Scored a new carb for my 302, now a question

[JasonB]

By some luck, i scored the carb I have been looking for the last couple years. I have a mildly built 302 Mercruiser 888 with the factory 2bbl Rochester. The carb i have purchased is a 450 or 600 cfm Ford labeled Holley 4160 marine from a 1973 Mercruiser 225 which was a 302. Outside the obvious need for a new intake and flame arrestor, anyone know what I will need to do to get the throttle linkage and fuel connector to hook up?<br /><br />Hopefully this change will help wake my engine up a bit.<br /><br />This carb has factory manual choke whuch I want to convert to electric. Anyone ever install one of Holley's conversion kits?

 

[Boomyal]

Re: Scored a new carb for my 302, now a question

JasonB, I'm going from a stock cast intake and a 2 bbl Holley to an Edelbrock 2121 Performer and a Holley 4160 4 bbl marine. As the previous carb was a Holley I think my carb linkage is similar. My problem is going to be with the mounting points on the intake manifold. They are not the same on the Edelbrock as they were on the factory.<br /><br />I think I will have to fabricate some kind of bracket. You may have it a little more difficult as you changed brands of Carbs as well.<br /><br />Additionally, my stock manifold had mounting points for the two big main harness connectors that the Edelbrock does not have. I'm a ways out yet to have to figure it all out. Just think fabrication.

 

[JasonB]

Re: Scored a new carb for my 302, now a question

Anyone know the exact specs of a Holley #6576? Such as actual CFM, and teh CFM of the primaries?

 

[Don S]

Re: Scored a new carb for my 302, now a question

Can't answer your question, but you might find some information below.<br /><br /> holley.com<br /><br />PS: Be sure it's a Marine carb, not an automotive.<br /><br />

 

[snapperbait]

Re: Scored a new carb for my 302, now a question

Jason.. If you have a dial caliper, or other way to get an accurate measurement of the throttle bore diameter and/or the venturi bore diamter, you can determine the cfm rating..<br /><br />Measurements listed in my Holley book for 4160's are as follows:<br /><br />On a 450cfm, the primary venturi bore would be 1 and 1/16"... The secondary venturi would be 1 and 3/16".. The throttle bore would be 1 and 3/8" on the primary, and 1 and 7/16" on the secondary..<br /><br />on a 600cfm, the primary venturi would be 1 and 1/4", and the secondary would be 1 and 5/16"... On the 600cfm, both the primary and secondary throttle bores would measure 1 and 9/16"..

 

[JasonB]

Re: Scored a new carb for my 302, now a question

Thanks Snapper. I know where I can get my hands on a caliper.<br /><br />Don, it is definetely Marine. I wouldn't have bought it otherwise.

 

[qaztwo]

Re: Scored a new carb for my 302, now a question

I converted my 351w from a two bbl to a 4. instead of buying a new throttle bracket and all the hardware that goes with it I took a small piece of sheet metal maybe 3x4 inches and bent a 90 degree lip on it and bolted it where the engine lift eye is bolted on the intake manifold. I also removed the shaft from the old throttle bracket that the throttle linkage mounts to and mounted it to the piece of sheet metal. Works perfect. As for the fuel line you could always bend some tubing to fit, I was going to do that but in the end I bought a brass barb fitting with some fine threads on it and cut one of the bards off. Used some 3/8 fuel hose from napa to run from the separator to the carb. <br />Good luck.

 

[tommays]

Re: Scored a new carb for my 302, now a question

Used some 3/8 fuel hose from napa to run from the separator to the carb. <br />Good luck. <br /><br />qaztwo<br />i hope you luck holds up thats not the best plan for a fuel line

<br /><br />tommays

 

[JasonB]

Re: Scored a new carb for my 302, now a question

Thanks for the info qaztwo. Not sure I want to use that fuel connection, but hoping I can adapt the existing one or get a new metal line fabbed up. Oddly, teh factory used a short section of rubber hose to go from the copper line from the tanks to the separator....Gotta replace that too.<br /><br />Good thinking on the throttle bracket. Holley makes something almost identical to your descriptiona nd charger $30 to $40 bucks for it.

 

[qaztwo]

Re: Scored a new carb for my 302, now a question

They due make rubber fuel hose that is uscg approved. I just don't like metal fuel lines, they conduct heat to well.<br />Good Luck