Engine Worn Pushrods, Loose Rockers. Little Patience

[1978Cobra2]

well my last post was not the best being about a broken rocker stud. Since then I have hand tapped (Don't get too angry) the old stud holes and installed screw-in studs. I am not using guide plates with these studs, they are Mr.Gasket brand. After the stud install I went ahead and got Comp roller rockers with push rods since a couple of my original rockers we badly worn. These new components have maybe 3 miles and 30 minutes of run time on them and all the proper procedures were taken when installing. (comp break-in lube, proper valve adjustment) After a few minutes of the first fire up I noticed a small tapping still coming from the driver side of the engine, it had not seemed to bad till the last little ride. I pulled the valve cover and to no surprise number six cylinder, both intake and exhaust rockers were way loose, intake more than exhaust. The stud has not unscrewed, the nut has not backed off. I readjusted properly and the noise is there immediate. I took the rockers off to switch to a different cylinder in case something was wrong there and that's when I noticed the rocker end of the push rods worn. Luckily the rockers show no signs at all of damage.

What do I do now? Is it a lifter? There was a slight miss but barely noticeable. The Cam, lifters, push rods, studs, rockers, springs/retainers/locks, all have under 5 miles on them. I remember when I first fire'd the engine for break in I had a loud ticking from the spot that led to the broken stud and now the worn push rods. All the other rockers on the driver's side still seem to be adjusted properly and have no excess play. I just need to get some ideas before I go pulling the intake. I am ruling out a flattened lobe for now (while not completely) mostly because if it was flat I was have pretty much a dead cylinder and plus the noise started right away during the break in. I have two pictures of one push rod, it is the exhaust valve, the intake rod is not far behind.

Good news is I just bough a 77 hatch the other day. More on that later. Thanks in advance!

 

[LILCBRA]

I'm going to guess it's a lube issue which could be anything from that cylinder's passages blocked within the block, excessive clearances concerning the oil passages for that cylinder, bad or clogged lifters, clogged push rods, an issue with the rocker arms not allowing oil to circulate or a misalignment caused by the hand tapping of the screw in studs causing no oil circulation. Which studs did you hand tap? All of them or just a handful? Do any of the push rods show any wear on the sides of them like they are rubbing the clearance hole in the head? I guess if it were me, my course of action would be locating a new-to-the-engine set of heads and starting there for the simple fact that it could have been something from my actions reworking the cylinder head that caused it. Then, while I had it apart, I could really check out the lifters and clean them, making sure they are as clean as I could possibly get them inside and out. I'm sure it's not the news you wanted to hear, but that's my view. Sorry!!

 

[Adieu]

I am not using guide plates with these studs

This is the cause of your issues more than anything. Guide plates are a must with roller rockers.

 

[LILCBRA]

I dunno if he's using roller rockers. In his earlier post about a pulled stud, the pics look like stock stamped rockers. I guess I was working on the assumption that is still the case. But agreed, if you did swap to roller rockers, guide plates are necessary. Not using them could lead to something like this since the rockers would freely "walk" back and forth on the valve tip causing misalignment between them and the push rod. Another question-what do the cups in the rockers look like? You may have smoked the rockers too....?


(edited some wording to clarify my thoughts....

 

[90sickfox]

I had an issue once kinda similar. My lifter broke the keeper and turned sideways. Caused havoc in my drive train. Pull the intake and check the lifters and cam. My old builder told me that part of the cause could've been the royal purple oil I was running. I think it was when I missed a shift and caused over rev. Knowing, good or bad, is better than not knowing at all.

 

[Adieu]

I dunno if he's using roller rockers. In his earlier post about a pulled stud, the pics look like stock stamped rockers. I guess I was working on the assumption that is still the case. But agreed, if you did swap to roller rockers, guide plates are necessary. Not using them could lead to something like this since the rockers would freely "walk" back and forth on the valve tip causing misalignment between them and the push rod. Another question-what do the cups in the rockers look like? You may have smoked the rockers too....?


(edited some wording to clarify my thoughts....

He mentioned he'd bought rollers so I assumed that's what he installed.

 

[1978Cobra2]

Thanks for all the info, I went with the Mr Gasket studs over ARP because I would not have to have the heads machined for the guide plates. Previously to installing the new rockers (which are roller tipped) when I ran the engine with that side valve cover off, there was plenty of oil supply to the top end. All of the rockers had a good oil flow. All 16 studs are hand tapped and pretty straight both horizontally and vertically. I managed to find a tap alignment tool for for that. The Push rods show no sign of wear on the sides as if they were rubbing and before install I inspected each one to see for any clogged passages. The part number for the kit I bought is 1431 and in the instructions it says the rockers are rail type. I mentions I should not use guide plates with these. I guess these rockers are self centering in that case.

Thanks for all the help, I just found it odd that number 6 cylinder has been the only one giving me issues since the first run of the cam.

