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Best Carb for 302 Ford |
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Bhedbloom 
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Joined: December-01-2004 Location: United States Status: Offline Points: 116 |
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 Topic: Best Carb for 302 FordPosted: July-23-2005 at 11:59am |
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Hello CC Fans,
I think I have too large a carb on my 302 Holman Moody Ford and need some advise. It is a 4160 Holley 600cfm. Would a 450cfm be better for my application? I don't want to lose horse power, but I don't think the engine is burning all the fuel that the 600cfm carb is dumping in. The exhaust has a raw fuel smell. Is that possible? What brand and model carb works best on these older Correct Crafts? Thanks for any and all help! |
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Barry, South Carolina
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Jim_In_Houston
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Joined: September-06-2004 Location: United States Status: Offline Points: 1120 |
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Posted: July-23-2005 at 12:22pm |
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Although I have a 450 CFM on my 289 and I am very happy with it, I think you should be able to set up your 600 CFM carb to perform well. Except for when the accel pump is squirting fuel, the carb does not "dump fuel" into the engine - the engine sucks fuel from the carb. With correct jetting the carb should provide a good air/fuel mixture. Yes, it is possible to get an unburnt fuel smell if things are not right.
Deciding which brand of carb works best is like deciding what color drapes look best in your living room. My advice on carb brand selection: Choose the one you think is pretty. (And that's the truth.) |
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Happy owner of a '66 and a '68 Mustang
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GottaSki
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Joined: April-21-2005 Location: NE CT Status: Offline Points: 3363 |
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Posted: July-23-2005 at 12:25pm |
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http://www.4secondsflat.com/Carb_CFM_Calculator.html
The best advantage of the 600 on a 302 is that at 34-36 mph ski speeds you're still on the primaries so throttle sensitivity can be better than if you have the secondaries partially open with a smaller carb. The 600 can be jetted to work correctly, if you are up for it, its cheaper. Else consider an out-of the box 450 cfm especially if your carb is already quite old. |
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"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."
River Rat to Mole |
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GottaSki
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Joined: April-21-2005 Location: NE CT Status: Offline Points: 3363 |
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Posted: July-23-2005 at 12:26pm |
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Heh, funny timing, similar answers!
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Jim_In_Houston
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Posted: July-23-2005 at 12:35pm |
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Excelent point GottaSki. I have never considered the open secondaries effecting throttle response - makes sense. This makes an argument for a giant 2V carb.
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Happy owner of a '66 and a '68 Mustang
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64 Skier
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Joined: February-08-2004 Location: United States Status: Offline Points: 415 |
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Posted: July-27-2005 at 10:26am |
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I run a 600 cfm and agree with the earlier statement from gottaski. The secondaries on my carb kick in at 4000 rpm so while skiing at 2400-3600 rpm, the engine is only getting 1/2 of the carb rating. Quite a rush when the secondaries open up though.
The H&M will have a mild cam and I own a few performance cams myself and they always smell "rich" due to valve overlap. If she's got a lot of hours on her, maybe it's time for a closer inspection of your internals. A Carb needing rebuild, a leaking exhaust valve etc will cause the fuel to run through he engine unburned. If it's an H&M, and runs well with only a mild exhaust smell...I'd leave her alone. |
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stang72
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Joined: July-31-2004 Location: United States Status: Offline Points: 1608 |
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Posted: August-03-2005 at 3:57pm |
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I had the same question a few weeks ago! I have the same carb as you ( on a 302 also ).After correcting a vacume leek at the carb spacer ...mine is runnig great. I would guess that if your carb is set up properly...it should be a good match for your engine.I am now very pleased with how mine is performing!
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nates78ski
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Joined: January-24-2005 Location: United States Status: Offline Points: 1041 |
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Posted: August-10-2005 at 9:04am |
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Servicing boats for 20 years I would not reccommend choosing which carb you like best. My preference for performance & low maintainance is the Edlebrock "performer" series 600cfm marine carb. Ease of adjustment is a big factor in this selection & power output is not effected. Spend $300.00 @Jegs will get you going.
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Shaughn
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Posted: August-10-2005 at 3:31pm |
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64 Skier, I have read in the instructions which came with the "quick change" secondary diphram spring kit (Holley 600 VacSec) that you shouldn't feel a "whoosh" when the secondaries open. If you're feeling that they should be opening slightly earlier by way of a softer spring. Get the kit, it's pretty cheap. I've got it but haven't had the boat in the water yet,
Cheers, Shaughn. |
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