Carb Spacer ... is it needed ??

I have just got a shiny new speed demon 650 carb with mech secondaries which I will be installing in the morning. The present set-up is a 600 holley on a weiand stealth manifold, but has a half inch edelbrock wooden spacer. Should I use this with the new carb, or am I better just plonking the carb straight onto the intake m/f ?? (with a new gasket of course ;) ) Also I am running an MSD set up with a vacuum advance on the distributor. With this new carb would I be better removing the vacuum advance and going just mechanical ??
Any advice gratefully received.
 
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Leave the spacer.

It insulates the carb from the heat of the motor. It also helps increase power with the pattern of the opening determining if you will see a small gain in torque (4 hole design) or upper RPM power (open design). There is a lot, and I MEAN ALOT more tech to it than that, but I just boiled it down to try and get the point across in less than 100,000 words. :)
 
I can certainly understand the physics involved related to separating the carb body from the heat of the engine, thus causing a cooler and denser charge...

But, I suppose my concern is what type of spacer should be used? A Weiand Stealth is a dual plane intake, right? If you have an open spacer, doesn't that sort of defeat the purpose? Wouldn't a ported spacer (4 ports or 2 oval/dual planed) be better?
 
you don't want to run an open spacer with a dual plane intake. i tried both open and split (2 oval openings) with my Performer RPM and Edelbrock carb and found the split spacer was a couple of tenths quicker in the 1/8th mile. made a lot better low end torque as well.
 
69PaleHorse said:
I can certainly understand the physics involved related to separating the carb body from the heat of the engine, thus causing a cooler and denser charge...

But, I suppose my concern is what type of spacer should be used? A Weiand Stealth is a dual plane intake, right? If you have an open spacer, doesn't that sort of defeat the purpose? Wouldn't a ported spacer (4 ports or 2 oval/dual planed) be better?


The spacer is one with 2 oval ports which I think is the correct one for the intake .... which is a dual plane type.
 
I dont see how a thin open spacer on top of a Stealth or RPM manifold would hurt anything. The RPM air-gap has a notch in the divider that does the same thing that a thin open spacer would do, minus the insulating ability of the spacer of course.
 
Agreed, but that notch is only like an 1/8 of an inch deep, and does not cover the full length of the divider. IIRC, it is only the last quarter of the divider where the secondaries would squirt. So for the most part, there would be no 'cross-over' (for lack of a better term) between the primaries. Put in an open spacer, even a thin one, and it changes that - thus making your induction act more like a single plane.
 
putting a carb on the intake without the spacer would present a few problems. Here are some reasons why you need a spacer. #1. It keeps the heat from the engine from boiling the fuel in the carb. #2. cooler fuel is always better, denser, atomizes better. #3. A spacer moves the carb up higher which provides a straighter, longer, faster, charge into the combustion chamber when the intake valve opens. All this equals better throttle respone, more torque, fuel efficiency. thanks

Jimmie