1970 429 SCJ

Intial timing should be 12 bdtc with the vacuum line plugged off and you should be using ported vacuum with it hooked up.

When you first got this engine I take it you checked the valve train and valve lash as SCJ's had solid cams in them.

rmk57 wrote:Intial timing should be 12 bdtc with the vacuum line plugged off and you should be using ported vacuum with it hooked up.

When you first got this engine I take it you checked the valve train and valve lash as SCJ's had solid cams in them.

Yes, my grandfather was there with me because he didn't believe i found a SCJ for $500. He knows much about these engines and came with me to verify everything. He never would have let me take it home if he thought something was wrong with it or not original. He took the valve covers off, intake manifold, the timing cover off, he asked the gentlemen if we could have a minute, we walked away and he said to me with a smile "this thing looks like it hasn't been used much more than 10k miles, lets load her up." We got back with it and he cleaned it up for me and put all new gaskets on it for me. I wrapped it up in clear plastic and stored it in my fathers garage which is climate controlled. This was about 6 years ago, i left for college, i moved and now i have time to put it together. And this is what it comes down too. I have not done anything other than install a new distributor and a new carb.

dragkid wrote:

stanger68 wrote:

dragkid wrote:

rmk57 wrote:  I'm not postive but didnt the original 429 SCJ 780 Holley have holes drilled in the primaries?  Are the mixture screws doing anything?  How much of the idle transfer slot is showing?

I would run 97. 93 has nowhere near the octane level needed when that engine is at operating temp.  

30+ years ago I had a 1970 Ranchero with a factory 429 SCJ in it and it would diesel on if I didnt stall the engine with the clutch. It would also ping a bit when the engine got hot with 12 degrees timing

and that was with chevron 94.

Randy

Randy,


I wish i had the original carb that came with it, i would have just rebuilt that and used it instead. I would have to check out idle transfer slot when i get home. The mixture screws do something yes. When i close them all the way, the RPM just increases, but dosent shut down on me, which i find odd. What timing do you reccoment I set it to? Would 14 be sufficient? Maybe 15-16?

If you screw the idle air mixture screws all the way in and it doesn’t kill the engine. You can stop trouble shooting you found the problem. The carb is leaking internally.

So you're suggesting the $500 Quickfuel Carb i just bought has an internal problem? My BG 750 did the same thing, but that carb is like 8-9 years old and it ran beautifully on my 383 i had. The engine i had in my 69 before was a 347 stroker and it had a Demon 750 on it, i regret every day selling that carb with the engine. It was such a great carb and never had issues with it. I have not spared a single dime putting this car together and i seem to be taking 2 steps forward and 3 steps back.

It would be extremely unlikely to have three bad carbs I agree. So maybe it is something else like a weak coil. But if you read the instructions that came with the carb it will tell you the same thing I did about the idle air mixture. This is not the same screw that adjusts the idle speed. The idle air screw is screwed directly into the metering block.

Dragkid,if you have any vacuum operated accesories hooked up,unplug them and cap off the fittings to eliminate the possibility of atf or brake fluid contaminating your mixture.A bad trans modulator or master cylinder can introduce fluid into your intake which will cause smoke and stench.If you do this and the engine runs normally after giving it time to burn off any residual then hook them back up 1 at a time to determine the cause.I haven' t seen in any of your posts whether the engine is missing or not because significant numbers of misfires can cause stinky exhaust even when the misfires are due to a too lean condition.Any misfire will discharge that unburned mixture into the exhaust.I agree that 3 different carbs failing to cause any change in the condition good or bad,would make me look elsewhere,especially when at least 1 was a previously proven good carb.

Dragkid,if you have any vacuum operated accesories hooked up,unplug them and cap off the fittings to eliminate the possibility of atf or brake fluid contaminating your mixture.A bad trans modulator or master cylinder can introduce fluid into your intake which will cause smoke and stench.If you do this and the engine runs normally after giving it time to burn off any residual then hook them back up 1 at a time to determine the cause.I haven' t seen in any of your posts whether the engine is missing or not because significant numbers of misfires can cause stinky exhaust even when the misfires are due to a too lean condition.Any misfire will discharge that unburned mixture into the exhaust.I agree that 3 different carbs failing to cause any change in the condition good or bad,would make me look elsewhere,especially when at least 1 was a previously proven good carb.

It would NOT be uncommon for three different carbs that sat around, with 10% ethanol gas eating up the rubber parts, to run like crap. I have a bunch of cars that I don't drive enough, and needle and seats and o rings are a constant problem from sitting.

cletus66 wrote:It would NOT be uncommon for three different carbs that sat around, with 10% ethanol gas eating up the rubber parts, to run like crap.  I have a bunch of cars that I don't drive enough, and needle and seats and o rings are a constant problem from sitting.  

