Carter/Weber carb size

[JasonB]

I have a Carter/Weber 4bbl carb from a '96-'97 Mercruiser 4.3LXH, carb# 9666S-0837. Anyone have a reference to how many CFM it is? I'm considering an upgrade to it from my current 2bbl Rochester 2GC on my Ford 302.

 

[John_S]

Re: Carter/Weber carb size

96XX is 625cfm. 97XX is 750cfm.

 

[JasonB]

Re: Carter/Weber carb size

Thanks John. that was exactly the info I needed. <br /><br />That seems like a large carb for a 4.3. Oh well, should work nicely on my 302.

 

[John_S]

Re: Carter/Weber carb size

Plenty of carb for a 302. It will need re-tuning with different jets, rods, and maybe springs. Not sure if this was ever used on a ford 302 production marine engine. I thought they mainly used Holley 600cfm carbs, and have seen marine holley 600's with base tuning for the ford 302. If you find that the ford 302 did use a version of the weber 625, would start with those specs. If not, probably the Mercruiser 305 (5.0L) specs would be in the ballpark. The good news is, this carb is probably one of the easiest to tune. And above all else, it is Bondo's favorite carb!

 

[JasonB]

Re: Carter/Weber carb size

I doubt it was ever used on a 302 from the factory. Due to the limited flow characteristics of my stock heads, the 4.3 tune may not be too far off. I have decent hopes for the upgrade since my 2GC is probably no more than 300cfm or so.

 

[Bondo]

Re: Carter/Weber carb size

With My 4.3LX mid90something,...<br /><br />I found the Standard Mercruiser Tuning of the carb to be Extremely Rich,...... That was with 4,1/2" Thru Pipes......<br /><br />I'd Clean it Up,+ Try it........<br /><br />The Tech. Link at Edlebrock,+ 1 of their Tuning Kits,...... You Love it Too........

 

[JasonB]

Re: Carter/Weber carb size

Thanks guys. Now I just need to pick out a manifold. I have a stock cast one off a '66 289, but maybe a new aluminum one would be better.... Freshwater only.<br /><br />BTW, Bondo, could I get your opinion on my Vacuum thread down the page?