tnmotown

iTrader: (107)

Ok I'm kinda stumped on what fuel system is used when going carb. I'm doing a ls1 swap in my '85 camaro which was originally carb setup. So If I stick with the carb setup for the ls1, do I keep the same fuel pressure (low pressure) and how would I feed the fuel? I'm having a brain fart, thanks in advance.

3pedals

iTrader: (3)

supply a steady 5-6psi to the carb inlet, and the carb will be happy

speedtigger

iTrader: (16)

Depending on the power levels you are going after will determine what changes will be made to the fuel system.

Does this third gen have a mechanical fuel pump or electric?

NemeSS

iTrader: (127)

3rdgens came with both type pumps thru out there run. his more than likely has the quadrajet/mech fuel pump found on 305 cars. of that yr.
the fuel system has to be overbuilt imo from the get go.
depends on your budget and goals. anything from the holley blue or black pumps to an aeromotive race type pump.

cody161

iTrader: (18)

I believe 5 lbs is a little low unless it's a side hung bowl. On center hung bowls it should be 6.5 lbs.

ZONES89RS

iTrader: (25)

Yep, i run no less than 6.5 on mine, fuel demand on the Ls motors at 6500 RPM up will be best making damn sure you have those bowls fed with fuel. If not, it will let you know, LOL.

speedtigger

iTrader: (16)

If this car will be on the street all the time, I am not a fan of the Holley red or blue. They were not designed for every day use. Every time I have seen them used in that capacity, they burn up or start to leak over time.

I would recommend using an in tank electric with a Holley return line regulator set up or a very high quality set up like the Aeromotive.

I just bought an Edelbrock 1791 because I was told they were quiet and designed to use for everyday use. I guess I will find out soon how durable they really are.

ZONES89RS

iTrader: (25)

Really, i run nothing but holley blue pumps and never have leaks or issues, hell, the one on my 89 has been used for 5 years now, LOL.

speedtigger

iTrader: (16)

Perhaps they have improved them in the last 15 years. I haven't used one since the 90s.

daschra79

iTrader: (2)

I agree with NemeSS on over building your fuel system to the best you can afford that way if things change you don't have to redo it later (always more expensive to do it twice). I'm running all Magnafuel (pump and reg.) on my Malibu and am as happy as can be. I run my fuel pressure at 7.25lbs.

tnmotown

iTrader: (107)

Hey thanks for all the info guys, yeah the car was originally a 305 carbed motor.

So no matter what then I should upgrade the fuel system, and also have to go with a electric pump and a low FPR with around 7lbs.

I'm looking to get around 400-450rwhp N/A then maybe a 150 shot down the road

ZONES89RS

iTrader: (25)

I am running the holley blue and regulator with the stock fuel line pulling from the stock tank, i should be mid 400 RWHP with my setup, but with the nitrous going on, i am using another holley blue pulling from a independent fuel cell under the hood so not to have too great a fuel demand on 1 pump and not worry about leaning the motor out.

Now, if i had done it right, i could have used a A100 Aeromotive or from what i hear, the Magnafuel units available and run the nitrous and engine off 1 pump.

cody161

iTrader: (18)

Do not run more than 7lbs of fuel pressure. We tell people 6.5lbs just in case their gauge is off by a little bit.

ZONES89RS

iTrader: (25)

Yea, i have had over 7 pounds just give the needle and seat hell.

cody161

iTrader: (18)

That and you end up setting your floats lower to compensate for the pressure being high and this makes you have less fuel in the bowl.

Oldsmobility85

iTrader: (1)

Yeah needle and seets are getting expensive these days. LOL. I only run around 4.5 on my carbs with absolutely no issues. All you are setting is seat pressure. When that pressure drops and the regulator opens its all at the mercy of the fuel pump to do the flowing. IMO I don't think what engine you have determins the fuel consumption as to how much power your making and how well the carb is tuned.

Also you can get a cheap pump from procomp off of Ebay for as little as 30 bucks but I would agree that if you have high hopes for the car anytime in the near future do the best fuel system you can. Although I myself am running a holley blue on the motor and a procomp 140gph on a seperate fuel cell for my spray and they blue does seep fuel from the gasket. But I have had it apart before so that could be the problem. Good luck.

thirdgenbum

iTrader: (17)

i'm running like 6.25 or something...works great!