Vacuum leak ?

[Robert]

Yeah, Keep, we kinda hinted around on that on the other post, on the 1st page, about vaccum leaks. Thought a vaccum gauge would be hooked up, [sigh]...oh well...anyway.
It'd be worth yanking the carbs off and getting new gaskets on there, doing it right, since all else is unknown at this point about the motor. But thats just me.
I'm with Mike, the Oil could cause a mess with the carbs. NEVER EVER RUN A OIL BREATHER LINE UP INTO THE AIRCLEANER, I DON"T GIVE A DAMN IF THE DIRECTIONS SAY SO OR THE MFG'ers SET IT UP LIKE THAT. Said oil will FOUL a carb, as per Mike....
He said there were no places tap in on the intake for vaccum, which is very strange. The only intakes I have seen with no NPT fittings on the manifolds were/are race manifolds....
Usually on the 2x4 intakes, the rear of the front carb has a hose line that most folks block off. Rear carb has one, too. I've seen many times when folks first start a motor, it'll sometimes backfire while setting the timing, blowing a vaccum plug off.
I would check all those vaccum plugs and lines before ripping things loose, it just might be that simple....
It has happened before....

Good point there.

Again, I reiterate though - - I cannot find any ports off the manifold at all, both carbs have brass tube ports.

 

[Robert]

Alot of diff. motors respond in diff. ways to diff. PCV setups.... especially long stroke motors. I'd say 95% of the time, the stock baffles in the right valvecovers usually cure oil pickup into the PCV system. On a strong long stroke motor, I've seen a misplaced PCV Hose/valve in the valvecovers wreak havok with other tuners and builders, causing a major mess.
On one particular Mountain Motor, I had to make a baffle can similar to the setup Bob made. Motor was strong, and healthy, but because of the long stroke/big bore it had a mess going on in the crankcase. And it leaked at the seals, also, but it won alot of races at Major Meets. I really had to work to keep it from oiling down a track.
I've also seen what Golly has described happen also. I've also seen porous castings causing vaccum leaks.
Now, we know Roberts motor has a leak at the bottoms there somewhere by the carbs bottoms....so I'd just dive in and fix it. God only knows what OTHER MESS he might find in there. Maybe a chunk busted out and JBWelded into place....hope not but you never know....
Close visual inspection with a flashlight, and a inspection mirror and some quality time with his motor might turn up a clue to the vaccum leak....might even be a simple, cheap fix....
If not a open/missing Vaccum cap on a line, probably a leaking base gasket. Maybe even loose base to throttle body screws....
Are the carbs Barry Grants/Demons by any chance?

EXACTLY. No, both carbs are Edlebrocks.

I will inspect the manifold surfaces VERY carefully as will for hairline cracks.