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Discussion Starter #1
I can provide more engine specifics if needed but I have a solid roller 557 bbc,stud girdle,prox .700 lift camed motor. This weekend at about 5000 r's I thought I blew my motor....k-bang k-pop ect. Long story short....when I pulled the valve cover ...a rocker arm jumped off the push rod on #3 exaust. I put it back together and made it out of a hurricane out of powell yesterday but I havent dared punch it again. Does this sound familiar to anyone?? Maybe a weak spring??:)Unsure
 

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I will say i have had rocker stud back out from the alum head, broken spring and a roller lifter or cam lobe that has failed in the past. Rockers just dont jump off and especially when there is a stud girdle in use.I would re-check before i put it back in the water,557's dont grow on trees.
I would check all the above and run a leak down on that cylinder... could a guide stick a valve even for a split second? maybe.
best of luck.
 

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could be a few things. Lifter sticking, valve ticking, pushrods too short, broken spring...
What heads?
 

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Exh, valve not opening will sound like hell. Will pop back through the carb, run rough, cough, you name it. But you need to find what caused it to kick the rocker.
 

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Discussion Starter #5
could be a few things. Lifter sticking, valve ticking, pushrods too short, broken spring...
What heads?
Heads are brodix bb2plus. I agree Hass, I would like to get to the bottom of it sooner than later. I thought for sure I lost my motor. I'll pull the valve cover and look a little harder at the spring and the stud ect. Motor is on its 3rd season ....never done that before. As far as a lifter or valve sticking.....not sure how to check or determine that. Something smacked the underside of the girdle in a spot or 2. I am almost certain that the rocker arm that I broke a season or 2 ago was on that same cyl. I just cant remember what valve. That rocker did have a small casting flaw.
 

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Exh, valve not opening will sound like hell. Will pop back through the carb, run rough, cough, you name it. But you need to find what caused it to kick the rocker.
We had an exhaust poly lock break a couple of years ag at a race. Info Jr. Said as I was pulling him out of the water that it started knocking mid track. And he drove it the mile to the outramp. :|err I could have killed him. lol. Had to splain that is what the jet skis are for.

But yea if the exhaust doesnt open the next time the intake opens, what was let in and ignited pops out the intake.
 

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We had an exhaust poly lock break a couple of years ag at a race. Info Jr. Said as I was pulling him out of the water that it started knocking mid track. And he drove it the mile to the outramp. :|err I could have killed him. lol. Had to splain that is what the jet skis are for.

But yea if the exhaust doesnt open the next time the intake opens, what was let in and ignited pops out the intake.
I broke an exh side poly lock once and it bent the intake pushrod from trying against the pressure in the cylinder. Was on NOS & boost too. You have to remember that when the exh doesnt open that you just forced the engine to compress that charge that was lit off and probably still expanding, then that much cylinder pressure against the square inches of surface area on the intake valve, well you better check that intake pushrod,lol.
 

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Discussion Starter #9 (Edited)
3 seasons on a 700 +/- lift motor and not checked for weak or broken valve springs? I'd look there first.

Jerry
This is my first roller motor. 90 or more percent of the time I am just cruising 3500-4000 ish....idle ect. What kind of life span do these things have? I'd be surprised if I had more than 30 or 40 run hours. Headed to the garage now to see if anything is obvious. I am starting to wonder if when that rocker arm blew(the one that broke)...if that bent the rocker shaft/stud. When I had it apart at the lake....there was something not right about the bottom of the rocker nut/lock. I may edit in a pic of it if it shows up.
 

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Had a similar thing happen to my 540. Turns out that I didn't have the flat spot on the rocker mount in the right place for the lock / jam nut. I think that the pressure just blew the ting off (alos broke the jam nut onto 4 pieces). Was able to find the pieces and jst replaced the rocker arm and put it together correctly and no problesm after. Made a LOt fo noise when it happened and shut it off pretty quickly.
 

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Discussion Starter #11 (Edited)
I would appear to have a broken stud. I dont have a socket deep enough to pull it. Could I pull it with the rocker nut/lock?:)sphss I guess I can go searchin for extra deep sockets. Any thing special I should know here fellas???....never been here done this before.
 

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I would appear to have a broken stud. I dont have a socket deep enough to pull it. Could I pull it with the rocker nut/lock?:)sphss I guess I can go searchin for extra deep sockets. Any thing special I should know here fellas???....never been here done this before.
You'll need a deep 11/16" socket. be careful as it may snap and leave the threads in the head. Check real close to make sure that it hasnt pulled the threads out of the head. I like to blue locktite them and I believe that they torque to 65lbs. Pull the pushrods from that cylinder and roll them on a smooth flat surface to make sure that they arent bent.
Did you do the midlift method for your pushrod lengths? Just from the pic it appears that the pushrods are way to short and may be causing you some problems.
 

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spring pocket

In the picture it looks like the spring pockets may be to tight on the spring, thus not allowing the spring to operate correctly. Maybe false coil bind to early with this lift combination. Take the keepers out and see if the springs can rotate in the pocket. If not, get them machined to proper diameter or different springs. Pushrods do look short also.
 

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Broken stud using a gurdle? Not saying it doesn't happen, but usually a sure sign that something else is a miss. Bad enough breaking a good quality stud without a gurdle. But with one, and all the studs tied together. Mmmmmm

PS. 30-40 hrs with that kind if lift on a solid roller is more than enough time that you need to be looking at the springs. At least test them. If you want to run with the big dawgs, you have to step up your game.

Exactly what the hell were you doing for the past 6-8 months. And the fall and winter before that. And before that?



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Discussion Starter #15
Broken stud using a gurdle? Not saying it doesn't happen, but usually a sure sign that something else is a miss. Bad enough breaking a good quality stud without a gurdle. But with one, and all the studs tied together. Mmmmmm

PS. 30-40 hrs with that kind if lift on a solid roller is more than enough time that you need to be looking at the springs. At least test them. If you want to run with the big dawgs, you have to step up your game.

Exactly what the hell were you doing for the past 6-8 months. And the fall and winter before that. And before that?
As far as what I was doing...I would get finger cramp if I told ya what I did all winter on my boat right now...capping painting ect. That was an honest question on the springs thank you for an answer. I dont know shit but I think the stud likely cracked when I had a rocker failure on that stud 2 years ago....but what do I know.:)sphss:)grn
 

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Discussion Starter #16
On the pushrod length issue....I didnt assemble this motor. I left it up to someone I trusted at the time. Good to know that looks bad...thanks.
 

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Broken stud using a gurdle? Not saying it doesn't happen, but usually a sure sign that something else is a miss. Bad enough breaking a good quality stud without a gurdle. But with one, and all the studs tied together. Mmmmmm

PS. 30-40 hrs with that kind if lift on a solid roller is more than enough time that you need to be looking at the springs. At least test them. If you want to run with the big dawgs, you have to step up your game.

Exactly what the hell were you doing for the past 6-8 months. And the fall and winter before that. And before that?
i broke a stud once. replaced 'em all. broke a rocker arm once too, crane gold. since they were past their 21st birthday, kicked 'em all outta the house and replaced 'em with new babies. :)
 
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