quote:Originally posted by Tom@Seal Beach:
Ok who's the carb genius? I'm researching 750 cfm 4 barrels to replace my Edelbrock 600 spreadbore for the new and improved engine. I've noticed some carbs have annular boosters which are said to improve low to mid range power due to better atomization of the fuel. Has anyone experienced the difference between an Annular booster carb and a Down leg booster carb on a 351 C? Not sure if the same carb principles apply with a cleveland port when it comes to boosters?
I have used both but I'm not a carb genious.
I have used a 750 down leg and a 800 Annular.
You are correct the annulars pull sooner and harder. You wont have to cover up a hole in the curve with accelerator pump or power valve timing.
Here my altitude is 4500ft so it might respond differently to where you are.
From what I researched at the time the annulars are better for people who want to run a large carb on a small engine for the reasons I listed above. A carb that is too large will have a big hole in the curve. Some people feel the annulars are a flow restriction but I can't prove that.
At my altitude a straight booster like in a 3310 750 vac secondary works best. Also because of my altitude I tend to run smaller carbs than what might be normally chosen. I woke a cleveland up bigtime going to a 700 dp from a 800 dp on another pantera. Both were downleg carbs.Throttle response change was significant.
The 800 annular worked pretty good after I sorted it but in reality it was too big for what I was doing. It would have been a great Drag race carb.
The Downleg 750 dbl pump was a little better on the bottom but had hic-up I couldn't get out of it.
I ended up not using either carb and went to the 750 vacuum secondary with the straight boosters.
Good luck