rocker arm stud weirdness

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chachi
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rocker arm stud weirdness

Post by chachi » Tue Oct 18, 2011 1:06 pm

...
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1991 vanagon NAHT, RJE 2.3

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RSorak 71Westy
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Re: rocker arm stud weirdness

Post by RSorak 71Westy » Tue Oct 18, 2011 2:31 pm

Yes it can be repaired with a Helicoil kit.....The kit includes a drill to drill out the hole to a larger size. And a tap to thread that hole for the insert. Then some inserts to screw in that return the hole to it's original size.
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Rick
Stock 1600 w/dual Solex 34's and header. mildly ported heads and EMPI elephant's feet. SVDA W/pertronix. 73 Thing has been sold. BTW I am a pro wrench have been fixing cars for living for over 30 yrs.

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Re: rocker arm stud weirdness

Post by Amskeptic » Wed Oct 19, 2011 1:20 am

chachi wrote:went over to help a friend adjust his valves today after he was complaining of having lost a cylinder. when we got the rocker cover off the pass. side we immediately saw the problem. the retaining nut on the right side #1 rockers was off. upon closer inspection however, it was evident that this was not his real problem. the stud on the left hand side pulled right out. what is the solution for this besides a new head? can an insert be put in?

here's the pic, note the weird square spacers which i've never seen before:
This must be a repeat of the post I saw in troubleshooting forum. If you can get a straight 10X8Xwhatever length stud and tap out the holes to a clean 10mm thread, I would hesitate to use helicoils because this is a very demanding enviroment, unlike a simple exhaust thread. The vibration of a valve train at speed is something to see. The combustion chamber heat just underneath is also going to work those helicoils into a froth of fretful.
Colin
(p.s. assume that the rocker stand shims are mandatory for valve train geometry. Please make sure that they are fully contacting the rocker stands, i.e. perfectly aligned underneath)
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chachi
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Re: rocker arm stud weirdness

Post by chachi » Wed Oct 19, 2011 7:57 am

Amskeptic wrote: This must be a repeat of the post I saw in troubleshooting forum. If you can get a straight 10X8Xwhatever length stud and tap out the holes to a clean 10mm thread, I would hesitate to use helicoils because this is a very demanding enviroment, unlike a simple exhaust thread. The vibration of a valve train at speed is something to see. The combustion chamber heat just underneath is also going to work those helicoils into a froth of fretful.
yeah, he posted a thred on TS, same pics. i just like you guys better. :)

but...yeah...i was worried about what you're talking about. there's so much vibration and..."action" going on in that location. so can you just get a larger stud size? we were wondering how the studs stay in when they originally put them in...how do they not loosen up? for that matter, how do the heli-coil inserts stay in?
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Re: rocker arm stud weirdness

Post by Amskeptic » Wed Oct 19, 2011 6:23 pm

chachi wrote: we were wondering how the studs stay in when they originally put them in...how do they not loosen up? for that matter, how do the heli-coil inserts stay in?
Studs directly in contact with the aluminum will do fine so long as they are a nice snug installation. Helicoils are merely a steel thread wound up like a spring and will vibrate and chafe to the springs' harmonics and erode the aluminum .... don't.
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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chachi
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Re: rocker arm stud weirdness

Post by chachi » Wed Oct 19, 2011 7:31 pm

...
1974 transporter panel, 2.0 dual solex
1991 vanagon NAHT, RJE 2.3

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chachi
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Re: rocker arm stud weirdness

Post by chachi » Wed Oct 19, 2011 7:32 pm

...
1974 transporter panel, 2.0 dual solex
1991 vanagon NAHT, RJE 2.3

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RSorak 71Westy
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Re: rocker arm stud weirdness

Post by RSorak 71Westy » Wed Oct 19, 2011 7:52 pm

I disagree that a Helicoil will fail in this spot, but that's irrelevant, if you can find a step stud. That is an easier repair, but only marginally easier.
Take care,
Rick
Stock 1600 w/dual Solex 34's and header. mildly ported heads and EMPI elephant's feet. SVDA W/pertronix. 73 Thing has been sold. BTW I am a pro wrench have been fixing cars for living for over 30 yrs.

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Re: rocker arm stud weirdness

Post by vdubyah73 » Sat Oct 22, 2011 2:36 am

step studs available at napa. the stripped hole was an 8mm stud you need is a 10mm on the head end and an 8mm on the rocker block end.
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Re: rocker arm stud weirdness

Post by ruckman101 » Sun Oct 30, 2011 12:12 pm

I had those studs strip out of my 1200 cc heads many a moon ago. Baffling lack of power, then nada. At the time, I had help and kinda recall pulling the head so a machine shop could do the work. Sheesh, like thirty years ago. Dang I'm a geezer.


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