a reason, and it's going to continue to cause failures if you don't identify it. Lots of people are running those guide plates without trouble; Dart wouldn't keep using them if they just immediately failed on every motor they were used on. Find out what the real issue is and take care of it, otherwise you will be right back where you are now in another 3000 miles. It's 100% certain that the material the guide plates are made from is not the root cause of your failure.

It's impossible to calculate compression ratio from those readings. There are far too many variables. However, 150-160 psi is fairly typical for a street-type motor, so I would say those cyls are OK.

mefreema

I am using crane roller tip rockers so they are not self aligning.

I bought the heads on the internet so the casting is a dart iron eagle head but the valves, springs, studs, guide plates, pretty much everything else was installed by the guy selling the heads. So who know what he used?!?!?! I noticed the comp cams guides looked beefier that the ones that failed. Is their a way to test the old guide plated to see if they are not hardened? Maybe fire up the grinder and see how easy the stone wears into the metal? I have hardened bolts I could grind on to use as a comparison. hahahaha hummm I'm sure their is a better way than that! Any ideas?

Maybe the old guide plates were a 3/8 and the new are 5/16 their seem to be more play in the old set. Maybe there was too much slop in the old setup?

If nothing else I will be pulling a valve cover every couple hundred miles for a while to keep an eye on things to make sure it doesnt happen again!

RB83L69

You could test them and see if they're any different... just FYI the Rockwell test method is to embed a pointed thing into the metal with a known amount of force and measure how far it goes.

I have a set of GM guides on a set of heads that have run about 140,000 miles so far; first with a 282 solid lifter cam for 110,000, then with a 274 hydraulic for about 10,000, then with a 282 hydraukic roller for the remainder, all with 1.6 roller tip rockers. Every one of those cams is bigger (more lift) than yours. If any guide plates in the world are made of crappy metal it would definitely be the GM ones. Yet, they showed no visible wear last time I looked at them. Compare hundreds of thousands of miles to hundreds of miles, then be honest with yourself and figure out whether harder metal is really going to make any difference. And of course, soft guide plate material won't make the push rods bend.

I know you don't want to hear this, but that won't change the fact: the guide plates themseves are not your problem. They are merely the symptom of the real problem, whatever it is. Any guide plates you put back in there will suffer the same fate, or if they are sufficiently strong that they manage to survive, the next weakest link in your system will fail instead. Next time you could end up with bent valves, broken studs, push rods that gnaw their ends off in the end of the rocker, broken push rods, etc. instead of merely wiped out guide plates.

edit: Physically check your rockers by looking at them, see if they're self-aligning. Don't assume anything. Your problem is obviously 2 systems attempting to align the rockers to 2 slightly different locations, and the guide plates are losing the fight; if the push rods clear the heads, then the only other possibility is that you have SA rockers.

mefreema

Huh..... Cant argue with that! Too bad I have never had this problem before so I dont know how to fix it. Everything looks normal and nothing seems to be binding. Do I need to oblong my holes in the guide plates to try and get a better alignment? What should I try or be looking for? Also could I have possibley wiped out a lifter and that could be causing the low compression?

mefreema

Oops missed the edit: part of your last post. They are crane roller top rockers so I pretty sure they are not self aligning. The push rod only comes in contact with the lifter, guide, and rocker. There is no contact with the head (very close on some but no contact). I will take some digital pictures of the the heads as they are now. Sinse I put the new hardware on you wont be able to see it as it was but I'll take pictures of the failed guides though. Maybe you can spot something that I'm missing.

RB83L69

Show the underside of the tip of a rocker in a good clear closeup pic, from an angle to the side... we're looking for little ridges on either side of the roller in the tip, that being the "self-aligning" feature. Crane makes those, so that may be what you have.

There is probably no damage to lifters.

Do not alter the guide plates in any way, except that if the push rod contacts the end of the slot in it, lengthen the slot toward the stud. Most especially do not widen the slot.

mefreema

ok.... will do!

