Carb size

[smallblock]

Looking for suggestions on a good carb for a mild built 318. It has a completly rebuilt set of 302 casting closed chambered heads with stock valves, cam is .477-.480 if I remember right. Roller rockers and a Weiand X-celerator intake. Headers and 2 1/2 exhaust with flowmasters. For now I have one of those cheap chrome 600 hollyes from Allstate Carburetor that I got off ebay( dont know if anyone else has seen these or not) just so I could drive it for awile. It dosent seem like it is even close to being enough carb when I get on it ( even in a 318 )and if I park on even a slight hill its very hard to start. Lately it wants to load up while ideling, ive adjusted the mixture several times and it still runs real fat. You cannot adjust the float level on these. Anyways now I need a real carb but dont want to go to big and wash the ring out of the thing but have enough when I need it. Any suggestions? Want to stick with a holley also.

[mopardave]

both holley and edlebrock have a complete listing by applications on the website, you can plug in the info and it will suggest the carb size for your application.

[Chryco Psycho]

650 is as large as I would go to on a warmed 318 , it soulds like more of a tuning issue or a problem with the carb you have now , the new Avanger series could ba a good choice for you

[MEK-Dangerfield]

The smallest Street Avenger carb Holley makes is 670 CFM, but if you are willing to spend the money, that's a good choice. It has some nice features, and we are here if you need any tuning advice. Generally they run a tad rich right out of the box.


  Mike

[Chryco Psycho]

Not true Holley has a 570 Avenger I have used on 318s before

[71chally416]

The size of a carb has nothing to do with "Washing the rings out".  The calibration does. The old standard Holley 3310 or any of the clones should work OK but my choice on ANY SB Mope is the carb many of them came with, including some 318's, the Thermoquad. Failing that, the other carb they came with would be my choice, the AVS (Thunder series Ed carb) that bolts on a square flat Intake. If the 318 was all stock with stock exhaust I'd stay small, but with your mods I'd go bigger. You find on the engine dyno a seemingly "too big" carb never hurts hp. It just flattens out the TQ curve and helps the car move down the track better. BTW, every single fast SB Mope you'll see racing stock and super Stock has a Thermoquad on it. They have to use the stock part # carb that came from the factory. None used Holleys from the factory but the 6 pak cars. 

[Bluemonster71RT]

I had/have a 670 Street Avenger on my 383 and It needed bigger jets. Once added I found it better than the 4150 I had. So a stock 670 might be good for your 318. CP how does the 570 run at WOT on the 318? No starving?

[Chryco Psycho]

seems fine although the engine is stil new & a bit tight to pin it to redline yet

[femtnmax]

For my Edel 650 AVS on the old Ford 416, I adjusted for elevation using the book they give you.   STill ran way too rich.  So I bought the Edel o2 sensor, just the cheap one with a half dozen lights to tell you the mixture.  Worked great.  Was even able to dial in the transfer slot mixture.   Well worth the investment  IMO.  Now I can use it on my dodge when its up and running.

[smallblock]

Thanks for the info. Started thinking about the X-cellerator intake I used ( because I already had it ). Its a single plane intake thats pretty tall. Will that make it bogg and stumble also? Timing is dead on, the throttle response is incredable when just reving and not under a load. Once the car gets past its initial bogg it has plenty of power. Acc pump is working as it should also.

[71chally416]

Don't know that anyone has ever went fast with one of those Intakes on a Mope. For whatever reason(s) when in mild form small block mopes like yours they like dual plane Intakes. I would bet that even a cast iron 4 bbl Intake would give you a better ET at the track than what you have now. The best choice IMO would be the old ED dual plane made specifically for the 318 that had the Chrysler part # on it. The newer EDs like the RPM AirGap have the bigger port size for 340/360 heads. There's one on Ebay right now>
http://cgi.ebay.com/ebaymotors/EDELBROCK-LD4B-340-dodge-cuda-intake-manifold-mopar_W0QQitemZ180341559475QQihZ008QQcategoryZ46098QQssPageNameZWDVWQQrdZ1QQcmdZViewItem