| 450 hp on a NA motor just with these carbs... This seller should put out the crack pipe. (Where is the blower or turbos) Why would someone want to emasculate a Z with its efficient and elegant fuel management system for this "stone age setup". Carbs (especially Holly) are wonderful pieces of engineering when used "properly" and can even rival EFI in terms of hp. Each of these carbs are Holly 500cfm (cubic feet per minute) carbs that makes a total of 1000cfm. Cool if your feeding a well sorted rat motor with cams etc. As far as I remember the Holly 4 BBL Dominator is a 1000cfm carb and is too large for a 350ci small block ~ 5700cc. And when tuned only has 2 effective throttle positions: Closed and wide open. This shit wont work on a 2960cc engine and be drivable for the following reasons - I'm sure there are more: Lets put this carb sizing in Z context. A NA 2960cc engine needs to flow 383cfm @ 7000rpm (that's presuming 100% volumetric efficiency!!!) 1. This is a common plenum intake. Both carbs feed into one large common plenum. Potentially this the best setup for hp on a big-block but it kills intake charge velocity unless you can move serious amounts of air like a 454ci motor, which the VG30DE is not. 2. This common plenum setup also has the most appalling fuel distribution between the cylinders. Remember the intake charge in a carb system is wet with gas which does nasty stuff like condense out of the charge in areas of low pressure in the intake system. This effect in my opinion would be amplified due to the "Look daddy, what I made in shop today" design. 3. Efficient carburettor operation relies heavily carb sizing. If the venturi cross-sectional area is too large (as they would be in this case) then the venturi air velocity is too low to suck the fuel through the metering jets into the air stream in the way it was intended by the designer. Perhaps with a month of "messing" with emulsification and main jet sizes, a Z engine might even run at one throttle position. 4. Change the throttle position and here are more problems. Acceleration mixture tuning would be f*&%^$g hell. Imagine you have this setup and you have "managed" to get it to idle, if you were to nail the gas, on opening the throttle, the intake manifold vacuum would go to ZERO, the venturi air velocity would be pissy and would lead to an extreme lean mixture condition (liquids have inertia). Carbs use an acceleration enrichment cam operated pump to squirt gas into the venturi when the throttle is suddenly opened to overcome this, but in this setup I doubt that any cam available for the holly carbs would be big enough. 5. So far we have an unstable air/fuel ratio that always tends to lean whenever the gas pedal is pressed. This this will cause the most wonderful intake manifold backfires. This is not an issue with Fuel Injection as the air in the intake tract and plenum is dry. Holly carbs use a manifold vacuum driven high speed/load enrichment valve that a good backfire will blow as far as mars. 6. Idle! Again carb sizing will mess this up. You could end up with the air adjustment screws turned fully in and still be idling too high. I've seen this on a Buick 215ci ~ 3500cc engine with ONE Holly 650cfm carb. 7. It would just be pissy..... That's my 2 cents...
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