Lauren?
Sometimes the brain works a little slow here, especially in the winter. When I first bought my car, I had some definate plans for the exhaust and intake if I was going to keep the existing engine. Well, I am keeping it, so one of the first things I went looking for was alternative induction. The setup currently on the car is a 390 Holley four-barrel, vacuum secondary, which is fine. It fits on this manifold:
As you can see, Offenhauser specifically designed this manifold for a vac secondary carb - the plenums are, indeed, split, so the secondary half really doesn't do anything until they open. From Offy's website, "The quad manifold (competition design) will actually allow the engine to perform with proper balance throughout all stages of RPM resulting from the high rate of velocity in the primary circuit and perfect balance that automatically results when the secondary or acceleration portion takes over."
Ok... all well and good. In theory that should give reasonable gas mileage, too. But I'm for one to go overboard and do stupid things, like purchasing these:
Twin 40 DCOE webers on a central manifold by B&N. This kit is still available through a select few manufacturers for well over $2K, and I found this set rebuilt for less than a quarter of that. I had stumbled across the manufacturer's website when I was daydreaming about the build one day (http://www.compperformancegroupstores.c ... FourBarrel for those that want to check it out), and I knew I had to have it.
What never crossed my mind was that the center manifold was open:
The wider portion would be where the vac secondaries would be on a regular four-barrel carb. Ah... interesting dilema! I know I'll need a spacer under the unit if it works just to clear the rocker covers. My question to the rocket scientists amoungst us and those that understand fuel/air ratios better than I: Other than the anticipated poorer gas mileage, will this setup actually function as it should on a manifold designed to "split the load" from a four-barrel vac secondary carb? If the setup would fit length-wise on the block, it's possible that I could physically make a partition in the manifold, and have one carb come in a little later than the "primary", but as it is, it will only fit across the block:
Which, when fitted with small screens on the trumpets instead of the big box filters, is going to look pants when the block is finished and painted!
So... thoughts?