83ttopgt

I have a mostly stock 302, Longtube headers, Offenhauser intake, pretty lumpy cam (not sure of specs, but it idles like hell) dual exhaust. It has an Edelbrock 500 cfm on it right now, but I was told I should be running a larger carb.

Also the carb has had the choke butterfly removed. What is the advantage of removing it? The car came that way, and starts like $h** when cold, so I was considering replacing the missing parts, but wonder why they are missing in the first place

ACE

someone who was bored decided to take them out haha. My best suggestion is to get a holley 600 vacuum secondary carb with an electric choke.

wildcobrar

I would go 650 Double pump holley. That carb will grow with your combo somewhat if you choose to go better heads and such. Also it can be bumped to a 750 HP style holley carb if you need more carb just by changing the center body.

Joe

my77stang

^ thats the winning post. i chopped my choke horn off of my 600 and gained a bump in power for sure, but it sure is a hard starter when cold even in florida.

83ttopgt

so the choke was pulled to "cover" the small carb prob. I should just get a bigger one that will grow with my motor? What size is recommended for a 347 build? would this size carb be too big for a 302?

my77stang

a 650 is too big for a 302 unless its very radical, but would be a great fit on a 347. if your dead set on going bigger on your 302, look at a 650 vacuum secondary carb not a double pumper.

i removed my choke tower because of the air flow restriction the choke tower has, especially when you have a thin air cleaner assembly.

see?

wildcobrar

Something to think about. Take a 302 with a single plane intake and place a 600 cfm carb on it. Take same 302 and place a dual plane intake on it with a 650 double pump carb. Which engine sees "more carb" at the cylinder?



Dual plane intake takes a carb an divides it in half.

I built a 306 inch 302 with a Ford Racing flat hydraulic cam(220/230@.050 .496 and .509 lift) and home ported D2/D3 heads. Performer RPM intake and less than ideal headers. Dura spark ignition 100 GPH mechanical fuel pump with 9.0 to 1 compression. It had less than ideal 2 inch exhaust. 3.73 rear gears and a T 5 transmission. It was all just junk that had been collecting dust in the shop. Car with driver came in a 3050 pounds. It6 had a 600 VS Holley but felt like it wanted more Carb. So off went the 600 and on went a 750 HP Holley carb. It picked up 4 10ths in the 1/4 mile. Car ran a best of 12.54 @ 108 on engine with 26 inch slicks.

I don't think a 650 to 750 is too big for a 302. Why run the risk of choking an engine when you can go to the high side and tune it to what it likes vs having to just accept the 600 as a bad choice if it turns out to be a choke point on the engine?

An added advantage to a 650 Double pump is it shares the same throttle base plate as a 750 Double pump. When the engine needs to see more carb, the 650 can be bumped to a 750(HP style at that) for about $109.00 bucks. Again an added value and advantage to using a 650 Double Pump holley carb.


Joe

83ttopgt

so I found an edelbrock 650 locally with vacuum secondaries and electric choke. Would this be a good choice?

wildcobrar

It is ok, but the 650 Holley can be upgraded at little expense to a 750 HP Holley style carb when your project grows performance wise. I have messed around with both makes of carbs and I give the Holley the edge in performance and ease for tuning. There are many books out there as well that will help you learn how to repair/tune a holley.

Joe

83ttopgt

I eventually want to run a big holley, but I am going to build my stroker motor first. In the mean time will the edelbrock 650 be ok for the summer? I am more of a holley fan, but I can get the edelbrock cheap, and its in good working order, I can hear it on the car running