Sorting through a 67 Hemi that had not been run for years. I had the heads and timing chain off the engine.

With a vacuum gauge hooked up I am getting a reading in the 5-10 lb range at about 750 RPM. The engine acts like it has a small vacuum leak, as it will pick up 200-250 RPM if I cover up the primaries on the front or rear carb. The engine has to be warmed up to get it sit and idle, and at that it is a little of a struggle for it to stay running.

My question is this. If the timing chain is off a tooth, (as the vacuum gauge shows late valve timing) would it also cause it to have a vaccuum leak?

I have pretty much ruled out the leaking intake, checked all around the out side, and pumped acetylene down the dip stick,nothing shows up.

I'm not really buying the idea that the chain is off a tooth but I'm out of ideas.


Thanks
Dan

I think a vac leak is causing the low vac reading. yes vac gauges have that low scale that says late valve timing. 4 a start I would do a simple compression test & post what u get. How much cam/scr do u have which'll influence what cpmpression #'s you get but a jumped tooth would lower them (plus the idle vac) if you have any idea/baseline on what you SHOULD have. but w it speeding up when you choke it that is a classic vac leak symptom. may need to open up the intake & visual/replace the intake gaskets & less likely one of the carbs. I'd add some unlit propane into the carb at idle & see how it reacts