As for new heads, I still need a few bucks. Haha!

 

[LILCBRA]

First, @74stang2go, I re-read his first post again and must've concentrated more on the problem. I see where he typed in that he installed roller rockers, so my apologies to you and all around.

Now, on to wth is going on?!? I had a set of those rockers a long time ago. I'm sure they are a quality product and you aren't having the issue that I had with them, but I'll tell you what I ran into just in case. The "rail", as I'm sure you know, are the raised sides with the roller in between. Where I had a problem was with my heads, which were ported 289 heads with 1.6 and 1.94 valves. The "rails" were contacting the spring retainer instead of the top of the valves like they were supposed to. The valves that were installed I'm pretty sure were just your ordinary run of the mill Chevy valves which, if memory serves, have a shorter tip length than Ford valves - hence where I had issues. Now, where I think you may have a problem is the "rails" are keeping your rockers where they are supposed to be, but you possibly offset your fulcrum point (screw-in studs) causing the push rod to not seat in the cup of the rocker properly. In operation, the push rod is pushing up, but the rocker being offset is causing a side load. When the valve is closed, the push rod can spin freely, giving you the uniform pattern. So, in this instance and in my opinion, just swapping a new set of rockers and/or adding guide plates is not going to solve your problem. The problem lies in the head. They may look good to the naked eye, but if you were to set them up on a mill or maybe even a surface plate and take some measurements, I'll bet dollars to donuts that your number 6 cylinder studs are not located properly. Now, you have a couple courses of action to take. You can take them into a reputable machine shop, have them check the locations and squareness of the threaded holes for your studs and maybe they can drill them over-sized, plug and redrill/tap or maybe even use a Heli-coil type product on location for you, or find yourself another set of heads and basically start over. Like I said before, I know this isn't the news you want to hear, but I think this is where your problem is. Not that I'm mad at you like you state in your first post, I think you're probably mad enough at yourself. But hand drilling and tapping for screw in studs isn't recommended for this reason. There is an alignment issue in all ways to consider, both left and right and forward and back. Looking straight in line with the rest of the studs is one part of it, but it also has to be in line with the valve and the lifter. There is also the squareness of the hole to your mounting surface. If the hole isn't square, then the stud won't be square and will also offset the rocker. This is where the machine set-up is key. So there are your options as I see them. I'm sorry you have to go through all of this.....

 

[1978Cobra2]

Thanks again! No need to apologize, the reason I come to this forum in particular is the good group of guys here. As far as betting on the studs being off, you'd win that bet. I can assure they are not machine straight. I was trying to keep from taking the heads off and since the hole left from the press in stud was perfect for the 7/16 tap, I said... Why not? I figure not having to drill out the holes to a larger size takes one variable away. I'm not too mad at myself, I thought I knew a good bit about engines but after all this I have only seen the tip of the ice berg I guess you could say. Tomorrow after work I think I will pull the intake to inspect the lifters just because they are the only thing that could "Possibly" be wrong that I have not inspected yet. If I pull the intake and it is not the lifters, it is going to need to come off for new heads anyway! The only thing that is frustrating is that I put this cam in when I had the transmission rebuilt, the warranty is only 6 months and the owner of the rebuild shop said he wanted to drive it to test it out. Needless to say, I have under 20 days left of that warranty. Ill get her figured out!

Thanks again LILCBRA I appreciate the time you put into your responses! It definitely seems like a WTH!! sort of problem so far.

 

[1978Cobra2]

So I did not take the intake off today, but I did manage to get a bore scope and take some pictures of the lifters up close. I also took video of the lifters when I was cranking but I can't seem to upload them. I can get them onto YouTube If you think it would help. What I noticed is that the Exhaust lifter on #6 when cranking moves up and does not return down until I stop cranking. The intake lifter of #6 seems to move up and down fine with rotation just like one of the valves on #5.

This is number 5 cylinder exhaust lifter - no problems, just for reference.

Number 6 Intake lifter - most damage on this push rod

Number 6 Exhaust, little wear on push rod. This was the broken stud.


These look good to me, but i'm not to sure what to look for and these pictures might not be enough to tell if they are faulty.

What other 302 heads will work on my 73 block without changing push rod length and will accept my springs and screw in studs?

Thanks!

 

[90sickfox]

Hard to tell if they're bad or not. That lifter not dropping back seems a little strange. The only way to determine if the lifter has spun would be to look at the flat sides for orientation. They should all be parallel to the head. Don't know if you'd even be able to distinguish that with that scope.

The only other thing I can think of is to check the lift with a dial indicator. You could also measure the height of the lifter body with the cam lobe at full height. The 5 and 6 lifter should have the same distance between the lifter and the head. Lifters themselves can collapse internally but the outter body is the same. If the roller wears the height of the body will change.

