Once I got to the cowl area I transitioned back to -08 braided and fed it to the Aeromotive regulator inlet port. Another nice feature of this regulator is a built in 1/8” pipe port that I direct threaded a Ashcroft dampened (not liquid filled, just dampened) gauge that I got from BG Products. I also ran a line from one side of the regulator to an Auto Meter fuel pressure gauge I have mounted on the cowl so I can keep track of pressure at all times. The other outlet port feeds a -08 braided into the -08 braided dual feed fuel line that supplies the 650 Speed Demon carb.

This is the Demon Carburetion 650 cfm mechanical secondary “Crate Motor” carb. The supply line is also from Barry Grant.

A top view of the nicely flowing venturi area shows the attention to detail in the Demon.

Wow, is this a nice carburetor! I selected the Demon carb for many reasons but this thing is a work of art! The IHRA rule book says you must use a generally available Holley TYPE carburetor and my spec sheet says up to 750 cfm. I e-mailed Mike Baker at IHRA a couple of times and he didn’t say I couldn’t use it, so I took that as a yes. Also, Demon pays contingency for Stock so it must be OK.

Originally, I was going to go with a 750 Speed Demon but after a conversation with Scott Witmer at BG/Demon he told me they had this 650 Speed Demon calibrated specifically for the 320 hp/302 crate engine. He assured me that the 650 cfm would be plenty adequate for my 302 and that because of their design the Demons actually flow more than a typical Holley of the same rating. After looking at this thing, I believe it.

The choke horn and venturi areas are blended seamlessly and have down leg boosters. The metering blocks are machined billet instead of cast “pot metal” and the bowl sight

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glasses are clear so no more spilled fuel when checking the float levels—nice! I ordered the mechanical secondary version for racing purposes but a vacuum secondary version is also available.

Another exclusive feature of the Demon carbs is called Idle-Eze. Hidden down inside the threaded bore of the carb that you insert the air cleaner hold down screw is a nifty additional adjustment for idle mixture. Once you have the basic idle speed and mixture screws adjusted for you application, the Idle-Eze allows you to make that last little final adjustment for idle quality and smoothes out the transition point to part throttle. You simply insert a small screwdriver into the hole and carefully turn the Idle-Eze adjuster for optimum quality.  BG/Demon includes very detailed instructions for tuning the carburetor and you also get a video.

In my particular case, I have had to make absolutely zero adjustments from out of the box except for turning up the idle speed. So far I have been out to the track twice and have yet to even change the jetting. I would say Demon got it pretty close! More tuning will be ahead, of course, when we start running in good air, but so far I am very impressed with the Speed Demon carb.

To finish off the fuel system I installed one of BG’s RUSH performance air filter assemblies and wired up the fuel pump with a relay kit from BG. The relay setup will always ensure a full 12 plus volts to the pump and is a nice finishing touch.