fun with holleys!!
10-20-2008, 06:29 PM
#1
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Join Date: Dec 2006
Location: Citrus County, FL
Posts: 8,007
fun with holleys!!
just chopped my choke tower off my 4160 600, going to add a secondary metering block and quick change secondary spring cover. i'll throw some pics up when im done cleaning it all up tomorrow, but i just wanted to share my fun for the day
10-21-2008, 03:15 PM
#2
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Location: Citrus County, FL
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figured i'd post the pics, even though nobody seemed interested. for what its worth between the lighter secondary spring, the secondary metering block, and the choke horn removal i went from a slight bog from idle when stomping on it in gear to spinning the tires in a straight line with no brake torquing.
consider my 600 officially "pimped" lol
consider my 600 officially "pimped" lol
10-21-2008, 09:42 PM
#4
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Location: Citrus County, FL
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not too hard, just used the dremel tool with a small cutoff wheel attachment and the little barrel roll sandpaper things. took like 3 or 4 cutoff wheels to do it all, and you definately have to take the carb apart to clean it when your done - but all in all it was just a little bit of time is all and its basically free hp
10-22-2008, 12:18 AM
#8
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Join Date: Sep 2008
Location: CA
Posts: 715
You can simply just remove the choke butterfly also, it does help. Personally I like having a choke since I live in Norcal where it gets pretty cold in the winter. Nothing better than getting in, pumpin it once, and gettin on down the road. Nice job with the cutting though, definitely better for a race application versus a street one. Also, I'm kindof surprised to see someone putting so much work into a 600 vacuum secondaries carb. I'm a double-pumper kinda guy myself.
10-22-2008, 09:25 AM
#9
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bw, driving this thing on the street i believed a vac sec setup was the way to go and would help prevent overcarbing the motor since the secondaries will only open when the motor needs it.
i cant really offer a step by step tutorial, but heres a few pics of where i cut and the tools i used to do it.
you have to leave the vent tube and the threads for the air cleaner screw, so just cut around it with a small cutoff wheel. then use 1/2" and 1/4" round sanding drums to clean everything up and smooth off any sharp edges using the following tools.
lastly, take the bowls and metering blocks off the carb and clean to remove all traces of the metal shavings that will be all over every damn thing. this is a great excuse for you to go thru your carb anyways, you know you've needed to for awhile now. you should only need 1 or 2 metering block gaskets and 2 bowl gaskets which are available at most autoparts stores and are very cheap.
the point of all this is to improve airflow. proform sells a carb main body replacement for the 750's and claim 25-50 hp depending on application. i wont claim that kinda gain, but i bet its worth 10-20 on a mildly modified motor.
here is a very crude drawing to show what the air flow restriction looks like with a drop base aircleaner like alot of you may have due to hood clearance issues and the choke tower blocking the airflow.
i cant really offer a step by step tutorial, but heres a few pics of where i cut and the tools i used to do it.
you have to leave the vent tube and the threads for the air cleaner screw, so just cut around it with a small cutoff wheel. then use 1/2" and 1/4" round sanding drums to clean everything up and smooth off any sharp edges using the following tools.
lastly, take the bowls and metering blocks off the carb and clean to remove all traces of the metal shavings that will be all over every damn thing. this is a great excuse for you to go thru your carb anyways, you know you've needed to for awhile now. you should only need 1 or 2 metering block gaskets and 2 bowl gaskets which are available at most autoparts stores and are very cheap.
the point of all this is to improve airflow. proform sells a carb main body replacement for the 750's and claim 25-50 hp depending on application. i wont claim that kinda gain, but i bet its worth 10-20 on a mildly modified motor.
here is a very crude drawing to show what the air flow restriction looks like with a drop base aircleaner like alot of you may have due to hood clearance issues and the choke tower blocking the airflow.
10-22-2008, 10:01 AM
#10
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Join Date: Aug 2006
Location: North East Texas on the Red River
Posts: 886
On a race car, removing the air horn allows air to more easily flow into the top of the carburetor. It will also do the same thing on a steet car, but.......
.......on a street car from which long engine life is desired, removing the choke is very unhealthy for the engine. Without a choke, you have to pump the accelerator on cold starts to squirt some raw fuel in for startup. This raw fuel dillutes the oil on the cylinder walls RAPIDLY wearing the cylinder walls, pistons and rings.
Several years ago I bought a phenolic gadget that slipped over the top of the carburetor to funnel in air. It works REALLY well and allows you to keep the choke. I don't know if they are still available and I don't remember what they are called, but it would be a GREAT compromise for a street car.
.......on a street car from which long engine life is desired, removing the choke is very unhealthy for the engine. Without a choke, you have to pump the accelerator on cold starts to squirt some raw fuel in for startup. This raw fuel dillutes the oil on the cylinder walls RAPIDLY wearing the cylinder walls, pistons and rings.
Several years ago I bought a phenolic gadget that slipped over the top of the carburetor to funnel in air. It works REALLY well and allows you to keep the choke. I don't know if they are still available and I don't remember what they are called, but it would be a GREAT compromise for a street car.