Okay, what did I do wrong? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**PRattenbury** · 07-28-2010, 08:47 AM

I started the engine in my truck, moved the truck outside, turned the idle way up again, and was going to let the cam burn in some more. I started to hear some valve train clatter, which lasted a couple minutes, ending with a clink sound and the noise went away. But when I lowered the idle back down, it ran like crap. Later in the day, I took the truck for a ride around my block. It ran like it had 200000 miles on it, chugging and so forth. Before I pull the valve cover, I am going to guess a rocker fell off a valve. They are stock stamped steel rockers. Cam is an Edelbrock Performer, quite mild. Springs are stronger than stock. The studs are screw-in. No guide plates. Anyway, there is a question. What did I do (or not do) that would have prevented this problem???

STOCKISH · 07-28-2010, 09:05 AM

HArd to tell but sounds like you may have lost a rocker arm. If you did you may want to buy new locking nuts for the rockers. Pretty cheap insurance.

**PRattenbury** · 07-28-2010, 09:19 AM

That would be cool if the nut just backed off. That'd be simple to fix. I'll hope that's all it is.

68 TT · 07-28-2010, 09:30 AM

^ or you broke a rocker arm stud or broke a rocker arm. I have done both a bunch of times. It will act quite differently if you broke an intake side part or an exhaust side part.

What brand screw in studs are you running?

You could have lost a lobe on the cam or bent a push rod too. No telling without pulling the valve covers and checking things out.

You should be able to hear the clatter on one side or the other so you only have to pull the one valve cover.

I hate to say it but if the lifters were adjusted just a little too tight it could have flattened a bunch of lobes too. I have seen this more than once when people follow the twist the pushrod method for checking preload.

**PRattenbury** · 07-28-2010, 10:34 AM

Crap. I hope it's not that disastrous. We shall see.

**PRattenbury** · 07-28-2010, 11:21 AM

Well, I didn't expect to see what I found at all. I did find a rocker off a valve. #4 intake was the culprit. The nut was on the stud just fine. The pushrod was not bent or broken. The screw-in stud had backed out of the head. I have never seen that happen before. Is the a proper torque value for these studs? Hopefully between torquing and some loctite I'll be back in business. The threads on the stud look fine. I'll have a look at the ones in the hole before I reinstall...

Mattman2010 · 07-28-2010, 12:05 PM

50 ft lbs as said by this website

http://boxwrench.net/specs/chevy_sb.htm

**PRattenbury** · 07-28-2010, 12:13 PM

I checked the threads on the stud, they're good. Checked the threads in the head. Also good. Applied red loctite and torqued the stud to 50 foot pounds. Gonna put the rocker back on, take the lash out with cam at base circle, start the engine and run all the valves. Should be the end of that.

Hoods69BadBowTie · 07-28-2010, 05:03 PM

Hope that's all man that would be sweet for sure but damn that's pretty crazy to lol!

**PRattenbury** · 07-28-2010, 08:57 PM

Did all of the above, and it seems to be fine. I hope I don't get any others to do that. I'm contemplating buying a 5/8" crows foot to check the torque on all of them.

68 TT · 07-29-2010, 11:41 AM

Quote:

Originally Posted by PRattenbury

Did all of the above, and it seems to be fine. I hope I don't get any others to do that. I'm contemplating buying a 5/8" crows foot to check the torque on all of them.

It's possible that one didn't get torqued down but I would be safe and check them all.

Glad it was something simple and not a big problem.

07-28-2010, 08:47 AM	#1
PRattenbury Senior Member Join Date: Feb 2010 Location: Maumelle, AR Posts: 478	Okay, what did I do wrong? I started the engine in my truck, moved the truck outside, turned the idle way up again, and was going to let the cam burn in some more. I started to hear some valve train clatter, which lasted a couple minutes, ending with a clink sound and the noise went away. But when I lowered the idle back down, it ran like crap. Later in the day, I took the truck for a ride around my block. It ran like it had 200000 miles on it, chugging and so forth. Before I pull the valve cover, I am going to guess a rocker fell off a valve. They are stock stamped steel rockers. Cam is an Edelbrock Performer, quite mild. Springs are stronger than stock. The studs are screw-in. No guide plates. Anyway, there is a question. What did I do (or not do) that would have prevented this problem???

07-28-2010, 09:05 AM	#2
STOCKISH Formerly- 1972SuperCheyenne Join Date: Oct 2008 Location: Wake Forest NC Posts: 5,782	Re: Okay, what did I do wrong? HArd to tell but sounds like you may have lost a rocker arm. If you did you may want to buy new locking nuts for the rockers. Pretty cheap insurance. __________________ --Josh My Build Thread:http://67-72chevytrucks.com/vboard/s...d.php?t=799218 A good crossthread is better than Loctite any day. Life is not about what you have, but who you have to share it with.

