Carburetor information

[tcooley]

I am having some carburetor problems and was looking at replacing the stock carburetor. I have a 5.0 220hp in my Tahoe 204WT. I know a four barrel is not going to give me that much more HP. I was wondering if anyone knows what the CFM is of the stock carburetor?

 

[achris]

Do you have an engine serial number. And what is the current carb (2 bbl, mercarb?)

To put a 4 bbl on will mean a new manifold too. Recommended 4bbl carb is Edelbrock 1409.

Chris......

 

[tcooley]

What I have found is that it is a MerCruiser 866142A04 carburetor. I was under the impression that a four barrel was only going to give me about 1 to 2 mph more.

 

[achris]

Yeah, the 4bbl is 'worth' about 30 to 40 hp, and that usually does end up being only a few knots on the top end. Unless you're speed racing, it's more often than not, not worth the extra expense.

There are quite a few carburetor exchange places that are good value for getting a good carb. You have the number, and that makes the whole job a heap easier.

Chris..........

 

[Scott06]

I think the mercarb is about 300-350 cfm.

 

[tcooley]

Thank for the information. I that is was about a 300 CFM. Would a 500 CFM be good or would it be to much CFM?

 

[Rick Stephens]

If you up the carburetor, you should use the 600 CFM Edelbrock 1409. That motor is right in the sweet spot for that carburetor. I have one on my 4.3L V6. In my opinion that smaller motor can't quite use the last 25% of the CFM capabilities, but I seldom, virtually never, open the secondaries except to pull something needs all the motor I can get. The 1409 is the easiest to work on, simplest to calibrate and best made carburetor for this general size motor, 4.3L up to 5.7L.

Also consider an Edelbrock Marine Performa manifold to go underneath.

 

[tcooley]

What manifold fo you recommend with the Edelbrock 1409?

 

[Scott Danforth]

a marine 4-barrel manifold such as the 2506 for older motors https://www.summitracing.com/parts/e...EaAgIzEALw_wcB

or the 2516 for vortec heads https://www.summitracing.com/parts/edl-2516