Rocker Arm stud Question

This is the place to discuss, or get help with any of your Type 4 questions.

Moderator: Type 4 Unleashed

Post Reply
buzzkillg230rc
Posts: 5
Joined: Fri Sep 15, 2017 10:08 am

Rocker Arm stud Question

Post by buzzkillg230rc » Mon Nov 27, 2017 4:52 pm

HI All,
I had my heads rebuilt for my Porsche 2 liter. After receiving the heads I reassembled the engine. After re-assembly I ran the engine for 20 mins @ 2500 rpm to break in the heads, everything sounded great.
after a few days, I went to pull the car out and it started making a claking noise from the number 3 and 4 valve cover. come to find out my rocker arm stud on number 3 pulled from the head.
I took the head to the machine shop and had it repaired, it looks like they welded the area and tapped it with a helicoil. my question is, the rocker arm stud is not bottomed out, meaning i can tighten the stud, however if i tighten it all the way, it leaves me with no thread to attach my rocker assembly.
currently, I have them back out 1.5 turns out from bottoming out, which lets me get full thread on the rocker assembly. should i loc-tite the stud? or leave it as it?

Any info is appreciated

DeAngelo

User avatar
Clatter
Posts: 1682
Joined: Sun Apr 28, 2002 3:01 am
Location: Santa Cruz

Re: Rocker Arm stud Question

Post by Clatter » Mon Nov 27, 2017 6:38 pm

They make bigger studs for motors with big cams, etc.
Might look into a set of those - they use a bigger nut, and fit tighter to the rocker shaft.
Some are longer as well. Cheap insurance.

Short of that, I wouldn't hesitate to try a bit of Red Loc-Tite..
"Oh, You don't need to do all that... The valve seats are just going to fall out of it anyway!"
- Doug Ellsworth

Beginners' how-to Type 4 build thread ---> viewtopic.php?f=1&t=145853

buzzkillg230rc
Posts: 5
Joined: Fri Sep 15, 2017 10:08 am

Re: Rocker Arm stud Question

Post by buzzkillg230rc » Mon Nov 27, 2017 11:15 pm

Thank you for the response. I called the machine shop and they recommended using red Loc-Tite.

User avatar
Type 4 Unleashed
Moderator
Posts: 2142
Joined: Wed Nov 09, 2005 1:43 am
Location: Aliso Viejo, CA

Re: Rocker Arm stud Question

Post by Type 4 Unleashed » Fri Dec 01, 2017 3:37 pm

If they used a heli coil, then their shouldn't of needed to weld the head ? And for a rocker stud to pull it had to of been way way over torqued.

EMW carries the larger 8mm rocker studs, which are also longer for use with rocker base shims for room to set rocker geometry.

Most of the rocker stud holes can be seen on the bottom except maybe 2, so the rocker studs won't bottom out they will go thru the bottom side too far, making them too short.

Image
Richard

EMW

“Have you ever noticed how some people never
have the money to do it right, but can always
find the money to do it twice ?”

User avatar
Piledriver
Moderator
Posts: 21888
Joined: Sat Feb 16, 2002 3:01 am
Location: Van Alstyne, Texas

Re: Rocker Arm stud Question

Post by Piledriver » Fri Dec 01, 2017 4:06 pm

The stock rocker studs the 7mm part should surely let go first, no?
The hd studs are recommended even on a stock rebuild.
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

User avatar
Type 4 Unleashed
Moderator
Posts: 2142
Joined: Wed Nov 09, 2005 1:43 am
Location: Aliso Viejo, CA

Re: Rocker Arm stud Question

Post by Type 4 Unleashed » Fri Dec 01, 2017 4:54 pm

Before the 8mm stud upgrade, I never saw a pulled or broken stock rocker stud.

The larger 8mm upgrade allows for an increase in torque and better supports the rocker stands and the longer studs also allow for longer valves to increase installed height in springs for higher lift cams. I forget the torque on the stock rocker studs, 8 to 10 pds ?

The 7mm rocker studs, the stands, the adjusters, and the rockers are hardened steel, the rocker shafts are mild steel, who would of thought.
Richard

EMW

“Have you ever noticed how some people never
have the money to do it right, but can always
find the money to do it twice ?”

wreck
Posts: 200
Joined: Thu Aug 14, 2014 2:07 am
Location: Brisbane Australia

Re: Rocker Arm stud Question

Post by wreck » Fri Dec 01, 2017 6:14 pm

I used type 1 HD studs(EMW was out of stock of their studs) , I had to cut them down a bit . I needed the extra length because of the valve/spring set up . I've about 7mm of spacers . If using the type 1 studs you need to drill the rocker gear to fit the bigger studs .
No matter where you go , there you are !

Post Reply