So i currently have a 93 lx 5.0 mustang with keith black 116 domed pistons, a Lunati Voodoo .571/.587 lift .282/.290 duration and a 110 degree lobe separation cam, now i have the stock junk E7 heads which have been ported and this is supposed to be a budget build and later on it will have a set of blue print muscle car series heads on it, also has a weiand 8020 intake with a holley 650dbl pump carb and long tubes....i installed the cam used stock push rods and rocker arms....bent a few sets of the push rods, so i ordered chromoly comp cam push rods, because JEGS said it was necessary (all the push rods from stock to the chromoly ones are all 6.248'' stock length) I installed those today, torqued it down, fired it up and boom broke 2 rocker arms one of which was in two pieces and one of them the push rod went through where the rocker arm rests on it, replaced them with stock ones again because my thought was they were hurt from the previous push rods bending, then broke 2 more....the weirdest thing is its only on the intake side and only on cylinders 1-4 nothing is wrong with cylinders 5-8, so i again thought well it must of broke the other 2 that was weak....first start was cylinders 2 and 4 second start was cylinder 1 and 3, a close friend of mine said the stock rockers dont move far enough for that big of a cam, another friend said the cam is to big.....any help would be much appreciated! and THANK YOU IN ADVANCE!!!!
Stock rocker arm breaking
- Thread starter Darwin1990
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Coil bind dude...When you are bending and breaking stuff something is hitting things.Springs stacking, or valves hitting,..both are bad.
ive checked ptv and had plenty of room, ive also seen this cam ran in a bone stock gt40p motor from a 96 explorer....bun flat top pistons make a big difference then domed pistons....i just dont want to waste 300.00 on a cam i cant use lol so i guess ill sale this one and move on to the next cam, thank you CarMichael!
no not stock springs, i dont have stock springs either lol
I do not understand why people join, ask a question, then choose to just outright reject answers without even considering or checking their helpfulness. Valve train parts do not break without a reason. What are folks hoping for, an incantation to use with a Harry Potter style magic wand?
Here is one to try. If you do not have a wand, use your best breaker bar.
”Partsum Fixum Maximus!”
Here is one to try. If you do not have a wand, use your best breaker bar.
”Partsum Fixum Maximus!”
Well honestly I didn’t outright ignore anything, he said there’s clearance issues and I replied there’s no ptv issues however you’re talking a bout a huge lift cam with stiff valve springs on BONE STOCK ROCKERS so I said I’d move one to the next cam (meaning smaller) thanks for your input though!
You checked ptv clearance and all good, next step should be checking push rod length, actually that should have been done before.
Now I see a mark on top of the valve stem, I also see a mark on the cap thing next to the valve stem, that tells me there is a fitment problem, like the rocker arm in hitting it, I'm not a engine builder but you are wasting your time and money with those E7 heads.
Your cam is big considering the stock cam is what(?) 266/444.
I think the heads are going to continue to be a problem with valve train unless you go to a stock or a letter (b,e,f) cam.
It's a poor plan to use those heads for anything but a stock build.
This is just my opinion, and my opinion is you are wasting your time with the E7 heads no matter what cam you use.
Now I see a mark on top of the valve stem, I also see a mark on the cap thing next to the valve stem, that tells me there is a fitment problem, like the rocker arm in hitting it, I'm not a engine builder but you are wasting your time and money with those E7 heads.
Your cam is big considering the stock cam is what(?) 266/444.
I think the heads are going to continue to be a problem with valve train unless you go to a stock or a letter (b,e,f) cam.
It's a poor plan to use those heads for anything but a stock build.
This is just my opinion, and my opinion is you are wasting your time with the E7 heads no matter what cam you use.
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Honesty I did check pushrod length and coil bind and ptv the one thing I honestly though was maybe the rockers wasn’t able to move far enough? And that’s why it’s popping them but another thing that really got me is it’s only the intake rockers breaking and only on #1-#4 cylinders... I know I’m wasting money on the E7 heads also, they won’t be on the car but about 5 more months maybe less...
The cam I pulled out of the car was a tfs stage one .499/.510 cam I can’t remember the exact specs but I remember the lift...
Also thank you all for the input I really do appreciate it even if it doesn’t sound like I’m listening I am, I just know what I’ve already checked and obviously something isn’t right somewhere for it to be doing what it’s doing however I am going to a little smaller cam and roller rockers my question is what exactly is cause if it to break the rockers like that, if it’s the proper pushrod length (I checked and measured) proper torque, no ptv issues, no coil bind issues....would it be that the stock rockers just do rotate enough?
People especially ignore electrical diagnosis procedures first all the time.
You should see what is limiting movement and check for further damage before swapping cams. @CarMichael Angelo is usually right.
You should see what is limiting movement and check for further damage before swapping cams. @CarMichael Angelo is usually right.
All I’m offering here is an opinion. It is by no means a guaranteed fix. And I’m not ruling out that the rocker just might not be up to the task, but “ stiffer springs” do not automatically mean that they aren’t binding at full lift. If the rocker was hitting something to cause it not travel it’s full range, it won’t take too many collisions before there be some evidence of that, either on the fulcrum, or the rocker itself, and not just a snapped in two remnant.
When there are bent pushrods first in the mix, they were telling you then that something was hitting.
OldManRiver
Active Member
What's up with these retainers,looking at the first rocker in the pic the spring looks as though it's almost pushing itself past the retainer on the low side.The retainers also look mismatched but may be the pic.
This is my biggest irritant on forums. Now this particular poster seems to be listening now and learning so good on him. But i totally agree. There's been many that ask for help and get 10 long time experienced mustang guys telling them the same thing and they just keep refusing to listen. Makes you not want to even respond.
Rant over!
Good info given on this topic. Find the problem before you start changing a bunch of parts. No need to start over breaking all new parts. I'm curious what that big cam was matched to or was it just slapped in there? Certainly wasn't matched to what you've listed.
So the issue I had was I was using bone stock pedestal mount rocker arms, so the issue was the slot wasn’t made for a cam with much more then .520 lift so having a cam that has .571/.587 lift was just complete destruction so with that being said the cam was matched to the intake and the heads that is going on the car later, so in all honest simple mistake by not knowing much about the stock rocker arms lol could of cost me a lot more then it did and I am so thankful for the help and advice given here.... I understand how bull headed people can be and it’s bs when someone gives good advice and the person asking for advice spits in their face...people like that need smacked! I’ve also put a x303 cam in with bone stock rocker arms...not sure how that motor is now that it’s been sold for 3 years and I didn’t know then what I do now lol.This is my biggest irritant on forums. Now this particular poster seems to be listening now and learning so good on him. But i totally agree. There's been many that ask for help and get 10 long time experienced mustang guys telling them the same thing and they just keep refusing to listen. Makes you not want to even respond.
Rant over!
Good info given on this topic. Find the problem before you start changing a bunch of parts. No need to start over breaking all new parts. I'm curious what that big cam was matched to or was it just slapped in there? Certainly wasn't matched to what you've listed.
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