Holley model 4160, series 3310 carbs

[dcdoug]

I didn't lose the cap, it just wasn't there when I went to hook up the gauge. Maybe I knocked it off somehow when I took the carb off to remove the TP.

[patrickt]

Originally Posted by dcdoug

I didn't lose the cap, it just wasn't there when I went to hook up the gauge. Maybe I knocked it off somehow when I took the carb off to remove the TP.

OK, first thing you have to do is get a cap on it. You can't leave it open. Take the cap off the ported vacuum right above your passenger side idle mixture screw and put that one on it and then stick a piece of tubing or something over the ported vacuum fitting, even duct tape, to seal it up until you can get a cap from the auto parts store, take it for a ride and see how it runs. Just plugging that manifold leak might make quite a difference. FWIW, on my build, which is similar to yours, I run 13.5" of vacuum and the needle wobbles about an inch (meaning "one") or so. With the cams we're running that's perfectly normal.

[patrickt]

... and do I remember you telling me that you have yet to adjust your valves? If so, solid flat tappets that are out of adjustment can make your needle wobble.

[dcdoug]

Originally Posted by patrickt

... and do I remember you telling me that you have yet to adjust your valves? If so, solid flat tappets that are out of adjustment can make your needle wobble.

I was told that it was probably enough to do it annually and is on my list to do soon. My vacuum does seem quite low though. Thought non-emissions engines should be at 10 inches at least.

[patrickt]

Originally Posted by dcdoug

I was told that it was probably enough to do it annually and is on my list to do soon. My vacuum does seem quite low though. Thought non-emissions engines should be at 10 inches at least.

The "once a year" only applies after you've adjusted them for the first time, say around 1500 miles. Your valve are probably a good bit out of adjustment, but after you adjust them you can then do them once a year or maybe even less often than that. But there's a big difference between zero to 1500 miles and 1500 to 3500 miles when it comes to your engine breaking itself in.

[dcdoug]

Originally Posted by patrickt

The "once a year" only applies after you've adjusted them for the first time, say around 1500 miles. Your valve are probably a good bit out of adjustment, but after you adjust them you can then do them once a year or maybe even less often than that. But there's a big difference between zero to 1500 miles and 1500 to 3500 miles when it comes to your engine breaking itself in.

Sounds like a rookie move to me.

[patrickt]

Originally Posted by dcdoug

Sounds like a rookie move to me.

Adjust the valves, adjust the idle mixture screws, double check the timing, and your car will be perfectumundo.