Broke the rocker stand stud and T&D rocker shaft.

I was using Doorman 3" long studs to hold the max wedge style rocker stands and the drivers side front stud broke after about 200 street miles? Do I have bad luck, or is there a problem running about 770+ open spring pressures on these Victor heads?

Shaft broke because the stud broke. I'm not sure what grade a Dorman stud is but I don't use them for anything significant. You can buy individual studs directly from ARP. Tell them what size you want. My paired T&D's had 2 studs on each mounting bridge that I thought should be longer. Bought new ones from ARP, reasonable.
Doug

When I had my Stage 6's I had rocker issues until I added these

and changed the studs to 7/16"


http://www.timesert.com/html/bigsert.html



Chris. .

Scrap the Dorman. Cheap material for such a build.
Step up on quality bolts and there strength.

I agree the stud went first... not sure if it
was loose or just weak

Probably a reason Dorman is at the hardware store, and ARP is at the Speedshop.



...and I stand corrected

http://www.summitracing.com/parts/rnb-675-099

...but I'd probably been looking more this direction

http://www.summitracing.com/parts/arp-aj3-15l

to my knowledge all those hardware/auto store studs are grade 5.

99% of the bolts in my car are grade 8 or above
except for some sheet metal screws

[quote=Chris'sBarracuda]
When I had my Stage 6's I had rocker issues until I added these

and changed the studs to 7/16"

Another stage 6... pulled the threads, bent broke the shaft. the heads weren't drilled deep enough for a longer bolt/ more thread engagement. Fixed it the same way as Chris.

Jim, you have ARP fasteners on everything else in/on that engine. Why did you go Doorman for the rocker shafts?

another prob Trendz is using those factory hold downs. They'll elongate the shafts over time and the rockers won't slide off the shafts.... found that out the hard way before going to aluminum hold downs with more surface area...

With race cars after they hit a certain point you can spend a lot of money hopefully once the first time or do it on the cheap MANY times. The choice is yours.

I used studs with 120k psi rating.

When I ordered the studs from Summit, they did not have a 3" long ARP, and the Dorman studs I used are advertised as Grade 8? I even checked their catalog.

These were torqued to 35ft/lbs, do you think I need more pre-load?
ARP shows 45 ft/lbs for 3/8", 180,000 psi bolts?

I did order some ARP studs to replace these.

The heads have already been modified with 3/4" long timesert thread inserts, after milling the stock shafts off and using the Max wedge type rocker stands/hold downs. I'm not sure how I could goto 7/16" with the reduced diameter T&D shafts and have the rockers oil through the rocker shaft?

How much would it cost to have ARP make some custom studs???

FWIW, I ordered these: ARP-AJ3000-5B
Summit has the material listed wrong as 4037?

This is the description from ARP:
Stud, 8740 Chromoly, Black Oxide, 3/8-16 in. Base Thread, 3/8-24 in. Top Thread, 3.0 in. Length, Each

These ARP individual studs are made from 8740 chromoly steel with 190,000 psi tensile strength. They are precision centerless-ground and thread-rolled to Mil-S-8879 specs and have a black oxide finish. A nut and washer are sold separately.

yes, but note that nasty "pinch" on the Dorman stud where the threaded part meets the non threaded part.... I'm betting you won't see that on an ARP, and hopefully the ARP isn't threaded most of the length like the Dorman.

Hmmm, got me thinkin' as I run a couple of Dorman studs on my Victor/Sharp setup. I don't remember why but, like you, I'm sure it was because I couldn't find the right length ARP at the time. Dorman did list as grade 8. Are those stands positively located or just located by the studs? I remember your center rocker stand issues from a few years ago which prompted me to install inserts deeper in head before bolting them on. Thanks for posting back then. I hope your valve train issues go away soon...

What I didn't like about the ARP 3" studs was that they are not threaded long enough on either end.

http://www.mcmaster.com/#standard-threaded-rods/=yfs8yu

If those don't work I'll use some grade 9 stuff:

http://www.mcmaster.com/#standard-cap-screws/=yfscrf

Sorry to see you are having problems again!

I ended up using the indy rocker studs that allowed me to have full thread engagement in the victor heads using the T&D rockers.

I got an E-mail from ARP and they said this part number:

PN: AJ3.050-1LB is an 8740 stud with .825" of 3/8-16 and .850" of 3/8-24. Torque would be 50 ft/lbs using the ARP Ultra Torque Lube.

Best regards,

Alan Nichols
Sales & Technical

Automotive Racing Products
1863 Eastman Ave.
Ventura, CA 93003
Toll Free: 800-826-3045


So, I ordered some of these too.

I think part of the problem was not enough pre-load on the studs with only 35 ft/lbs?

Can you be certain valvetrain instability didn't break the stud and the shaft?

Studs break for a few reasons.........One, they are cheap, stretch when you torque them and cause a stress riser..........Two, improper clamping. IE you THOUGHT everything was tightened down and slop out, but it wasn't........Three, something is stressing the stud. Like a retainer hitting the top of a valve guide. Springs rubbing rockers, incorrect geometry or anything trying to push the stud over

I should have the replacement shaft, adjusters, and ARP studs to get this fixed this weekend. I will inspect the other studs to see if they show any signs of fatigue.

Better check w/ T&D on how much torque they want to see used w/ their shafts. Just because ARP says 50#s doesn't mean the shafts can stand up to that much w/o getting "squished" out of round at the mounting points.

Got me, but that's some serious spring pressure for a street-driven car IMHO. I'm only going to be running about 600#s open and am already concerned if I'll encounter any shaft mounting issues w/ my Victors.

He uses rocker stands. Shouldn't apply.



Chris. .

You don't think those aluminum stands will distort if torqued too much? Maybe he needs to check w/ the maker of the stands on how they think 50#s will work out.

You may be 100% right, but having ovaled good shafts using nice steel hold-downs and far less torque, I'm a lil' suspect.

I doubt I will be using 50 ft/lbs, but I'm not too worried about getting the shaft out of round. These shafts are smaller diameter and thick material when compared to the stock sized rocker shafts, but this also presents a different issue relating to oiling through the rocker shaft.
The three inner studs have a reduced diameter so oil can flow around them, so they will have to be torqued to a lower setting. It is interesting none of those broke?

I E-Mailed Jesel to see what they have, and this is their reply:

"We do a pro series rocker kit for that head. There is machining required. The factory style cast in rocker shaft pedestals have to be removed for our steel stand to bolt down to the head. Then our shaft bolts to our steel stand. The rocker kit costs $1700.00 and takes about 7-10 days to build to your desired ratio.

Jon Fodor
JESEL, Inc.
732-901-1800 xt. 161
732-901-6777 fax
jonf@jesel.com"

For someone thinking of using these heads and looking for a rocker system, the Jesel setup may be the way to go? The T&D system is almost $1200, then I spent another $200+ on the aluminum stands and hardware, so their rocker kit would not be much more than what I already have in my T&D setup?

Speaking of the rocker oiling system, I have been thinking that it might be an improvement to drill the second and forth rocker stands and connect them together with some small 1/8" copper tube so the oil from the fourth stand will also send oil to the second stand. The holes in the bottom of the rocker shaft are slightly larger to allow the oil to flow into the hollow shaft to oil the rockers. With this modification, I could use the studs without reducing the center diameter of them for the oiling?

What got me thinking about this, it the new Trick Flow head are supposed to re-route the rocker arm oiling so the oil does not flow between the intake port walls.