Setting Valve Lash Issue

[chiefmd]

This is my first Z so I am still learning. I'm about ready to put my car on the road, 1977 280Z. I have taken it out for test runs and all seems well. At idle it it seems to be loading up and running a little ruff so I thought it would be wise to check the valve lash.

But when I get the #1 exhaust lope in the vertical position the rotor in the dizzy is pointing at #4? If I set the rotor to point at #1 on the cap and the timing mark is set on zero (tdc) the #1 exhaust lope is about 90 degrees off of vertical. Any help would be greatly appreciated.

[Mn_Z_Man]

your cam lobes for #1 will not be pointing up at TDC compression, they will be at about 10:00 and 2:00, both valves closed. That is the position to check your valve timing behind the cam sprocket. To set lash, you just rotate the cam with a vice grips (between the lobes!) to get them pointing straight up, or you can bump the engine. If you need more info on how to do it, and why, you should look into getting a manual, I recomend "how to rebuild your Datsun/Nissan engine", you will pick up all kinds of good ideas on how to do anything to these engines. Good luck.

Eric

[chiefmd]

Excellent Zman. You answered my question.

[sblake01]

I use a remote starter to rotate the cam. Though it probably does no harm, the thought of grabbing the cam with 'vice grips' just doesn't appeal to me.

[Walter Moore]

I just pull the plugs, and turn the engine with a ratchet, but then I have the 1 1/6" socket that fits on the bolt head.

I also notice that I usually end up bleeding from all kinds of scratches where my arm inadvertently touches the radiator. But at least I am sure that it doesn't damage the cam doing it this way.

[=Enigma=]

A remote starter switch is cheap insurance against physical damage to your self and the car.

[lmcguffin]

It may not matter with a stock cam, however we had a Schneider aftermarket cam and if we didn't get the cam lobe 180 deg from the rocker wipe pad then we would induce random small errors (+/- ~.002) in the lash setting. Just rotating the cam until the rockers had slack would not result in an accurate setup, and a noisy(er) valve train was the result. Also got best results doing the hot setup. I used a socket on the crank pulley with the plugs out (as Walter described) to get the cam in position.

Yes, it beats your hands up, but ya gotta luv it . . .

[beandip]

Mechanics gloves work vary well . Barked knuckles with grease in the sore is a bi&^% to scrub with a brush. I use them all the time and have a few pair. Cheap at Harbor freight or Costco.

[gerry240]

I found that best way to turn the engine for valve or points adjustment is to have the car on a nice flat surface in 4th or 5th gear. Then gently rock the car forward or back and you easily make the engine turn small amounts to put the cam right where you want it.

[Diseazd]

Ditto for me gerry 240, and also for setting points.

Edited May 18, 2009 by Diseazd