Hell my big block idles at 800 and in gear 700 sounds nasty sitting that low... drives great.. once warm with a tunnel ram and dual carbs I can flip a switch and bump the button fires right up with no hitting the gas pedal. Carb tuning is going to be your fun times coming. Honestly I would spray starting fluid or carb and choke cleaner around all areas start around the carb base where it attaches to intake, Then no every port on intake, then down to intake meeting up with the heads.. you will find something.. If not rip that carb off cause its not working right. Idle screws only work when the throttle blades are closed enough for them to meter fuel. the little pesky transition slot is a pain but once you get it.. a whole new world...
There's no such thing. !!!! Pedal ratio on the gas pedal is really important. The more HP available then the more important it is. Proper parts, in unison with a Proper tune and you'll be happy. The Quadra jet is the most tunable carb in existence. It's also a mystery because of that
Well that will tell you if it's running lean, but that can be caused by more than just a vacuum leak.
Dont go chasing your rear. Chances are like someone said earlier the throttle blades are too far open on the carb and is past the transfer circut running on the mains. Go get your box of drill bits and a roll of solder and buy this book http://www.cliffshighperformance.com/buy_book_2.html I have drilled the shit out of several of these carbs to get them to idle right. Q jets are great, the can be made to idle nice, start right up after sitting for years and get good fuel economy and power. Dont be intimidated, the book explains everything in great detail and once you read it you will understand what is going on and what to do to fix it. You know there is more to performance than just an engine. things need to be build as a combination of engine transmission and rear. What cam are you running and what are the specs? Do you have a stall converter?? and what gear in the rear? All this is very important to making the engine perform properly....
Thanks for all the reply's guys, I gotta say I am not a mechanic, in my farm business I do machinery repairs when needed and that's about it. The good news is that I am reading from you guys that I should be able to cruse nicely with this engine if it is set up right. Every bit if info I have I will post; I bought a 383 Stroker from Blueprint company, they sell through Summit racing. That is where I found this engine. It is listed as 383 base engine 430 hp. for carburetor cars. It is a 750cfm Q jet that I rebuilt, originally on a 400cid small block pickup truck. I have a 2000 stall converter which my trans shop recommended. The timing at idle is about 8, kinda hard to tell as the engine idles quite rough. Cam numbers are.528 intake, 536 exhaust 221 intake and 226 exhaust duration @.050-110 degree lobe separation. Compression is 10.0 to 1 I have been putting in premium gas from the pump, I do not hear any pinging or any other gas related bad noises. The heads have 2.02 intake and 1.60 exhaust. I think I set the plugs at .32 or .35 thousands I don't recall off the top of my head. I also have 4.11 rear gears and it seems to shift at about 2000 from 1st to 2nd and also from 2nd to third at about 2000. I can feel the converter lock up at about 2200 as there is a slight rpm drop. I think I will have to get the trans adjusted as it does not shift into overdrive. There you go guys, that is all the info I have about my drive train, thanks.
thats a pretty mild set up. it should run (and idle) nice once you get it tuned properly. You may also want to look at the distributor curve as well. To make your life easier during the tune I would fix the timing IE no vacuum advance and wired the mechanical s so they cant move. This will simplify the car tuning. Once you get the carb right you can start working on the distributor and getting the advance right. One thing at a time
The advance curve is probably a big part of the problem, it could be that it comes in too early, and makes the engine idle faster..then when you slow down the idle, it drops timing and slows too far. I recently when thru this with a mallory distributor, the car was pretty hard to drive like that. I ended up putting in a stiffer spring in the mechanical advance, as well as limiting the amount of travel, and that really helped.
Your welcome. The book will give you several starting points for modifications, you can pretty much match your engine spec's to what is listed in the book, make those mods and be up and running right!
you could also call up Scott at Blueprint, ask what would be a good carb and ignition to run on the engine...
Hi. Most likely not what you wish to hear but I would make life much simpler for an old man & install a hopped up Model A or a flathead, change rear in ratio & or add an overdrive & I would have one heck of a street or Hwy driver with jillions of times less upkeep problems & really be in better form with what Your Model A really is. At my age my life is in the slow lane but when driving my 46 Coupe I know I must drive with the traffic or cause a wreck. My little Chevy with its ring & pinion change and slightly hopped up 235 six cylinder does quite well running with the Hwy traffic down here. Having a ball with it and at local shows I do get a lot more respect & great comments from the visiting public than any of the older street rods with the big V 8 engines. I have no desire to impress the teenage crown by going with the giant engines. But to each their own. Good luck, jimmie
If you can feel the trans lock-up and there's a slight drop in RPM's then it's in overdrive. 700R4 convertor should lock-up electronically in overdrive only.
I don't have any interest in learning how to grow my own food...so I have no problem with a farmer maybe not wanting to know all about how to tune an engine!
I have not read all of the responses... But a simple cam/carb/converter (assuming you have a high stall converter) change can make that 383 as street friendly as you want. I do have ask... What is so "radical" about it? I've driven 300 horsepower cars like they had 600 and I've driven 600 horsepower cars like they have had 300... If everything is matched correctly, your right foot controls it all.
Regarding compression... Your cam grinder can grind a cam to bleed off dynamic compression ratio... So no need to change pistons.
Jesus Norm... Just read your posts. You just need to check a few things. Check the centrifugal weights in the advance. Too light of a spring will make it hunt. Also, vacuum leaks and or the transfer slots being exposed will. Deisel ing could be too lean on idle and or timing.
Well it is possible to have too much horsepower for two reasons one is that the driver is not up to the challenge and the other is one that I proved at the track about 4 years ago now. We had been running consistent 12s with the little '27 in 7.50x16s. The driver said it needed more power, well that was easy enough I had been keeping the tune dialed back a little bit, so I set it on kill and sent him out there. He ran a 13 and change and spun the tires pretty much the length of the track. LOL Now for the original question at hand, a 383 can be a very sweet driving motor and as dependable as a hammer. A quick cam change (and perhaps the intake) can make it a very sweet and healthy cruiser. I would not dial it back so far as to make it a granny motor but it does not have to be balls to the walls to drive it and be happy with it. I would not lower the compression at all compression is your friend.
I would bet you know not to buy the green hamburger, the sguishy carrots, or the blackened oranges. even if you have no interest in becoming a farmer. Buying another carb and distributer might only put more parts on the shelf. You may/will have to tune them as well. Paying someone else to do it is not a bad idea. But wouldnt you like to know what they are doing and why they are doing it so that you can make a good decision and not waste your money?
Having been around for a while , I'd guess that of the current crop of "hotrodders" less than 10% know anything about their cars , other than polishing them, what's more , few care !!! This has been a real disappointment to me , in the '60's , most of us [hotrodders] actually built & tuned our cars ! dave
Its the same with anything with wheels. I actually had a guy bring me a Harley last spring for plug wires. Give me a break, plug wires? There is only two of them. We are not from the world that we live in, this "brave new world" is not ours and perhaps we have worn out our welcome.
one thing I like about carbs and distributors, vs EFI and computers, is that you generally only have to set up the carb and distributor once. Might need a little maintenance after that, but that's it. The efi guys are always having to mess with the tune, probably because it's so complicated. Get the distributor working right, get the carb working right, and drive it. Qjets are pretty forgiving, if they haven't been mangled by someone who doesn't know what he's doing. But if you don't want to know how to get it working, find a reference for some new parts that will work right out of the box. They do exist. fwiw my avatar shows a kinda powerful engine running a couple box stock carbs. No tuning needed, I just had to undo the mods the previous owners had made to them.
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