The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 07-04-2011, 11:32 PM   #1
sduckworth13
Registered User
 
sduckworth13's Avatar
 
Join Date: Mar 2011
Location: Kansas City, Missouri
Posts: 3,507
Broke my rocker arm stud today

What are the chances that I won't have to pull my head to get this rocker arm stud fixed. I've not exactly sure how this would happen other than slamming downing the pedal and smoking the tires off. What causes the rocker arm stud to break off. I'm not a mechanic, but would this be caused from not having the rocker arm not properly torqued. What is my best option in this situation? repair the stud or replace the heads entirely with a used set.
Attached Images
  
__________________
Scott

Last edited by sduckworth13; 07-04-2011 at 11:39 PM.
sduckworth13 is offline   Reply With Quote
Old 07-05-2011, 05:48 AM   #2
Lee H
Registered User
 
Lee H's Avatar
 
Join Date: Jun 2010
Location: Upland Ca
Posts: 4,005
Re: Broke my rocker arm stud today

You'll have to pull the hard and take to a machine shop.
Posted via Mobile Device
__________________
1972 C10 SWB, Air, PS, PB, 350/350THM. Second owner.

1965 Corvette roadster, 44K miles, 327/365 SHP, 4 speed, side exhaust, knockoffs, teak, second owner (bought in 1970), Have ALL numbers matching components.

My frame off restoration thread: http://67-72chevytrucks.com/vboard/s...d.php?t=556703
Lee H is offline   Reply With Quote
Old 07-05-2011, 08:23 AM   #3
shortbed70
Registered User
 
shortbed70's Avatar
 
Join Date: Mar 2002
Location: Forney TX
Posts: 4,503
Re: Broke my rocker arm stud today

Since there's no threads probably going to have to pull it off. Are your rocker arm nuts rounded on the bottom also? Looks like it's upside down. Been a while since I've seen regular rocker arm nuts.
Posted via Mobile Device
__________________
Troy

1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb

my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884

Big Red Dog build
http://67-72chevytrucks.com/vboard/s...d.php?t=572274
shortbed70 is offline   Reply With Quote
Old 07-05-2011, 04:09 PM   #4
fastwillie 696969
Registered User
 
fastwillie 696969's Avatar
 
Join Date: May 2005
Location: CALIFORNIA NOR CAL
Posts: 9,708
Re: Broke my rocker arm stud today

push in stud or screw in > ?
__________________
is it fast ? it has a lighting bolt donut?


B___H please, I can remove 90% of your so called "beauty" with a kleenex
fastwillie 696969 is offline   Reply With Quote
Old 07-05-2011, 06:05 PM   #5
raceman6135
Dino burner
 
raceman6135's Avatar
 
Join Date: Nov 2002
Location: Calgary, Alberta, Canada
Posts: 598
Re: Broke my rocker arm stud today

You can replace a push-in rocker arm stud without removing the head from the engine, but that shouldn't be the thing you're worried about. I'd be more concerned about WHY it broke!

A broken rocker arm stud is usually caused by a serious case of interference, and that can come from a number of places:
- valve contacting the top of the piston
- retainer contacting the top of the valve guide
- valve springs going into coil bind
- the slot in the rocker arm is too short for the lift of the camshaft, which causes the rocker arm slot to contact the rocker arm stud
raceman6135 is offline   Reply With Quote
Old 07-05-2011, 08:02 PM   #6
Marv D
Registered Truck Offender
 
Marv D's Avatar
 
Join Date: May 2008
Location: hells training ground (aka Ariz)
Posts: 3,113
Re: Broke my rocker arm stud today

Yup, was going to say the same thing raceman,,
If you can get enough thread to pull the stud,,, you can cut the guide and thread it for a screw-in while it's on the engine (provided you keep the debris out of things)

But fixing it just to others do the same thing is the issue. WHY would be my first question.
__________________
Still playin with trucks, even at my age!

When you're dead, it's only a problem for the people around you, because you don't know you're dead.
.....It's kinda the same when your STUPID.


I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral.

