I know this has probably been asked before but what is the right torque spec for the rocker bolts in Al (Edelbrock) heads? The OE spec for iron heads is 40-45# iirc but that seems a bit dangerous in aluminum. I got to thinking about this after breaking another rocker stand in the FE stroker. Time to replace my rocker assy i think. Any help appreciated.

to 40 lb/ft. Been 9-? years and never a failure. This of course with a .63 lift flat tappet. Big roller cams aren't as easy on rocker mountings.


LarryK

1964 Galaxie 2dr 390/6-71/4spd
1964 Country Sedan Wagon 428/5spd
1969 F100 428/4spd
1967 F100 352/now a 4 spd!
1959 B Model Mack

I'm only running about .560" lift on flat tappet cam. I'll keep doing 40#.

It's about bolt stretch, not the head material. If you don't torque them as required to stretch the bolt for proper holding power, then the fastener can loosen or otherwise fail to perform. If the underlying part can't take the torque, that's a different problem. the inserts in aluminum heads should not have any problems taking the load.

1967 Falcon 4 door 351C-4V
1970 Mustang 351C-2V
http://raceabilene.com/kelly/hotrod
Owner built, owner abused.

Never heard of one breaking before.

You should use studs on Edelbrock or any other aluminum heads for the rocker shaft supports. Torque to 35 Lb-ft.



1912 Model T Ford touring Salmon (ugh!)
1913 Model T Ford Touring original Black paint
1915 Model T Ford Roadster Black
1915 Model T Ford touring Black of course!
1967 Cougar GT 390 Cardinal Red / Black
1968 Cougar GTE 427 Augusta Green / Saddle
http://www.supermotors.net/vehicles/registry/15029/50071-2

My nephew put it on and forgot to chase the threads. The oiling bolt bottomed out, and though it torqued, the stand wasn't all the way down. It slapped until it cracked. I was running the valves about three weeks later and discovered it. The bolt, original, had been stretched too so that didn't help. Alot of guys don't run drain tins either, I would reccomend studs if you do this because that bolt just gets down in there the thickness of the tin and takes a chance of bottoming out. A stack up of bolt stretch, long bolt short boss, crap in the bottom, can all bite you on the butt.

One of my nieghbors is a die hard Chevy Guy and one day I walked in his garage to find him torqing down a SBCs Rod Nut as if it were a Main Bolt. Sure enough he was going for a Main Cap Torque figure. I told him "you can't use that bolt it's stretched to hell..." He did anyway as far as I could tell, and soon after car SOLD the car with the fresh motor.

the first was when i took some "advice" from a guy who told me that if i cut through one side parallel to the shaft I would get better clamping force on the shaft. Sounds good in theory but it weakens the stand to the point that they crack over certain lift levels or spring rates. I cracked a couple before i replaced them.

The second i saw yesterday when i grabbed a spare stand out of my parts box and cleaned it off. This unit came from a non-adjustable rocker set that i picked up for spare parts. I took it to the wire wheel to clean it off and found the unit was cracked in a radial fashion around the top bolt hole just below the upper edge. I can't do a picture since i'm traveling.

I will convert to studs when i go to a roller set-up.

The factory Iron Stands Ive seen/have are all I believe cut through one side parallel to the shaft. I would get better clamping force on the shaft. but the difference between Iron and Alum is pretty hefty in flexibility I guess.

being asked to do alot. A bolt by nature is only pulling on the top two threads of the insert or threads in the material with the spring tension highest down there. A stud is pulling its full thread length and the concentration of stretch is much better spread because of the nut clamping the stud and pulling against all of those threads with the higher compression at the nut using the stand to brace the spring pressure in the stud much more effectively.

I have pulled the treads out of iron heads from using too much spring for too long and winding it up too high. 4 -3/8" bolts at that loose interference fit to the shafts and stands are not going to be happy for long over 350 lbs even with wrap around end stands. Geometry is important too, if you are over centering toward the exhaust it will beat them out, too much leverage. Studs would hold up provided the geometry is right, in fact 450-550 lbs will be fine. After 500-550 lbs its a crap shoot though. The Ersons are supposed to be good, but really T&D and machining the head bolt bosses put so much more strength there. Thats 900-1000 lb territory and 9000 rpms, but its not going to hurt at 600 and 7500 either. You can also bottom out a bolt and it will strip those aforementioned top two threads. You keep tightening and it takes another one, pretty soon the insert or threads are gone. Always chase the threads and clean them, if any crap gets down there and the bolt bottoms out you are in trouble. I am not using anything but studs any more.

I'll convert to studs when i go to rollers. I'm leaning toward the Ersons as an out-of-the-box solution and like that i can keep my push rods. My car is a street rod so <6K rpm. I don't want to pull the heads and do any machining work if i can help it. Thanks for all the info! <br>
Dan

You need to make double dog sure that your bolts aren't bottoming out in the head before they reach torque. I have seen where a too-long rocker shaft bolt torqued into an AL head knocked a hold in the port/water jacket below the bolt. It will cost you very little to convert to studs and you get better clamping (since you use all of the threads) and you don't need to worry about bottoming out--JMO

http://www.supermotors.net/vehicles/registry/9026

I can't recall if i actually checked the hole depth. I may have *ass*umed that it all worked. I can confirm that the stands are definitely held down but don't know the actual clearance at the bottom of the hole. I'll check that. thanks!

It tells you about cutting off the oil supply hole rocker stud bolt, for example. Lots of other useful information too. If you don't have yours it is posted on the Edelbrock web site.



1912 Model T Ford touring Salmon (ugh!)
1913 Model T Ford Touring original Black paint
1915 Model T Ford Roadster Black
1915 Model T Ford touring Black of course!
1967 Cougar GT 390 Cardinal Red / Black
1968 Cougar GTE 427 Augusta Green / Saddle
http://www.supermotors.net/vehicles/registry/15029/50071-2

Bolts excessively stress the rocker thread inserts in aluminum head. Use studs in this application.

Shoe.

For crying out loud use studs not bolts. This is aluminum, not iron.

http://www.fefords2nv.com

Is there one available with a cut down shaft? Seems like straight grade 8 studs would work for the rest of them.

on Edelbrock's website.