73 duster possible fuel problems?

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beebeeri000

beebeeri000

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hi i have a '73 duster with an origional /6 in it and i tried power braking(i almost never do but i was leaving a car meet) and the revs never got up and it never broke traction. also when i have it in park and i brings the revs up to fast it dies and when i let go when theyre up it shutters and dies/almost dies. i think it might be the fuel pump starting to die but that's just a guess.
 
That's right and guesses are usually wrong:D

Here are the causes of your problems, in order:

1. Slant six with 105hp back when it was new 40 years ago.

2. Tight converter with almost no stall speed.

3. 2.76 rear gear ratio.

4, 5 and 6. Holley 1920 carburetor. Not a great carb to begin with and most are running on parts store rebuilds which are even worse. I promptly replaced mine with something else. they simply are prone to hesitate and stall at random so your car is running fairly normal.

Good news is you can cure all this. More engine equals more performance. Just don't expect the moon from a Slant unless you want to go through it top to bottom and start fresh with advice from guys here that have made them run.

Otherwise, pull the slant before you blow it up, and drop in a 360. I did a 318 swap and it wasn't nearly enough added performance over the Slant to do it again unless I built a high rpm screamer.

Just my .02...enjoy your car for what it is in the meantime!
 
lol yea i got a 360 that im rebuilding and stroking out to 408 and a 727 to put in it but the thing that confuses me is that my friend has a scamp with a slant 6 in it and it'll burn through tires
 
beebeeri000 said:
what you sayin
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Ignore him. He's a Yankee mouthpiece opinion-giver. One of those guys who has no work to show on his own, yet feels that the rest of us are waiting with baited breath for his vaunted opinion. Like...HELL.

Anyway...my history with old Slant's is that despite their mythical status, they don't like high] rpms or low oil when they get elderly.So, may not want to push it too hard until it's time to pull it out.

Be sure you upgrade the rear end and run VERY good driveshaft and U-joints when you get the new engine in.
 
yer buddy that burns through tires, he got the SAME slant 6 set up, you do? HIS might have a 4 barrel on it, and makes a world of difference on a slant 6.....That make his a super-pak 225, OR, what was the other one? Hi-Po 225????

There is a bit of difference with them depending on the carb set up, and what one it has!

It could merely be he has other then the Holley 1920 you have.....

Its funny how it works but you'd swear they weren't the same C.I.D with just 2 different carburetors feeding each engine!!!!!
 
GEO said:
The main problem sounds like the owner
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Occurs to me we need an "UNTHANK" button on this forum

2367225988.jpg
 
TylerW said:
Ignore him. He's a Yankee mouthpiece opinion-giver. One of those guys who has no work to show on his own, yet feels that the rest of us are waiting with baited breath for his vaunted opinion. Like...HELL.

Anyway...my history with old Slant's is that despite their mythical status, they don't like high] rpms or low oil when they get elderly.So, may not want to push it too hard until it's time to pull it out.

Be sure you upgrade the rear end and run VERY good driveshaft and U-joints when you get the new engine in.
Click to expand...

i hate it when people act like that on forums, its just like were all here just to have fun and learn somethen. also yea im looking at a dana 60 and since a 904 transmission is linger im gonna have to get a new diveshaft anyways i think im gonna go for aluminimum.
 
67 Power Wagon said:
yer buddy that burns through tires, he got the SAME slant 6 set up, you do? HIS might have a 4 barrel on it, and makes a world of difference on a slant 6.....That make his a super-pak 225, OR, what was the other one? Hi-Po 225????

There is a bit of difference with them depending on the carb set up, and what one it has!

It could merely be he has other then the Holley 1920 you have.....

Its funny how it works but you'd swear they weren't the same C.I.D with just 2 different carburetors feeding each engine!!!!!
Click to expand...

his is the same but he has the stock rochester 1 barrel carb. i didnt this that it make a difference because theyre both stock 1bbl carbs lol eventually when i put efi on my 408 im gonna try to get him to put my 800 cfm thermoquad on it lol so much carb for that engine
 
GEO said:
If you want to see my latest work look in my picture gallery ,big mouthO:)
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Ok then..seems to me like you should have enough to occupy you without bullying people in the Slant forum and elsewhere. The court of public opinion is against you at this point. Suggest you deal with whatever is preventing you from treating people with respect.
 
beebeeri000 said:
his is the same but he has the stock rochester 1 barrel carb. i didnt this that it make a difference because theyre both stock 1bbl carbs lol eventually when i put efi on my 408 im gonna try to get him to put my 800 cfm thermoquad on it lol so much carb for that engine
Click to expand...

It could be that too, the Holley 1920 was known to be a crapper single barrel, and the Rochester 1 barrel was to be half decent....BOTH are very fickle if not adjusted right Altho, the Holley seems to have the most issues with it, that are known....

A lot of times, the stock settings on a single barrel will greatly differ between engines of the same C.I.D. in a close the same car....Almost most so much as night and day such as this!

Are you going to switch the 408 and the Slant 6 when the 408 is done? OR is that engine going into another car?

I say look at the carburetor a bit closer, FINE tooth comb the thing, see what happens, if your going to keep the slant in the car its currently in, replace that Holley 1920 and put a Rochester in place of it, and see if that doesn't solve some issues! IF you plan to replace the whole motor, then I say get it to run a bit smoother till yer ready to put the 408 in it, and call it good! Put the money into the 408, and carry on....

IF you plan to keep the slant 6 in the car, I say re-do the carburetion with something better....I think the Rochester is the better choice, Carter is no slouch either.....Just hard as it is to believe Holley is to make some really GOOD carburetors but, that 1920 was a troublesome little thing! Change it out to something else and I BET you'd be good to go!
 
67 Power Wagon said:
It could be that too, the Holley 1920 was known to be a crapper single barrel, and the Rochester 1 barrel was to be half decent....BOTH are very fickle if not adjusted right Altho, the Holley seems to have the most issues with it, that are known....

A lot of times, the stock settings on a single barrel will greatly differ between engines of the same C.I.D. in a close the same car....Almost most so much as night and day such as this!

Are you going to switch the 408 and the Slant 6 when the 408 is done? OR is that engine going into another car?

I say look at the carburetor a bit closer, FINE tooth comb the thing, see what happens, if your going to keep the slant in the car its currently in, replace that Holley 1920 and put a Rochester in place of it, and see if that doesn't solve some issues! IF you plan to replace the whole motor, then I say get it to run a bit smoother till yer ready to put the 408 in it, and call it good! Put the money into the 408, and carry on....

IF you plan to keep the slant 6 in the car, I say re-do the carburetion with something better....I think the Rochester is the better choice, Carter is no slouch either.....Just hard as it is to believe Holley is to make some really GOOD carburetors but, that 1920 was a troublesome little thing! Change it out to something else and I BET you'd be good to go!
Click to expand...

ok i have to keep this holley for right now cause i dont have the money for a new carb but thanks, is there any tricks to get more power from a 1920? lol you taught me something new i havent had any real problems that werent nomal carb problems so far besides a bir of smoke before i rebuilt it
 
The air flow is fixed so unless you change the main throat size (which you can't) the power is fixed. Other things need to be changed to effect total airflow.

BTW, it is not a problem to make a 1920 run A-OK.
 
See if you can wiggle the throttle shaft back and forth any at all. While you're there have a look see at the carb on both ends of the throttle shaft. Does it look like fuel has run down the side and evaporated? Biggest problem I've run across with the 1920s is worn throttle shafts. Don't take much wear to start sucking air around the shaft and running like crap...
 
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