LS 80Vette

I have been struggling with this since the beginning of this engine set-up, at the moment I have an 800 Edelbrock, constantly burns rich, also it shows on the plugs, they are black and wet with a gas smell. I have contacted Lars for his papers on timing and carb adjustments and this was his response.

"Timing papers attached. I do not have any papers covering the Carter AFB carb (aka, "Edelbrock Performer"). We don't have much luck with those carbs, so we don't do any work on them or use them on any customer engines. Have you considered going with a Q-Jet or a Holley-based platform (I.e. QuickFuel, Proform, Demon, Holley or AED)?"

I value his comments, he does know his stuff....

This is what I have :
1. 383 stroker
2. Edel. Performer RPM air gap 7501
3. Edel. Performer RPM camshaft 7102
4. Edel. Performer RPM head 60889
5. Hooker super comp. side mount headers......soon to be Stan's Tri-Y headers, and PYPES 2 1/2" exhaust w/X-pipe, w/race pro mufflers
6. 700R4 stage 3, from Bowtie overdrives
7. 2400 stall converter
8. 3.70 rear end
9. mostly normal driving and some spirited driving ( when conditions allow ).
when I first got this set-up I was planning on taking it to the track and such, but now that I am older and not in that " mid life crisis " anymore, I just want to drive and enjoy it and not have to smell like gas fumes anymore...so...Which carb would be best for this set-up.... Model and size ...... Thanks in advance

terrys6t8roadster

800 cfm is to big. 750 is marginaly to big but can be jetted correctly to work nicely. the q-jet on a 350 is a 650cfm. a bigger cfm carb increases air flow for higher rpm and quicker acceleration if you have the cam and head flow allowing you to dump more fuel and air into your 383cid . I agree with Lars about the Holley platform,every speed shop carries parts for fine tuning. a friend with a 383 told me he did some research and came with the recommendation of a 735cfm. as always double pump, dual feed, mechanical secondaries. electric choke since you live in a cold place might be nice. good choice on top end stuff. PS you'll like the PYPES system

427Hotrod

A Holley 750 Street HP would do fine. I've used them out of the box on the dyno and on the street and tune is about dead on. Much leaner for street cruising than a normal 750 double pumper.

JIM

bluedawg

Holley 750 of 780 ultra hp.

FKING1

I run a Holly 750 Double Pumper on my 383, but, autocross the car,
My suggestion is a regular Holly 750.

Bagmup

I don't agree with putting a double pumper on a street driven auto car.

MotorHead

That's good to hear, anyway just get a Holley 4779 750 DP with mechanical secondaries, that's the grandaddy of all Holleys and not expensive and runs good with little tuning, it's a hot rod, I start mine up on a cold day and drive it first gear or second around 1500RPM and it warms up in a couple of minutes or if you have good neighbors just sit there with your foot on the gas for a couple of minutes

diehrd

Quick fuel 750 vac .. way better then Holley , Easier to tune and just all around a better carb . Now that's not to say a q-jet is not a great carb .. But if your looking for a aftermarket carb,, quick fuel is the deal.

bluedawg

I don't have any issues starting or running my double pumper carb, its got no choke or fast idle warm up cam in the carb, but only takes a few minutes until it will idle on its own. It's a myth that a double pumper doesn't work on a street driven carb.

scottyp99

And this is coming from a guy who lives in Alaska! Brrrrrrr!!

Anyway, I think this is the part of the post we should be paying attention to:

"When I first got this set-up I was planning on taking it to the track and such, but now that I am older and not in that " mid life crisis " anymore, I just want to drive and enjoy it and not have to smell like gas fumes anymore."

A vacuum secondary carb may be the way to go, here. Have you considered shopping around for an old Holley 3310 (vacuum secondary 750cfm) and rebuilding it? They made about a gazillion of them, you could probably find a good rebuildable one for 50 bucks, and throw a rebuild kit into it.

Scott

glen242

I am using a Lars tweaked Q-Jet on my 383 with Performer RPM intake, TF 23* 64cc heads on a '0' decked block, CC XE274 hydraulic cam, long tube headers into a chambered 2 1/2" exhaust system

edd gordon

I've run Holley Avenger 670 on My 406 ran lean enough and got 17mpg. Also same engine used a Quadrajet that I built and ran fine also. There are so many choices to make on Carbs that I don't think anyone can tell You that one carb is better then the other. Until You dino the engine I personally think it is a crap shoot which carb You choose.

LS 80Vette

Thanks guys, I guess a 750 would be the best and I could always tweak it down a bit if I need to.

427Hotrod

No need to tweek it down. It's the most universal carb ever made. The Street HP will run great. I used one on a 400' and made 555 HP without touching it on pump gas. Idled clean.

It's currently on a pretty healthy 388" in a '65 and he loves it.


JIM

cv67

prefer the newer hp series they have all the adjustable air bleeds etc that the cheaper/older carbs dont. To me its not worth rebuilding an old carb anymore by the time you buy the kit cleaner, your time then fooling wiht it constantly trying to perfect it coulda just paid a little more and got one thats spot on or real close right out of the box. Those extra features can really make a DP carb enjoyable.

drwet

I have a very similar setup. 383, 700R4, RPM Air Gap, 2500 stall convertor, 3.55 gears. I run a Holley Avenger 770. Awesome carb. Bolted it on and ran it for years without touching it. Hooked up an air-fuel mixture guage last winter and it turns out the carb runs a little rich (12.5-13.5 range), so I'll be playing with jetting, but I can't imagine the car running any better.

gkull

You don't have much in the way of advice here. Edelbrocks like yours are rich out of the box and made for bigger ci motors. VS carbs can be much bigger and not suffer drivability problems. Because they are an on demand CFM. The secondary's don't open unless the vacuum rises.

Your second saving grace is your dual plane having a split plenum. So each side only sees @ 400CFM max

So your size is fine. I ran Edelbrock on my vette for 10 years. You just need to learn how they work. First off I would read the manual about how to drop the idle and cruise AF ratio 6%. Then you can fine tune it by doing the math of flow area of the jet minus the area of the rod. Use online calculators for area. They sell the spring kit so you can change how fast your rods react.

They are a wonderful carb.

You can pm me with question or here in posts.

Your stall is way to low

U17

My ZZ383 was run at GM with a 750... That's what I ordered and it's great ...

bluedawg

Brrrrrrrr...... Scotty we reached 64 today, then it rained, how can you say brrrrrr, at least it aint -20*f, my girl doesnt do good in the rain, so if traction in the rain is a concern, dont go double pumper, now then if you can stand adrenaline coursing through you viens and have traction issues on dry pavement the double pumper is your drug.....

LS 80Vette

No worry about the rain, she never sees it