Timz2882

iTrader: (1)

Okay since im goin to be goin turbo in a few months, i figured id do some more reserch on blowthru carbs. after finding out it will be a hassel to mod the edelbrock carb for a blowthru set up, i think im desiding on a holley.

now alot of things ive read and heard are people always havin to adjust there holleys, like they dont hold a tune for long. is this true or is this just like a hear-say kinda thing?

this company about 10 mins from me (how lucky) does custom rebuilt carbs (thats the shops name also). i was at the swap meet this weekend and they had a booth set up and there work looks like top notch and they know what there takin about.

also the guy recommended either a 650DP or a 730DP thats already set up with no choke horn.

which one would be better for my 305? the 650 he said would giveme a little bit better streetablity then the 730. now like in carb to english terms how much of a difference streetablity is there goin to be a differnce between them?

IHI

iTrader: (1)

Other than doing Jet changes to suit air going for max ET/mph, I have'nt touched my Holley since it was new 3yrs ago. Every winter I drain the bowls and squirt WD40 down the vent tubes till the bowls are full, pump the throttle a few times to get the WD throughout the carb and call it a day. It smokes a little when you fire it the next year, but so far have'nt had any troubles with cracked/leaking seals.

Between the 2 carbs I dont think you'll notice any difference in streetability, the smaller carb may have an edge on bottom end throttle ressponse is all. but running a turbo your going to have the motor singing at mid-high revs so I'd personally opt for the larger carb. When I first had my 355 and did the 6 carb swap the same year (600VS-950HP), once I got the carb tuned all I went was faster and did'nt lose any driveability.

Timz2882

iTrader: (1)

okay kool. because even just lookin at the 2 i think id end up spending a few bucks more or less for the 730 then the 650 since it has no choke horn on it already and only needs to have those few little things on it switched for the blowthru set up. and the 650 theyd have the shave down the choke horn and all the other stuff.

thats good about the streetablity and it holdin a tune and i think if i end up with a problem, there only 10 mins from my house so to rip it off and drop it off is no problem.

F-BIRD'88

What is the big hassle modding a Edelbrock carb for a blow thru setup?

Both carbs need the same things modded.

Timz2882

iTrader: (1)

no one makes solid floats for an edelbrock/carter carb

F-BIRD'88

From what I've read the Carter/Edelbrock brass floats are quite strong and can withstand quite a bit of pressure without collapsing. They are relativly small.

For very high boost blow thru applications you can reinforce a stock float by cutting a slot in the side of the float and sliding in a piece of sheet metal, then solder up the slot to reseal the float. This mod would add a minor amount of mass to the float requiring a slightly nonstock float adjustment to get the right fuel level in the blowl.

About a half hour of work and might cost you $5

Ok, what else is holding you back?

Timz2882

iTrader: (1)

well the thing with the stock floats they can only hold 5-8 lbs of boost at the most. ive never seen the little sheetmetal mod with the float before. kinda neat.

F-BIRD'88

You would want to make the slot as narrow as possible
(less solder weight to seal it back up) You could get the material for the reinforceing rib by cutting up an old brass float. (nice and thin and light weight)
This would make the float plenty strong enough for any practical amount of boost.

Carter AFB's were used sucessfully in OEM Paxton supercharged Studebakers from the 50's with only a few mods from stock.

Are you going to put the carb in a sealed Airbox?

SSC

Ive played with a few different carb on the BT turbo. A Holley/Demon would be better suited. I'll chime in latter when i have more time and explain it if someone else doesent.

Timz2882

iTrader: (1)

ill be using a carb hat, no box. i think the hat is from extreme velocity. theres someone on this board running the same hat , cant think of his name right now but he has a yellow 84 i think z28.