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From: At my Bar drinking and wrenching in Lafayette Colorado
The black plastic baffle is the standard anti-slosh baffle for "normal" cars - earlier versions were formed brass sheet metal of the same shape. It prevents fuel, under acceleration, from sloshing back against the rectangular bowl vent slot at the top of the metering block and spilling into the throttle bores. When that happens, you get a massive bog, which can actually kill the engine. For cars with good traction and hard acceleration, you want to remove that little "standard" part and install a "Whistle" to prevent the problem. Performance Holleys have the Whistle installed like this:
If your carbs are mounted sideways, the baffle or the whistle serves no purpose other than if you do hard cornering, so you can remove it for drag racing. Guys doing autocross will install the whistle on the secondary side as well to prevent fuel slosh going into the throttle bores under hard braking, which will kill the engine (there is no baffle or Whistle installed on the secondary side in a stock Holley).
Lars
These carbs were put on by my dad. It used to be his car..he called it a street machine. Said everyone in California in the 70s who had a street machine had a tunnel ram, so I've kept it. I'm rebuilding these because of two issues 1) regardless of float level etc it'll randomly shoot gas out of the vent tube...I mean full on glugging fuel and spraying it everywhere! 2) it bogs....guess you helped me on that one!
You might want to check float levels and fuel pressure. Verify fuel pressure is under 7 psi.
Lars
i have a fuel pressure gauge and it fluctuates between 6-7, my cars a 68, no return line, noticed the cap wasn't vented so I fixed that. I'll check float levels.
From: At my Bar drinking and wrenching in Lafayette Colorado
Those are Whistles, but it's not going to solve your problem - if you have the stock slosh baffles installed, you are not experiencing fuel slosh over your bowl vents in a street car on street tires. You have other tuning & setup issues.
To verify a vent slosh problem, simply take a section of 1/4" rubber hose and stick it onto the vent tube coming up out of the primary bowl. Loop it over the carb and stick the other end on the secondary bowl vent tube. Cut a little hole in the top surface of the hose at the peak of the arch. This vent system positively prevents any fuel slosh into the throat of the carb, yet provides bowl venting. If this solves your problem, you have a slosh problem and the whistle will help you. If the problem is unchanged, you do not have a vent slosh problem.
Lars
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
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Tunnel ram Carb rebuild