I've never done this but seems like it may give some insight if you don't want to pull the intake.

 

[LILCBRA]

The exhaust lifter that is not returning down might be fine as far as that aspect of it goes. It could be "sticking" in the bore because of the oil. If it returns under light pressure, I wouldn't worry about it. The bore scope pics aren't really going to tell you much if the lifter is bad or dirty. It will be internal to the lifter mechanism. About the best you can do is when you tear the heads off, remove the lifters and soak them in something made to break down crappy oil, but not water based. So, in other words, don't stick them in a bucket of dishwater . You will probably be safest soaking them in a small tub of gasoline or Seafoam, leaving them in there a day or so. When you remove them, be sure to blow them out with compressed air and then soak them in a tub of clean motor oil for a little bit before you re-install them. That is about all you can do without taking them completely apart and running the risk of losing and/or breaking something. As far as heads go, to the best of my knowledge any small block head will bolt up, except 351W heads require a larger diameter bolt/stud. You can work around this by using hardened washers between your bolt head/nut and the head. My suggestion, as I believe I suggested before, try to find a pair of GT40 (not "P") heads from an Explorer if at all possible. They are supposed to be the best flowing stock small block head produced and should take all of your current stuff without issue. Just remember to take them in somewhere to have them drilled/tapped for studs to avoid your current predicament. You may need to research the valve springs, they may require a little extra "tweaking". I do know that to run them in a Fox 5.0, you have to upgrade the springs. They are sold in a couple of different kits and the retainers are offset from intake to exhaust. But you may not have to do that - like I said, you will have to research it. If you have a Pull-A-Part near you, they aren't horribly priced. They run about $60 per head here, as well as any other head you may pick up from them. To save yourself a little money, if you get a set of heads, check to see if the valves close completely. Basically, put a little water or other liquid into the ports and watch where the valve seats. If they leak, you can disassemble the head and lap the valves at home to get a pretty good seal. The valve spring tool isn't horrible expensive (like $15-$20 IIRC) and they aren't all that hard to take apart/re-assemble. Besides, you would be able to install your new valve springs yourself this way too. So, basically the only thing you will have to have the machine shop do would be set up the heads and drill/tap for your studs. But like I said, research your valve springs with GT40 heads if you go that route! Anyway, enough typing!! I hope this helps!! Good luck!!!

 

[LILCBRA]

The only way to determine if the lifter has spun would be to look at the flat sides for orientation. They should all be parallel to the head. Don't know if you'd even be able to distinguish that with that scope.

He is running a 73 block and I don't believe he is using roller lifters. They are more than likely flat tappets. But if they are roller lifters, most definitely make sure they are orientated correctly!

 

[LILCBRA]

Oh, one other thing, when you pull the lifters, pay attention to the cups. I was just looking at the pics again and it looks like the #6 intake cup is out of round. The exhaust cup kinda looks like it too, but it could just be distorted pics from the light of the bore scope. Just something to pay attention to when you get to it.....

 

[1978Cobra2]

Thanks for the info. The cam is a hydraulic flat tappet, so rollers to worry about turning. I'll take the intake off and try and clean them out the best I can. Is there some sort of test while they are out I could preform? I know they have a little spring on the inside that should have a little push back to it. As for the sticking lifter, I figured it might just be some sort of suction or something from the oil. From what I could see there is plenty of oil coming through them. When I first got them I soaked them in fresh oil for a day or so, maybe some dirt could have gotten into one and possible a metal bit from tapping the heads. As for new heads, anything I can find that is reasonable I might pick up, not looking to gain anymore power, just want to drive all this work to the car show and back! haha

Thanks again, ill keep you all posted!

 

[LILCBRA]

No test that I'm aware of. Good luck!!

 

[90sickfox]

Flat tappet...no keepers or rollers. Sorry man, thought it was retrofitted. I hope you can get it sorted out and let us know. I've gotta learn to read....before commenting. Smh

 

[1978Cobra2]

No worries man! I think I might be onto something, I replaced the two bad push rods with the old ones (which only had a couple miles on them) for a test. I went through and re adjusted them and noticed a few other seemed loose. I keep adjusting and now the driver side has no noise to it. I will run it a bit longer to tell, then go through and re adjust the passenger side. Right or wrong I appreciate any information!

 

[1978Cobra2]

Today I went through and re adjusted all of the rockers by going cylinder to cylinder on TDC. I pulled a few rockers off and most of the push rods are pretty beat up. I just threw some from the old set in there for now. I fired it up and it ran great with no valve noise at all. I took it for a 6 mile drive and now they are ticking again but only when you put your head closer to the engine, no where near as loud as before. Tomorrow I think I will go threw and check them all again. I believe this is the fix. Thanks for all the great idea's and help, I have gain a lot of knowledge because of this! Maybe next Friday I will get it to the first local car show of the year!

 

[LILCBRA]

Good luck!!