I just pulled these off while getting ready to install my new heads. I have been having a ticking noise and decided to finally pull the heads and inspect my caddy lifters. I have been seeing post of others who have had failures and figured I would check and replace mine. I also figured while the head was off, now was the time too upgrade that as well. Knowing that I didn't want to do this again, I decided to go over every part with the evil eye. This is what I found. 12 out of 16 rockers all have cracks on the nose. Some have cracks on both sides of the roller, others just one. Here are some pics.

I am running Patriot gold dual extremes, set up at 1.78. Here is a post from an old thread were I was chasing down a valve float problem. The solution was new springs with higher seat pressure. The crane 832's weren't cutting it. The extremes set up at 150 lbs at 1.8". I am at 1.78 so a bit over 150lbs.

"Ok, got the new springs installed. I used a snap gauge to do all my measuring and set them up around 1.78. Took the car out for a spin and low and behold, 7k no float. Looks like the crane springs were under gunned for my setup. I plan on having a couple tested to see what the spec out at.

I did notice that the Patriot retainers sit further down on the stem than the crane's. This is most likely why the cranes reuired more shim height to get to 1.78 than the Patriot springs did. I ended up with just the base and a .030 shim to get right around 1.78 installed.

Now all that is left is to figure out if this ticking noise is normal or if I too have a bad Caddy lifter."

I am going to check the spring installed height again. The heads are still on the car. I do not recall seeing the cracks when installing the new springs. The new springs worked great and I had no idea if these cracks were there. I bought the Jesel's along with the heads. I did not notice them then or when we diagnosed the valvefloat issue and replaced the cranes. I think they developed while running the new springs at 150+ spring pressure. These are older J2K's. They should be designed to withstand these seat pressures. Like I said, I will recheck coil bind and spring height tommorrow, but I don't expect a problem here since I am only shimmed at 1.78 and checked all this when we installed them.

Anybody else have a failure like this. I plan on contacting Jesel in the morning. If I do not put shaft mounts back in, what do you guys think of the rebuilt stock rockers, and what seat pressure for my cam ( comp Xer 232/235 .595/.601 114+4). I know the stock rockers are lighter so I would like to keep seat pressure at a rate that matches the cam and weight of rockers for best performance.

 

I don't think it has anything to do with running the new springs. What is possible on the other hand is damage being done, or these cracks being starting when you were experiencing your valve float. It is EXTREMELY hard on your valve train. Double check your push rods too to make sure they're still straight.

 

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WOW, I use Jessel on all my engines. Much more power & pressure.
Never had an issue. You are damn lucky you didn't lose the whole damn motor. Good luck.

.

 

I will check the pushrods tommorrow as well. I really don't recall seeing any cracks when all the rockers were pulled to replace the spings. we handled them for quite sometime while setting up the new springs and none of us noticed it. It could have been there as you stated but my gut says no. With this many rockers having cracks, I just can't see how we could have missed seeing at least one. That is how I noticed today. I saw one and then knew where to look on the others. I had these in my hands before and would have seen it. Any ideas help so I appreciate them all.

Mike

 

This is what I'm thinking, you said that once you replaced the springs, on the very first start up you were hearing that ticking sound, as before, most definitely the rockers. What probably did happen, were hairline fractures that had started from valve float, even there when you took off the rockers before, but so fine you couldn't see them with the naked eye. Plus you also mentioned that they came with the heads when you bought them, so I'm assuming they were used, so who knows what those rockers have been through. First time I've ever seen them fail...

This is all so very funny to me too, because just today I noticed that my HS modded LS7 rockers are all toasted, the bearing are f'ed, and that is ALSO the first time I've ever seen and or heard of the HS mod failing. My springs are beehive, PSI's with 170# seat / 360# open pressures, but I still don't think it was the springs that caused the failures for me, I'm not entirely sure what caused it infact, because I never overreved, or had any valvefloat. so I dunno wtf is going on with my stuff.

Now looking over all of your measurements again, what is the coil bind of this setup? I'm finding it weird that you needed 30thou shims to get you to the proper install height, what heads are you running, and has there been any machining done to the seats?

At max lift measure how far from coil bind you are, you should be 50thou, anything less, and you were probably binding those springs out, and putting extra pressure on those rockers, and your lifters.

Also, what was coil bind on the old setup? Are you sure that the reason for the valvefloat wasn't because there wasn't enough pressure? What if those springs were binding at valvefloat? That would pretty much destroy your valvetrain...

 

Wasn't there some discussion on the Jesel failures, just recently??
AIRC, Jesel came w/ a reply about material/heat treat problems??
Got "CRS", but do remember a similar thread...

 

I posted recently that on my LSX454 I popped a shaft mounted Jesel coming home from the Hot Rod Power Tour. The engine was at highway speed crusing steady at 75mph and the rocker broke. By definition, my cam is a baby street cam with less than .650 lift so it's not like I'm pushing the envelope here.

 

Actually the tick has been there since day one of the engine install. I bought an 02 f body pull out and installed the new caddy lifters,new cam, ported heads and valvle train that I bought used. The heads had just been gone through and I purchased the Jesels along with the heads and valve cover spacers. The heads had the crane springs at that point. From very early on we had a tick. Even weeks before I got it to the tuner who tuned it on the dyno. This is when we noticed the valvle float. It was when he was making pulls to tune the car. We determined it needed new springs and I ordered the Patriot extremes. This fixed the valve float but never got rid of the tick. That is why I have always thought it was a lifter. It very well still is. This is a new problem that has arissen. As I said, the valve train noise has started to get worse. I figured it was my lifter getting worse but obviously it is now also the rockers.


coil bind is 1.090. springs are setup at 1.78. lift is .595/.601. Gunnar said this is way fine. I plan to remeasure installed height as soon as I get a spring compressor back over here. heads are from pete at cnc heads out of St Pete. Unsure of machining to seats. I plan on having the heads looked over.

