Aluminum conducts heat faster than iron does due to the density, but the net result is the same, over time. What is the difference in the casting alloy between origional Carter AVS and the Edelbrock (Weber or whoever does the raw castings).....I don't know but I'm sure its a proprietary blend....at least that's what they want you to believe....but its probably not the common 380-Z diecast alloy. Perhaps its the dimensions of the internal drilled passageways that may effect the percolation issues. The Reid Vapor Pressure (a measure of the volitility index or evaporation index) of the fuel blend (% of ethanol in blend) is an additional consideration.
My comment to C.S.G, was about the overall thickness of the spacer sandwich and the overall effect of the fuel mixture velocity. Does the spacer sandwich result in an "open plenum" under the carb? If it does, this will result in a mixture velocity drop, or decrease, due to the expansion factor related to the sudden change in area. This usually results in poor part throttle response and mixture distribution until the RPM builds to re-establish the velocity speed. Long duration/high lift cams with more overlap, tend to aggravate mixture velocity at low RPM and the open plenum contributes.
If he needed or wanted more carb isolation, why not consider a tunnel ram manifold ?
My intent was to provide a little educational information. Wether he chooses to believe the info, or not, is totally up to him.....I really don't care......
BOB RENTON
