Another problem with my 383! [Archive]

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mcarlo383

11-05-2007, 08:27 PM

Any ideas on what would keep my motor from turning over? i just finished my 383 build, finally pulled it outside to get its first burnout, and the car stalled at about 4000rpm. Keep in mind its a full roller 2bolt, with 11:1 comp. and im pretty sure the starter is good. Also the carb is fresh out of the box, yet to be tuned. and previous to the stall the motor wouldnt turn off? it would take about 45 seconds for the motor to turn off after turning the key off... Any help is much appreciated!! Im going insane!! hehe' :roll: :roll:

rabiddawg

11-06-2007, 03:28 AM

are you saying its dieseling?
thats a timing issue

bjuice

11-06-2007, 04:13 AM

I AGREE WITH THE TIMING ISSUE..

who set TDC ?....I would recheck all of this if i were you...the only true way to set TDC is to pull the head and place a dial indicator on #1 .....what you can do that will be somewhat close...is take off the 1,3,5,7 valve cover ( assuming your chevy)and all spark plugs ( easier to roll over motor)....roll motor over until you see #1 piston all the way at the top of cylinder..a flash light will do...the 2nd and most imprtant thing is make sure both valves are closed on the #1 piston when its up..its possible for #1 piston to be up and the valves be open...this is called over lap....many people have made the mistake of getting #1 up but did not take off valve cover to make sure both valves were closed..and their timing was 180 degress off...which will not work i assure you...

once you do this roll the motor over to where your pointer on the harmonic balancer is on "0" degrees....if TDC was set up properly beforehand this should be TDC....NEXT JUST ROLL MOTOR ON AROUND REAL SLOW AND PLACE THE POINTER WHERE YOU WANT YOUR FINAL TIMING TO BE EX" 35 DEGREES, 37 DEGREES...ETC.....

you must roll the balancer on around to the desired timing..if not and you tray to start at "0" ..it will not fire..

hope this was descriptive enough for you.

Brian

SST4530

11-06-2007, 01:22 PM

Running after you turn off the key- Aside from the dieseling or timing issue, this may ocurr if your running an alternator or electric fans and they aren't isolated from the ignition circiut.

mcarlo383

11-06-2007, 02:19 PM

thanks guys, im pretty sure it is the timing, im going to try setting it again tomarrow.. I just dont understand how the timing could have changed when i have timing gears? unless the distributer could have walked..

cepx111

11-07-2007, 03:07 AM

Well guys I think its not a dieseling issue anymore if the motor wont even turn over anymore, gathering from this qoute.

"Any ideas on what would keep my motor FROM turning over? i just finished my 383 build, finally pulled it outside to get its first burnout, and the car stalled at about 4000rpm"

I would try and turn the motor by hand manually with a socket on the harmonic balancer.
If you cant get it to turn over then you proabaly have some internal issues.
So pulling the motor would be manditory, and then some exploratory surgey.
Goodluck, Charles

bjuice

11-07-2007, 01:59 PM

i didn't pick up in his message that is was 100% locked down..if this is the case,,you got more then timing problems...please clear this up for us ..is the motor locked down?..i took it as it stumbled or cut back at 4,000 rpm's ????? but i am getting old and DO NOT READ OR TYPE so well anymore. LOL

WELL AFTER I RE-READ IT I SAW WHERE HE SAID 1ST SENETENCE IT WOULD NOT TURN OVER...just didn't register at the moment..i read to far ahead...

Brian

SST4530

11-07-2007, 03:26 PM

i am getting old and DO NOT READ OR TYPE so well anymore. LOL

Me too Brian! Guess it didn't register with me either at first. LMAO!!!

