Author Topic: increasing cfm?  (Read 1613 times)

Offline 70burntorangeT/A

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increasing cfm?
« on: May 15, 2011 - 01:14:46 AM »
i was told that instead of buying a bigger carb that i can get a bigger bottom plate and bigger jets and make my 600 an 850. Is this true or does this guy not have any idea what hes talking about?
66 f-100 black  240 straight 6  3 on the tree.....currently blown up :(
70 challenger burnt orange 440 727 3:23-weekend cruizer




Offline MEK-Dangerfield

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Re: increasing cfm?
« Reply #1 on: May 15, 2011 - 03:54:57 AM »
If we are talking Holley's here, I would think you would need to swap out the main body too. The metering blocks and fuel bowls would be the same.


EDIT: I did some checking, and it appears the 650 thru 850 have the same body. I'm not sure about a 600.
« Last Edit: May 15, 2011 - 05:30:02 AM by MEK-Dangerfield »

Mike

1970 Challenger - SOLD
2016 SXT+.  1 of 524 SXT+'s in Plumb-crazy for 2016.

Offline 72cudamaan

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Re: increasing cfm?
« Reply #2 on: May 15, 2011 - 09:22:54 AM »
 :popcorn:
If I cant fix it, it's broke
 
Andy  (phukker whither)

Offline Cooter

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Re: increasing cfm?
« Reply #3 on: May 15, 2011 - 09:48:53 AM »
One can increase the CFM rating a little but NOT BY THE SIZE OF THE "Butterflys"(Throttle valves) in the base plate if we're talking Holley here. The size of the holes in the main body determine CFM rating of a Holley carb and any other as far as I know...No way to increase CFM rating other than removing the choke horn and assy., but this doesn't seem to be popular with this croud...Doing what your "Buddy" says would be like installing 2.25 In. and 1.880 Ex. valve in a set of heavily ported "915" heads and still running the stock exhaust manifolds. Kinda like taking a shower with your rain coat on, or Screen doors on a submarine...
« Last Edit: May 15, 2011 - 09:52:40 AM by Cooter »
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Offline 70burntorangeT/A

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Re: increasing cfm?
« Reply #4 on: May 15, 2011 - 10:39:33 AM »
so just buy a new carb
66 f-100 black  240 straight 6  3 on the tree.....currently blown up :(
70 challenger burnt orange 440 727 3:23-weekend cruizer

Offline MEK-Dangerfield

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Re: increasing cfm?
« Reply #5 on: May 15, 2011 - 03:55:32 PM »
Is this carb on your Challenger? If so, even if your engine is stock, that is something I would put on a 318. You have much to gain by going bigger. I have an 850 on mine, with a carb spacer. Chryco says I'm probably near 900 with the spacer. I'll just say it feels like it.   :burnout:  The top end is a whole lotta fun.    :naughty:

Mike

1970 Challenger - SOLD
2016 SXT+.  1 of 524 SXT+'s in Plumb-crazy for 2016.

Offline MEK-Dangerfield

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Re: increasing cfm?
« Reply #6 on: May 15, 2011 - 04:55:36 PM »
My 1 barrel carburetor flows 1212cfm!  :2cents:   :lol2:

That is a sight like I have never seen before.   :wow:

What is that carburetor?

Mike

1970 Challenger - SOLD
2016 SXT+.  1 of 524 SXT+'s in Plumb-crazy for 2016.

Offline shadango

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Re: increasing cfm?
« Reply #7 on: May 16, 2011 - 07:31:08 AM »
Nothing is impossible! 



Offline HP2

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Re: increasing cfm?
« Reply #8 on: May 16, 2011 - 09:44:01 AM »
Anyone remember the Predator 1 bbl, variable venturi carb? Rated from 600-900 cfm, based on engine demand with no jets or power valves, they were supposed to be the shiznit back in the late 80s, early 90s.

Evidently they are still around; http://www.predatorcarb.com/performance/carburetor.html