77 911s running issues

[RoninLB]

Originally Posted by SkaggsRC

RoninLB
Are you running yours permanently 35 retarded?

When I bought this car someone had been working on it & I think there might be some vacuum lines connected in the wrong place. This care appears to have a vacuum limiter & I think the top vacuum line is suppose to go to the valve body but does not.

I'm still running 35deg total advance with carbs. My engine has 8.5:1 compression

If you think you have a vacuum leak and have tried the usual leak finding techniques and have not found it maybe buy one of these. CIS is vacuum leak prone in my opinion. Shopping for one should be less than $100. Some mfg's use same model under their brand name. It's a great tool for the box.

[RoninLB]

Originally Posted by yundar

RoninLB, Not to hijack this thread

'74 CIS car converted to Zeniths and an MSD ignition.

Not sure where to run the vacuum advance from the distributor?

Right now I just have it plugged at the dist. Will this work?

What would be the timing setting? How are you set up?

If a stock CIS dizzy run total at 35deg with vacuum line plugged permanently.

I've found that carbs run better with a re-curve from the stock CIS dizzy. I could either have had it rebuilt or bought a new 2.7 RS/ '74-'76 2.7 Carrera Euro dizzy. It offers a 10deg initial with a total of 35deg. The 10deg initial is with vacuum line permanently disconnected. The dizzy is cheap if you scout around. PN 0.231.184.004. It should cost around $325. A new dizzy comes with a new cap and basic non limiting rotor, which is a great Bosch rotor with MSD. This may not be the most aggressive advance for carbs on an engine with 8.5:1 engine compression but it's plenty good and leaves room for running hot deserts without pinging. I tried testing cold starts with the stock dizzy set at 5deg initial and at 10deg initial. 10deg initial in winter time NY gives me a nicer cold start. My stock dizzy was old and bushings almost worn to the point of being a problem.

With MSD multiple sparks a timing light with the adjustable timing knob may be difficult to read initial accurately.

[yundar]

Thanks, I will try resetting the timing with the advance plugged this weekend.

Andy.