a few months ago my dad and I picked up decent 49 ford coupe. the engine came equipped with Holley 600 cfm vacuum secondary 4 barrel carb. personally I think it's too big for the engine, but this is the first flathead I have worked on. what I know the engine has, Block is 30 over, cam I don't know specs, but it sounds far from stock, headers & dual exhaust, Edelbrock heads & Intake .I do know the heads & intake are pre 2007 what would you guys recommend is the best 4 barrel carb for this engine
I had a 390 CFM Holley on a 276" Merc with all the regular speed stuff (finned heads, cam, headers, and an MSD ignition) and it was just fine. The one thing you didn't mention is what kind of ignition you have. If you still have the stock loadamatic distributor, the only carburetor that will work is the stock one that came on the car. The distributor and carb work together in a unique way that cannot be duplicated with any other carb. If this is the case, get your ignition situation straightened out (with either an aftermarket or modified SBC distributor) or just go back to the stock carb and intake. All of that notwithstanding, I would think that a 600 on a close to stock flathead is too much carburetor.
i'm unsure about the distributor, I don't really know anything about it but here is a pic from what I have been told it has been in it's current configuration for at least 15 years (minus the pertronix electronic ignition)
that's the loadomatic. as tubman said, it's only good with the stock 2 barrel. the 600 is way too big. a general rule of thumb is to multiply your engine's displacement by .75 to get your carb size. that 390 holley or 2 two barrel carbs is all that's needed on the majority of flatheads. your +.030 engine would be about 245" and would need around 190 cfm. the 390 holley will only use half its cfm rating most of the time since it runs on the primaries until you goose it...
Also to clarify. The problem the loadamatic presents with a non-stock carb is not the quality of the spark, but the timing of it. Thus, the installation of the Pertronix unit, while probably well-intentioned, is of really no help. A quick search of this board will yield all of the information you will need to correct the problem.
Times whatever on the Holley 390 and dizzie change. I have the MSD plug and play and have to remember to "not hold the key on Start". It fires that quick.
Come back and let us know how everything turns out. Do me a favor, though. Could you change your avatar? The current one creeps me out!
In 1964 I used a Rochester 4 jet on my 53 Merc motor. Can't remember what I did for a distributor but it ran great.
I use a Briggs and Stratton side draft on my flathead and my plugs are still black. guys think carbs are like ***s. Bigger isn’t better. okay, I lied.
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