Last edited by Marv D; 07-05-2011 at 08:07 PM.
Marv D is offline   Reply With Quote
Old 07-05-2011, 08:48 PM   #7
Blue Rat
Registered User
 
Join Date: Dec 2010
Location: Arkansas
Posts: 608
Re: Broke my rocker arm stud today

Being the 882 heads. I would say fatigue is playing a big role in this case. Those are most likely the original rockers an hardware. I have seen a many of stock stuff give away with a decent camshaft. I would say it is time to give everything a good look.
Blue Rat is offline   Reply With Quote
Old 07-05-2011, 09:20 PM   #8
shortbed70
Registered User
 
shortbed70's Avatar
 
Join Date: Mar 2002
Location: Forney TX
Posts: 4,503
Re: Broke my rocker arm stud today

Yea a nut and a bunch of washers would pull it out but there's not enough threads to do that and I don't think a Heman grip would get vise grips to clamp enough to pull it.
Posted via Mobile Device
__________________
Troy

1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb

my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884

Big Red Dog build
http://67-72chevytrucks.com/vboard/s...d.php?t=572274
shortbed70 is offline   Reply With Quote
Old 07-06-2011, 01:04 PM   #9
sduckworth13
Registered User
 
sduckworth13's Avatar
 
Join Date: Mar 2011
Location: Kansas City, Missouri
Posts: 3,507
Re: Broke my rocker arm stud today

Thanks guys for all the help, I am going to give it a try and tap the bolt to the bottom and try and work it out with a stack of washers and nut and force it up. Hope it works. If I have to take the head off I might as well take both off and get a nice set off aluminum heads and change my whole top end set up. I am most concerned about what caused it. I will double check everything before I put it back together. The engine was rebulit by the previous owner about 5000 miles on it. Its a 1967 327 bored .30 over. It has 10.1 pistons in it.
Posted via Mobile Device
__________________
Scott
sduckworth13 is offline   Reply With Quote
Old 07-06-2011, 01:43 PM   #10
fastwillie 696969
Registered User
 
fastwillie 696969's Avatar
 
Join Date: May 2005
Location: CALIFORNIA NOR CAL
Posts: 9,708
Re: Broke my rocker arm stud today

tip: add some grease to the tap and filing will stick to the grease and not in the engine ,
__________________
is it fast ? it has a lighting bolt donut?


B___H please, I can remove 90% of your so called "beauty" with a kleenex
fastwillie 696969 is offline   Reply With Quote
Old 07-06-2011, 02:30 PM   #11
sduckworth13
Registered User
 
sduckworth13's Avatar
 
Join Date: Mar 2011
Location: Kansas City, Missouri
Posts: 3,507
Re: Broke my rocker arm stud today

Great tip, thank you. I will do that. Appreciate the help
Posted via Mobile Device
__________________
Scott
sduckworth13 is offline   Reply With Quote
Old 07-07-2011, 09:11 PM   #12
sduckworth13
Registered User
 
sduckworth13's Avatar
 
Join Date: Mar 2011
Location: Kansas City, Missouri
Posts: 3,507
Re: Broke my rocker arm stud today

Well, I attempted to pulll the stud out today. I used Fastwillies tip about the grease on the stud, it worked perfect. I got a 7/16 14 (fine thread) die and made my threads put a stack of washers and threaded the nut down to the washers. I thought I had broke the stud free but I had actually just stripped the nut...twice. The good thing is, that I didn't break the stud in half (yet).
Attached Images
     
__________________
Scott
sduckworth13 is offline   Reply With Quote
Old 07-07-2011, 09:13 PM   #13
sduckworth13
Registered User
 
sduckworth13's Avatar
 
Join Date: Mar 2011
Location: Kansas City, Missouri
Posts: 3,507
Re: Broke my rocker arm stud today

Its still in the head so back to the drawing board.
__________________
Scott
sduckworth13 is offline   Reply With Quote
Old 07-07-2011, 10:48 PM   #14
truckdude239
Senior Member
 
truckdude239's Avatar
 
Join Date: Sep 2005
Location: Lewisville, Nc
Posts: 9,934
Re: Broke my rocker arm stud today

its time to pull the had and have the machine shop but screw in studs in
__________________
David fuller
Ase Certified Mechanic
Click here to help support our board!!


1971 Chevy c-10 under going a 4.8l LSx swap

Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305

2007 Honda Accord my daily 101kmiles
2002 Honda Accord 4 door With 275k(sisters car)
2003 Honda Accord 109k( brothers car)
2002 Sububran 5.3 225k
2000 Tahoe 5.3l 369k

General manager for Marco's Carwash & lube
truckdude239 is offline   Reply With Quote
Old 07-07-2011, 10:55 PM   #15
sduckworth13
Registered User
 
sduckworth13's Avatar
 
Join Date: Mar 2011
Location: Kansas City, Missouri
Posts: 3,507
Re: Broke my rocker arm stud today

