Question about 540 CI Dart Motor

[Xpock182]

Originally Posted by Vegas69

You will need a minimum of a 150 gph pump with less than 7 lbs of pressure.

I'd start with a 10w30 and look at your oil pressure, hot at idle. If it's below 15-20, bump it up to a 10w40 or 15w50. Us a detergent oil as mentioned.

Redline is likely around 6200 with a hydraulic cam, 6500 with a mechanical.

Unless things have changed, Edelbrock's biggest carb is 750 cfm. That's to small for a 540. I agree that people think they look cool but you will need to go to a holley if you want to swap to one carb. I'd take a good look at the plugs if you think it's not running correctly.

Call the car what you want.

Would this work as a solution? Also would I need a regulator since it is set at 7.5 lbs of pressure and not 7?

https://www.holley.com/products/fuel...arts/12-454-25

[Vegas69]

Holley seems to think that it doesn't. I would put a NON LIQUID filled gauge on it to ensure you aren't getting to much pressure. Also, your supply line to the pump needs to be sufficient.

[uxojerry]

Dart 325 heads would be a normal selection for a 540. With Lemon's headers and a 3.5 inch exhaust, Im thinking your 540 is something more, maybe Dart 345s. A run of the mill 540 is 650hp. A trick 540 is 850hp or so.

There aren't many BBC fans here. Remember you'll make more hp with a plug wire off, than most with a perfect tune, lol.

[Xpock182]

Originally Posted by uxojerry

Dart 325 heads would be a normal selection for a 540. With Lemon's headers and a 3.5 inch exhaust, Im thinking your 540 is something more, maybe Dart 345s. A run of the mill 540 is 650hp. A trick 540 is 850hp or so.

There aren't many BBC fans here. Remember you'll make more hp with a plug wire off, than most with a perfect tune, lol.

Could you tell me more about what you are referring to here? Also I am trying to figure out why the car is not cranking up immediately all of the time. It seems that after it sits for a week or so it won't crank.

I took the air filter off and try to crank it but I don't think it's getting gas. However if I pore a small amount of gas directly into the carburetor it cranks right up and runs fine.

I cleaned the fuel filter (it was a mess) cleaned the distributed cap & sprayed carburetor cleaner in both carbs.


Unfortunately the car does not have a fuel pressure gauge. This car sat for about 2 years before I purchased it.

Any advice? Is this a bad fuel pump?? Spark plugs?? Perhaps this car was not built for street gas??


Would love some help.

[AMSOILGUY]

Originally Posted by Xpock182

Could you tell me more about what you are referring to here? Also I am trying to figure out why the car is not cranking up immediately all of the time. It seems that after it sits for a week or so it won't crank.
When you say it won't crank do you mean the engine won't turn over or it just won't start and just cranks? Take your battery and have it tested. I keep a trickle charger on my car alot of the time and I bet alot of others do as well.

I took the air filter off and try to crank it but I don't think it's getting gas. However if I pore a small amount of gas directly into the carburetor it cranks right up and runs fine.
Pumping the gas peddle should accomplish the same thing i'm guessing you have done that?

What kind of gas are you pouring into the carb? Is it the same fuel thats in the tank?
I cleaned the fuel filter (it was a mess) cleaned the distributed cap & sprayed carburetor cleaner in both carbs.


Unfortunately the car does not have a fuel pressure gauge. This car sat for about 2 years before I purchased it.
Have a regulator and fuel pressure guage installed if you can't do it yourself.

Any advice? Is this a bad fuel pump?? Spark plugs?? Perhaps this car was not built for street gas??

Pull a fuel line and see if you have pressure. If you do then you need to make sure its the correct amount. Pull a plug and check the gap i'm thinking it should be around .035.



Would love some help.

Not a whole lot of help but this should be pretty easy to get figured out. Sounds to me its just a little cold blooded. Once you get it started does it not hard start after that until you let it sit again for a while?

[Xpock182]

Originally Posted by AMSOILGUY

Not a whole lot of help but this should be pretty easy to get figured out. Sounds to me its just a little cold blooded. Once you get it started does it not hard start after that until you let it sit again for a while?