07-28-2010, 09:19 AM	#3
PRattenbury Senior Member Join Date: Feb 2010 Location: Maumelle, AR Posts: 478	Re: Okay, what did I do wrong? That would be cool if the nut just backed off. That'd be simple to fix. I'll hope that's all it is.

07-28-2010, 10:34 AM	#5
PRattenbury Senior Member Join Date: Feb 2010 Location: Maumelle, AR Posts: 478	Re: Okay, what did I do wrong? Crap. I hope it's not that disastrous. We shall see.

07-28-2010, 11:21 AM	#6
PRattenbury Senior Member Join Date: Feb 2010 Location: Maumelle, AR Posts: 478	Re: Okay, what did I do wrong? Well, I didn't expect to see what I found at all. I did find a rocker off a valve. #4 intake was the culprit. The nut was on the stud just fine. The pushrod was not bent or broken. The screw-in stud had backed out of the head. I have never seen that happen before. Is the a proper torque value for these studs? Hopefully between torquing and some loctite I'll be back in business. The threads on the stud look fine. I'll have a look at the ones in the hole before I reinstall...

07-28-2010, 09:30 AM	#4
68 TT Still plays with trucks Join Date: Jul 2009 Location: Spokane, WA Posts: 3,556	Re: Okay, what did I do wrong? ^ or you broke a rocker arm stud or broke a rocker arm. I have done both a bunch of times. It will act quite differently if you broke an intake side part or an exhaust side part. What brand screw in studs are you running? You could have lost a lobe on the cam or bent a push rod too. No telling without pulling the valve covers and checking things out. You should be able to hear the clatter on one side or the other so you only have to pull the one valve cover. I hate to say it but if the lifters were adjusted just a little too tight it could have flattened a bunch of lobes too. I have seen this more than once when people follow the twist the pushrod method for checking preload. __________________ miSSed opportunity - ground up creation of an AWD 1994 454 SS that never was http://67-72chevytrucks.com/vboard/s...d.php?t=795577 69 C10 shortbed stepside 400 small block - built like what a super sport truck could have been 69 K20 lwb TBI 350 4L60E NP208 14-bolt Dana-44 w/disc 68 Camaro SS / RS 500hp 439 inch roller cam big block 4L80E 79 Malibu TPI 350 4L60 w/ Z28 steering & sway bars

07-28-2010, 12:05 PM	#7
Mattman2010 Registered User Join Date: Jun 2010 Location: Pittsburg, KS Posts: 953	Re: Okay, what did I do wrong? 50 ft lbs as said by this website http://boxwrench.net/specs/chevy_sb.htm __________________ 1980 K10 - 6.2L Diesel/SM465/NP205 Build Thread 1984 K30 CC Dually - "The Tank" 12V Cummins/Nv4500/Np205/D60/D70HD 4" lift & 37's Build Thread 1960 C-60 Dump Truck Make it road worthy! Thread

07-28-2010, 12:13 PM	#8
PRattenbury Senior Member Join Date: Feb 2010 Location: Maumelle, AR Posts: 478	Re: Okay, what did I do wrong? I checked the threads on the stud, they're good. Checked the threads in the head. Also good. Applied red loctite and torqued the stud to 50 foot pounds. Gonna put the rocker back on, take the lash out with cam at base circle, start the engine and run all the valves. Should be the end of that.

07-28-2010, 05:03 PM	#9
Hoods69BadBowTie Chevys Kick A$$ Join Date: Jan 2005 Location: Zootown, MT Posts: 12,699	Re: Okay, what did I do wrong? Hope that's all man that would be sweet for sure but damn that's pretty crazy to lol! __________________ HOODS is what I answer too -'79, '77, '88 Pickup Sold, '85 Camaro, '83 T/A, '81,'83,'90 K5 Blazer All Sold -'79 3/4 ton "Big Yellow Bananna" Lifted 4spd. 39.5 TSL Swampers, The money Pit -'86 K5 Blazer Silverado 6.2 4" lift 35"s -'95 Ext. Cab Shorty 4" Tuff Country rolling 35" M/T's -'83 Monte Carlo T-Tops. 126,500 Original Miles -LATER I would rather push a Chevy then drive a ford!!

07-28-2010, 08:57 PM	#10
PRattenbury Senior Member Join Date: Feb 2010 Location: Maumelle, AR Posts: 478	Re: Okay, what did I do wrong? Did all of the above, and it seems to be fine. I hope I don't get any others to do that. I'm contemplating buying a 5/8" crows foot to check the torque on all of them.



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