Wondering what carbs most are using on stock-ish Cleveland motors..
thanks
John
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quote:Originally posted by micks74:
...I've started running the Eldebrock750 and have had no troubles for 2 years and it installed with minimul adjustments. also, I had an increase in gas mileage by 2 to 3 MPG. ...
quote:Originally posted by Coz:
Holly 750 DP. 72 Primary and 80 Secondary.
quote:Originally posted by DeTom:
Holley double pumper of somekind. Not real sure what number it is. Where does it say????
quote:Originally posted by george pence:
Day in, day out, the right carb for a standard displacement 351C is a 750 Holley (equivalent to a 650 Demon). Vac secondaries will improve fuel economy, double pumpers will improve throttle response.
In times past, the Holley always required tuning to work properly, they were always too rich out of the box, with insufficient accelerator pump for a Cleveland. I've no experience with the new flavors of carb Holley is selling, if any of them are close out of the box, I doubt it however. The message here is, don't expect to buy it, bolt it on & have the motor pull strong at every rpm without stumbles or bogs.
Running a smaller carb is not a cardinal sin however. It will have stronger signal at low rpm, with the trade off being less torque at higher rpm, and the motor will flatten out sooner. The 750 CAN be tuned to pull just as well at lower rpm as the smaller carb.
The 600 cfm street carb is a Chevy camp thing. That's the carb that is always recommended by the magazines for the sbc operated on the street. The sbc is a high velocity motor that weezes through a set of small intake ports. The Cleveland is a whole different animal, Chevy rules do not apply.
In the '70s & '80s, building motors for clients in California meant having to build a motor that could pass visual inspection & tailpipe emission smog testing. I tuned & built several hydraulic cammed motors with power outputs between 350 to 400 bhp using the spread bore Autolite carb (4300D). That carb was rated by Ford at 750 cfm, I'm sure it flows at least the equivalent of a 700 cfm Holley. I have left the 4300D carb on my motor, I see no reason to change it, there would be nothing gained in doing so. This carb is not as adjustable as a Holley or Demon, and the fuel supply system will run out of steam at some point, but installed on a motor with good vacuum signal at idle & cruise, making 400 bhp or less, this carb works OK.
Your friend on the DTBB, George
quote:Originally posted by PanteraDoug:
You have to consider the size of the idle air bleeds and the main bleeds.
What you guys are getting into is as complicated as jetting Webers but you can only increase the size of the air bleeds (air jets) since they are pressed into the carb housing.
quote:Originally posted by PanteraDoug:
I haven't played with the Demons yet. I would say that the Holley is actually more complicated to deal with the the Webers.
It is not really a great comparison. It's like asking if I would rather be eaten alive by a lion or a bear? Thank God dem Emu's don't eats no meats.
quote:Originally posted by PanteraDoug:
You have to consider the size of the idle air bleeds and the main bleeds.
What you guys are getting into is as complicated as jetting Webers but you can only increase the size of the air bleeds (air jets) since they are pressed into the carb housing.
quote:Originally posted by comp2:
...we have been succesfull at getting the these things to run like they are fuel injected...None of this would have been remotly possible without an LM-1...
quote:The Holley has emulsion tubes too.............
OK, everyone finished cussin' now? You just can't change 'em...yet. Yeha!
quote:Your brother is crazier then I am.
quote:Originally posted by johnk:
I ordered my Holley HP 750 DP 82751 from an Ebay vendor last night. Saved an addition 20% off of Jegs/Summit which was very surprizing as they typically have some of the best prices, got free shipping and got a T-shirt to boot!
Thanks all.,, great thread.
quote:Originally posted by PanteraDoug:quote:Originally posted by DeTom:
Holley double pumper of somekind. Not real sure what number it is. Where does it say????
DeTom, there is a number stamped into the air horn on the primary side. The DP's are 4776(600),
4777(650), 4778(700), 4779(750), 4780(800), 4781 (850).
quote:Originally posted by cuvee:
Dont leave out the older 4150-735cfm, from the 390-428 engines.
quote:Originally posted by mikee:
I have a 735 cfm on the shelf and planning to install this soon. What jettings would you recommend on a stock engine?quote:Originally posted by cuvee:
Dont leave out the older 4150-735cfm, from the 390-428 engines.
quote:Originally posted by johnk:
The new carb and accessories arrived today. Man, when Holley says the HP carbs are wet tested, they mean it. Carb was wet right out of the box, and good thing I wasn't looking up the pump nozzles when I winged the throttle on the work bench, pumps were still full and the bowls weren't completely drained. Neat carb with alot of nice features right out of the box. We'll see how well it works..