Yeah once its warmed up its starts immediately from that point forward. Idk if its just a cold start (its 94 degree's in Georgia) or if the carburetor is getting gummed up or if the fuel pump is going bad.

Originally Posted by AMSOILGUY

When you say it won't crank do you mean the engine won't turn over or it just won't start and just cranks? Take your battery and have it tested. I keep a trickle charger on my car alot of the time and I bet alot of others do as well.

The battery is good, I have a Volt Meter it reads about 14. Battery is a new Optima. The motor turns over perfect I just can't get it to fire as easy as I would like it to.

Originally Posted by AMSOILGUY

Pumping the gas peddle should accomplish the same thing i'm guessing you have done that?

Yeah If it doesnt crank up after a few seconds I heal the break and Toe the gas. Still doesn't seem to be getting any gas until after its cranked... then it runs just fine. And its the same gas from the tank that Im putting in the carb, 93 Pump gas.

Originally Posted by AMSOILGUY

Have a regulator and fuel pressure guage installed if you can't do it yourself.

I already have a regulator but not sure what the GPH is on it. I would assume 7-7.5. I need to get a fuel pressure gauge installed asap.

Originally Posted by AMSOILGUY

Pull a fuel line and see if you have pressure. If you do then you need to make sure its the correct amount. Pull a plug and check the gap i'm thinking it should be around .035.

Pulling a fuel line is a good idea, I'll try that today. As for the spark plugs I have been putting that off as they are a total pain in the ass to get to, but I probably need to do it.

[Ron in SoCal]

So the motor runs fine when you do the ol' pour gas in the carb trick which means (to me) your fuel pump is probably fine cause it spins fast enough and moves enough fuel when the motor is running, but your lines or filter are crap when you turn it over via the starter.

Not sure if you've done this but figure out if the carb is getting fuel when cold. If not, have your flex lines tested and check / replace the filter.

I hate diagnosing over the interwebz.

[intocarss]

Originally Posted by uxojerry

Dart 325 heads would be a normal selection for a 540. With Lemon's headers and a 3.5 inch exhaust, Im thinking your 540 is something more, maybe Dart 345s. A run of the mill 540 is 650hp. A trick 540 is 850hp or so.

There aren't many BBC fans here. Remember you'll make more hp with a plug wire off, than most with a perfect tune, lol.

Originally Posted by Xpock182

Could you tell me more about what you are referring to here? Also I am trying to figure out why the car is not cranking up immediately all of the time. It seems that after it sits for a week or so it won't crank.

I took the air filter off and try to crank it but I don't think it's getting gas. However if I pore a small amount of gas directly into the carburetor it cranks right up and runs fine.

I cleaned the fuel filter (it was a mess) cleaned the distributed cap & sprayed carburetor cleaner in both carbs.


Unfortunately the car does not have a fuel pressure gauge. This car sat for about 2 years before I purchased it.

Any advice? Is this a bad fuel pump?? Spark plugs?? Perhaps this car was not built for street gas??


Would love some help.

What uxojerry is referring to is the port volume of the heads.... .

If that car has been sitting for a couple of years and is running rubber braided fuel hose, the rubber could be coming apart inside the hose and clogging things up.

Another thing I've seen when a car sits for a long while is the fuel pump diaphram gets weak as do accelerator pumps in the carbs and does not pump enough fuel when trying to start it via cranking it over...IMOHO get rid of the 2 carbs and get a single Holley or electronic EFI unit. BTW very nice car

[Flash68]

Originally Posted by intocarss

What uxojerry is referring to is the size or flow numbers of the heads.... 325 cfm or 345 cfm.

Actually I think those are the intake runner volumes.... like AFR 227 vs 235, etc. etc.....

Those heads surely better flow a lot better than 325 or 345!

[intocarss]

Originally Posted by Flash68

Actually I think those are the intake runner volumes.... like AFR 227 vs 235, etc. etc.....

Those heads surely better flow a lot better than 325 or 345!

You're rt it's port volume