That may be for poorly stored carbs,but in the original post he said 2 of the carbs were new so I don't think they fall into that category.If I remove a carb for long term storage for possible reuse I remove the bowls spray everything down with carb cleaner and blow it dry with air before reinstalling the bowls paying particular attention to the accelerator pump circuit.I agree 100% with the ethanol gas thing learned that lesson the hard way,to the point that anymore I pay the extra money for the ethanol free premium for any of my carbureted cars that don't get regularly driven.

This might be a longshot. I had to tweak a throttle cable bracket after an intake swap caused misalignment between my throttle cable and carb linkage. It was just enough to slightly move the throttle blades to expose a large area of the transfer slots. It was enough so that it would draw fuel from the boosters, run pig rich, and make my headers glow. It's worth a shot since you have 3 different carbs with the same exact problem.

Bryan

427John wrote:Dragkid,if you have any vacuum operated accesories hooked up,unplug them and cap off the fittings to eliminate the possibility of atf or brake fluid contaminating your mixture.A bad trans modulator or master cylinder can introduce fluid into your intake which will cause smoke and stench.If you do this and the engine runs normally after giving it time to burn off any residual then hook them back up 1 at a time to determine the cause.I haven' t seen in any of your posts whether the engine is missing or not because significant numbers of misfires  can cause stinky exhaust even when the misfires are due to a too lean condition.Any misfire will discharge that unburned mixture into the exhaust.I agree that 3 different carbs failing to cause any change in the condition good or bad,would make me look elsewhere,especially when at least 1 was a previously proven good carb.

I have my PCV and c6 Modulator hooked up. Vacuum advance i never use. But it's there if i need it. I also do not have power brakes.

I'd hook up your vacuum advance. After it's connected you may be able to turn the idle down and at least stop it from dieseling not to mention better cooling, driveability, throttle response.

I want to add something to this. I forgot to mention that i have a ZEX nitrous plate installed. I took the QFT off with gentle hands yesterday so i can go over everything and the baseplate of the QFT carb matched so well with the ZEX plate, i forgot it was on there... Would there be any reason that plate would cause any kind of vacuum leak? Yes, it is all properly hooked up and i have brand new Fuel and Nitrous valves hooked up with the proper jets installed. I used it on my 347 stroker that was previously in it. It's not being used or anything but it worked great as a spacer plate. But before i took everything off, i warmed up the car and i sprayed some carb cleaner around the intake and i noticed it bogged down between the Upper Intake and the Carburetor on the drivers side? It was sucking the carb cleaner in and started to stall... I have started putting 1 and 2 together and after realizing that swapping my carbs around, maybe that leak has something to do with my bogging when i whack the throttle, but that would not cause my car to run super rich? True or False?

I took everything off, i cleaned the Upper Intake carb surface really well and i bought all new gaskets.

I am extremely dissapointed with my QFT Brawler, i really am. It came with nothing but the carb and a warranty card. No extra gasket, no nuts or bolts or anything. I had everything for it but I'm use to getting some extra goodies when ourchasing a new carb.. I had some other issues with it that I'm not going to put down here, maybe i got a bad deal out of it and i don't want to discredit it when it could be great for others.

rmk57 wrote:  I'd hook up your vacuum advance. After it's connected you may be able to turn the idle down and at least stop it from dieseling not to mention better cooling, driveability, throttle response.

I will hook it up and see if it makes any difference.

Update:

I don't want this to be a case closed just yet.

So i was out there messing around with it. I took my advice and changed out that nitrous plate. It did in fact help out. I cleaned the surface and i installed a Mr.Gasket 1" spacer with all new gaskets. I fired her up and it felt noticeably different. Throttle response was on point.

I adjusted the throttle bracket to make the springs a bit tighter. During start up, i was having no vacuum whatsoever. None. My gauge indicated i had 5hg before i changed that plate out. After i changed it, i had 0... When i would whack the throttle, it would shoot to 15hg.

Dumbfounded, i took my vacuum modulator off and hooked up the vacuum advance. Started her back up and i had near 20hg of vacuum, and when i would whack the throttle, it dropped to 0.

I'm happy with the fact I have normal engine vacuum and amazing throttle response.

However. I still am running rich. Not nearly as bad as before. I know some will say "Well, turn your idle screws in more and you'll be good to go", but herea the thing, my primaries are turned only 3/4 out and my secondaries are 3/4 out. And that is my concern. The last thing i want is to run it lean.

Without using a A/F ratio gauge, how would i know if I'm running too lean? I hear no popping or anything from the exhaust. I noticed that i don't have that dreaded diesel effect anymore when i shut off the engine.

I know this is alot but i appreciate everyone who has helped out so far. I'm also writing all othis as a reminder formyself.of

Are you running the stock iron intake, or something else?