Yeap, I'm just procrastinating. I was trying to figure a way around it though. I'm looking for a new set of heads right now. I'm going to put a set of heads on that get me in the 325hp or 350hp range. I didn't want to pull the heads until I have everything ready to go back on.
__________________
Scott
sduckworth13 is offline   Reply With Quote
Old 07-11-2011, 11:20 PM   #16
sduckworth13
Registered User
 
sduckworth13's Avatar
 
Join Date: Mar 2011
Location: Kansas City, Missouri
Posts: 3,507
Re: Broke my rocker arm stud today

Took off the heads, and now the fun begins. Finding the money the replace them...lol. I went to one of the local auto repair shops that builds hipo engines. The owner of the shop suggested that I go with the Dart Sportsman or the S/R Torquer. He suggested that because, I told him i was interested in a vortec setup, he said that after the machine shop would be done with all the work needed on a set of heads to get the performance I'm looking for out the vortec that I'd be better off going with either of those two heads. Which will be a better performing head. I'm replacing the heads and they are going on my 327 .30 over 1967 GMC 1/2 ton with ps, pb. I have a L79 cam 327/350hp. I plan on changing my intake, cam and carburetor, but trying to get a idea on which heads to use first.
Attached Images
    
__________________
Scott

Last edited by sduckworth13; 07-11-2011 at 11:25 PM.
sduckworth13 is offline   Reply With Quote
Old 07-12-2011, 12:26 AM   #17
cableguy0
Senior Member
 
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,952
Re: Broke my rocker arm stud today

Your better bet is the aftermarket heads. Your machinist is being completely honest with you. Vortec heads are the best STOCK heads gm ever made for the sbc but they dont flow well past .480 lift. By the time you have screw in studs installed and new springs etc etc etc. Your pushing the cost of a much better set of heads.
__________________
Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.
cableguy0 is offline   Reply With Quote
Old 07-12-2011, 09:08 AM   #18
Marv D
Registered Truck Offender
 
Marv D's Avatar
 
Join Date: May 2008
Location: hells training ground (aka Ariz)
Posts: 3,113
Re: Broke my rocker arm stud today

Pay CLOSE attention to chamber size on your new heads. Those look to be the small 62-64cc chambers. and a normal 327 will have 9.1:1 with those heads and flat tops with eyebrow pistons. If you use a head with 76cc you will barely eek out 8.0:1. Your already a bit soft on compression, 8:1 would be sorely lacking to support that L79 cam.

Vortec heads are a good match to the small inch street bound motor IMO. But not necessarily GM vortecs. Like the CableGuy said the GM offerings have a shortcomings, and require machine work to get them real useful. Add the required $300 vortec carburator intake, buying self aligning rockers... it all adds to the total in a big hurry.

Myself I'm not a fan of the SR-Torquers,, there barely more than a stock GM head. If your going to spend the money for an aftermarket head,, why not invest that money wisely to somethng that is a step up.
__________________
Still playin with trucks, even at my age!

When you're dead, it's only a problem for the people around you, because you don't know you're dead.
.....It's kinda the same when your STUPID.


I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral.
Marv D is offline   Reply With Quote
Old 07-12-2011, 11:09 AM   #19
ka_jd7and1
is a fungineer
 
ka_jd7and1's Avatar
 
Join Date: Jan 2009
Location: Bakersfield, CA
Posts: 789
Re: Broke my rocker arm stud today

Quote:
Originally Posted by cableguy0 View Post
Vortec heads are the best STOCK heads gm ever made for the sbc but they dont flow well past .480 lift.
They flow just fine above .480 lift, they just can't take anything above .480 lift without having machine work done for the springs to have clearance.
__________________

2003 S10, 2.2 auto- the daily driver, currently with a 2"/2" drop and some minor engine bolt-ons

1978 Impala 2-door, race 350/T350 - the new race car, in progress

1968 Chevy C10 longbed- 3/5 drop, currently undergoing a heart transplant
ka_jd7and1 is offline   Reply With Quote
Old 07-12-2011, 08:57 PM   #20
cableguy0
Senior Member
 
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,952
Re: Broke my rocker arm stud today

check these out for the great flow above .480. They dont flow anymore past .500 lift thus they dont flow above that. If you cant move anymore air with a larger cam than using a larger cam is a waste. You will end up losing low end and not gain any top end performance. http://racingfeed.com/downloads/chevy_flow_data.pdf . They are over rated. Just the same as Camel hump heads were over rated for years and still are. Most of the as cast decent aftermarket casting are leaps and bounds ahead. The vortec specific parts hit the wallet hard. The upgrade always ends up costing more than planned.
__________________
Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.
cableguy0 is offline   Reply With Quote
Old 07-12-2011, 09:44 PM   #21
sduckworth13
Registered User
 
sduckworth13's Avatar
 
Join Date: Mar 2011
Location: Kansas City, Missouri
Posts: 3,507
Re: Broke my rocker arm stud today