Maybe rod to block clearance, or rod to camshaft clearance issues, or he got the cam timing way off when he installed the gear drive and the valves are hitting the pistons..... Ooouch! Hope none of these ar the problem. :?

bjuice

11-07-2007, 04:26 PM

mcarlo383

11-10-2007, 06:06 PM

Actually i just finished fixing the timing today, and you guys were right, it was way off for some reason, and that fixed that problem... BUT afterwards it started pouring oil out of the header collector, so i believe i may have either shreaded a ring, or bent a valve... not to sure until i pull the motor

mcarlo383

11-10-2007, 06:08 PM

WHHHHYYYY MEEE!!! lol

SST4530

11-10-2007, 08:58 PM

Was it the cam timing?

A bent valve wouldn't cause oil to pour out of the header. Busted piston on the other hand ? :(

mcarlo383

11-11-2007, 09:45 PM

yah it was the cam timing, so, what could cause oil to come out of the header? Any ideas?

SST4530

11-12-2007, 03:02 PM

Not sure how you vented the block but maybe it got into the headers through the evacuation system. Could be several different things, busted piston, broke ring, are other things that come to mind.

billhendren

11-13-2007, 02:40 PM

Could be as simple as int gasket, any blowby out the valve covers? Bill

mcarlo383

11-14-2007, 08:23 PM

I have breathers on both sides, but yes i do have alot of blowby... Ive never heard of this problem before..

edvancedengines

11-15-2007, 03:16 AM

You need to go backwards to the basic checks.

For your future info, iF you turn ignition off and engine does not immediately kill, turn key quickly back on and let it run a little tiny bit and turn it off again. It is very possible if that thing was just sitting there knocking and dieseling for 45 seconds. you could have done some internal damage. When one is dieseling, something is burning that is not supposed to be burning at that time.

Remove all spark plugs and block carb open.
Remove either the distributor cap or the coil wire. Not really necessary but helpful to keep all the plug wires from trying to fire if they are close to a grounding source.

Run a compression test in this manner.
Start at #1 and do all on that siade first.
Watch the pressure at first crank. Write it down. (trust me you won't remeber them all)
Clear the guage to 0 next crank engine several crank rotations until you get maximum compressioin on the guage. Write it down.

Check every cylinder exactly the same and do this with a fully charged battery. I usually connect a battery charger before running the test and leave charger connected during the test.

If any cylinders show 10 # or more lower than the others, try to squirt just a little oil in that cylinder and re-check it. Write those down too.

Come back here and post to us what information you got from the compression test. Do not start and run engine. Just do what I suggest and don't get too quick to try to make it run.

Ed

SST4530

11-15-2007, 04:00 PM

Good advice Ed! :)

mcarlo383

12-04-2007, 05:32 PM

Tod74

12-04-2007, 06:21 PM

I just went ahead and pulled the motor to be safe, i found pistons 4 & 5 were no longer there, just a pile of rubble in the oil pan lol. im running 11.something comp. i think i should have spent the money on a forged rotating assembly from the start, but i suppose i learned the hard way.

wow that sucks. :( sorry to hear that. I guess it proves the old saying pay me now or pay me later. Been there and it isn't fun.

gdmii

12-04-2007, 06:44 PM

I just went ahead and pulled the motor to be safe, i found pistons 4 & 5 were no longer there, just a pile of rubble in the oil pan lol. im running 11.something comp. i think i should have spent the money on a forged rotating assembly from the start, but i suppose i learned the hard way.

I don't know that a forged assembly would have helped in this case. It sounds like you had some clearance issues there. Were the rods on those 2 pistons bent or any chunks taken out at the base of the cylinders? Any gouges on the cam? Any evidence of contact on the heads?

George

SST4530

12-04-2007, 10:30 PM

I just went ahead and pulled the motor to be safe, i found pistons 4 & 5 were no longer there, just a pile of rubble in the oil pan lol. im running 11.something comp. i think i should have spent the money on a forged rotating assembly from the start, but i suppose i learned the hard way.

Well I don't know for sure, call me a skeptic, :lol: :lol: :lol: But that might cause alittle blow by and oil in the headers! :wink:

I know it's a bitter pill to swallow, but far as the foreged pistons go your beter off having learned this lesson on a cheaper set first I think.