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383 bad experience

F

funbiz99

Active Member
Apr 18, 2005
104
0
26
OK heres the deal. I am having a 383 installed in my suburban. I took it to an engine builder to have it made and installed. I droped the truck off on dec 22 06. i told him i wanted a forged crank and 400hp with lots of torque. he called me on monday and said he was having a problem but should have it ready tuesday (the problem was there are 8 carburator holes in the intake and 4 where open i reaally dont get it he said if i had a holley i wouldnt have the problem) . he called tuesday night and said come pick it up. wednesday morning i arrive and the truck is running right away i'm nervous. the owner said he put 93octane in it because it was dieseling (not turning off). well he turned it off and it was still dieseling. he said take it for a test drive. i get in am already not happy because when i put it in drive it stalls. then it starts hard he says you have to put the pedal 1/4 way and it will start right away BS. it still starts like crap. drove to the corner and tried to spin the wheel no f%%kn power. also stalled while backing up and turning. i return it and tell him its not accetable its running like crap. he says its the carb i provided him a new 750 vacuum edelbrock (he said to get a 750 didnt mention brand) needed to be changed to a holley or speed demon. i personally dont think its the carb but if i tell what i think and waste his time he'll blame me.

383
edelbrock 750
edelbrock intake
chevy heads
new ignition w/wire and plugs (he said it neede colder plugs)


any thoughts on the symptons stalling no power dieseling
 

Sounds like he may have the wrong vibration damper or flywheel?

Maybe he dropped the distributer off a few teeth?

If he says the carb will not work and needs the holley instead tell him to put that in writing and you will send it to edelbrock and complain, watch him change his tune.
 
Colder plugs are possible.
Dieseling is useally caused by too high an idle and a mistuned engine. The 750 Edelbrock is nothing more than a Carter AFB which is a good carb if turned correctly.

Sounds like you need a NEW mechanic.
 
i looked at the damper and its the right one for a 383. he said he retarded the timing with no affect on dieseling. i am thinking thats why it starts bad, retard on the distributor. i told him to put whatever carb to make it work i can always sell the edelbrock. i am trying not to get in a pissing match with this guy in case there is a bad valve or a leak in a gasket. i personally suspect some sort of vacuum problem
 
Take the #1 plug out and put your thumb over the hole. Have a friend slowly bump the starter switch until the compression form the piston moving up pushes your thumb away from the plug hole. This should be top dead center. Then remove the distributor cap and see the rotor is pointing at the #1 cylinder. If it is not remove the distributor and reinstall it so that it is. This can be a real pain because you have to turn the rotor a little at a time so that the gear at the bottom of the distributor meshes with the cam gear, you may have to try more than once to get it right. It sounds like he has it advanced way to much which will cause the problems you described.

If it does this after the motor is hot but not when its cold it also could be something called vapor lock. This is caused when the fuel in the bowls of the carb becomes to hot and more or less turns into a vapor ( something alone those lines ) the fix for this is to get a carb spacer which you can buy at any speed shop or you can make one your self out of 1/2 to 1 inch particle board. If your good with a saw.

Do you know any details on the comp ratio and the size of the cam? It very well could be a mismatch in parts as well. You just don't throw any cam into a motor and expect big power numbers. 383's are not really intended to be high RPM engine so you don't need a huge cam to make big numbers. I myself built one not long ago with a comp cam that spec ed out to ......lift 509"/528" duration @50:222/230 ( still have the cam card ) and with around 10 to 1 comp and a set of vortec heads it made around 430 hp and 500 foot pounds of torque at less then 5000 rpm on 93 octane. In a heavy Chevy truck with 3.73 gears it would blow the tires off of it when you stomped into at 60 mph!
 
That 383 is a stroker correct??? 350 stroked out. That to me sounds like timing totally unless theres an airleak somewhere. Thats crazy he said its ready what the he!! kind of mechanic cant tell when a vehicle isnt running right?? is the exhaust new??? Ive seen mufflers and cats clog or not flow free and cause goofy things exspecially power robbing. Carb is a possible problem forsure but he should be able to straighten that out. as far as wrong carb BRAND there are adaptor plates. A 750 is a pretty big carburetor are you sure its not flooding out??? those carbs have to be set right or forget it its one big nightmare. I would think a 650cfm would be fine on that 383
 
King i am sure the distributor is in correct. As far as vapor that is something i need to look at. thanks i will try and get the cam card , 9 to 1 compression and rebuilt chevy heads nothing special.
Tony the ekhaus is not new although i have a set of shorty headers. I wouldnt suspect the exhaust because it was running fine when i dropped it off. yes it is a stroked 350 (looking for torque).

One more thing i shoud have mentioned this truck was originally fuel injected. He put a regulator on set at 6psi. the thing is both the lines from the tank are going to the reg 1 from pump and one return. A friend has told me the smaller line is not a return. he said if you leave it disconnected fuel will pump through it .

does anyone know exactly how these line work??
 
the deiseling does sound like a timing issue. another common problem that some of these have is when they set the distributor they put number 1 up on the exhaust stroke. now the motor can run with the dist cranked with 180 out. this will also give it the low power that you are issuing. if the carb is 2 big then the bugger should smoke black hard from overfueling. but the volumetric effeciency of 92 percent in a 383 it should run with a 750 cfm edelbrock.might be a touch rich on the low end but a proper build 383 should just scream towards the top with it. if it has a vacumn leake bad enought o cause it to run like that you should be able to hear it. the only leak that would would not hear would be a pcv valve and that also is an easy one to test.
 
I called all day with no luck getting anyone on the phone. I will try saturday morning. will keep you posted.

welcome to the weekend
 
ok finally spoke to the shop today. the mechanic said the torque converter is bad.

this somewhat makes sence to me. he said when you put it in drive the converter is pulling the idle down 700 rpm. idle@1000 droping to 300 = stalling out. now you have to turn things up to compensate.

the converter is new so its going back to the trans shop to be changed out.
 

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