Cool, thanks cableguy0 for the link for the heads. I don't know how to read the graph completely, I'm not much of a engine guy...but I'm a motivated student. What do the numbers in green represent?
__________________
Scott
sduckworth13 is offline   Reply With Quote
Old 07-12-2011, 09:48 PM   #22
sduckworth13
Registered User
 
sduckworth13's Avatar
 
Join Date: Mar 2011
Location: Kansas City, Missouri
Posts: 3,507
Re: Broke my rocker arm stud today

I'm just looked up how to read flow chart numbers, I'm going to read up tonight.
__________________
Scott
sduckworth13 is offline   Reply With Quote
Old 07-12-2011, 11:39 PM   #23
cableguy0
Senior Member
 
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,952
Re: Broke my rocker arm stud today

The important numbers are the intake/exhaust flow at a given lift. most street engines are going to be under .550 lift for the sake of streetability. Once you go into the .550 and up lift neighborhood your getting into very big cams requiring a lot of compression and a very healthy bottom end not to mention the high rpms you will be turning. The choice largely depends on your budget and what your looking to get out of the engine. Stock bottom end also plays a role. If your completely stock with dish pistons and no balance job spinning past 5500rpm on a regular basis will lead to sweeping up pieces of metal from the blacktop when they are ejected through the oil pan.Theres a ton to consider and head swaps often turn into full rebuilds. New heads on a worn bottom end lead to blow by and loss in performance.
__________________
Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.
cableguy0 is offline   Reply With Quote
Old 07-13-2011, 11:37 AM   #24
ka_jd7and1
is a fungineer
 
ka_jd7and1's Avatar
 
Join Date: Jan 2009
Location: Bakersfield, CA
Posts: 789
Re: Broke my rocker arm stud today

Quote:
Originally Posted by cableguy0 View Post
check these out for the great flow above .480. They dont flow anymore past .500 lift thus they dont flow above that. If you cant move anymore air with a larger cam than using a larger cam is a waste. You will end up losing low end and not gain any top end performance. http://racingfeed.com/downloads/chevy_flow_data.pdf . They are over rated. Just the same as Camel hump heads were over rated for years and still are. Most of the as cast decent aftermarket casting are leaps and bounds ahead. The vortec specific parts hit the wallet hard. The upgrade always ends up costing more than planned.
Let me clarify my statement then:

Compared to a stock head, an 882, a camel hump, whatever, Vortecs have more flow below .500 lift, and above .500 lift. I see your point about not having any increase in flow above .500; however, how long is a valve open above 500 lift if you have a .520 lift cam? Most of the air is going to be going in and out well before you reach .500 lift. I could see it being an issue in a race motor, but not really in a stock street motor. Plus, this assumes that the head is the choke point, and not the carburetor, intake, or exhaust.

That's my $.02, don't want to start a pissing match and sorry to hijack the thread.
__________________

2003 S10, 2.2 auto- the daily driver, currently with a 2"/2" drop and some minor engine bolt-ons

1978 Impala 2-door, race 350/T350 - the new race car, in progress

1968 Chevy C10 longbed- 3/5 drop, currently undergoing a heart transplant

Last edited by ka_jd7and1; 07-13-2011 at 04:38 PM.
ka_jd7and1 is offline   Reply With Quote
Old 07-13-2011, 11:40 AM   #25
ka_jd7and1
is a fungineer
 
ka_jd7and1's Avatar
 
Join Date: Jan 2009
Location: Bakersfield, CA
Posts: 789
Re: Broke my rocker arm stud today

Quote:
Originally Posted by sduckworth13 View Post
Cool, thanks cableguy0 for the link for the heads. I don't know how to read the graph completely, I'm not much of a engine guy...but I'm a motivated student. What do the numbers in green represent?
The green numbers are exhaust flow as a % of intake flow.
__________________

2003 S10, 2.2 auto- the daily driver, currently with a 2"/2" drop and some minor engine bolt-ons

1978 Impala 2-door, race 350/T350 - the new race car, in progress

1968 Chevy C10 longbed- 3/5 drop, currently undergoing a heart transplant
ka_jd7and1 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 04:18 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Copyright 1997-2013 67-72chevytrucks.com