Cam Nut Removal Issue

[1987 Porsche]

Guys, this is my first engine teardown since I found a broken headstud. I've been reading up on the cam nut removal and decided today to take it off. I used a 1 13/16 socket with the impact gun. The issue that happened was I didn't loosen the valve adjustment nuts and when taking off the left side cam nut for cylinders 123 the cam rotated from 12 oclock to 10 oclock position. Nut did come off but afraid the rotation could be an issue. Your thoughts?

[boyt911sc]

Originally Posted by 1987 Porsche

Guys, this is my first engine teardown since I found a broken headstud. I've been reading up on the cam nut removal and decided today to take it off. I used a 1 13/16 socket with the impact gun. The issue that happened was I didn't loosen the valve adjustment nuts and when taking off the left side cam nut for cylinders 123 the cam rotated from 12 oclock to 10 oclock position. Nut did come off but afraid the rotation could be an issue. Your thoughts?

I don’t think there would be any serious problem with the cam movement from 12 o’clock position to CCW 10 o’clock(?). Were you using a Carrera 3.2 cam holding tool during the nut removal? If not, why? How would you torque the cam nut/s back later? In summary, you need a cam holding tool to do this simple job correctly and safely.

Tony

[1987 Porsche]

Tony,

Its Lou. I figured I would use the impact gun to break the nut for just the removal then when reinstalling use the necessary tools recommended by Porsche, crows foot etc

[cmcfaul]

gonna have to retime the cams anyway. So no big deal.

Chris
89 Carrera

[Walt Fricke]

I always use an impact gun to remove this nut. Then the holder and torque wrench to reinstall it while timing it on the rebuild end of things.

As long as you still had the chains hooked up and tensioned (you can do this with your hand on the chain if you have removed the tensioners) when breaking it loose, the crank will move with the cam, so no issue with valves hitting anything. The rockers and springs will work to keep the everything in place, too.

If you had the chains off (or loose), then the crank and cam did not turn together as they should. When you get the heads off you should carefully inspect the tops of the pistons to see if, perchance, a valve hit a piston. If one did, would be a good idea to pull the valve or valves and put them in a lathe or valve grinding machine to spin them to see if a valve got tweaked.

[1987 Porsche]

Thanks for the replies. Chains tensioners and sprockets were already removed when hitting the cam nut with the impact gun. I guess next time if I do use the impact gun I should keep everything tensioned. I'll be sure to inspect the top of the pistons and valves. Thanks again guys.

[boyt911sc]

Originally Posted by 1987 Porsche

Thanks for the replies. Chains tensioners and sprockets were already removed when hitting the cam nut with the impact gun. I guess next time if I do use the impact gun I should keep everything tensioned. I'll be sure to inspect the top of the pistons and valves. Thanks again guys.

Lou,

How could you remove the cam sprocket when the 46-mm cam nut is still installed and torqued? I am a little bit lost by your statement above. Am I missing something obvious? Thanks.

Tony

[1987 Porsche]

Tony,

I should of clarified more, but I meant the idler arm sprocket. It was removed along with the tensioners prior to hitting the cam nut with the impact gun.

[boyt911sc]

Lou,

I have a week before I leave for Florida. PM me if you still need to borrow the 46-mm crowfoot wrench and the cam holding tool. I could drop them at your place before the middle of this month. Leaving January 17th. Please advise. Thanks.

Tony