F-BIRD'88

Are you using Crane Energizer rockers?


Be sure you didn't get Ford rockers, they are both 1.6:1 ratio, they look identical but the geometry is different.

Check to see if the pushrod is contacting the root of the guide plate nearest the rocker stud ,,, while someone turns the motor over by hand.

You still sound unsure as to wether your rockers are self aligning type or not. Crane sells both.
Did you by chance get a set of offset push rod seat rockers?

F-BIRD'88

....

F-BIRD'88

...

mefreema

Here is a pic of the rocker tip so you can see if it is self aligning or not. I dont think it is.

mefreema

The lower right guide on left side was the one that failed. Upper left showed no visiable signs of wear except some discoloration and the others show signs of wear.

mefreema

Close up of #8 cylinder. You can see the shiny mark on the retainer where the rocker tip came into contact with it.

mefreema

Another pic of the failed set with the new guides so you can see alignment and all that stuff this pic is more clear.

mefreema

here is a clear pic of a couple cylinders to see alignment, how it is setup, maybe you can see something that I can't. Hopefully none of you are on a dial up connection. You'll probably want to shoot me trying to open up this thread! The guides seem to be holding the tips right on the vavle stems where they should be and their is not contact with the head but it is very close on some. There are no guide holes in the heads themselves like the stockers which you should be able to see.

RB83L69

The first thing I see that just jumps off the pics is that you have the wrong retainers... looks like 1.45" springs and 1.25" retainers. Measure the springs and get the right retainers.

They don't look like self-aligning rockers.

mefreema

The springs should be 1.25 as well as the retainer. It is just that it may look short on one side because it hangs over on the other. When it sits inside the spring it has a little room to move around so it may not be perfectly centered.

mefreema

I will double check the the retainer and spring size but could that be the cause of my problem? If so I have another set if heads with retainers springs that I could use that would handle the cam im running.

mefreema

Just thougt of something else. Sence the spring seats are gound for bigger springs as well do I need to be running a retainer of some sorts on the bottom of the spring as well to keep it from moving around?

mefreema

Can anyone make anything out of these pics to see what my problem might be? On some my studs they do not seem to lign up with the valve stem tip so the rocker is a little turned. But the guide corrects that and puts the rocker tip right over the valve stem tip so it would seem right. Is that slight angle putting too much of a load from the pushrod onto the guide while it is correcting the alignment?

mefreema

oops forgot the picture

RB83L69

You're right, I misinterpreted the pic, it's the spring pocket that's 1.45", not the spring itself...

You can either get spring seats from someone such as Comp (check their catalog at www.compcams.com ) or get the larger springs & retainers. I'd upgrade the springs, personally; but that's just me. I wouldn't spend extra money to preserve an inferior parts choice, if I was going to spend money I'd use it to improve something if possible.

It's normal for the rockers to be turned, in fact it's an essential part of the design. That forces the rocker tip to move at an angle across the valve tip i.e. out near the edge of the tip not straight across the middle, which forces the valve to rotate; that way it wears evenly all the way around.

mefreema

is it really necessary? could that be causeing my problem? I'd rather not get new springs because if I do then I would want to go for the roller cam setup and the roller springs would be too much for the hydralic lifters and i dont want to drop all the cash just yet. I already spent a bunch on the heads cam & intake. The current spring is good for a .550 lift which is plenty for me at this point.

mefreema

After seeing the pictures does the conclusion still stands that the guide plates wern't junk but there is a problem with the setup?

RB83L69

The springs won't be "too much" for the lifters.

If the springs aren't retained properly, they "walk" all over the place. Look closely at the spring seat and see if there are any interesting marks, I'd bet there are. When they do that, they wobble from side to side, **** the retainers at odd angles, and otherwise misbehave; you can't see any of this with the naked eye, especially not when they're at rest, unless you watch it while the engine is running at speed with a strobotach or a "dial-back" timing light (which is basically a strobotach calibrated in degrees). The action of the cam on the springs is much like hitting them with a hammer. To get a good idea of how wild they'll behave, go get a rear spring out of a car and just throw it on the pavement out in a parking lot or something somewhere where there's lots of space for it to fly around, and just see for yourself how wild a spring acts under impact. Valve springs do the same stuff, just in miniature. If they're not restrained they get real jiggy.