BBFTorino wrote:Are you running the stock iron intake, or something else?

Stock intake.

I can be wrong, but I believe the stock intake is a 4 hole carb pattern. You have a nitrous spacer plate that is an open style.
So the air/fuel mixture is hitting the edges of the intake and breaking up the mixture.
You may try bolting the carb directly onto the intake, because you are running an open plenum type of situation, then trying to feed it through 4 smaller holes. I would think that the mixture distribution would be all out of whack like that!

BBFTorino wrote:I can be wrong, but I believe the stock intake is a 4 hole carb pattern. You have a nitrous spacer plate that is an open style.
So the air/fuel mixture is hitting the edges of the intake and breaking up the mixture.
You may try bolting the carb directly onto the intake, because you are running an open plenum type of situation, then trying to feed it through 4 smaller holes. I would think that the mixture distribution would be all out of whack like that!

I think you're actually correct on that. I attempted to put the carb on by itself but failed miserably. When i pulled the carb off, i noticed fuel sitting on the inside pockets of the intake?? I cleaned it up and installed that Mr.Gasket spacer and it covers them pockets up. The flow is now being directed straight into the barrels. I think that helped out majority of my issue.

VERY common for bad gas to make these engines run on, idle too high will also do it, PUTTING THE CAR IN LOW GEAR,AND THEN SHUTTING IT OFF was a main deal back then.or 1st gear with foot on the brake as you let the clutch out at the same time you turned off the key.

ford used and idle kicker on these engine,elect act. It would shut the thotttle blades when key was shut off, thus no run on when everything else was set correct.


If you dont have the org carb,or a idle controll on this carb( Ididnt read all the posts) this is your main problem. Having owned at least 35 of these engines It is something you learn



-Rich

I'm using a Holley 950 hp for the track and a Quick fuel 750 Q series for the street on a 502 in a 57 Ford. Both carbs have around 3/4 turns out on the 4 mixture screws. I have a wideband setup and can get the Holley to around 13.5 to 14 :1 at idle, then it goes to 11.5 to 12.5 off idle and light cruise, then to 12.5-12.7 at full throttle. The Quick fuel I can get 14-15:1 at idle and 16-17:1 at light cruise then 12.5 at full throttle. The Quick fuel is a far superior carb for street use IMO whereas the Holley runs rich, especially at light cruise.
Good to hear your getting it sorted out. And as Boss 429 mentioned the original carb had a solenoid that would close off the butterfly's to prevent dieseling and as he said leave the car in gear, load the engine with brake a little then shut it off. If you can I would run that 97 or even 100 if it's available.

rmk57 wrote:  I'm using a Holley 950 hp for the track and a Quick fuel 750 Q series for the street on a 502 in a 57 Ford. Both carbs have around 3/4 turns out on the 4 mixture screws. I have a wideband setup and can get the Holley to around  13.5 to 14 :1 at idle, then it goes to 11.5 to 12.5 off idle and light cruise, then to 12.5-12.7 at full throttle. The Quick fuel I can get 14-15:1 at idle and 16-17:1 at light cruise then 12.5 at full throttle. The Quick fuel is a far superior carb for street use IMO whereas the Holley runs rich, especially at light cruise.
Good to hear your getting it sorted out. And as Boss 429 mentioned the original carb had a solenoid that would close off the butterfly's to prevent dieseling and as he said leave the car in gear, load the engine with brake a little then shut it off. If you can I would run that 97 or even 100 if it's available.

I may need to break down and get a decent A/F gauge. What is that solenoid called? If i can recall, Holley makes something like that solenoid i believe. I'm glad to hear yours run on 3/4 out, i feel like thats where it runs best for me.

Pricey little devils.... these guys have them https://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwiNsqLF-a_jAhXtJzQIHSe4BgQQFjAAegQIAhAB&url=https%3A%2F%2Fwww.deadnutson.com%2F&usg=AOvVaw3cAAaiWl_Twa8JQAoyI-1u

Boss 302, 429, Cobra-jet cars had them.

ONCE UPON A TIME....

dragkid wrote:...I have a 1970 ALL STOCK...the gentlemen i bought it from said it sat under a cover for 20 years.

rmcomprandy wrote:
...it would not surprise me at all if some rings are stuck...

THE END.

Paul Kane wrote:ONCE UPON A TIME....

dragkid wrote:...I have a 1970 ALL STOCK...the gentlemen i bought it from said it sat under a cover for 20 years.

rmcomprandy wrote:
...it would not surprise me at all if some rings are stuck...

THE END.

If it wasn't for bad luck, I'd have no luck at all...

I will assume that you have already done a compression check, and they all show within specs?

BBFTorino wrote:I will assume that you have already done a compression check, and they all show within specs?

He posted Compression was between 148-151 psi but somebody said a stock 429 SCJ should be 190-200 psi?