Manifold Vacuum Advance what am I not getting?

Manifold vacuum can work for some combos, but I always say be prepared to swap it back to ported, because it doesn't work for everything. Very simple to swap back and forth.

I agree. Using MV is a crutch for a piss poor build.

That’s what this guy has. A piss poor build. If it wasn’t, there is no way in HELL it would need or want that much timing at idle.

I don’t know what heads the OP has but if they are P car heads he ain’t nowhere near 12:1. It might be 11 but again, who knows.

He can do a cranking compression test but all he will know is he didn’t have enough so it’s jack a bunch of timing it it to make it move.

I’ll say it publicly and I don’t care what people think

If you build engines AND your **** constantly needs outrageous initial timing YOU ******* SUCK AS AN ENGINE BUILDER and you need to shag your sorry *** to the nearest fast food joint and see if they will let you work the drive through.

It is beyond incompetent to build **** like that.

It’s evident that the OP has way too much cam and not nearly enough compression.

So my advice to the OP is two fold.

1. Fix the thing correctly. That means swapping out the can to what the engine needs.

Then fix your tuneup and it won’t require MV to idle.

2. Hook it to MV and live with it.

2 is cheaper but it ain’t the right way to do it.

And for those about to come along and tell me you’ve been doing MVA since Moses was fighting the Egyptians then refer to point 1 above. Be a that is YOU.