Accidently posted this on in the "New to the HAMB section", but thought I might be able to get a few more opinions on the main board. Thanks! I'm running a 307 Chevy in my '51 Buick, and a while back I threw on a 4 bbl 600 cfm Edelbrock. Since I've had that carb on there, it just hasn't run right. The carb was new out of the box. It's always run really rich,so what I figured is maybe I should change out the jets to lean it out? Does anyone know what size jets come with an Edelbrock 600 out of the box (electric choke), and what jet size would best suit a 307 SBC? I'm not really concerned about horsepower, I just want to lean it out a bit. It runs REALLY rich. Even when the mixture screws are turned in all the way it still runs. Thanks! -Julian
if the carb was new, it should have come with a manual detailing rejetting. if you don't have that manual, hit up edelbrocks website and download it. it lists factory settings, and what to change to get to where you want to be.
edelbrock has a pretty good table of the jetting your carb to what motor you have and the elevation you live at etc. i rember calling them one time when i was rejetting my 2 850s on a tunnleram they were more then happy to answer any and all of my questions
If you need that book PM me your addy and i have an extra one that tells how to make changes on alot of diff Edelbrock carbs 500 on up.
You also should check for proper float level settings...I've seen a lot of them that were way too high from the factory. Frank
You have to change jets and rods most times. What you didn't say was, what kind of cam you're running. If the cam is a few notches above stock you may be able to change metering rod springs and cure the problem. And if the cam is stock - or very mild - sometimes a rod change will do it, but it's best to follow Edelbrocks recommendations and swap rods and jets. The altitude you live at makes a big difference as well. I went two steps leaner on the 750 Edelbrock in my 32 roadster when I moved from 350' altitude to 3300' altitude. The whole darned Edelbrock tuning and specification manual is here: http://www.edelbrock.com/automotive/eps_intro.html Order rods & jets and other stuff from Summit. They have a Reno, NV warehouse and the stuff gets delivered pretty fast to my location here in Sunny N/W Arizona, true for California as well.
My buddy is running a 600 CFM Edelbrock Carb (1406) on his 307 Chevy SB, some people are telling him it's to big, what do you guys say.
I'm running a 500 edel in my 28 with a sbf 302. Ran a 600 holley before that and i think i prefer the holley.
Thought I'd put my $0.02 in here with a similar engine size - a 292 Chevy 6. When I first ditched the stock 1-bbl carb, I went to a 600 CFM Edelbrock 4-bbl with plans of building up a real fire breather. Plans fell through and the motor stayed pretty much stock...and never ran quite right despite fiddling with the rods and jets. I moved to a 500CFM Edelbrock and immediately noticed several changes - much improved throttle response, more power from idle to 4000 RPM (which is to say ALL of the streetable rev range of my stock motor), and slightly better economy in around town driving. Overall, it was a MUCH happier motor and simply "felt" like it ran better. Since my 292 is only 15 inches smaller than your 307, I thought it might be a useful analogy.
This might be a bit late. My recent experience with the 1406 carb is that it is a lean carb per Edelbrock. The 1405 is the same carb but richer. Buy the Calibration kit for the 1405 and put in the baseline jets and rods to start. The kits from Summit are under $50.00. The baseline for the 1405 would be: .098 primary jet, Met rods .075 x .047, yellow springs or 4"hg. With the alcohol in the fuel we need to jet 8-10% richer anyway to color the plugs any. T
If it runs with the idle screws all the way in its a needle an seat or float problem. The jets are already lean to keep Al Gore happy. Wastedchildhood
Edelbrocks are touchy when it comes to fuel pressure and seem more so with the 600. Lots of people have battled with they're float's and seats when all they had to do was drop there pressure down to around 4lbs.
My best advice is to call Edelbrock! They are really good with bench talking their carbs. They even send you necessary parts to make the adjustments! Jay
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