Do not know the specs of the old springs other than what they were setup at. It is in one of my old post.

Rockers are going back to jesel for evaluation though I do not expect much.

Mike

 

If it turns out to be a heat treatment issue, they should replace the rockers free of charge.

As far as the spring setup goes, yes, you're well in the clear, you've got 89 thou clearance on the low end, and can run another 39thou lift if you wanted.

Its hard to say on the old setup thou, if you didn't have enough clearance, and you were getting coil bind, that is where your ticking cam from, and the valve-float as well. I would track back as much as possible to see if you were pushing those springs past 50thou before coil bind.

Are you sure these jesels are 1.7 ratio, and not 1.8? You'd still be right around 54 thou before coil bind, but its getting close.

 

they are stamped 1.7 on the bottom. we also checked pushrod length with a checker gauge. At 7.4 we were at 0 lash. We used 7.450 for a .050 preload. I really went the extra mile to set everything up. This car is plagued Some people just throw what ever one their cars and have no problems. I buy some of the best stuff, double check my work and end up having defective parts. For example, a new stock LS4 oil pump that had over 140 psi pressure. That kind of ****.

 

LOL, I know what you mean man, for real, no doubt. Same thing happens to me all the time as well, I feel as if my car is plagued for life. You obviously did everything right, so as of now its up to Jesel to figure out what the problem was.

How in the hell did you get 140 psi oil pressure? Thats unreal!

 

No clue, bought a brand new oil pump when building the motor. Motor had about 30k on it so figured while its out, get a new pump. I was told that the new LS4 pumps flowed a bit more and were a good upgrade so I bought one. We installed it fine and when we were on the dyno, I checked my peak hold on my gauges, 140 psi. I reset it and on the next pull, sure enough it was pegged at 140 again. Ended up having to pull the pump and put a stock Ls6 one in. No more problem. Max of 75-80 psi. i guess the over pressure relief was defective. My luck.

Mike

 

I might have missed it above, but any sign of piston-to-valve contact?

Jim

 

nope, just pulled one head this evening. No contact at all. Broken rockers on both heads so expect other side is the same.

no coil bind as well. It is starting to look like stress fatigue with the stiifer springs?

Mike

 

There is just no way that those rockers failed because of the new springs. The pressures on those springs are not out of the ordinary to cause failures like this.

Did you buy these rockers new? Or did they come with the heads, and they were used? How old are the rockers? It seems to me that the more likely possibility is that these rocker arms had some pain in the past, or they were improperly heat treated causing them to be weaker than they should be. But, I guarantee you, get a brand new set of those rockers, and you can run the most extreme pressures even on a solid roller motor and they will not have a problem.

Something else caused those cracks, not the pressures of the new springs, unless you want to argue that the higher pressures caused the "weaker" rockers to then fail, yes, that is true, but it was not directly related to the springs, the rocker arms or its past is where the failure occured, the springs just exposed that problem, sorry for the run-on haha.

 

I'd bet the guys @ Jesel would be most glad to venture thier opinion[s]...

 

I'm curious to see what Jesel says. The engineer in me almost thinks that the aluminum just reached the end of its fatigue cycle. ALL aluminum rockers fail eventually. Usually I see it at the bottom of the fulcrum, not at the nose. Doesn't mean the fulcrum didn't have a higher safety factor than the hose of the rockers, afterall you can't have the nose hit the spring retainers.

Ask a materials or mechanical engineer sometime, steel has almost an infinite fatigue life when compared with aluminum, its just the nature of the material. No ammount of heat treating, annealing, shot peening or annodizing can cure this. I can however be prolonged.

 

If you valve floated a solid roller, the impact loads could have been so high they caused the cracking. And you never know how much time they spent at high rpm before you even got them.

I'm also curious what Jesel thinks. I hope it works out OK.

Jim

 

The rockers were used along with the heads. I don't think they were bad when I got them but they were used and are an older set of Jesel's. They are 4-5 years old I think. By no means do I mean to imply that I bought a brand new set of Jesel's and they failed right off the bat. I am unsure how much abuse they had in the past but who buys this level of product if they don't plan on racing their motor.

when I got them, I experienced some valve float with the crane 832's. I changed to the extremes. Maybe the guy who sold me the heads experienced the same. I just never had the cracks until after changing springs. Like mentioned above by drew04gto and myself as well as others, I think they were at the end of there life for an aluminum rocker. They were also pretty heavy at the nose. I believe this is why I needed heavier springs. That and the XEr cam.

I just received my YT ultralites. I have been adjusting swipe and setting installed height. If Jesel offers anything, I will let you guys know.

Mike

 

LOL You should be happy! Stupid people get away with anything and everything. You will be alright.

I have run many Jesels on drag race engines with 400 psi seat pressure and seen this on one set of exhaust rockers. Never could really find a reason and since have put another Jesel in its place and keeping and eye on them with no signs of faliure yet. Strange crap does go down in valve float.