L18 manifold studs, vacuum advance questions

[zed]

How do I fix these studs in the cylinder head? Do I put Loctite or threadlocker on them? What stops the stud turning in the head when you torque the nuts on them? Will this not strip the thread inside the head?

Also, how do I test if the vacuum advance on my dizzy is ok? If I suck on the pipe, with the dizzy cap off, there is only little movement - maybe 5mm.

thanks for any advice

[datzenmike]

The stud is turned down until it runs out of thread and tightens. That's it. If, when tightening down the nut, the stud turns a bit, then it wasn't all the way down and will only turn until tight. It's very unlikely the head will strip because there are more threads holding the stud than there are on the nut being tightened. It's more likely the stud will snap off first. If not sure use a torque wrench to prevent over tightening.

 

Check that the vacuum hose isn't leaking by removing from the distributor and sucking on the one end and with your finger over the other. Remove distributor cap and re-connect hose. First of all, suck on the end of the hose and place your tongue over the end..... Does the vacuum hold or does it leak out. A good vacuum canister should hold the suction indefinitely. If it won't hold the vacuum the canister is leaking and needs replacing. The plate with the points or EI rotor should move several centimeters. Twist with your hand in the counter clockwise direction. It might just be rusty and stiff so move it and try to loosen it up.

[datsunaholic]

For the first question, use loctite only if you never want them ever to come out again. Ever. Even if they break. If your heads are disposable then go ahead and loctite them, but if you want the head to last beyond one manifold change then I'd strongly suggest you don't.

 

For the second question, that's what the shoulder on the stud is for.

 

For the third question, it will if you're like my buddy "100 Ft/lb Descargar" who torqued everything to "as much weight as he could put on it". I got to "help" him helicoil a Detroit 6V53 boat engine blower case when he did that with the air box. Otherwise, it won't strip anything at the proper torque. And I antisieze the manifold studs.

Edited January 8, 2009 by datsunaholic