Help Choosing a new carb

[Anonymous]

Hello, im new to this forum, my name is dave and i have a 73 comet with a 250-1v i wanted to know if anyone had an idea of a new carb and intake that would be a good application for street use but be fast when i need it to be.preferably a 2 or 4 barrel. i also dont want to lose alot of gas mileage. and does anyone know what the stock cfm's is on this vehichle. thanks.


~Dave

 

[ochretoe]

I went with the weber 32/36. 1 barrel most of the time 2 barrel when I need it. It get comperable to a little better gas mileage than mu carter 1v did. Others will have more options and probably better ones.

 

[BaldEagleMav]

Hi Dave,

I'd like to support the recommendation of a Weber carb, but would like to propose a smaller, cheaper version - the Holley-Weber 5200 progressive 2 barrel.

I also have the 250 engine and the C4 automatic tranny in a '73 Maverick.

I bought my 5200 from Tom Langdon at Stovebolt Engine Company. Tom's company caters to inline 6 Ch*vy's, but he has been great to deal with for my Ford 6.

The stock Carter RBS is rated to flow around 170 cfm - the H-W 5200 is rated to flow around 215 cfm - a 25% increase.

A rebuilt 5200 from Tom runs around $85 with an electric choke. Tom also sells an adapter to go from the 2 bbl carb to the 1 bbl manifold. The adapter was around $15, if I remember correctly.

The primary barrel of the 5200 is smaller than the barrel of the Carter, so you can expect better fuel mileage if you can keep your foot out of the secondary. I can really feel the kick when the second barrel opens - it's a lot of fun!

I had to do a little fabrication to get the throttle cable to connect up to the 5200 - but it wasn't too challenging.

I am actually working on my own adapter and a new throttle connection, but I successfully used the adapter from Tom for over a year - and very happily.

If you talk with Tom beforehand, he will ensure that the jetting for the carb and the throttle connection are correct for your car - he did so for me.

Regards - and good luck,

 

[BaldEagleMav]

Hi Dave,

Sorry, I meant to mention that the intake manifold on the 250 (and all small Ford sixes) is cast into the head - so you can't change the intake.

Well, you can if you're up to a LOT of fabrication, cutting off the original manifold, machining some sort of a mount, and making up a new manifold.

AzCoupe is working on a new head, in case you want to wait for that!

Again, regards,

 

[CZLN6]

Howdy Dave:

The Stock Carter RBS is rated at 215 CFM.

Holley/Webers range from 235 to 270 cfm depending on application and year. All will require an adapter or adaptation. Adding an adapter will likely cause hood clearance issues.

Tom Langdon's adapters are for Chevy 6s and require slight modification to work on our engines.

Another option is to use an adapter from Clifford's to mount an Autolite 2100 or a Holley 2300. The Autolite two barrel comes in a variety of sizes ranging from 287 cfm for the common 1.08 to 351 cfm with the 1.21/1.23 commonly used on 351 ci V8 engines.

We've found the 1.21 Autolites to be very adaptable to 250s. Autolite 2100 have an annular discharge venturi booster which makes for a little nicer driver. They are a very simple, easy to work on and durable carb.

Ideally, any carb upgrade to a two barrel is best done by modifiying the log to accept the direct mount of the two barrels. This eliminates the funnel of the adapter and reduces hood clearance concerns.

I hope you've already optimize your initial advance setting for mileage and performance.

Adios, David

 

[BaldEagleMav]

Hi David,

Thanks for correcting my error!

And Dave, my apologies for making it.

I knew there was a 215 cfm in there somewhere - I just had it backwards! The stock 1 bbl flows 215 cfm and the H-W 5200 flows 25% more.

Regards,