CORNER CARVER

I have a 1977 911S w/ 2.7 engine. Can an intake valve spring be removed with engine in the car, just valve covers off? I got done with valve adjustment, was double checking my work, I was able to open #5 intake valve with a 13mm wrench and minimal force. Checked other valves and I am not a strong as I thought. Other intake valve that was on base circle was a ton stiffer. This leads to my question. Thanks for your help, Tim.

Peter Zimmermann

Yep, put the engine on TDC for the cylinder with the broken spring, remove the spark plug and install your leak down tester set at 100 psi. The leak tester will hold the valve closed while you hook up your spring removal tool and do your work. The tricky part is installing the keepers when you're installing the new spring!

CORNER CARVER

If the cyl is on TDC how far will the valve fall into the cyl. This is an interference engine right? I dont have a leak down tester.

Peter Zimmermann

Far enough so you won't be able to remove/install the keepers...

Edgy01

This is not an interference engine.

jakeflyer

I have used the following for aircraft engines. With both rockers removed so that both valves are closed, pack in cord a little smaller that clothing line or lawn mower starter with the piston at bottom dead center. Rotate the piston up as far as you can, compressing the line. This will keep the valve in place while you change the spring. You MUST keep the crank/piston in place and not let them rotate. Then you pull the line out. A/C plugs are larger than the 911 plug so it may be time consuming to get the cord in.

Peter Zimmermann

Now that's clever!

jakeflyer

Thanks Peter, I appreciate the compliment. In fact I think am going to brag to my wife and boy about it. A little credibility never hurts.