LD28 w/ Triple Dellortos running super rich

[SickLD28]

Hello peeps,

 

my LD28 with triple dellorto's is brand new with less than 30 miles,  sychronized, and sounds amazing. I have made sure that the timing is on point at 10. I have a holley black fuel pump with a fuel pressure regulator, at 3-4psi.

 

Despite the above, i am blowing out black smoke even at the leanest tuning on the carbs. I've even switched the fuel pump to a carter 4600hp and took out the fuel pressure regulator, and it still blows out foul. Not to mention I even changed my fuel filter, aligned the oil pump and the punch mark, aligned the distribuor at 11:25 oclock.

 

My only guesses to my problem are:

 

my carbs are used, but looked in good condition. But, I think I am missing the air bypass screws on all carbs. The fuel mixture screws are there and even when i tune them to the leanest condition, there is still so much black smoke.

 

 

I'm new to forums, and desperate for help, advice, or anything that can point me in the right direction.

 

This is the build i have:

 

Datsun 3.0 Liter Stroker Long Block Engine.  V07 crank, n42 head

L24 8MM Rods

KA24 Cast Pistons

Rare V07 Maxima Diesel Crankshaft

Schneider284-94F Nissan L-6 Camshaft

Stainless Steel Valves

 

 

 

 

[datzenmike]

First I don't think you could really call it an LD28 if running gas. L28 or perhaps L30 stroker?

 

Pull the plugs. If two are black and caked with soot then the carb running them is flooding. If all are black then all three carbs are rich. This may at least narrow it down to a single carb.

[TENDRIL]

pictures?

[devilsbullet]

 

Hello peeps,

 

my LD28 with triple dellorto's is brand new with less than 30 miles,  sychronized, and sounds amazing. I have made sure that the timing is on point at 10. I have a holley black fuel pump with a fuel pressure regulator, at 3-4psi.

 

Despite the above, i am blowing out black smoke even at the leanest tuning on the carbs. I've even switched the fuel pump to a carter 4600hp and took out the fuel pressure regulator, and it still blows out foul. Not to mention I even changed my fuel filter, aligned the oil pump and the punch mark, aligned the distribuor at 11:25 oclock.

 

 

 

 

 

 

try a new regulator.  may have just been your regulator was bad and what you thought was 3-4 psi was blowing fuel into the carbs. and I agree with mike, it aint a ld28. its an l28 or l30 stroker. you can, of course, call it whatever you like. but when you're trying to explain things it will throw people off some if you call it an ld28 and then you start talking about regular gas.

[ArchetypeDatsun]

You can actually use an LD28 block seen it done before since the LD block is stronger and converted to gas.

[EricJB]

Pressure regulator. You will need the regulator for the red pump. Blue and black don't go down far enough. Dial reg wont work. I run a blue pump with the red regulator. Any more than 3 1/4 psi, (autometer gauge) it starts blowing past the needle and seat. I keep it at 3. Also check to make sure the diaphragm on the regulator isn't damaged or cracked. Had one do that years ago, and pressure went full on. New diaphragm kit fixes it. 

[SickLD28]

pictures?

 

http://i567.photobucket.com/albums/ss115/squannn/photo3.jpg

 

 

Pressure regulator. You will need the regulator for the red pump. Blue and black don't go down far enough. Dial reg wont work. I run a blue pump with the red regulator. Any more than 3 1/4 psi, (autometer gauge) it starts blowing past the needle and seat. I keep it at 3. Also check to make sure the diaphragm on the regulator isn't damaged or cracked. Had one do that years ago, and pressure went full on. New diaphragm kit fixes it. 

try a new regulator.  may have just been your regulator was bad and what you thought was 3-4 psi was blowing fuel into the carbs. and I agree with mike, it aint a ld28. its an l28 or l30 stroker. you can, of course, call it whatever you like. but when you're trying to explain things it will throw people off some if you call it an ld28 and then you start talking about regular gas.

 

My bad about calling it a Ld28, it just has a diesel crank, but yes it does run regular gas.

 

I changed the fuel pump to a Carter 4600Hp, a low PSI pump. With this setup I also took off the regulator, and ran a return line with a needle valve to control the amount of return.

Despite this, I am still running rich, blowing out black smoke. I have adjusted the carbs to the leanest condition, and it shows no change in richness.

 

I even looked into every barrel to ensure none of them were dripping. They all spray evenly.

 

My guess to what the problem is that my jets, idle jets are the wrong size.

I also realized that I was missing the air bleed screws on every carb.

[EricJB]

Even if the idle jets are the size of barn doors, you should be able to lean it to death with the air/fuel mixture screws. They work like a faucet, in = lean out = fat. You should be able to literally turn off a cylinder with one. Fat idle jets will come into play from just off idle to about 3k rpm. It will chug at light throttle.