There are no 1.25" springs on the planet that will survive at .550" lift, period. Note that no one making that claim will warranty any valve train part whatsoever; but anyone who warranties valve trains will void the warranty if a 1.25" spring is used with predicted theretical lift exceeding .500". Check with Comp, Crane, Lunati, Ultradyne, or any other cam mfr.

Out of curiosity, what cam are you running? That hasn't been mentioned I don't believe.

I still have no doubts that the guide plates are the victims of something, not the actual culprit.

mefreema

I am running a Comp Cams XE 268 the lift is intake/exhaust .477/.480 . I guess that makes sence because their are hydralic roller lifters arent their. I guess some crazy grind for solid roller cams may be in issue.

RB83L69 I just have to say thanks for all your input! It is so hard to find people who actually know what they are talking. I'll see if I can find marks from the spring walking around and kick around getting new springs or seats. Anything else I can check for? Or just do springs or seats, run it and keep an eye on things?

RB83L69

No that's not a roller, it's a flat...but that's OK, those same lifters are used with bigger cams such as the very next one up in that series, the XE274, which is spec'd for the springs that you would be getting, as well as some REALLY huge ones. That's a good cam; I wouldn't get too excited about replacing it just yet. It shoudl be just fine once you get the other issues sorted out.

mefreema

I know the XE268 is a flat tappet cam I must have worded that wierd. So I should look up the specs recomendations for the XE274 buy that spring and I will be set to run some big roller cams in the future if I wish and it might also resolve my current problem, correct? Thanks again for all your help!

F-BIRD'88

It takes a massive amount of force to destroy a guide plate like that. These parts should show absolutly no wear or trama.
You'd best check the actual cam lift in your motor with a dial indicator before you run out and buy parts.
I'd say either your springs are near coil bind and you over reved it, or some other massive upset has happened.
Even if the guide plates were installed out of alignment you wouldn't see damage like that. Some thing about your setup is not as it seems.

Wouldn't be the first time a camshaft was mislabled.
I'd pull the cam and lifters for inspection too.
How's your valve to piston clearance? I would not assume any thing at this point.

mefreema

My head is spinning trying to figure out why this thing failed. I check springs specs and took measurements for installed height coil bind ect. Everything looks cool.
So I started to concentrate on why my compression was so low in bad cylinder and I did the cranking compression test with and without oil in the cylinder. Well I got 50-60 without adding oil but with a couple squrits of oil it shot up to 100psi. So does that mean my rings are bad?
I will be pulling the engine soon but this sucks! I am going to miss woodward dream cruise. I want to have it back together soon so I can make it to the track for some 1/4 mile times. Oh well screw woodward for this year anyway those people are bruital! Unless you are driving around a $70,000 + car (oh lets say an authentic shelby cobra) people rag on you. I was going to hang a sign of my car that said "rag on my car if your gay" or "If you like to chew on wrinkly sacks and rub ball sweat on your face make fun of my car". Can ya tell that place left a bitter taste in my mouth. Who am I kidding, I will be back reguardless because I love to look at all the sweet cars! I just need to get some paint on mine!

maverick351ci

ive seen luckyer on a 92 eagle talon with a 2.0 valve bender as with most of the at 80,000 its killed a timming belt and it did it when the motor was turning 6 grand the kid said but i had to pull the head becuse all of them bend the valves when that happeds and there laying in number 2 and 3 cylnder is 4 valve heads in each the motor had no score marks no pistion damage i was ****ing amazed i had to take pics of it to show people that pic hangs in the shop i work in to show people why at 70,000 miles we recomend a timming belt on those 2.0 motors